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Full text of "Title 24, Part 3, 2010 California Electrical Code"

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California Code of Regulations 
Title 24, Part 3 

i California Building Standards Commission 
Based on 2008 National Electrical Code® 



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JANU^RYI 



(For Errata and SupptemelltS'--'s|f-;kistory ■Not® Append 



2011 




California Code of Regulations 
Title 24, Part 3 

Galifornia Building Standards Gommission 
Based on 2008 National Electrical Code® 







^MM 



EFFECTIVE 
JANUARY 1,2011 

(For Errata and Supplemenis, sea History NoleAppendixJ 



Portions of this publication are reproduced with permission from the National Electrical Code"", 2008 
edition, copyright © 2007 National Fire Protection Association, Quincy, MA 02269. AH rights reserved. 
No portions of NEC® material may be reproduced except with permission of the National Fire 
Protection Association. 



ISBN 9781557016843 

Copyright © to 2008 NEC Held By 

National Fire Protection Association 

1 Batterymarch Park (P.O. Box 9146) 

Quincy, MA 02269-9959 

Copyright © to all unique California State Provisions 

Held by 

California Building Standards Commission 

2525 Natoma Park Drive, Suite 130 

Sacramento, CA 95833-2936 

Printed in The United States 

Published and Printed by BNi Publications^ Inc 



National Electrical Code'' and ^EC^ are registered trademarks of the National Fire Protection 

Association, Inc, Quincy, MA. 



2010 California Electrical Code 



# 



Preface 



This document is the 3rd of 12 Parts of the official triennial compilation and publication of the 
adoptions, amendments and repeal of administrative regulations to California Code of Regulations, Title 
24, also referred to as the California Building Standards Code, This Part is known as the California 
Electrical Code and incorporates, by adoption, the 2008 edition of the National Electrical Code of the 
National Fire Protection Association with the California amendments 

The California Building Standards Code is published in its entirety every three years by order of the 
California legislature, with supplements published in intervening years. The California legislature 
delegated authority to various State agencies, boards, commissions and departments to create building 
regulations to implement the State's statutes. These building regulations or standards, have the same 
force of law, and take effect 180 days after their publication unless otherwise stipulated. The California 
Building Standards Code applies to occupancies in the State of California as annotated. 

A city, county or city and county may establish more restrictive building standards reasonably necessary 
because of local climatic, geological or topographical conditions. Findings of the local condition(s) and 
the adopted local building standard(s) must be filed with the California Building Standards Commission 
to become effective and may not be effective sooner than the date filed with the Califomia Building 
Standards Commission and in no case sooner than the effective date of this edition of California 
Building Standards Code, Local building standards that were adopted and applicable to previous 
editions of the California Building Standards Code do not apply to this edition without appropriate 
adoption and the required filing. 

To familiarize yourself with the format of this code, it is suggested that users review the following 
contents: 

• How To Distinguish Model Code Language From Califomia Amendments 

• Matrix Adoption Tables, located at the beginning of each chapter. 

Should you find publication (e.g., typographical) errors or inconsistencies in this code or wish to offer 
comments toward improving its format, please address your comments to: 



Califomia Building Standards Commission 

2525 Natomas Park Drive, Suite 130 

Sacramento, CA 95833-2936 

Phone: (916)263-0916 
FAX: (916)263-0959 

Web Page: www.bsc.ca.gov 



2010 Califomia Electrical Code 



Acknowledgement 



The 2010 California Building Standards Code (Code) was developed through the outstanding 
collaborative efforts of the Department of Housing and Community Development, the Division of 
State Architect, the Office of the State Fire Marshal, the Office of Statewide Health Planning and 
Development, the California Energy Commission, and the Building Standards Commission 
(Commission). 



This collaborative effort included the assistance of the Commission's Code Advisory Committees and 
many other volunteers that worked tirelessly to assist the Commission in the production of this Code. 



Governor Arnold Schwarzenegger 

Members of the Building Standards Commission 

Acting Secretary Tom Sheehy - Chair 

Isam Hasenin - Vice-Chair Christina Jamison 

James Barthman Stephen Jensen f^U 

Craig Dailey Michael Par avagna 

Susan Dowty Richard Sawhill 

Tony Hoffman Steven Winkel 

David Walls - Executive Director 
Thomas Morrison - Deputy Executive Director 



For questions on California state agency amendments; please refer to the contact list on the following page. 



2010 California Electrical Code 



California Code ofRegulationSj Title 24 
California Agency Information Contact List 



California Energy Commission 

Energy Hotline (800) 772-3300 

or (916) 654-5106 
Building Efficiency Standards 
Appliance Efficiency Standards 
Compliance Manual / Fornns 

California State Lands Commission 

Marine Oil Terminals (562) 499-6317 

California State Library 

Resources and Information (916) 654-0261 

Government Publication Section (916) 654-0069 

Corrections Standards Authority 

Local Adult Jail Standards (916) 324-1 914 

Local Juvenile Facility Standards (916) 324-1914 

Department of Consumer Affairs - Acupuncture 
Board 

Office Standards (916) 445-3021 

Department of Consumer Affairs - Board of 
Pharmacy 

Pharmacy Standards ) (916)574-7900 

Department of Consumer Affairs - Bureau of 
Barbering And Cosmetology 

Barber and Beauty Shop and (916) 574-7570 

College Standards (800)952-5210 

Department of Consumer Affairs — 

Bureau of Home Furnishings and Thermal insulation 

Insulation Testing Standards (916) 574-2041 

Department of Consumer Affairs - Structural Pest 
Control Board 

Structural Standards (800)737-8188 

(916)561-8708 
Department of Consumer Affairs - Veterinary Medical 
Board 

Veterinary Hospital Standards (916) 263-2610 

Department of Food and Agriculture 

Meat & Poultry Packing Plant 

Standards (916) 654-1447 

Dairy Standards (916)654-1447 



Department of Public Health 

Organized Camps Standards (916)449-5661 

Public Swimming Pools Standards (916) 449-5693 

Asbestos Standards (510) 620-2874 

Department of Housing and Community 
Deyelopment 

Residential - Hotels, Motels, Apartments, 
Single-Family Dwellings (916)445-9471 

Permanent Structures in Mobilehome 
and Special Occupancy Parks (916) 445-9471 

Factory-Built Housing, Manufactured 
Housing and Commercial Modular .... (916) 445-3338 

Mobile Homes - Permits & Inspections 

Northern Region (916) 255-2501 

Southern Region (951) 782-4420 

Employee Housing Standards (916) 445-9471 

Department of Water Resources 

Gray Water Installations Standards........ (916) 651-9667 

Diyjsion of the State Architect - Access Compliance 

Access Compliance Standards (916) 445-8100 

DiyJsion of the State Architect - Structural Safety 

Public Schools Standards (916) 445-8100 

Essential Services Building Standards... (916) 445-8100 
Community College Standards (916) 445-81 00 

Diyision of the State Architect - State Historical 
Building Safety Board 

Alternative Building Standards (916)445-8100 

Office of Statewide Health Planning and Deyelopment 

Hospital Standards (916) 440-8409 

Skilled Nursing Facility Standards (916)440-8409 

Clinic Standards (916) 440-8409 

Pemiits (916)440-8409 

Office of The State Fire Marshal 

Code Development and Analysis (916) 445-8200 

Fire Safety Standards (916)445-8200 

Fireplace Standards (916) 445-8200 

Day Care Centers Standards (916) 445-8200 

Exit Standards (916)445-8200 



2010 California Electrical Code 



How to Distinguish Between Model Code Language 

and 
California Amendments 



To distinguish between model code language and the incorporated California amendments, including 
exclusive California standards, California amendments will appear in italics. 

Symbols in the margins indicate the status of code changes as follows: 



[SFM] This symbol identifies which State agency(s), by its "acronym", has amended a section of the 
model code. For a complete listing of the State agency acronyms, see the Application Section 
within Chapter 1 . 

C 

A This symbol indicates a California amendment has been made to the model code. 



This symbol indicates that a change has been made to a California amendment. 



-— ^ This symbol indicates deletion of California language. 

NOTATIONS USED IN THE NA TIONAL ELECTRICAL CODE 

The following notation appears in the National Electrical Code to aid the user: 



Shaded text inciicate^'thatUhe^^^^ the previous edition. The user 

should inspect this text carefully, as some requirements may have been changed. 

I A vertical line in the margin indicates an entirely new article. 



2010 California Electrical Code 




2010 California Electrical Code 



CONTENTS 



ARTICLE 

C 89 General Code Provisions 70-1 

A 90 Introduction 70-21 

Chapter 1 General 

100 Definitions 70-24 

I General 70-^4 

n Over 600 Volts, Nominal 70-31 

110 Requirements for Electrical Installations 70-32 

I General 70-32 

n 600 Volts, Nominal, or Less 70-36 

ffl Over 600 Volts, Nominal 70-38 

IV Tunnel Installations over 600 Volts, Nominal 70-40 

V Manholes and other Electrical Enclosures 

Intended for Personnel Entry, All Voltages 70-41 

Chapter 2 Wuing and Protection 

200 Use and Identification of Grounded Conductors 70-43 

210 Branch Circuits 70-45 

I Gaieral Provisions 70-45 

n Branch-Circuit Ratings 70-49 

m Required Outlets 70-52 

215 Feeders 70-55 

220 Branch-Circuit, Feeder, and Service Calculations 70-57 

I General 70-57 

n Branch Circuit Load Calculations 70-58 

in Feeders and Service Load Calculations 70-60 

IV Optional Feeder and Service Load Calculations 70-62 

V Farm Load Calculations 70-66 

225 Outside Branch Circuits and Feeders 70-67 

I General 70-67 

E More Than One Building or Other Stmcture 70-70 

m Over 600 Volts 70-72 

230 Services , 70-^3 

I General 70-73 

n Overhead Service-I>op Conductors 70-74 

in Underground Service-Lateral Conductors 70-75 

IV Service-Entrance Conductors 70-76 

V Service Equipment — General 70-78 

VT Service Equipment — E)isconnecting Means 70-78 

Vn Service Equipment — Overcurrent Protection 70-80 

Vm Services Exceeding 600 Volts, Nominal 70-81 

240 Overcurrent Protection 70-83 

IGeneral 70-83 

n Location ...70-86 

m Enclosures 70-90 

IV Disconnecting and Guarding 70-90 

VPlug Fuses, Fuseholders, and Adapters 70-90 

VI Cartridge Fuses and Fuseholders 70-91 

vn Circuit Breakers 70-91 

VTH Supervised Industrial Installations 70-92 

DC Overcurrent Protection Over 600 Volts, Nominal 70-93 



ARTICLE 

250 Grounding and Bonding 70-94 

IGeneral 70-94 

n System Grounding 70-97 

in Grounding Electrode System and 

Grounding Electrode Conductor .^.....^ 70-104 

IV Enclosure, Raceway, and Service Cable ^t^ecims 70-109 

VBonding S.. '...:...... 70-109 

VI Equipment Grounding and Equipment 

Grounding Conductors 70-1 13 

vn Methods of Equipment Grounding 70-117 

vm Direct-Current Systems 70-120 

DC Instruments, Meters, and Relays 70-121 

X Grounding of Systems and Circuits of 

1 kV and Over (High Voltage) 70-121 

280 SurgeAn:esters,ov^lfc¥ 70-123 

IGeneral 70-123 

n Installation 70-124 

in Connecting Surge Arresters 70-124 

285 ^igerl^^o^(^eDe^^es;(SPDs)i^lkV<arl^^ 70-124 

IGeneral 70-124 

n Installation 70-125 

m Connecting SPJDs 70-125 

Chapter 3 Wiring Methods and Materials 

300 Wiring Methods 70^126 

I General Requirements 70-126 

n Requirements for Over 600 Volts, Nominal 70-136 

310 Conductors for General Wiring 70-138 

312 Cabinets, Cutout Boxes, and Meter Socket Enclosures 70-164 

I Installation 70-164 

n Construction Specifications 70-165 

314 Outlet, Device, Pull, and Junction Boxes; 

Conduit Bodies; Fittings; and Handhole Enclosures 70-167 

I Scope and General 70-167 

n Installation 70-168 

ni Constmction Specifications 70-174 

IV Pull and Junction Boxes for Use on 

Systems Over 600 Volts, Nominal 70-175 

320 Amiored Cable: Type AC 70-175 

IGeneral ■ 70-175 

n Installation 70-175 

in Construction Specifications 70-177 

322 Flat Cable Assemblies: Type FC 70-177 

ICjeneral 70-177 

n Installation 70-177 

m Constmction 70-178 

324 Flat Conductor Cable: Type FCC 70-178 

IGeneral 70-178 

ninstallation 70-178 

mConstruction 70-180 



2010 California Electrical Code 



70-ix 



CONTENTS 



ARTICLE 

326 Integrated Gas Spacer Cable: Type IGS ..70-180 

I General 70-180 

n Installation 70-180 

ni Construction Specifications 70-181 

328 Medium Voltage Cable: Type MV 70-181 

I General 70-181 

n Installation 7Ckl81 

in Construction Specifications 70-182 

330 Metal-Clad Cable: Type MC 70-182 

I General 70-182 

n Installation : 70-182 

m Construction Specifications 70-183 

332 Mineral-Insulated, Metal-Sheathed Cable: Type MI 70-184 

I General 70-184 

n Installation 70-184 

ni Construction Specifications 70-185 

334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS 70-185 

I General 70-185 

n Installation 70-185 

in Construction Specifications 70-187 

336 Power and Control Tray Cable: Type TC 70-188 

IGeneral 70-188 

n Installation 70-188 

ni Construction Specifications 70-188 

338 Service-Entrance Cable: Types SE and USE.. 70-189 

IGeneral 70-189 

n Installation 70-189 

mConstmction 70-190 

340 Underground Feeder and Branch-Circuit Cable: TypeUF 7(^190 

IGeneral 70-190 

n Installation 70-190 

m Construction Specifications 70-191 

342 Memiediate Metal Conduit: Type MC 70-191 

IGeneral 70-191 

n Installation 70-191 

ni Construction Specifications 70-192 

344 Rigid Metal Conduit: Type RMC 70-192 

IGeneral 70-192 

n Installation 70-193 

nt Construction Specifications 70-194 

348 Flexible Metal Conduit: Type FMC 70-194 

IGeneral : 70-194 

n Installation 70-195 

350 Liquidtight Flexible Metal Conduit: Type LFMC 70-196 

IGeneral 70-196 

n Installation 70-196 

m Construction Specifications 70-197 

352 Rigid Polyvinyl Chloride Conduit: Type PVC 70-197 

IGeneral 7(^197 

n Installation 70-197 

HI Construction Specifications 70-200 



ARTICLE 

353 High Density Polyethylene Conduit: Type HDPE Conduit 70-200 

IGeneral 70-200 

n Installation 70-200 

ni Construction Specifications 70-201 

354 Nonmetallic Underground Conduit with Conductors: TypeNUCC 70-201 

IGeneral 70-201 

n Installation 70-201 

in Construction Specifications 70-202 

355 R^nlbipeaThmmsettiM'E^laCp 70-203 

I. General 70-203 

n. Installation 70-203 

DI. Construction Specifications 70-204 

356 Liquidtight Flexible Nonmetallic Conduit: Type LFNC 70-205 

IGeneral 70-205 

n Installation , 70-206 

ni Construction Specifications 70-207 

358 Electrical Metallic Tubing: Type EMT 70-207 

IGeneral 70-207 

n Installation 70-207 

in Construction Specifications 70-208 

360 Flexible Metallic Tubing: Type FMT 70-208 

IGeneral 70-208 

n Installation 70-209 

m Construction Specifications 70-209 

362 Electrical NonmetalHc Tubing: Type ENT 70-210 

IGeneral 70-^10 

n Installation 70-210 

in Construction Specifications 70-211 

366 Auxiliary Gutters 70-212 

IGeneral 70-212 

ninstaUation 70-212 

ni Construction Specifications 70-213 

368 Busways ..; 70-214 

I General Requirements 70-214 

n Installation 70-214 

mConstiuction 70-215 

IV Requirements for Over 600 Volts, Nominal 70-216 

370 Cablebus 70^16 

372 Cellular Concrete Floor Raceways 70-217 

374 Cellular Metal Floor Raceways 70-218 

IlnstaUation 70-219 

n Constmction Specifications 70-219 

376 Metal Wireways 70-219 

IGeneral 70-219 

n Installation 70-219 

m Construction Specifications 70-220 

378 Nonmetallic Wireways 70-221 

IGeneral 70^21 

n Installation 70-221 

in Construction Specifications 70-222 

380 Multioutlet Assembly 70-222 

382 Nonmetallic Extensions 70-222 

IGeneral 70-222 

n Installation 70-223 

ni, C<Histmotioti Specifications (concealable Notimetallic 
E^tensiofisoMy)..!! ....^... „. \ 70-224 

384 Strut-Type Channel Raceway 70-224 

IGeneral 70-224 

ninstaUation 70-224 

ni Constmction Specifications 70-225 



70-x 



2010 California Electrical Code 



CONTENTS 



ARTICLE 



ARTICLE 



386 Surface Metal Raceways 70-226 

I General 70-226 

n Installation 70-226 

in Constmction Specifications 70-226 

388 Surface Nonmetallic Raceways 70-227 

IGeneral 70-227 

n Installation 70-227 

HI Constmction Specifications 70-227 

390 Underfloor Raceways 70-228 

392 Cable Trays ; 70-229 

394 Concealed Knob-and-Tube Wiring 70-235 

IGeneral 70-235 

n Installation 70-236 

ni Constmction Specifications 70-236 

396 Messenger Supported Wiring 70-237 

IGeneral 70-^37 

n Installation 70-237 

398 Open Wiring on Insulators 70-237 

IGeneral 70^37 

n Installation 70-238 

in Constmction Specifications 70-239 

Chapter 4 Equipment for General Use 

400 Flexible Cords and Cables 70-240 

IGeneral 70^40 

n Constmction Specifications 70-249 

m Portable Cables Over 600 Volts, Nominal 70-250 

402 Fixture Wires 70-251 

404 Switches 70-^55 

I Installation 70-255 

n Constmction Specifications 70-258 

406 Receptacles, Cord Connectors, and Attachment Plugs (Caps) 70-258 

408 Switchboards and Panelboards 70-262 

IGeneral 70-262 

n Switchboards 70-263 

m Panelboards 70-263 

rV Constmction Specifications '. 70-264 

409 Industrial Control Panels 70-265 

IGeneral 70-^65 

n Installation 70-266 

in Constmction Specifications 70-266 

410 Luminaires, Lampholders, and Lamps 70-267 

IGeneral : 70-267 

n Luminaire Locations 70-268 

ni Provisions at Luminaire Outlet Boxes, Canopies, and Pans 70-269 

IV Luminaire Supports 70-269 

V Grounding 70-270 

VI Wiring of Luminaires 70-271 

Vn Constmction of Luminaires 70-272 

Vnilnstallation of Lampholders 70-273 

IX Constmction of Lampholders :.70-273 

X Lamps and Auxiliary Equipment 70-274 

XI Special Provisions for Flush and Recessed Luminaires 70-274 



Xn Constmction of Flush and Recessed Luminaires 70-274 

Xm Special Provisions for Electric-Discharge Lighting Systems of 1000 

Volts or Less 70-274 

XTV Special Provisions for Electric-Discharge Lighting Systems of More 

Than 1000 Volts 70-276 

XV Lighting Track 70-277 

XVI Decorative Lighting and Similar Accessories 70-277 

41 1 Lighting Systems Operating at 30 Volts or Less 70-278 

422 Appliances 70-278 

IGeneral 70-278 

n Installation 70-279 

in Disconnecting Means 70-281 

IV Constmction 70-282 

VMaridng 70-283 

424 Fixed Electric Space-Heating Equipment 70-284 

IGeneral 70^84 

n Installation 70-284 

in Control and Protection of Fixed Electric Space-Heating 

Equipment 70-284 

IV Marking of Heating Equipment 70-286 

V Electric Space-Heating Cables 70-286 

VI Duct Heaters 70-288 

vn Resistance-Type Boilers 70-289 

Vin Electrode-Type Boilers 70-290 

IX Electric Radiant Heating Panels and Heating Panel Sets 70-290 

426 Fixed Outdoor Electric Deicing and Snow-Melting Equipment 70-292 

IGeneral 70-292 

ninstaOation 70-293 

ni Resistance Heating Elements 70-293 

IV Impedance Heating 70-294 

V Skin-Eflfect Heating 70-294 

VI Control and Protection 70-295 

427 Fixed Electric Heating Equipment for 

Pipelines and Vessels 70-295 

IGeneral 70-^95 

n Installation 70-296 

ni Resistance Heating Elements 70-296 

IV Impedance Heating 70-297 

V Induction Heating 70-297 

VI Skin-Efifect Heating 70-298 

vn Control and Protection 70-298 

430 Motors, Motor Circuits, and Controllers 70-298 

IGeneral 70-298 

n Motor Circuit Conductors 70-304 

in Motor and Branch-Circuit Overload Protection 70-306 

IV Motor Branch-Circuit Short-Circuit and Ground-Fault Protection70-310 

V Motor Feeder Short-Circuit and Ground-Fault Protection 70-3 13 

Vt Motor Control Circuits 70-313 

vn Motor Controllers 70-315 

Vm Motor Control Centers 70-316 

IX Disconnecting Means 70-3 17 

X Adjustable — Speed Drive Systems 70-320 

XI Over 600 Volts, Nominal 70-32 1 

Xn Protection of Live Parts — All Voltages 70-322 

xm Grounding — All Voltages 70-323 

XIVTables 70-324 



2010 California Electrical Code 



70-xi 



CONTENTS 



ARTICLE 

440 Air-Conditioning and Refrigerating Equipment 70-327 

I General 70-327 

n Disconnecting Means 70-329 

in Branch-Circuit Short-Circuit and 

Ground-Fault Protection 70-330 

IV Branch-Circuit Conductors 70-331 

V Controllers for Motor-Compressors 70-331 

VI Motor-Compressor and Branch-Ciicuit 

Overload Protection 70-332 

Vn Provisions for Room Air Conditioners 70-333 

445 Generators 70-334 

450 Transformers and TransfomiCT Vaults (Including Secondary Ties) 70-335 

I General Provisions 70-335 

n Specific Provisions Applicable to 

Different Types of Transfonners 70-339 

m Transformer Vaults 70-341 

455 Phase Converters 70-342 

I General 70-342 

n specific Provisions Applicable to 

Different Types of Phase Converters 70-343 

460 C^acitors 70-344 

1 600 Volts, Nominal, and Under 70-344 

n Over 600 Volts, Nominal 70-344 

470 Resistors and Reactors 70-345 

1 600 Volts, Nominal, and Under 70-345 

n Over 600 Volts, Nominal 70-346 

480 Storage Batteries 70-346 

490 Equipment, Over 600 Volts, Nominal 70-347 

IGeneral , 70-347 

n Equipment — Specific Provisions 70-347 

in Equipment — Metal-Enclosed Power Switchgear and 
Industrial Control Assemblies 70-350 

IV Mobile and Portable Equipment 70-352 

V Electrode-Type Boilers 70-352 

Chapter 5 Special Occupancies 

500 Hazardoiis (Classified) Locations, Classes 

I, n, and ffl, Divisions 1 and2 70-354 

501 Class I Locations 70-362 

IGeneral 70-362 

n Wiring 70-363 

mEquipment 70-368 

502 Class n Locations 70-372 

IGeneral ...70-^72 

n Wiring 70^72 

mEquipment 70-374 

503 Class m Locations 70-378 

IGeneral 70-378 

n Wiring ; 70-378 

mEquipment 70-379 

504 Intrinsically Safe Systems 70-380 

505 Class I, ZoneO,l, and 2 Locations 70-384 

506 Zone 20,21,22 Locations forCombustibleDustsP^S 

^^^ Z 70-398 

510 Hazardous (Classified) Locations — Specific 70-404 

511 Commercial Garages, Repair and Storage 70-404 

513 Aircraft Hangars 70-407 



ARTICLE 

514 Motor Fuel Dispensing Facilities : 70-410 

515 Bulk Storage Plants 70-414 

516 Spray Application, Dipping, and Coating Processes 70-419 

517 Health Care Facilities 70-425 

IGeneral 70-425 

n Wiring and Protection 70-427 

m Essential Electrical System 70-430 

IV Inhalation Anesthetizing Locations 70-437 

V X-Ray Installations 70-440 

VI Communications, Signaling Systems, Data Systems, 
Fire Alarm Systems, and Systems Less Than 120 Volts, 

Nominal 70-441 

vn Isolated Power Systems 70-442 

518 Assembly Occupancies 70-443 

520 Iheaters, Audiaice Areas of Motion Picture and Television Studios, 
Perfomiance Areas, and Similar Locations 70-444 

IGeneral 70-444 

n Fixed Stage Switchboanls 70-446 

m Fixed Stage Equipment Other Than Switchboards 70-447 

IV Portable Switchboaixls on Stage 70-448 

V Portable Stage Equipment Other Than Switchboairis 70-451 

VI Dressing Rooms 70-452 

vn Grounding 70-453 



iiPgloS^Sa^i 70^53 

I. General 70453 

n. Control Circuits 70453 

m. Control Circuit Wiring Methods 70454 

525 Carnivals, Circuses, Fairs, and Similar Events 70-455 

I General Requirements 70-455 

n Power Sources 70-455 

m Wiring Methods 70-456 

IV Grounding and Bonding 70-457 

530 Motion Picture and Television Studios 

and Similar Locations 70-457 

IGeneral 70-457 

n Stage or Set 70-458 

m Dressing Rooms 70-460 

IV Viewing, Cutting, and Patching Tables 70-460 

V Cellulose Nitrate Film Storage Vaults 70-460 

VI Substations 70-460 

540 Motion Picture Projection Rooms 70-461 

IGeneral 70-461 

n Equipment and Projectors of the Professional Type 70-461 

m Nonprofessional Projectors 70-462 

rv Au(io Signal Processing, Amplification, 

and Rqjroduction Equipment 70-462 

545 Manufectured Buildings 70-462 

547 Agricultural Buildings 70-463 

550 Mobile Homes, Manufectured Homes, and Mobile Home Parks ... 70-466 

IGeneral 70-466 

n Mobile and Manufectured Homes 70-467 

m Services and Feeders 70-474 

551 Recreational Vehicles and Recreational Vehicle Pari<s 70-475 

IGeneral : 70-475 

n Combination Electrical Systems 70-477 

ffl Other Power Sources 7CM77 

IV Nominal 120-Volt or 120/240-Volt Systems 70-478 

V Factory Tests 70-485 

VI Recreational Vehicle Paries 70-485 



70-xii 



2010 California Electrical Code 



CONTENTS 



ARTICLE 

■ 552 Paik Trailers 70-488 

I General 70-488 

n Low-Voltage Systems 70-488 

m Combination Electrical Systems 70-489 

IV Nominal 120-Volt or 120/240-Volt Systems 70-490 

V Factory Tests 70-496 

553 Floating Buildings 70-497 

IGeneral ..70^97 

n Services and Feeders 70-497 

niGroxinding ...70497 

555 Marinas and Boatyards 70-498 

590 Temporary Installations 70-501 



Chapter 6 Special Equipment 



600 Electric Signs and Outline Lighting 70-504 

IGeneral 70-504 

n Field-Installed Skeleton Tubing aiid Wirmg 70-508 

604 Manufactured Wiring Systems ....70-509 

605 Office Fiffnishings (Consisting of Lighting 

Accessories and Wired Partitions) 70-510 

610 Cranes and Hoists 70-511 

IGeneral 70-511 

n Wiring : 70-512 

m Contact Conductors 70-514 

rv Disconnecting Means 70-515 

V Overcmrent Protection 70-515 

VI Control 70-516 

Vn Grounding 70-516 

620 Elevators, Dumbwaiters, Escalators, 
Moving Walks, Wheelchair Lifts, and 
Stairway Chair Lifts !..70-517 

IGeneral 70-517 

n Conductors 70-519 

m Wiring 70-520 

IV Installation of Conductors 7(^-523 

V Traveling Cables 70-523 

VI Disconnecting Means and Control 70-524 

vn Overcurrent Protection 70-526 

Vni Machine Rooms, Control Rooms, 

Machinery Spaces, and Control Spaces 70-526 

IX Grounding 70-527 

X Emergency and Standby Power Systems 70-527 

625 Electric Vehicle Charging System ....70-527 

IGeneral 70-527 

n Wiring Methods 70-528 

in Equipment Constmction 70-528 

IV Control and Protection 70-529 

V Electric Vehicle Supply Equipment Locations 70-529 

6^d-Efotr|iiedTii;ick>aiteg Spaces 70-531 

IGeneral '.1 70-531 

n. Electrified Truck Paridng Spaces Electrical Wiring Systems 70-532 

m. Electrified Tmck Parking Space Supply 70-533 

IV. Transport Refiigerated Unites (TRUs) 70-535 



ARTICLE 

630 Electric Welders 70-536 

IGeneral '. 70-536 

n Arc Welders 70-536 

m Resistance Welders 70-537 

P/ Welding Cable 70-538 

640 Audio Signal Processing, Amplification, 

and Reproduction Equipment 70-538 

IGeneral 70-538 

n Permanent Audio System Installations 70-542 

ni Portable and Temporary Audio System Installations 70-542 

645 Information Technology Equipment 70-544 

647 Sensitive Electronic Equipment 70-546 

650 Pipe Organs 70-547 

660 X-P^y Equipment 70-548 

IGeneral 70-548 

n Control 70-549' 

HI Transformers and Capacitors 70-549 

IV Guarding and Grounding 70-549 

665 Induction and Dielectric Heating Equipment 70-550 

IGeneral. 70-550 

n Guarding, Grounding, and Labeling 70-551 

668 Electrolytic CeUs 70-551 

669 Electroplating 70-554 

670 Industrial Machinery ; 70-555 

675 Electrically Driven or Controlled Irrigation Machines 70-556 

IGeneral 70-556 

n Center Pivot Irrigation Machines 70-558 

680 Swimming Pools, Fountains, and Similar Installations 70-558 

IGeneral 70-558 

n Pennanently Installed Pools 70-561 

niStorable Pools 70-568 

IV Spas and Hot Tubs 70-568 

VFountains 70-570 

VI Pools and Tubs for Therapeutic Use.. 70-572 

vn Hydromassage Bathtubs 70-572 

682 Natural and Artifically Made Bodies of Water 70-573 

IGeneral 70-^73 

n Installation 70-573 

in Grounding and Bonding 70-574 

685 Integrated Electrical Systems 70-575 

IGeneral : 70-575 

n Orderly Shutdown ;.. 70-575 

690 Solar Photovoltaic Systems 70-575 

IGeneral 70-575 

n Circuit Requirements 70-578 

EI Disconnecting Means 70-580 

IV Wiring Methods 70-581 

V Grounding 70-583 

VIMaridng..' 70-585 

vn Connection to Other Sources 70-585 

Vni Storage Batteries 70-587 

DC Systems Over 600 Volts 70-588 



2010 California Electrical Code 



70-xiii 



CONTENTS 



ARTICLE 

692 Fuel CeU Systems 70-588 

I General 70-588 

n Circuit Requirements 70-589 

in Disconnecting Means 70-589 

IV Wiring Methods 70-590 

V Grounding 70-590 

VI Marking 70-590 

Vn Connection to Other Circuits 70-590 

Vm Outputs Over 600 Volts 70-591 

695 Fire Pumps 7(^591 

Chapter 7 Special Conditions 

700 Emergency Systems 70-596 

I General 70-596 

n Circuit Wiring 70-597 

m Sources of Power 70-598 

IV Emergency System Circuits for Lighting and Power 70-600 

V Control — Emergency Lighting Circuits 70-600 

VI Overcmrmt Protection 70-600 

701 LegaUy Required Standby Systems 70-601 

I General 70-601 

n Circuit Wiring 70-602 

m Sources of Power 70-602 

IV Overcurrent Protection 70-603 

702 Optional Standby Systems 70-604 

I General 70-604 

n Circuit Wiring 70-605 

in Grounding 70-605 

IV Sources of Power 70- 605 

705 Interconnected Electric Power Production Sources 70-605 

I. General 70-605 

n. Utility-Interactive Inverters 70-608 

m. Generators 70-609 

7C^:CBiM'C^M€«b$'Fd^#'S^siwi:fCC^ 70-609 

L General 70-609 

n. Circuit Wiring and Equipment 70-610 

in. Ppower Sources and Connection 70-612 

IV. Overcurrent Protection 70-613 

V. System Performance and Analysis 70-614 

720 Circuits and Equipment Operating at Less , 

Than 50 Volts 70-614 

725 Class 1 , Class 2, and Class 3 

Remote-Control, Signaling, and Power-Limited Circuits 70-614 

I General 70-614 

n Class 1 Circuits 70-615 

ffl Class 2 and Class 3 Circuits 70-^17 

IV Listing Requirements 70-622 

727 Instrumentation Tray Cable: Type rrC 70-624 

760 Fire Alami Systems 70-625 

I General '. 70-625 

n Non-Power-Limited Fire Alami (NPLFA) Circuits 70-626 

m Power-Limited Fire Alami (PLFA) Circuits 70-628 

IV Listing Requirements ...70-631 

770 Optical Fiber Cables and Raceways 70-633 

I General 70-633 

HCabl^CXitsae^idEi^OTigBi;#3^ 70-634 

Ifl Protection .'....'...7..;.....'.........' 70-635 

IV"aHiii®ig]S^^Q^ 70-635 

VteaIM<mS»odsWt8MBilib^ 70-636 

yiLisiirigRequiremmts 70-638 

Chapter 8 Communications Systems 

800 Communications Circuits 70-640 

I General 70-640 

n Wires and Cables Outside and Entering Buildings 70-641 

m Protection 70-642 

IV Grounding Methods 70-644 

V M^M^Msjl^^ Wires and Cables Within Buildings 70-645 

VI Listing Requirements 70-647 



ARTICLE 

810 Radio and Television Equipment 70-649- 

IGeneral 70-649 

n Receiving Equipment — Antenna Systems 70-650 

in Amateur Transmitting and Receiving 

Stations — Antenna Systems 70-652 

IV Interior Installation — Transmitting Stations 70-653 

820 Community Antenna Television and Radio 

Distribution Systems 70-653 

IGeneral : 70-653 

n|MB Cables Outside and Entering Buildings 70-654 

m Protection 70-655 

IV.Grounding Methods 70-656 

V gHHSlSifiSti Within Buildings 70-657 

VI Listing Requirements 70-559 

830 Networic-Powered Broadband Communications Systems 70-660 

IGeneral 70-660 

n Cables Outside and Entering Buildings 70-662 

mProtection 70-664 

IV Grounding Methods 70-666 

V fosfciiiado^ Methods Within Buildings 70-667 

VI Listing Requirements 70-669 

TABLES 

Chapter 9 Tables 



1 Percent of Cross Section of Conduit and 

Tubing for Conductors 70-671 

2 Radius ofConduit and Tubing Bends 70-671 

4 Dimensions and Percent Area ofConduit 

and Tubing (Areas ofConduit or Tubing 
for the Combinations of Wires Permitted 
inTablel, Chapter 9) 7C^-672 

5 Dimensions of Insulated Conductors and 

Fixture Wir^s 70-676 

5ACompact^^HAluminumBuildingWire 

Nominal Dimensions and Areas 70-680 

8 Conductor Properties 70-681 

9 Alternating-Current Resistance and 

Reactance for 600-Volt Cables, 3-Phase, 
60 Hz, 75°C (167°F) — Three Single 
Conductors in Conduit 70-682 

1 1(A) Class 2 and Class 3 Alternating-Current 

Power Source Limitations 70-684 

1 1 (B) Class 2 and Class 3 Direct-Current Power 

Source Limitations 70-684 

12(A) PLFA Alternating-Current Power Source Limitations 70-685 

12(B) PLFA Direct-Current Power Source Limitations 70-685 

Annex A 70-686 

AnnexB 70-689 

Annexe 70-^03 

Annex D 70-^63 

AnnexE 70-^73 

Annex F 70-774 

AnnexG 70-776 

AnnexH 70-778 

Index 70-785 



70-xiv 



2010 California Electrical Code 



CALIFORNIA MATRIX ADOPTION TABLES 



California Matrix Adoption Tables 

Format of the Matrix Adoption Tables 

The matrix adoption tables, which follow, show the user which state agencies have 
adopted and/or amended given sections of model code for applications within their 
respective authorities. See Article 89, Sections 089.102 through 89.114, for building 
application and enforcement responsibilities. 

The side headings identify the scope of the state agencies' adoption as follows: 

Adopt the entire NEC article without state amendments 

If there is an "X" under a particular state agency's acronym in this row, it means that 
particular state agency has adopted the entire model code chapter without any state 
amendments. 



Example: 



ARTICLE 89 - GENERAL CODE PROVISIONS 




Adopting Agency 



BSC 



SFM 



HCD 



DSA 



AC SS 



OSHPD 



1 



DPH 
AC 



Adopt Entire Article 



Adopt Entire Article as amended 
(amended sections listed below) 



Adopt only those sections that are 
listed below 



Article / Section 









:£Z.^ 



89.101 



89.102 



Adopt the entire NEC article as amended (amendments listed below) 

If there is an "X" under a particular state agency's acronym in this row, it means that 
particular state agency has adopted the entire model code chapter, with state amendments. 

Each state-amended section that the agency has added to that particular chapter is 
listed. There will be an "X" in the column, by that particular section, under the agency's 
acronym, as well as an "X" by each section that the agency has adopted. 



The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2. 



2010 California Electrical Code 



70-xv 



CALIFORNIA MATRIX ADOPTION TABLES 



Example: 



ARTICLE 89 - GENERAL CODE PROVISIONS 



Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


DPH 


1 


2 


AC 


ss 


1 


2 


3 


4 


Adopt Entire Article 
























Adopt Entire Article as amended 
(amended sections listed below) 


X 




& 


/■■ {■■■'■'-■ 








:' ■ .r 
;■' ' -A 








Adopt only those sections that are listed 
below 




%.. 


1 J IP 


,3 , ''' 






Article / Section 










89.101 


X 






















89.102 


X 























Example: 



Adopt only those sections which are listed below: 

If there is an "X" under a particular state agency's acronym in this row, it means that 
particular state agency is adoption only specific model code or state-amended sections 
within this chapter. There will be an "X" in the column under the agency's acronym, as 
well as an "X" by each section that the agency has adopted. 

ARTICLE 89 - GENERAL CODE PROVISIONS 




Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


DPH 


1 


2 


AC 


ss 


1 


2 


3 


4 


Adopt Entire Article 
























Adopt Entire Article as amended 
(amended sections listed below) 
























Adopt only those sections that are listed 
below 


X 






m\ : i 


'P\ 


,;,! 


■ ,,■ 


. 




Article / Section 




" ■ 






' ". '' 


89.101 


X 






















89.102 


X 























Legend of Abbreviations of Adopting State Agencies 

BSC California Building Standards Commission 

SFM Office of the State Fire Marshal 

HCD Department of Housing and Community Development 

DSA-AC Division of the State Architect - Access Compliance 

DSA-SS Division of the State Architect - Structural Safety 

DSA-SS/CC Division of the State Architect - Structural Safety/Community Colleges 

OSHPD Office of Statewide Health Planning and Development 

DPH California Department of Public Health 



The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2. 
'^^■^^^ 2010 California Electrical Code 



ARTICLE 89 CALIFORNIA MATRIX ADOPTION TABLE 



ARTICLE 89 - GENERAL CODE PROVISIONS 



Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


DPH 


1 


1-AC 


2 


AC 


SS 


SS/CC 


1 


2 


3 


4 


Adopt Entire Article 




























Adopt Entire Article as amended 
(amended sections listed below) 




























Adopt only those articles / sections tliat 
are listed below 


X 


X 


X 


X 


X 


X 


X 


X 










X 


Article / Section 


89.101 


X 


X 


X 


X 


X 




X 


X 


X 


X 


X 


X 


X 


89.102 


X 


























89.107 


























X 


89.108 






X 


X 


X 


















89.109.1 












X 
















89.109.2.1 














X 














89.109.2.2 
















X 












89.110.1 


















X 










89.110.2 




















X 








89.110.3 






















X 






89.110.4 
























X 




89.111 




X 





















































The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is apphcable to structures subject to HCD 1 and/or HCD 2. 
2010 California Electrical Code 




The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2. 

2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



CALIFORNIA ARTICLE 89 
GENERAL CODE PROVISIONS 



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SECTION 89.101 
GENERAL 



89.101.1 Title. These regulations shall be known as the 
California Electrical Code, may be cited as such and will be 
referred to herein as ''this code. " The California Electrical 
Code is Part 3 of twelve parts of the official compilation and 
publication of the adoption, amendment, and repeal of 
electrical regulations to the California Code of Regulations, 
Title 24, also referred to as the California Building Standards 
Code. This part incorporates by adoption the 2008 National 
Electrical Code of the National Fire Protection Association 
with necessary California amendments. 

89.101.2 Purpose. The purpose of this code is to establish the 
minimum requirements to safeguard the public health, safety 
and general welfare through structural strength, means of 
egress facilities, stability, access to persons with disabilities, 
sanitation, adequate lighting and ventilation, and energy 
conservation; safety to life and property from fire and other 
hazards attributed to the built environment; and to provide 
safety to fire fighters and emergency responders during 
emergency operations. 

89.1013 Scope. The provisions of this code shall apply to the 
construction, alteration, movement, enlargement, replacement, 
repair, equipment, use and occupancy, location, maintenance, 
removal and demolition of every building or structure or any 
appurtenances connected or attached to such building or 
structures throughout the State of California. 

89.101.3.1 Nonstate-Regulated Buildings, Structures^ 
and Applications. Except as modified by local ordinance 
pursuant to Section 89.101.8, the building standards in 
the California Code of Regulations, Title 24, Parts 2, 2.5, 
3, 4, 5, 6,9, 10 and 11 shall apply to all occupancies and 
applications not regulated by a state agency. 

89.101.3.2 State-Regulated Buildings, Structures, and 
Applications, The model code, state amendments to the 
model code, and/or state amendments where there are no 
relevant model code provisions shall apply to the 
following buildings, structures, and applications 
regulated by state agencies as referenced in the Matrix 
Adoption Tables and as specified in Sections 89.102 
through 89.114, except where modified by local 
ordinance pursuant to Section 89.101.8. When adopted 
by a state agency, the provisions of this code shall be 
enforced by the appropriate enforcing agency, but only to 
the extent of authority granted to such agency by the state 
legislature. 



Note: See Preface to distinguish the model code 
provisions from the California provisions. 

1. State-owned buildings, including buildings 
constructed by the Trustees of the California State 
University, and to the extent permitted by California 
laws, buildings designed and constructed by the 
Regents of the University of California, and regulated 
by the Building Standards Commission. See Section 
89.102 for additional scope provisions. 

2. Reserved for Corrections Standards Authority. See 
Section 89.103 for additional scope provisions. 

3. Reserved for the Department of Consumer Affairs. 
See Section 89.104 for additional scope provisions. 

4. Reserved for the California Energy Commission. 
See Section 89.105 for additional scope provisions. 

5. Reserved for the Department of Food and Agriculture. 
See Section 89.106 for additional scope provisions. 

6. Organized camps, laboratory animal quarters, public 
swimming pools, radiation protection, commissaries setving 
mobile food preparation vehicles and wild animal 
quarantine facilities regulated by the California Department 
of Public Health (DPH). See Section 89.107 for additional 
scope provisions. 

7. Hotels, motels, lodging houses, apartment houses, 
dwellings, dormitories, condominiums, shelters for 
homeless persons, congregate residences, employee 
housing, factory-built housing, and other types of dwellings 
containing sleeping accommodations with or without 
common toilets or cooking facilities. See Section 
89. 108.2.1.1 for additional scope provisions, 

8. Accommodations for persons with disabilities in 
buildings containing newly constructed covered 
multifamily dwellings, new common use spaces serving 
existing covered multifamily dwellings, additions to 
existing buildings where the addition alone meets the 
definition of ''COVERED MULTIFAMILY 
DWELLINGS,*' and common-use spaces serving 
covered multifamily dwellings which are regulated by 
the Department of Housing and Community 
Development. See Section 89.108.2.1.2 for additional 
scope provisions. 

9. Permanent buildings and permanent accessory 
buildings or structures constructed within mobilehome 
parks and special occupancy parks regulated by the 
Department of Housing and Community Development See 
Section 89. 1 08. 2. 1 . 3 for additional scope provisions. 



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2010 California Electrical Code 



70-1 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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10. Accommodations for persons with disabilities 
regulated by the Division of the State Architect. See 
Section 89. 1 09. 1 for additional scope provisions. 

11. Public elementary and secondary schools, 
community college buildings, and state-owned or state- 
leased essential service buildings regulated by the 
Division of the State Architect. See Section 89.109.2 for 
additional scope provisions. 

12. Qualified historical buildings and structures and 
their associated sites regulated by the State Historical 
Building Safety Board with the Division of the State 
Architect. See Section 89.109.3 for additional scope 
provisions. 

13. General acute care hospitals, acute psychiatric 
hospitals, skilled nursing and/or intermediate care 
facilities, clinics licensed by the California Department 
of Public Health (DPH) and correctional treatment 
centers regulated by the Office of Statewide Health 
Planning and Development. See Section 89.110 for 
additional scope provisions. 

14. Applications regulated by the Office of the State 
Fire Marshal include, but are not limited to, the 
following in accordance with Section 89.111: 

1. Buildings or structures used or intended for use as an: 

1.1. Asylum, jail. 

1.2. Mental hospital, hospital, home for the elderly, 
children's nursery, children's home or institution, 
school or any similar occupancy of any capacity. 

1.3. Theater, dancehall, skating rink, auditorium, 
assembly hall, meeting hall, nightclub, fair building, or 
similar place of assemblage where 50 or more persons 
may gather together in a building, room or structure 
for the purpose of amusement, entertainment, 
instruction, deliberation, worship, drinking or dining, 
awaiting transportation, or education. 

1.4. Small family day care homes, large family day 
care homes, residential facilities and residential 
facilities for the elderly and residential care facilities. 

1.5. State institutions or other state-owned or state- 
occupied buildings. 

1.6. High rise structures. 

1. 7. Motion picture production studios. 

1.8. Organized camps. 

1.9. Residential structures. 

2. Tents, awnings or other fabric enclosures used in 
connection with any occupancy. 

3. Fire alarm devices, equipment and systems in 
connection with any occupancy. 

4. Hazardous materials, flammable and 
combustible liquids. 



5. Public school automatic fire detection, alarm, and 
sprinkler systems. 

6. Wildland-Urban Interface (WUI)fire areas. 

15. Reserved for the State Librarian. See Section 89,1 12 for 
additional scope provisions. 

16. Reserved for the Department of Water Resources. See 
Section 89.1 13 for additional scope provisions. 

17. Reserved for the California State Lands Commission. 
See Section 89.1 14 for additional scope provisions. 

89.101,3,3 Exempted from this Code. This code does 
not cover: 

(A) 1. Installations in ships, watercraft other than 
floating dwelling units, railway rolling stock, 
aircraft, automotive vehicles, commercial coaches, 
mobilehomes, and recreational vehicles. 

(B) 2. Installations underground in mines, mine 
shafts and tunnels. 

(C) 3. Installations of railways for generation, 
transformation, transmission, or distribution of 
power used exclusively for operation of rolling stock 
or installations used exclusively for signaling and 
communication purposes. 

(D) 4. Installation of communication equipment 
under the exclusive control of communication 
utilities, located outdoors or in building spaces used 
exclusively for such installations. 

(E) 5. Installations under the exclusive control of 
electrical utilities for the purpose of communication, 
or metering; or for the generation, control, 
transformation, transmission, and distribution of 
electrical energy located in buildings used 
exclusively by utilities for such purposes or located 
outdoors on property owned or leased by the utility 
or on public highways, streets, roads, etc., or 
outdoors by established rights on private property. 

Exception to (D)4 and (E)5: In places of 
employment, the following shall apply: installations 
of conductors, equipment and associated enclosures 
subject to the jurisdiction of the California Public 
Utilities Commission, that are owned, operated and 
maintained by an electric, communications or 
electric railway utility, but not including conduit, 
vaults, and other like enclosures containing 
conductors and equipment of such a utility when 
located indoors or on premises not used exclusively 
for utility purposes, but do not apply to the utility 's 
conductors and equipment therein. 

(F) 6. Installations on highways or bridges. 



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70-2 



2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 




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89.101.4 Annexes, Provisions contained in the annexes of 
this code shall not apply unless specifically adopted by a 
state agency or adopted by a local enforcing agency in 
compliance with Health and Safety Code Section 18901 et 
seq. for Building Standards Law, Health and Safety Code 
Section 17950 for State Housing Law and Health and 
Safety Code Section 13 869. 7 for Fire Protection Districts, 
See Section 89 J 01. 8 of this code. 

89.101.5 Referenced Codes, The codes, standards and 
publications adopted and set forth in this code, including 
other codes, standards and publications referred to therein 
are, by title and date of publication, hereby adopted as 
standard reference documents of this code. When this code 
does not specifically cover any subject related to building 
design and construction, recognized architectural or 
engineering practices shall be employed. The National Fire 
Codes, standards and the Fire Protection Handbook of the 
National Fire Protection Association are permitted to be 
used as authoritative guides in determining recognized fire 
prevention engineering practices. 

89.101.6 Non-Building Standards, Orders and 
Regulations. Requirements contained in the National 
Electrical Code, or in any other referenced standard, code 
or document, which are not building standards as defined 
in Health and Safety Code Section 18909 shall not be 
construed as part of the provisions of this code. For 
nonbuilding standards, orders, and regulations, see other 
titles of the California Code of Regulations. 

89.101. 7 Order of Precedence and Use. 

89.101.7.1 Differences. In the event of any differences 
between these building standards and the standard 
reference documents, the text of these building standards 
shall govern. 

89.101.7.2 Specific Provisions, Where a specific 
provision varies from a general provision, the specific 
provision shall apply, 

89.10L7.3 Conflicts, When the requirements of this code 
conflict with the requirements of any other part of the 
California Building Standards Code, Title 24, the most 
restrictive requirements shall prevail. 

89.101.8 City, County, or City and County Amendments, 
Additions or Deletions. The provisions of this code do not 
limit the authority of city, county, or city and county 
governments to establish more restrictive and reasonably 
necessary differences to the provisions contained in this 
code pursuant to complying with Section 89.101.8.1. The 
effective date of amendments, additions, or deletions to 
this code by city, county or city and county filed pursuant 
to Section 89.101.8.1 shall be the date filed. However, in 
no case shall the amendments, additions or deletions to 
this code be effective any sooner than the effective date of 
this code. 



Local modifications shall comply with Health and Safety 
Code Section 18941,5 for Building Standards Law, Health 
and Safety Code Section 1 7958 for State Housing Law or 
Health and Safety Code Section 13869.7 for Fire 
Protection Districts. 

89,101.8.1 Findings and Filings. 

1. The city, county, or city and county shall make 
express findings for each amendment, addition or 
deletion based upon climatic, topographical, or 
geological conditions. 

Exception: Hazardous building ordinances and 
programs mitigating unreinforced masonry buildings. 

2. The city, county, or city and county shall file the 
amendments, additions, or deletions expressly 

marked and identified as to the applicable findings. 
Cities, counties, cities and counties, and fire 

departments shall file the amendments, additions or 
deletions, and the findings with the California 

Building Standards Commission at 2525 Natomas 
Park Drive, Suite 130, Sacramento, CA 95833, 

3. Findings prepared by fire protection districts 
shall be ratified by the local city, county, or city and 
county and filed with the California Department of 
Housing and Community Development, Division of 
Codes and Standards, P.O. Box 1407, Sacramento, CA 
95812-1407 or at 1800 3rd Street, Room 260, 
Sacramento, CA 95811. 

89.101.9 Effecdve Date of this Code. Only those standards 
approved by the California Building Standards Commission 
that are effective at the time an application for building permit 
is submitted shall apply to the plans and specifications for, and 
to the construction performed under, that permit For the 
effective dates of the provisions contained in this code, see the 
History Note page of this code. 

89.101.10 Availability of Codes. At least one complete 
copy each of Titles 8, 19, 20, 24, and 25 with all revisions 
shall be maintained in the office of the building official 
responsible for the administration and enforcement of this 
code. Each state department concerned and each city, 
county or city and county shall have an up-to-date copy of 
the code available for public inspection. See Health and 
Safety Code Section 18942 (d) (1) and (2). 

89.101.11 Format This part fundamentally adopts the 
National Electrical Code by reference on a chapter-by- 
chapter basis. Such adoption is reflected in the Matrix 
Adoption Table of each chapter of this part. When the Matrix 
Adoption Tables make no reference to a specific chapter of the 
National Electrical Code, such chapter of the National 
Electrical Code is not adopted as a portion of this code. 

89.101.12 Validity, If any chapter, article, section, 
subsection, sentence, clause or phrase of this code is for 
any reason held to be unconstitutional, contrary to statute, 



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2010 California Electrical Code 



70-3 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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exceeding the authority of the state as stipulated by 
statutes, or otherwise inoperative, such decision shall not 
affect the validity of the remaining portion of this code. 

SECTION 89.102 

BUILDING STANDARDS COMMISSION 

89,102,1 Specific scope of application of the agency 
responsible for enforcement, the enforcement agency, and 
the specific authority to adopt and enforce such 
provisions of this code, unless otherwise stated. 

L State Buildings for all occupancies. 

Application - State buildings (all occupancies), including 
buildings constructed by the Trustees of the California 
State University and the Regents of the University of 
California where no state agency has the authority to adopt 
building standards applicable to such buildings. 

Enforcing Agency ~ State or local agency specified by 
the applicable provisions of law. 

Authority Cited - Health and Safety Code section 
18934.5. 

Reference ~ Health and Safety Code, Division 13, Part 
2,5, commencing with section 18901. 

2, University of Californiay California State Universities, 
and California Community Colleges, 

Application - Standards for lighting for parking lots 
and primary campus walkways at the University of 
California, California State Universities, and 
California Community Colleges, 

Enforcing Agency - State or local agency specified by 
the applicable provisions of law. 

Authority Cited- Government Code section 14617. 

Reference - Government Code section 1461 7, 

3, Existing State-Owned Buildings, including those owned 
by the University of California and by the Calif omia State 
University- Building seismic retrofit standards including 
abating falling hazards of structural and nonstructural 
components and strengthening of building structures. See 
also Division of the State Architect 

Enforcing Agency - State or local agency specified by 
the applicable provisions of law. 

Authority Cited- Government Code section 16600 

Reference - Government Code sections 16600 
through 16604 

4, Unreinforced Masonry Bearing Wall Buildings, 

Application - Minimum seismic strengthening standards 
for buildings specified in Appendix Chapter 1 of the 
California Code for Building Conservation, except for 
buildings subject to building standards adopted pursuant 
to Part 1.5 (commencing with Section 17910). 



Enforcing Agency - State or local agency specified by 
the applicable provisions of law. 

Authority Cited - Health and Safety Code section 
18934.6 

Reference - Health and Safety Code sections 18901 
through 18949 

89.102.2 Alternative Materials, Design And Methods Of 
Construction And Equipment. 

The provisions of this code are not intended to prevent the 
installation of any material or to prohibit any design or 
method of construction not specifically prescribed by this 
code, provided that any such alternative has been approved. 
An alternative material, design or method of construction shall 
be approved where the building official finds that the proposed 
design is satisfactory and complies with the intent of the 
provisions of this code, and that the material, method or work 
offered is, for the purpose intended, at least the equivalent of 
that prescribed in this code in quality, strength, effectiveness, 
fire resistance, durability and safety. 

89.102.2.1 Research Reports. Supporting data, where 
necessary to assist in the approval of materials or 
assemblies not specifically provided for in this code, shall 
consist of valid research reports from approved sources. 

89.102.2.2 Tests. Whenever there is insufficient evidence 
of compliance with the provisions of this code, or 
evidence that a material or method does not conform to 
the requirements of this code, or in order to substantiate 
claims for alternative materials or methods, the building 
official shall have the authority to require tests as 
evidence of compliance to be made at no expense to the 
jurisdiction. Test methods shall be as specified in this 
code or by other recognized test standards. In the 
absence of recognized and accepted test methods, the 
building official shall approve the testing procedures. 
Tests shall be performed by an approved agency. Reports 
of such tests shall be retained by the building official for 
the period required for retention of public records, 

SECTION 89.103 

RESERVED FOR CORRECTIONS STANDARDS 
AUTHORITY 

SECTION 89.104 

RESER VED FOR THE DEPARTMENT OF 
CONSUMER AFFAIRS 

SECTION 89.105 

RESERVED FOR THE CALIFORNIA ENERGY 
COMMISSION 

SECTION 89.106 

RESERVED FOR THE DEPARTMENT OF FOOD 
AND A GRIGUL TURE 



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70-4 



2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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SECTION 89.107 

CALIFORNIA DEPARTMENT OF PUBLIC 
HEALTH 

89,107 Specific scope of application of the agency 
responsible for enforcement, the enforcement agency, and 
the specific authority to adopt and enforce such 
provisions of this code, unless otherwise stated. 

Application -Commissaries serving mobile food 
preparation units and public swimming pools 

Enforcing Agency - The California Department of 
Public Health and the local health agency. 

Authority Cited ~~ Health and Safety Code sections , 
114304, 116050, and 131200. 

Reference - Health and Safety Code sections 
114304, 116050, 116053 and 131200. 



SECTION 89,108 

DEPARTMENT OF HOUSING AND COMMUNITY 
DEVELOPMENT 

89.108.1 Purpose, The purpose of this code is to 
establish minimum standards to protect the health, 
safety, and general welfare of the occupant and the 
public against hazards that may arise from the use of 
electricity by governing the design, construction, 
reconstruction, installation, quality of materials, 
location, operation, and maintenance or use of 
electrical equipment, wiring and systems. 

89.108.2 AUTHORITY AND ABBREVIATIONS 

89,108,2,1 General, The Department of Housing 
and Community Development is authorized by law 
to promulgate and adopt building standards and 
regulations for several types of building 
applications. These applications are grouped and 
identified by abbreviation in the Matrix Adoption 
Tables to show which model code sections and 
amendments are applicable to each application. 
The applications under the authority of the 
Department of Housing and Community 
Development are listed in Sections 89,108.2.1.1 
through 89. 108.2. L3. 

89,108,2,1,1 Housing Construction, Application - 
Hotels, motels, lodging houses, apartment houses, 
dwellings, dormitories, condominiums, shelters for 
homeless persons, congregate residences, employee 
housing, factory-built housing and other types of 
dwellings containing sleeping accommodations with or 
without common toilet or cooking facilities including 
accessory buildings, facilities, and uses thereto. 
Sections of this code which pertain to applications 
listed in this section are identified in the Matrix 
Adoption Table using the abbreviation 'HCD 1 ". 



Enforcing Agency-Local building department 
or the Department of Housing and Community 
Development. 

Authority Cited: Health and Safety Code 
Sections 17040, 17050, 17920.9, 17921, 
1 7921. 3, 17921.6, 17921.10, 17922, 17922.6, 
17922.12, 17927, 17928, 17959.6, 18300, 18552, 
18554, 18620, 18630, 18640, 18670, 18690, 
18691, 18865, 18871.3, 18871.4, 18873, 
18873.1, 18873.2, 18873.3, 18873.4, 18873.5, 
18938.3, 18944.11, and 19990; and Government 
Code Section 12955.1. 

Reference: Health and Safety Code Sections 
17000 through 17062.5, 17910 through 17995.5, 
18200 through 18700, 18860 through 18874, and 
19960 through 19997; and Government Code 
Sections 12955.1 and 12955.1.1. 

89,108,2,1,2 Housing Accessibility, Application- 
Covered multifamily dwellings as defined in 
Chapter llA of the California Code of 
Regulations, Title 24, Fart 2, also known as the 
California Building Code (CBC) including, but not 
limited to, lodging houses, dormitories, 
timeshares, condominiums, shelters for homeless 
persons, congregate residences, apartment houses, 
dwellings, employee housing, factory-built housing 
and other types of dwellings containing sleeping 
accommodations with or without common toilet or 
cooking facilities. 

Sections of this code identified in the Matrix 
Adoption Table by the abbreviation 'HCD 1- 
AC" require specific accommodations for 
''PERSONS WITH PHYSICAL DISABILITIES, " 
as defined in CBC Chapter 11 A. The 
application of such provisions shall be in 
conjunction with other requirements of this 
code and apply only to newly-constructed 
''COVERED MULTIFAMILY DWELLINGS" as 
defined in CBC Chapter 11 A. 'HCD 1-AC" 
applications include, but are not limited to, the 
following: 

(1) All newly constructed ''COVERED 
MULTIFAMILY DWELLINGS'' as defined in CBC 
Chapter 1 1 A. 

(2) New "COMMON USE AREAS" as defined in 
CBC Chapter llA serving existing covered 
multifamily dwellings. 

(3) Additions to existing buildings, where the 
addition alone meets the definition of 
"COVERED MULTIFAMILY DWELLINGS" as 
defined in CBC Chapter 11 A. 

(4) Common use areas serving covered 
multifamily dwellings. 



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2010 California Electrical Code 



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CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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(5) Where any portion of a building's exterior is 
preserved, but the interior of the building is 
removed, including all structural portions of 
floors and ceilings, the building is considered a 
new building for determining the application of 
CBQ Chapter 11 A. 

"HCD 1-AC" building standards generally do 
not apply to public use areas or public 
accommodations such as hotels and motels. 
Public me areas, public accommodations and 
housing which is publicly funded as defined in 
Chapter 2 of the CBC are subject to the Division 
of the State Architect (DSA-AC) and are 
referenced in Section 109. L 

Enforcing Agency-Local building department or 
the Department of Housing and Community 
Development. 

Authority Cited: Health and Safety Code 
Sections 17040, 17050, 17920.9, 17921, 
17921.3, 17921.6, 17921.10, 17922, 17922.6, 
17922.12, 17927, 17928, 17959.6, 18300, 18552, 
18554, 18620, 18630, 18640, 18670, 18690, 
18691, 18865, 18871.3, 18871.4, 18873, 
18873.1, 18873.2, 18873.3, 18873.4, 18873.5, 
18944.11, and 19990; and Government Code 
Section 12955.1. 

Reference: Health and Safety Code Sections 
17000 through 17062.5, 17910 through 17995.5, 
18200 through 18700, 18860 through 18874, 
and 19960 through 19997; and Government 
Code Sections 12955,1 and 12955.1.1. 

89.108.2,1,3 Permanent Buildings in Mobilehome 
Parks and Special Occupancy Parks. Application - 
Permanent buildings, and permanent accessory 
buildings or structures, constructed within mobilehome 
parks and special occupancy parks that are under the 
control and ownership of the park operator. Sections of 
this code which pertain to applications listed in this 
section are identified in the Matrix Adoption Table 
using the abbreviation 'HCD 2 '\ 

Enforcing Agency — Local building department or 
other local agency responsible for the enforcement of 
Health and Safety Code, Division 13, Part 2.1, 
commencing with Section 18200 for mobilehome 
parks and Health and Safety Code, Division 13, Part 
2.3, commencing with Section 18860 for special 
occupancy parks; or the Department of Housing and 
Community Development 

Authority Cited: Health and Safety Code Sections 
17040, 17050, 17920.9, 17921, 17921.3, 17921.6, 
17921.10, 17922, 17922.6, 17922.12, 17927, 
17928, 17959.6, 18300, 18552, 18554, 18620, 
18630, 18640, 18670, 18690, 18691, 18865, 



18871.3, 18871.4, 18873, 18873.1, 18873.2, 
18873.3, 18873.4, 18873.5, 18944.11, and 19990; 
and Government Code Section 12955.1. 

Reference: Health and Safety Code Sections 
17000 through 17062.5, 17910 through 17995.5, 
18200 through 18700, 18860 through 18874, and 
19960 through 19997; and Government Code 
Sections 12955.1 and 12955.1.1. 

89.108,3 LOCAL ENFORCING AGENCY 

89.108.3.1 Duties and Powers. The building 
department of every city, county or city and county 
shall enforce all the provisions of law, this code, and 
the other rules and regulations promulgated by the 
Department of Housing and Community Development 
pertaining to the installation, erection, construction, 
reconstruction, movement, enlargement, conversion, 
alteration, repair, removal, demolition or 
arrangement of apartment houses, hotels, motels, 
lodging houses and dwellings, including accessory 
buildings, facilities, and uses thereto. 

The provisions regulating the erection and 
construction of dwellings and appurtenant structures 
shall not apply to existing structures as to which 
construction is commenced or approved prior to the 
effective date of these regulations. Requirements 
relating to use, maintenance and occupancy shall 
apply to all dwellings and appurtenant structures 
approved for construction or constructed before or 
after the effective date of this code. 

For additional information regarding the use and 
occupancy of existing buildings and appurtenant 
structures, see California Code of Regulations, Title 
25, Division 1, Chapter 1, Subchapter 1, 
commencing with Article 1, Section 1. 

89.108.3.2 Laws, Rules, and Regulations. Other than 
the building standards contained in this code, and 
notwithstanding other provisions of law, the statutory 
authority and location of the laws, rules, and 
regulations to be enforced by local enforcing agencies 
are listed by statute in Sections 89.108.3.2.1 through 
89.108.3.2.5 below: 

89.108.3.2.1 State Housing Law. Refer to the State 
Housing Law, California Health and Safety Code, 
Division 13, Part 1.5, commencing with Section 
17910 and California Code of Regulations, Title 
25, Division 1, Chapter 1, Subchapter 1, 
commencing with Section 1, for the erection, 
construction, reconstruction, movement, 

enlargement, conversion, alteration, repair, 
removal, demolition or arrangement of apartment 
houses, hotels, motels, lodging houses and 
dwellings, including accessory buildings, facilities, 
and uses thereto. 



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2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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89.108.3.2.2 Mobilehome Parks Act. Refer to 
the Mobilehome Parks Act, California Health 
and Safety Code, Division 13, Part 2.1, 
commencing with Section 18200 and California 
Code of Regulations, Title 25, Division 1, 
Chapter 2, commencing with Section 1000 for 
mobilehome park administrative and 
enforcement authority, permits, plans, fees, 
violations, inspections and penalties both within 
and outside mobilehome parks . 

Exception: Mobilehome parks where the 
Department of Housing and Community 
Development is the enforcing agency. 

89.108.3.2.3 Special Occupancy Parks Act. Refer 
to the Special Occupancy Parks Act, California 
Health and Safety Code, Division 13, Part 2.3, 
commencing with Section 18860 and California 
Code of Regulations, Title 25, Division 1, Chapter 
2.2, commencing with Section 2000 for special 
occupancy park administrative and enforcement 
authority, permits, fees, violations, inspections and 
penalties both within and outside of special 
occupancy parks. 

Exception: Special occupancy parks where the 
Department of Housing and Community 
Development is the enforcing agency. 

89.108.3.2.4 Employee Housing Act Refer to the 
Employee Housing Act, California Health and 
Safety Code, Division 13, Part 1, commencing with 
Section 17000 and California Code of Regulations, 
Title 25, Division 1, Chapter 1, Subchapter 3, 
commencing with Section 600 for employee 
housing administrative and enforcement authority, 
permits, fees, violations, inspections and penalties. 

89.108.3.2.5 Factory-Built Housing Law. Refer to 
the Factory-Built Housing Law, California Health 
and Safety Code, Division 13, Part 6, commencing 
with Section 19960 and California Code of 
Regulations, Title 25, Division 1, Chapter 3, 
Subchapter 1, commencing with Section 3000 for 
factory-built housing administrative and 
enforcement authority, permits, fees, violations, 
inspections and penalties. 

89.108.4 PERMITS, FEES, APPLICATIONS AND 
INSPECTIONS 

89.108.4.1 Permits, (a) Except as exempted in 
paragraph (b) of this subsection, a written construction 
permit shall be obtained from the enforcing agency 
prior to the erection, construction, reconstruction, 
installation, movement, or alteration of any electrical 
system. 

(b) Consistent with the requirements of Section 1 7960 of 
the Health and Safety Code, the local enforcing agency 



shall enforce the requirements of this code, but shall 
exempt the following activities from the requirement for 
a permit or inspection. 

1. Listed cord and plug connected temporary 
decorative lighting. 

2. Reinstallation of attachment plug receptacles, but 
not the outlets therefore. 

3. Repair or replacement of branch circuit 
overcurrent devices of the required capacity in the 
same location. 

4. Installation or maintenance of communications 
wiring, devices, appliances, apparatus or equipment 

Exemptions from permit and inspection requirements 
shall not be deemed to grant authorization for any work 
to be done in any manner in violation of any other 
provision of law or this code. 

89.108.4.2 Fees. Subject to other provisions of law, the 
governing body of any city, county or city and county 
may prescribe fees to defray the cost of enforcement of 
rules and regulations promulgated by the Department of 
Housing and Community Development The amount of 
the fees shall not exceed the amount reasonably 
necessary to administer or process permits, certificates, 
forms, or other documents, or to defray the costs of 
enforcement For additional information, see State 
Housing Law, Health and Safety Code, Division 13, 
Part 1.5, Section 17951 and California Code of 
Regulations, Title 25, Division 1, Chapter 1, Subchapter 
1, Article 3, commencing with Section 6. 

89.108.4.3 Plan Review and Time Limitations. Subject to 
other provisions of law, provisions related to plan 
checking, prohibition of excessive delays and contracting 
with or employment of private parties to perform plan 
checking are set forth in State Housing Law, Health and 
Scfety Code Section 17960.1, and for employee housing, 
in Health and Safety Code Section 17021. 

89.108.4.3.1 Retention of Plans. The building 
department of every city, county or city and county 
shall maintain an official copy, microfilm, or 
electronic or other type of photographic copy of the 
plans of every building, during the life of the building, 
for which the department issued a building permit 

Exceptions: 

1. Single or multiple dwellings not more than 
two stories and basement in height. 

2. Garages and other structures appurtenant to 
buildings listed in Exception (1). 

3. Farm or ranch buildings appurtenant to 
buildings listed in Exception (1). 



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2010 California Electrical Code 



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CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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4. Any one-story building where the span 
between bearing walls does not exceed 25 feet 
(7620 mm), except a steel frame or concrete 
building. 

All plans for common interest developments as 
defined in Section 1351 of the California Civil 
Code shall be retained. For additional 
information regarding plan retention and 
reproduction of plans by an enforcing agency, 
see Health and Safety Code Sections 19850 
through 19852. 

89.108.4,4 Inspections. Construction or work for 
which a permit is required shall be subject to 
inspection by the building official and such 
construction or work shall remain accessible and 
exposed for inspection purposes until approved. 
Approval as a result of an inspection shall not be 
construed to be an approval of a violation of the 
provisions of this code or other regulations of the 
Department of Housing and Community 
Development 

89.108.5 RIGHT OF ENTRY FOR ENFORCEMENT 

89.108.5.1 General. Subject to other provisions of 
law, officers and agents of the enforcing agency may 
enter and inspect public and private properties to 
secure compliance with the rules and regulations 
promulgated by the Department of Housing and 
Community Development. For limitations and 
additional information regarding enforcement, see 
the following: 

1. For applications subject to State Housing Law 
as referenced in Section 89.108.3.2.1 of this code, 
refer to Health and Safety Code, Division 13, Part 
1.5, commencing with Section 17910 and 
California Code of Regulations, Title 25, Division 

1. Chapter 1, Subchapter 1, commencing with 
Section 1. 

2. For applications subject to the Mobilehome 
Parks Act as referenced in Section 89,108.3.2.2 of 
this code, refer to Health and Safety Code, 
Division 13, Part 2.1, commencing with Section 
18200 and California Code of Regulations, Title 
25, Division 1, Chapter 2, commencing with 
Section 1000. 

3. For applications subject to the Special 
Occupancy Parks Act as referenced in Section 
89.108.3.2.3 of this code, refer to Health and 
Safety Code, Division 13, Part 2.3, commencing 
with Section 18860 and California Code of 
Regulations, Title 25, Division 1, Chapter 2.2, 
commencing with Section 2000. 

4. For applications subject to the Employee 
Housing Act as referenced in Section 89.108.3.2.4 



of this code, refer to Health and Safety Code, 
Division 13, Part 1, commencing with Section 
17000 and California Code of Regulations, Title 
25, Division 1, Chapter 1, Subchapter 3, 
commencing with Section 600. 

5. For applications subject to the Factory-Built 
Housing Law as referenced in Section 89.108.3.2.5 
of this code, refer to Health and Safety Code, 
Division 13, Part 6, commencing with Section 
19960 and California Code of Regulations, Title 
25, Division 1, Chapter 3, Subchapter 1, 
commencing with Section 3000. 

89.108.6 LOCAL MODIFICATION BY ORDINANCE 
OR REGULATION 

89.108.6.1 General. Subject to other provisions of 
law, a city, county or city and county may make 
changes to the provisions adopted by the Department 
of Housing and Community Development. If any city, 
county or city and county does not amend, add, or 
repeal by local ordinances or regulations the 
provisions published in this code or other regulations 
promulgated by the Department of Housing and 
Community Development, those provisions shall be 
applicable and shall become effective 180 days after 
publication by the California Building Standards 
Commission. Amendments, additions and deletions to 
this code adopted by a city, county or city and county 
pursuant to California Health and Safety Code 
Sections 17958.5, 17958.7 and 18941.5, together 
with all applicable portions of this code, shall also 
become effective 180 days after publication of the 
California Building Standards Code by the 
California Building Standards Commission. 

89.108.6.2 Findings, Filings, and Rejections of Local 
Modifications, Prior to making any modifications or 
establishing more restrictive building standards, the 
governing body shall make express findings and filings, 
as required by California Health and Safety Code 
Section 17958.7, showing that such modifications are 
reasonably necessary due to local climatic, geological, 
or topographical conditions. No modification shall 
become effective or operative unless the following 
requirements are met: 

1. The express findings shall be made available 
as a public record. 

2. A copy of the modification and express 
finding, each document marked to cross- 
reference the other, shall be filed with the 
California Building Standards Commission for a 
city, county or city and county and with the 
Department of Housing and Community 
Development for fire protection districts. 



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2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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3. The California Building Standards Commission 
has not rejected the modification or change. 

Nothing in this section shall limit the authority of fire 
protection districts pursuant to California Health and 
Safety Code Section 13869. 7 (a). 

89.108.7 ALTERNATE MATERIALS, DESIGNS, 
TESTS AND METHODS OF CONSTRUCTION 

89.108.7.1 General. The provisions of this code 
as adopted by the Department of Housing and 
Community Development are not intended to 
prevent the use of any alternate material, 
appliance, installation, device, arrangement, 
design or method of construction not specifically 
prescribed by this code. Consideration and 
approval of alternates shall comply with Section 

89.108.7.2 for local building departments and 
Section 89.108.7.3 for the Department of Housing 
and Community Development. 

89.108.7.2 Local Building Departments. The 

building department of any city, county or city and 
county may approve alternates for use in the 
erection, construction, reconstruction, movement, 
enlargement, conversion, alteration, repair, removal, 
demolition or arrangement of an apartment house, 
hotel, motel, lodging house, dwelling, or an 
accessory structure, except for the following: 

1. Structures located in mobilehome parks as defined 
in California Health and Safety Code Section 18214. 

2. Structures located in special occupancy parks as 
defined in California Health and Safety Code Section 
18862.43. 

3. Factory-built housing as defined in California 
Health and Safety Code Section 19971. 

89.108.7.2.1 Approval of Alternates. The 

consideration and approval of alternates by a local 
building department shall comply with the following 
procedures and limitations: 

1. The cpproval shall be granted on a case-by-case basis. 

2. Evidence shall be submitted to substantiate claims 
that the proposed alternate, in performance, safety, and 
protection of life and health, conforms to, or is at least 
equivalent to, the standards contained in this code and 
other rules and regulations promulgated by the 
Department of Housing and Community Development 

3. The local building department may require 
tests performed by an approved testing agency at 
the expense of the owner or owner 's agent as 
proof of compliance. 

4. If the proposed alternate is related to accessibility in 
covered multifamily dwellings or in facilities serving 
''COVERED MULTIFAMILY DWELLINGS'' as 
defined in CBC Chapter 11 A, the proposed alternate 



must also meet the threshold set for ''EQUIVALENT 
FACILITATION'' as defined in CBC Chapter 11 A. 

For additional information regarding approval of 
alternates by a local building department pursuant 
to the State Housing Law, see California Health 
and Safety Code Section 17951(e) and California 
Code of Regulations, Title 25, Division 1, Chapter 
1, Subchapter 1. 

89.108.7.3 Department of Housing and Community 
Development. The Department of Housing and 
Community Development may approve alternates for 
use in the erection, construction, reconstruction, 
movement, enlargement, conversion, alteration, 
repair, removal or demolition of an apartment house, 
hotel, motel, lodging house, dwelling, or an 
accessory thereto. The consideration and approval of 
alternates shall comply with the following: 

1. The department may require tests at the expense of 
the owner or owner 's agent to substantiate compliance 
with the California Building Standards Code. 

2, The approved alternate . shall, for its intended 
purpose, be at least equivalent in performance and 
safety to the materials, designs, tests, or methods of 
construction prescribed by this code. 

89.108.8 APPEALS BOARD 

89.108.8.1 General. Every city, county or city and 
county shall establish a local appeals board and a 
housing appeals board. The local appeals board and 
housing appeals board shall each be comprised of at 
least five voting members who shall serve at the 
pleasure of the city, county or city and county. 
Appointees shall not be employees of the jurisdiction 
and shall be qualified and specifically knowledgeable 
in the California Building Standards Codes and 
applicable local ordinances. 

89.108.8.2 Definitions. The following terms shall for 
the purposes of this section have the meaning shown. 

Housing Appeals Board. The board or agency of a 
city, county or city and county which is authorized by 
the governing body of the city, county or city and 
county to hear appeals regarding the requirements of 
the city, county or city and county relating to the use, 
maintenance and change of occupancy of buildings 
and structures, including requirements governing 
alteration, additions, repair, demolition, and moving. 
In any area in which there is no such board or 
agency, ''Housing Appeals Board" means the local 
appeals board having jurisdiction over the area. 

Local Appeals Board. The board or agency of a city, 
county or city and county which is authorized by the 
governing body of the city, county or city and county 
to hear appeals regarding the building requirements 
of the city, county or city and county. In any area in 



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2010 California Electrical Code 



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CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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which there is no such board or agency, "Local 
Appeals Board'' means the governing body of the 
city, county or city and county having jurisdiction 
over the area. 

89,108.8.3 Appeals. Except as otherwise provided by 
law, any person, firm, or corporation adversely 
affected by a decision, order, or determination by a 
city, county or city and county relating to the 
application of building standards published in the 
California Building Standards Code, or any other 
applicable rule or regulation adopted by the 
Department of Housing and Community 
Development, or any lawfully enacted ordinance by a 
city, county or city and county, may appeal the issue 
for resolution to the local appeals board or housing 
appeals board as appropriate. 

The local appeals board shall hear appeals relating to 
new building construction and the housing appeals board 
shall hear appeals relating to existing buildings. 

89.108.9 UNSAFE BUILDINGS OR STRUCTURES 

89.108.9,1 Authority to Enforce. Subject to other 
provisions of law, the administration, enforcement, 
actions, proceedings, abatement, violations and penalties 
for unsafe buildings and structures are contained in the 
following statutes and regulations: 

1. For applications subject to State Housing Law as 
referenced in Section 89.108.3.2.1 of this code, refer to 
Health and Safety Code, Division 13, Part 1.5, 
commencing with Section 17910 and California Code 
of Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 1, commencing with Section 1. 

2. For applications subject to the Mobilehome Parks 
Act as referenced in Section 89.108.3.2.2 of this code, 
refer to Health and Safety Code, Division 13, Part 2.1, 
commencing with Section 18200 and California Code 
of Regulations, Title 25, Division 1, Chapter 2, 
commencing with Section 1000. 

3. For applications subject to the Special Occupancy 
Parks Act as referenced in Section 89.108.3.2.3 of this 
code, refer to Health and Safety Code, Division 13, 
Part 2.3, commencing with Section 18860 and 
California Code of Regulations, Title 25, Division 1, 
Chapter 2.2, commencing with Section 2000. 

4. For applications subject to the Employee Housing 
Act as referenced in Section 89.108.3.2.4 of this code, 
refer to Health and Safety Code, Division 13, Part 1, 
commencing with Section 17000 and California Code 
of Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 3, commencing with Section 600. 

5. For applications subject to the Factory-Built 
Housing Law as referenced in Section 89.108.3.2.5 of 
this code, refer to Health and Safety Code, Division 13, 
Part 6, commencing with Section 19960 and California 



Code of Regulations, Title 25, Division 1, Chapter 3, 
Subchapter 1, commencing with Section 3000. 

89.108.9.2 Actions and Proceedings. Subject to other 
provisions of law, punishments, penalties and fines for 
violations of building standards are contained in the 
following statutes and regulations: 

1. For applications subject to State Housing Law as 
referenced in Section 89.108.3.2.1 of this code, refer to 
Health and Safety Code, Division 13, Part 1.5, 
commencing with Section 17910 and California Code 
of Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 1, commencing with Section 1. 

2. For applications subject to the Mobilehome Parks 
Act as referenced in Section 89.108.3.2.2 of this code, 
refer to Health and Safety Code, Division 13, Part 2.1, 
commencing with Section 18200 and California Code 
of Regulations, Title 25, Division 1, Chapter 2, 
commencing with Section 1000. 

3. For applications subject to the Special Occupancy 
Parks Act as referenced in Section 89.108.3.2.3 of this 
code, refer to Health and Safety Code, Division 13, 
Part 2.3, commencing with Section 18860 and 
California Code of Regulations, Title 25, Division 1, 
Chapter 2.2, commencing with Section 2000. 

4. For applications subject to the Employee Housing 
Act as referenced in Section 89.108.3.2.4 of this code, 
refer to Health and Safety Code, Division 13, Part 1, 
commencing with Section 1 7000 and California Code 
of Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 3, commencing with Section 600. 

5. For applications subject to the Factory-Built Housing 
Law as referenced in Section 89.108.3.2.5 of this code, 
refer to Health and Safety Code, Division 13, Part 6, 
commencing with Section 19960 and California Code of 
Regulations, Title 25, Division 1, Chapter 3, Subchapter 
1, commencing with Section 3000. 

89.108.10 OTHER BUILDING REGULATIONS 

89.108.10.1 Existing Structures. Subject to the 
requirements of California Health and Safety Code 
Sections 17912, 17920.3, 17922, 17922.3, 17958.8 and 
17958.9, the provisions contained in Chapter 34 of the 
CBC relating to existing structures shall only apply as 
identified in the Matrix Adoption Table under the 
authority of the Department of Housing and Community 
Development as listed in Sections 89.108.2.1.1 through 
89108.2.1.3 of this code. 

89.108.10.2 Moved Structures. Subject to the 
requirements of California Health and Safety Code 
Sections 17922.3 and 17958.9, the provisions relating to 
a moved residential structure shall, after July 1, 1978, 
permit the retention of existing materials and methods of 
construction so long as the structure does not become or 
continue to be a substandard building. 



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2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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SECTION 89 J09 

DIVISION OF THE STATE ARCHITECT 

89.109.1 DSA— AC — Division of the State Architect-Access 
Compliance. 

Note: For applications listed in Section 1.9.1 of the 
California Building Code, regulated by the Division of 
the State Architect—Access Compliance see California 
Code of Regulations, Title 24, Part 2 (California Building 
Code), Chapter 1 (Division 1 California Administration) 
under authority cited by Government Code Section 4450 
and in reference cited by Government Code Sections 
4450, through 4461, 12955.1 and Health and Safety Code 
Sections 18949 J, 19952 through 19959. 



89.109.2 DSA-SS - Division of the State Architect - 
Structural Safety. 

89.109.2.1. DSA-SS (Division of the State 
Architect - Structural Safety) 

1. Application - Public elementary and secondary 
schools, community college buildings, and state-owned 
or state-leased essential services buildings. 

Enforcing Agency ~ Division of the State Architect - 
Structural Safety (DSA-SS). 

The Division of the State Architect has been delegated 
the responsibility and authority by the Department of 
General Services to review and approve the design and 
oversee the construction of public elementary and 
secondary schools, community colleges, and state- 
owned or state-leased essential services buildings. 

Authority Cited - Education Code section 17310 and 
81142, and Health and Safety Code section 16022. 

Reference - Education Code Sections 17280 through 
17317 and 81 130 through 81147, and Health & Safety 
Code Sections 16000 through 16023. 

89.109.2.2. DSA'SS/CC (Division of the State 
Architect - Structural Safety/Community Colleges) 

Application - Community Colleges. 

The Division of the State Architect has been 
delegated the authority by the Department of General 
Services to promulgate alternate building standards 
for application to community colleges, which a 
community college may elect to use in lieu of 
standards promulgated by DSA-SS in accordance 
with Section 89. 109.2. L Refer to Title 24, Part 2, 
Section 1.9.2.2. 

Enforcing Agency - Division of the State Architect ~ 
Structural Safety/Community Colleges (DSA-SS/CC) 

The Division of the State Architect has been 
delegated the authority by the Department of General 
Services to review and approve the design and 



oversee construction of community colleges electing 
to use the alternative building standards as provided 
in this section. 

Authority Cited - Education Code Section 81053. 

Reference - Education Code Sections 81052, 81053, 
and 81 130 through 81147. 

89.109.3 SHE - State Historical Building Safety Board. 

See California Code of Code of Regulations, Title 24, 
Part 8 (California Historical Building Code). 



SECTION 89.110 

OFFICE OF STATEWIDE HEALTH PLANNING 
AND DEVELOPMENT 

89.110.1. OSHPD 1. Specific scope of application of the 
agency responsible for enforcement, enforcement agency, 
specific authority to adopt and enforce such provisions of this 
code, unless otherwise stated. 

OSHPD 1 

Application - General acute-care hospitals and acute 
psychiatric hospitals, excluding distinct part units or 
distinct part freestanding buildings providing skilled 
nursing or intermediate-care services. For Structural 
Regulations: Skilled nursing facilities and/or 
intermediate-care facilities except those skilled nursing 
facilities and intermediate care facilities of single story. 
Type V, wood or light steel-frame construction. 

Enforcing Agency -Office of Statewide Health Planning 
and Development (OSHPD). The office shall enforce the 
Division of the State Architect access compliance 
regulations and the regulations of the Office of the State 
Fire Marshal for the above stated facility types. 

89. 110. 1. 1 Applicable administrative standards. 

1. Title 24, Part 1, California Code of Regulations: 
Chapters 6 &7. 

2. Title 24, Part 2, California Code of Regulations: 
Sections 101 and 110 of California Chapter 1 and 
Appendix Chapter 1. 

89.110.1.2 Applicable building standards. 

California Building Standards Code, Title 24, Parts 
2,3,4, 5,9, 10 and 12, 

89.110.2. OSHPD 2. Specific scope of application of the 
agency responsible for enforcement, enforcement agency, 
specific authority to adopt and enforce such provisions of 
this code, unless otherwise stated, 

OSHPD 2 

Application —Skilled nursing facilities and intermediate- 
care facilities, including distinct part skilled nursing and 
intermediate-care services on a general acute-care or 
acute psychiatric hospital license, provided either in a 
separate unit or a freestanding building. For Structural 



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2010 California Electrical Code 



70-11 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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Regulations: Single-story, Type V skilled nursing facility 
and/or intermediate-care facilities utilizing wood or light 
steel-frame construction. 

Enforcing Agency — Office of Statewide Health Planning 
and Development (OSHPD). The office shall also enforce the 
Division of the State Architect access compliance regulations 
and the regulations of the Office of the State Fire Marshal for 
the above stated facility type. 

89.110.2.1 Applicable administrative standards: 

I- Title 24, Part 7, California Code of Regulations: 
Chapter 7. 

2. Title 24, Part 2] California Code of Regulations: 
Sections 101 and 1 ] of California Chapter 1 and 
Appendix Chapter 1 . 

89.110.2.2 Applicable building standards. 

California Building Standards Code, Title 24, Parts 
2,3,4,5,9, 10 and 12.%' 

89. 110. 3. OSHPD 3. Specific scope of application of the 

agency responsible for enforcement, enforcement agency, 
specific authority to adopt and enforce such provisions of 
this code; unless otherwise seated. 

OSHPD J 

Application —Licensed clinics and any freestanding 
building under a hospital license where outpatient 
clinical services are provided. :■ 

Enforcing Agency--Local building department. 

89.110.3.1 Applicable administrative standards. 

1. Title 24, Part 1, California Code of Regulations: 
Chapter 7. 

2. Title 24, Part 2, California Code of Regulations: 
Sections 101 arid 110 of California Chapter 1 and 
Appendix Chapter I. 

89.110.3.2 Applicable building standards. 

California Building Standards Code, Title 24, Parts 
2,3,4,5,9, IV and 12. ' ^ 

89.110.4. OSHPD 4. Specific scope of application of the 
agency responsible for enforcement, enforcement agency, 
specific authority to adopt and enforce such provisions of 
this code, unless otherwise stated. 

OSHPD 4 

Application —Correctional Treatment Centers. 

Enforcing Agency ~ Office of Statewide Health Planning 
arid Development (OSHPD). The Office shall also enforce 
the Division of the State Architect access compliance 
regulations and the regulations of the Office of the State 
Fire Marshal for the above stated facility types. 

89.110.4.1 Applicable administrative standards. 

I. Title 24, Part 1, California Code of Regulations: 
Chapter 7. 



2. Title 24, Part 2, California Code of Regulations: 
Sections 101 and 110 of California Chapter 1 and 
Appendix Chapter 1. 

89.110.4.2 Applicable building standards. California 
Building Standards Code, Title 24, Parts 2, 3, 4, 5, 9, 10 
and 12. 



SECTION 89.111 
OFFICE OF THE STATE FIRE MARSHAL 

89.111.1 SFM— Office of the State Fire Marshal. 

Specific scope of application of the agency responsible for 
enforcement, the enforcement agency and the specific 
authority to adopt and enforce such provisions of this 
code, unless otherwise stated. 

Application: 

Institutional, educational or any similar occupancy. Any 

building or structure used or intended for use as an 
asylum, jail, mental hospital, hospital, sanitarium, home 
for the aged, children *s nursery, children 's home, school 
or any similar occupancy of any capacity. 

Authority cited-^Health and Safety Code Section 13143. 

Reference — Health and Safety Code Section 13143. 

Assembly or similar place of assemblage. Any theater, 
dancehall, skating rink, auditorium, assembly hall, 
meeting hall, nightclub, fair building or similar place of 
assemblage where 50 or more persons may gather 
together in a building, room or structure for the purpose 
of amusement, entertainment, instruction, deliberation, 
worship, drinking or dining, awaiting transportation, or 
education. 

Authority cited — Health and Safety Code Section 13143. 

Reference — Health and Safety Code Section 13143. 

Small family day care homes. 

Authority cited — Health and Safety Code Sections 

1597.45, 1597.54, 13143 and 17921. 

Reference - Health and Safety Code Section 13143. 
Large family day care homes. 

Authority cited — Health and Safety Code Sections 

1597.46, 1597.54 and 17921. 

Reference - Health and Safety Code Section 13143. 

Residential facilities and residential facilities for the 
elderly. 

Authority cited — Health and Safety Code Section 13133. 

Reference — Health and Safety Code Section 13143. 

Any state institution or other state-owned or state- 
occupied building. 

Authority cited— Health and Safety Code Section 13108. 

Reference — Health and Safety Code Section 13143. 



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2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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High-rise structures. 

Authority cited— Health and Safety Code Section 13211. 

Reference — Health and Safety Code Section 13143. 

Motion picture production studios. 

Authority cited — Health and Safety Code Section 13143.1. 

Reference — Health and Safety Code Section 13143. 

Organized camps. 

Authority cited— Health and Safety Code Section 18897.3. 

Reference — Health and Safety Code Section 13143. 

Residential All hotels, motels, lodging houses, apartment 
houses and dwellings, including congregate residences and 
buildings and structures accessory thereto. Multiple-story 
structures existing on January 1, 1975, let for human 
habitation, including and limited to, hotels, motels and 
apartment houses, less than 75 feet (22 860 mm) above the 
lowest floor level having building access, wherein rooms 
used for sleeping are let above the ground floor. 

Authority cited — Health and Safety Code Sections 
13143.2 and 17921. 

Reference — Health and Safety Code Section 13143. 

Residential care facilities. Certified family care homes, 
out-of-home placement facilities, halfway houses, drug 
and/or alcohol rehabilitation facilities and any building 
or structure used or intended for use as a home or 
institution for the housing of any person of any age when 
such person is referred to or placed within such home or 
institution for protective social care and supervision 
services by any governmental agency. 

Authority cited — Health and Safety Code Section 13143.6, 

Reference — Health and Safety Code Section 13143. 

Tents, awnings or other fabric enclosures used in 
connection with any occupancy. 

Authority cited — Health and Safety Code Section 13116. 

Reference — Health and Safety Code Section 13143. 

Fire alarm devices, equipment and systems in 
connection with any occupancy. 

Authority cited— Health and Safety Code Section 13114. 

Reference — Health and Safety Code Section 13143. 

Hazardous materials. 

Authority cited — Health and Safety Code Section 13143.9. 

Reference — Health and Safety Code Section 13143. 

Flammable and combustible liquids. 

Authority cited — Health and Safety Code Section 13143.6. 

Reference — Health and Safety Code Section 13143. 



Public School Automatic Fire Detection, Alarm and 
Sprinkler Systems. 

Authority cited — Health and Safety Code Section 13143 
and California Education Code Article 7.5, Sections 
17074.50, 17074.52 and 17074.54. 

Reference — Government Code Section 11152.5, Health 
and Safety Code Section 13143 and California Education 
Code Chapter 12.5, Leroy F. Greene School Facilities Act 
of 1998, Article 1. 

Wildland-Urban Interface Fire Area. 

Authority cited — Health and Safety Code Sections 13143, 
13108.5(a) and 18949.2(b) and (c) and Government Code 
Section 51189. 

Reference — Health and Safety Code Sections 13143, 
Government Code Sections 51176, 51177, 51178 and 
51179 and Public Resources Code Sections 4201 through 
4204. 

89. 111. 2 Duties and Powers of the Enforcing Agency 

89.111.2.1 Enforcement. 

89.111.2.1.1 The responsibility for enforcement of 
building standards adopted by the State Fire 
Marshal and published in the California Building 
Standards Code relating to fire and panic safety 
and other regulations of the State Fire Marshal 
shall except as provided in Section 89.111.2.1.2 be 
as follows: 

1. The city, county or city and county with 
jurisdiction in the area affected by the standard 
or regulation shall delegate the enforcement of 
the building standards relating to fire and panic 
safety and other regulations of the State Fire 
Marshal as they relate to Group R-3 
occupancies, as described in Section 310.1 of 
Part 2 of the California Building Standards 
Code, to either of the following: 

1.1. The chief of the fire authority of the city, county 
or city and county, or an authorized representative. 

1.2. The chief building official of the city, county or 
city and county, or an authorized representative. 

2. The chief of any city or county fire department 
or of any fire protection district, and authorized 
representatives, shall enforce within the 
jurisdiction the building standards and other 
regulations of the State Fire Marshal, except 
those described in Item 1 or 4. 

3. The State Fire Marshal shall have authority to 
enforce the building standards and other 
regulations of the State Fire Marshal in areas 
outside of corporate cities and districts 
providing fire protection services. 



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2010 California Electrical Code 



70-13 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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4, The State Fire Marshal shall have authority to 
enforce the building standards -and other 
regulations of the State: Fire Marshal in 
corporate cities and districts providing fire 
protection services on request of the chief fire 
official or the governing body. 

5. Any fee charged pursuant to the enforcement 
authority of this section shall not exceed the 
estimated reasonable cost of providing the 
service for which the fee is charged pursuant to 
Section 66014 of the Government Code. 

89,111.2,1,2 Pursuant to Health and Safety Code 
Section 13108, and except as otherwise provided in 
this section, building standards adopted by the 
State Fire Marshal published in the California 
Building Standards Code relating to fire and panic 
safety shall be enforced by the State Fire Marshal 
in all state-owned buildings, state-occupied 
buildings, and state institutions throughout the 
state. Upon the written request of the chief fire 
official of any city, county or fire protection 
district, the State Fire Marshal may authorize such 
chief fire official and his or her authorized 
representatives, in their geographical area of 
responsibility, to make fire prevention inspections 
of state-owned or state-occupied buildings, other 
than state institutions, for the purpose of enforcing 
the regulations relating to fire and panic safety 
adopted by the State Fire Marshal pursuant to this 
section and building standards relating to fire and 
panic safety published in the California Building 
Standards Code. Authorization from the State Fire 
Marshal shall be limited to those fire departments 
or fire districts which maintain a fire prevention 
bureau staffed by paid personnel. 

Pursuant to Health and Safety Code Section 13108, 
any requirement or order made by any chief fire 
official who is authorized by the State Fire 
Marshal to make fire prevention inspections of 
state-owned or state-occupied buildings, other than 
state institutions, may be appealed to the State Fire 
Marshal. The State Fire Marshal shall, upon 
receiving an appeal and subject to the provisions 
of Chapter 5 (commencing with Section 18945) of 
Part 2.5 of Division 13 of the Health and Safety 
Code, determine if the requirement or order made 
is reasonably consistent with the fire and panic 
safety regulations adopted by the State Fire 
Marshal and building standards relating to fire 
and panic safety published in the California 
Building Code. 

Any person may request a code interpretation from 
the State Fire Marshal relative to the intent of any 
regulation or provision adopted by the State Fire 



Marshal When the request relates to a specific 
project, occupancy or building, the State Fire 
Marshal shall review the issue with the appropriate 
local enforcing agency prior to rendering such 
code interpretation. 

89,111,2.1,3 Pursuant to Health and Safety Code 
Section 13112, any person who violates any order, 
rule or regulation of the state fire marshal is guilty 
of a misdemeanor punishable by a fine of not less 
than $100.00 or more than $500,00, or by 
imprisonment for not less than six months, or by 
both. A person is guilty of a separate offense each 
day during which he or she commits, continues or 
permits a violation of any provision of or any 
order, rule or regulation of the state fire marshal 
as contained in this code. 

Any inspection authority who, in the exercise of his 
or her authority as a deputy state fire marshal, 
causes any legal complaints to be filed or any 
arrest to be made shall notify the state fire marshal 
immediately following such action, 

89.111.2.2 Right of entry. 

The fire chief of any city, county or fire-protection 
district, or such person 's authorized representative, 
may enter any state institution or any other state- 
owned or state-occupied building for the purpose of 
preparing a fire-suppression preplanning program or 
for the purpose of investigating any fire in a state- 
occupied building. 

The State Fire Marshal, his or her deputies or 
salaried assistants, the chief of any city or county fire 
department or fire protection district and his or her 
authorized representatives may enter any building or 
premises not used for dwelling purposes at any 
reasonable hour for the purpose of enforcing this 
chapter. The owner, lessee, manager or operator of 
any such building or premises shall permit the State 
Fire Marshal, his or her deputies or salaried 
assistants and the chief of any city or county fire 
department or fire-protection district and his or her 
authorized representatives to enter and inspect them 
at the time and for the purpose stated in this section, 

89.111.2.3 More Restrictive Fire and Panic Safety 
Building Standards, 

89.111.2.3.1 Any fire-protection district organized 
pursuant to Health and Safety Code Part 2.7 
(commencing with Section 13800) of Division 12 
may adopt building standards relating to fire and 
panic safety that are more stringent than those 
building standards adopted by the State Fire 
Marshal and contained in the California Building 
Standards Code. For these purposes, the district 
. hoard shall be deemed a legislative body and the 



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70-14 



2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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district shall be deemed a local agency. Any 
changes or modifications that are more stringent 
than the requirements published in the California 
Building Standards Code relating to fire and panic 
safety shall be subject to 101.8.1. 

89.111.2.3.2 Any fire protection district that 
proposes to adopt an ordinance pursuant to this 
section shall, not less than 30 days prior to noticing 
a proposed ordinance for public hearing, provide a 
copy of that ordinance, together with the adopted 
findings made pursuant to Section 89.111.2.3.1, to 
the city, county, or city and county where the 
ordinance will apply. The city, county, or city and 
county, may provide the district with written 
comments, which shall become part of the fire 
protection district's public hearing record. 

89.111.2.3.3 The fire-protection district shall 
transmit the adopted ordinance to the city, county, 
or city and county where the ordinance will apply. 
The legislative body of the city, county, or city and 
county, may ratify, modify or deny an adopted 
ordinance and transmit its determination to the 
district within 15 days of the determination. Any 
modification or denial of an adopted ordinance shall 
include a written statement describing the reasons 
for any modifications or denial. No ordinance 
adopted by the district shall be effective until 
ratification by the city, county, or city and county 
where the ordinance will apply. Upon ratification of 
an adopted ordinance, the city, county, or city and 
county, shall file a copy of the findings of the 
district, and any findings of the city, county, or city 
and county, together with the adopted ordinance 
expressly marked and identified to which each 
finding refers, in accordance with Section 101.8.1:3. 

89.111.2.4 Request for alternate means of protection. 

Requests for approval to use an alternative material, 
assembly or materials, equipment, method of 
construction, method of installation of equipment, or 
means of protection shall be made in writing to the 
enforcing agency by the owner or the owner's 
authorized representative and shall be accompanied 
by a full statement of the conditions. Sujficient 
evidence or proof shall be submitted to substantiate 
any claim that may be made regarding its 
conformance. The enforcing agency may require tests 
and the submission of a test report from an approved 
testing organization as set forth in Title 19, California 
code of Regulation, to substantiate the equivalency of 
the proposed alternative means of protection. 

The authority having jurisdiction may consider 
implementation of the findings and recommendations 
identified in a Risk Management Plan (RMP) as 
developed in accordance with Title 19, Division 2, 



Chapter 3, when evaluating requests for alternative 
means of protection. 

Approval of a request for use of an alternative 
material, assembly of materials, equipment, method of 
construction, method of installation of equipment, or 
means of protection made pursuant to these provisions 
shall be limited to the particular case covered by 
request and shall not be construed as establishing any 
precedent for any future request. 

89.111.2.5 Appeals. When a request for an alternate 
means of protection has been denied by the enforcing 
agency, the applicant may file a written appeal to the 
state fire marshal for consideration of the applicant's 
proposal. In considering such appeal, the state fire 
marshal may seek the advice of the State Board of Fire 
Services. The State Fire Marshal shall, after 
considering all of the facts presented, including any 
recommendations of the State board of Fire Services, 
determine if the proposal is for the purposes intended, 
at least equivalent to that specified in these regulations 
in quality, strength, effectiveness, fire resistance, 
durability and safety, and shall transmit such findings 
and any recommendations to the applicant and to the 
enforcing agency. 

89.111.3 Construction Documents. In addition to the 
provisions of this Section, see Title 24, Part 2, California 
Building Code, Appendix Chapter 1, Section 106 for 
additional requirements. 

89.111.3.1 Public schools. Plans and specifications 
for the construction, alteration or addition to any 
building owned, leased or rented by any public school 
district shall be submitted to the Division of the State 
Architect. 

89.111.3.2 Movable walls and partitions. Plans or 
diagrams shall be submitted to the enforcing agency 
for approval before the installation of, or 
rearrangement of, any movable wall or partition in 
any occupancy. Approval shall be granted only if there 
is no increase in the fire hazard. 

89.111.3.3 New construction high-rise buildings. 

1. Complete plans or specifications, or both, shall be 
prepared covering all work required to comply with 
new construction high-rise buildings. Such plans 
and specifications shall be submitted to the 
enforcing agency having jurisdiction. 

2. All plans and specifications shall be prepared 
under the responsible charge of an architect or a 
civil or structural engineer authorized by law to 
develop construction plans and specifications, or by 
both such architect and engineer. Plans and 
specifications shall be prepared by an engineer duly 
qualified in that branch of engineering necessary to 
perform such services. Administration of the work of 



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2010 California Electrical Code 



70-15 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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construction shall be under the charge of the 
responsible architect or engineer except that where 
plans and specifications involve alterations or 
repairs, such work of construction may be 
administered by an engineer duly qualified to 
perform such services and holding a valid certificate 
under Chapter 7 (commencing with Section 65700) 
of Division 3 of the Business and Professions Code 
for performance of services in that branch of 
engineering in which said plans, specifications and 
estimates and work of construction are applicable. 

This section shall not be construed as preventing the 
design of fire-extinguishing systems by persons 
holding a C-16 license issued pursuant to Division 
3, Chapter 9, Business and Professions Code. In 
such instances, however, the responsibility charge of 
this section shall prevail, 

89,11L3,4 Existing high-rise buildings, 1. Complete 
plans or specifications, or both, shall be prepared 
covering all work required by Section 3412, for 
existing high-rise buildings. Such plans or 
specifications shall be submitted to the enforcing 
agency having jurisdiction. 

2. When new construction is required to conform 
with the provisions of these regulations, complete 
plans or specifications, or both, shall be prepared in 
accordance with the provisions of this subsection. As 
used in this section ''new construction" is not 
intended to include repairs, replacements or minor 
alterations which do not disrupt or appreciably add 
to or affect the structural aspects of the building, 

89,111,3,5 Retention of Plans, Refer to Building 
Standards Law, Health and Safety Code Sections 
19850 and 19851, for permanent retention of plans. 

89.111,4 Fees 

89.111.4.1 Other fees. Pursuant to Health and Safety 
Code Section 13146.2, a city, county or district which 
inspects a hotel, motel, lodging house, or apartment 
house may charge and collect a fee for the inspection 
from the owner of the structure in an amount, as 
determined by the city, county or district, sufficient to 
pay its costs of that inspection. 

89.111.4.2 Large Family Day Care, Pursuant to 
Health and Safety Code Section 1597.46, Large 
Family Day-care Homes, the local government shall 
process any required permit as economically as 
possible, and fees charged for review shall not exceed 
the costs of the review and permit process. 

89.111.4.3 High-Rise, Pursuant to Health and Safety 
Code Section 1321 7, High-rise Structure Inspection: Fees 
and Costs, a local agency which inspects a high-rise 
structure pursuant to Health arid Safety Code Section 
1321 7 may charge and collect a fee for the inspection 



from the owner of the high-rise structure in an amount, as 
determined by the local agency, sufficient to pay its costs 
of that inspection, 

89.111.4.4 Fire Clearance Preinspection, Pursuant to 
Health and Safety Code Section 13235, Fire Clearance 
Preinspection, fee; upon receipt of a request from a 
prospective licensee of a community care facility, as 
defined in Section 1502, of a residential-care facility for 
the elderly, as defined in Section 1569,2, or of a child 
day-care facility, as defined in Section 1596, 750, the local 
fire enforcing agency, as defined in Section 13244, or 
state fire marshal, whichever has primary jurisdiction, 
shall conduct a preinspection of the facility prior to the 
final fire clearance approval At the time of the 
preinspection, the primary fire enforcing agency shall 
price consultation and interpretation of the fire safety 
regulations, and shall notify the prospective licensee of 
the facility in writing of the specific fire safety regulations 
which shall be enforced in order to obtain fire clearance 
approval A fee equal to, but not exceeding, the actual 
cost of the preinspection services may be charged for the 
preinspection of a facility with a capacity to serve 25 or 
fewer persons. A fee equal to, but not exceeding, the 
actual cost of the preinspection services may be charged 
for a preinspection of a facility with a capacity to serve 26 
or more persons, 

89.111.4.5 Care Facilities, The primary fire enforcing 
agency shall complete the final fire clearance inspection 
for a community care facility, residential-care facility for 
the elderly, or child day-care facility within 30 days of 
receipt of the request for the final inspection, or as of the 
date the prospective facility requests the final 
prelicensure inspection by the State Department of Social 
Services, whichever is later. 

Pursuant to Health and Safety Code Section 13235, a 
preinspection fee equal to, but not exceeding, the actual 
cost of the preinspection services may be charged for a 
facility with a capacity to serve 25 or less clients. A fee 
equal to, but not exceeding, the actual cost of the 
preinspection services may be charged for a 
preinspection of a facility with a capacity to serve 26 or 
more clients. 

Pursuant to Health and Safety Code Section 1313L5, a 
reasonable final inspection fee, not to exceed the actual 
cost of inspection services necessary to complete a final 
inspection may be charged for Occupancies classified as 
residential care facilities for the elderly (RCFE). 

Pursuant to Health and Safety Code Section 1569.84, 
neither the state fire marshal nor any local public entity 
shall charge any fee for enforcing fire inspection 
regulations pursuant to state law or regulation or local 
ordinance, with respect to residential-care facilities for 
the elderly (RCFE) which service six or fewer persons. 



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# 



70-16 



2010 California Electrical Code 



CALIFORNIA ARTICLE 89 - GENERAL CODE PROVISIONS 



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89.111.4.6 Requests of the Office of the State Fire 
Marshal Requests, Whenever a local authority having 
jurisdiction requests that the State Fire Marshal 
perform plan review and/or inspection services related 
to a building permit, the applicable fees for such shall 
be payable to the Office of the State Fire Marshal 

89.111.5 Inspections. Work performed subject to the 
provisions of this code shall comply with the inspection 
requirements of Title 24, Part 2, California Building 
Standards Code, Sections 109.1, 109.3, 109.3.4, 109.3.5, 
109.3.6, 109.3.8, 109.3.9, 109.3.10 109.5 and 109.6 as 
adopted by the Office of the State Fire Marshal 

89.111.5.1 Existing Group I-l or R occupancies. 

Licensed 24-hour care in a Group I-l or R occupancy 
in existence and originally classified under 
previously adopted state codes be reinspected under 
the appropriate previous code provided there is no 
change in the use or character which would place the 
facility in a different occupancy group. 

89.111.6 Certificate of Occupancy. A Certificate of 
Occupancy shall be issued as specified in Title 24, Part 
2, California Building Code, Section 111. 



Exception: Group R, Division 3 and Group U 

occupancies. 

89.111.7 Temporary Structures and Uses. See Title 24, 
Part 2, California Building Code, Section 107. 

89.111.8 Service Utilities. See Title 24, Part 2, California 
Building Code Sectionll2. 

89.111.9 Stop Work Order. See Title 24, Part 2, 
California Building Code, Section 115. 

89.111.10 Unsafe Buildings, Structures and Equipment. See 

Title 24, Part 2, California Building Code, Section 116. 

SECTION 89.112 

RESERVED FOR THE STATE LIBRARIAN 

SECTION 89.113 

RESER VED FOR THE DEPARTMENT OF WA TER 
RESOURCES 

SECTION 89.114 

RESERVED FOR THE CALIFORNIA STATE 
LANDS COMMISSION 



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2010 California Electrical Code 



70-17 



ARTICLE 90 - CALIFORNIA MATRIX ADOPTION TABLE 




70-18 2010 California Electrical Code 



ARTICLE 90 CALIFORNIA MATRIX ADOPTION TABLE 



ARTICLE 90 - INTRODUCTION 



Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


DPH 


1 


2 


AC 


SS 


ss/cc 


1 


2 


3 


4 


Adopt Entire Article 


X 




X 


X 




X 


X 


X 


X 


X 


X 




Adopt Entire Article as amended 
(amended sections listed below) 


























Adopt only those articles / sections that 
are listed below 


























Article / Section 






























The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2. 
20 iO California Electrical Code 70-19 



ARTICLE 90 - CALIFORNIA MATRIX ADOPTION TABLE 




70-20 20 10 California Electrical Code 



ARTICLE 90 - INTRODUCTION 



90.2 



NFPA 70 

National Electrical Code® 

2008 Edition 

IMPORTANT NOTE: This NFPA document is made 
available for use subject to important notices and legal 
disclaimers. These notices and disclaimers appear in all 
publications containing this document and may be found 
under the heading '^Important Notices and Disclaimers 
Concerning NFPA Documents,^' They can also be 
obtained on request from NFPA or viewed at 
www, nfpa, org/disclaimers, 

90.1 Purpose. 

(A) Practical Safeguarding. The purpose of this Code is 
the practical safeguarding of persons and property from 
hazards arising from the use of electricity. 

(B) Adequacy. This Code contains provisions that are 
considered necessary for safety. CompHance therewith and 
proper maintenance results in an installation that is essentially 
free from hazard but not necessarily efficient, convenient, or 
adequate for good service or ftiture expansion of electrical use. 

FPN: Hazards often occur because of overloading of wiring 
systems by methods or usage not in conformity with this 
Code. This occurs because initial wiring did not provide for 
increases in the use of electricity. An initial adequate 
installation and reasonable provisions for system changes 
provide for future increases in the use of electricity. 

(C) Intention. This Code is not intended as a design 
specification or an instruction manual for untrained persons. 

(D) Relation to Other International Standards. The 

requirements in this Code address the fundamental 
principles of protecfion for safety contained in Section 131 
of International Electrotechnical Commission Standard 
60364-1, Electrical Installations of Buildings, 

FPN: lEC 60364-1, Section 131, contains fundamental 
principles of protection for safety that encompass protection 
against electric shock, protection against thermal effects, 
protection against overcurrent, protection against fault currents, 
and protection against overvoltage. All of these potential 
hazards are addressed by the requirements in this Code. 

90.2 Scope. 

(A) Covered. This Code covers the installation of electrical 
conductors, equipment, and raceways; signaling and 
communications conductors, equipment, and raceways; and 
optical fiber cables and raceways for the following: 

(1) Pubhc and private premises, including buildings, structures, 
mobile homes, recreational vehicles, and floating buildings 

(2) Yards, lots, parking lots, carnivals, and industrial 
substations 



# (3) Installations of conductors and equipment that connect 
to the supply of electricity 
(4) Installations used by the electric utility, such as office 
buildings, warehouses, garages, machine shops, and 
recreational buildings, that are not an integral part of a 
generating plant, substafion, or control center. 

(B) Not Covered. This Code does not cover the following: 

(1) Installations in ships, watercraft other than floating 
buildings, railway rolUng stock, aircraft, or automotive 
vehicles other than mobile homes and recreational 
vehicles 

FPN: Although the scope of this Code indicates that the 
Code does not cover installations in ships, portions of this 
Code are incorporated by reference into Title 46, Code of 
Federal Regulations, Parts 1 1 0-1 1 3 . 

(2) Installations underground in mines and self-propelled 
mobile surface mining machinery and its attendant 
electrical trailing cable 

(3) Installations of railways for generation, transformation, 
transmission, or distribution of power used exclusively 
for operation of rofling stock or installations used 
exclusively for signaling and communications purposes 

(4) Installations of communications equipment under the 
exclusive control of communications utilities located 
outdoors or in building spaces used exclusively for 
such installations 

(5) Installations under the exclusive control of an electric 
utility where such installations 

a. Consist of service drops or service laterals, and 
associated metering, or 

b. Are located in legally established easements or 
rights-of-way designated by or recognized by 
public service commissions, utility commissions, 
or other regulatory agencies having jurisdiction 
for such installations, or 

c. Are on property owned or leased by the electric 
utility for the purpose of communications, 
metering, generation, control, transformation, 
transmission, or distribution of electric energy. 

FPN to (4) and (5): Examples of utilities may include those 
entities that are typically designated or recognized by 
govemmental law or regulation by public service/utility 
commissions and that install, operate, and maintain electric 
supply (such as generation, transmission, or distribution 
systems) or communication systems (such as telephone, 
CATV, Intemet, satellite, or data services). Utilities may be 
subject to compliance with codes and standards covering their 
regulated activities as adopted under govemmental law or 
regulation. Additional information can be found through 
consultation with the appropriate govemmental bodies, such as 
state regulatory commissions, the Federal Energy Regulatory 
Commission, and the Federal Communications Commission. 

(C) Special Permission. The authority having 
jurisdiction for enforcing this Code may grant exception 
for the installation of conductors and equipment that are 
not under the exclusive control of the electric utilities and 
are used to connect the electric utility supply system to 
the service-entrance conductors of the premises served, 
provided such installations are outside a building or 
terminate immediately inside a building wall. 



2010 California Electrical Code 



70-21 



90.3 



ARTICLE 90 - INTRODUCTION 



90.3 Code Arrangement. This Code is divided into the 
introduction and nine chapters, as shown in Figure 90.3. 
Chapters 1, 2, 3, and 4 apply generally; Chapters 5, 6, and 
7 apply to special occupancies, special equipment, or other 
special conditions. These latter chapters supplement or 
modify the general rules. Chapters 1 through 4 apply 
except as amended by Chapters 5, 6, and 7 for the 
particular conditions. 

Chapter 8 covers communications systems and is not 
subject to the requirements of Chapters 1 through 7 except 
where the requirements are specifically referenced in Chapter 8. 

Chapter 9 consists of tables that are f^pp}%<^M:M 
referenced. 

Annexes are not part of the requirements of this Code 
but are included for informational purposes only. 



Chapter 1-» General 



Chapter 2 - Wiring and Protection 



Chapter 3 - Wiring Methods and Materials 



Chapter 4 -^ Equipment for General Use 



Applies generally 
' to all electrical 
installations 



Supplaments or modifies ^ 
Chapters Uhrough 4 



Chapter 5 - Special Ocx)upanoies 



Chapter 6 -"Special Equipment 



Chapter 7 -Special Conditions 



Chapter 8 - Communications Systems 



Chapter 9 -« Tables 



Annex A through Annex H 



Chapter 8 is not sut)iect 
to the requirements of 
Chapters 1 through 7 ax(^pt 
'where the requiremente are 
speciioally referenced in 
Chapters. 

-Applicabte as referenced 

Jnformationaionly; 
not mandatory 



Figure 90.3 Code Arrangement. 

90.4 Enforcement. This Code is intended to be suitable 
for mandatory application by governmental bodies that 
exercise legal jurisdiction over electrical installations, 
including signaling and communications systems, and for 
use by insurance inspectors. The authority having 
jurisdiction for enforcement of the Code has the 
responsibility for making interpretations of the rules, for 
deciding on the approval of equipment and materials, and 



for granting the special permission contemplated in a 
number of the rules. 

By special permission, the authority having 
jurisdiction may waive specific requirements in this Code 
or permit alternative methods where it is assured that 
equivalent objectives can be achieved by establishing and 
maintaining effective safety. 

This Code may require new products, constructions, or 
materials that may not yet be available at the time the Code 
is adopted. In such event, the authority having jurisdiction 
may permit the use of the products, constructions, or 
materials that comply with the most recent previous edition 
of this Code adopted by the jurisdiction. 

90.5 Mandatory Rules, Permissive Rules, and 
Explanatory Material. 

(A) Mandatory Rules. Mandatory rules of this Code are 
those that identify actions that are specifically required or 
prohibited and are characterized by the use of the terms 
shall or shall not. 

(B) Permissive Rules. Permissive rules of this Code are 
those that identify actions that are allowed but not required, 
are normally used to describe options or alternative 
methods, and are characterized by the use of the terms shall 
be permitted or shall not be required, 

(C) Explanatory Material. Explanatory material, such as 
references to other standards, references to related sections 
of this Code, or information related to a Code rule, is 
included in this Code in the form of fine print notes 
(FPNs). Fine print notes are informational only and are not 
enforceable as requirements of this Code. 

Brackets containing section references to another NFPA 
document are for informational purposes only and are 
provided as a guide to indicate the source of the extracted 
text. These bracketed references immediately follow the 
extracted text. 

FPN: The format and language used in this Code follows 
guidelines established by NFPA and published in the NEC Style 
Manual Copies of this manual can be obtained from NFPA. 

90.6 Formal Interpretations. To promote uniformity of 
interpretation and application of the provisions of this 
Code, formal interpretation procedures have been 
established and are found in the NFPA Regulations 
Governing Committee Projects. 



70-22 



2010 California Electrical Code 



ARTICLE 90 - INTRODUCTION 



90.9 



90.7 Examination of Equipment for Safety. For specific 
items of equipment and materials referred to in this Code, 
examinations for safety made under standard conditions 
provide a basis for approval where the record is made 
generally available through promulgation by organizations 
properly equipped and qualified for experimental testing, 
inspections of the run of goods at factories, and service- 
value determination through field inspections. This avoids 
the necessity for repetition of examinations by different 
examiners, frequently with inadequate facilities for such 
work, and the confusion that would resuh from conflicting 
reports on the suitability of devices and materials examined 
for a given purpose. 

It is the intent of this Code that factory-installed 
internal wiring or the construction of equipment need not 
be inspected at the time of installation of the equipment, 
except to detect aherations or damage, if the equipment has 
been listed by a qualified electrical testing laboratory that is 
recognized as having the facilities described in the 
preceding paragraph and that requires suitability for 
installation in accordance with this Code. 

FPN No. 1 : See requirements in 1 10.3. 

FPN No. 2: Listed \^ defined in Article 100. 

FPN No. 3: Annex A contains an informative list of product 
safety standards for electrical equipment. 

90.8 Wiring Planning. 

(A) Future Expansion and Convenience. Plans and 
specifications that provide ample space in raceways, spare 
raceways, and additional spaces allow for future increases 
in electric power and communication circuits. Distribution 
centers located in readily accessible locations provide 
convenience and safety of operation. 

(B) Number of Circuits in Enclosures. It is elsewhere 
provided in this Code that the number of wires and circuits 
confined in a single enclosure be varyingly restricted. 
Limiting the number of circuits in a single enclosure 
minimizes the effects from a short circuit or ground fault in 
one circuit. 



90.9 Units of Measurement. 

(A) Measurement System of Preference. For the purpose 
of this Code, metric units of measurement are in 
accordance with the modernized metric system known as 
the International System of Units (SI). 

(B) Dual System of Units, SI units shall appear first, and 
inch-pound units shall immediately follow in parentheses. 
Conversion from inch-pound units to SI units shall be 
based on hard conversion except as provided in 90.9(C). 

(C) Permitted Uses of Soft Conversion. The cases given 
in 90.9(C)(1) through (C)(4) shall not be required to use 
hard conversion and shall be permitted to use soft 
conversion. 

(1) Trade Sizes. Where the actual measured size of a 
product is not the same as the nominal size, trade size 
designators shall be used rather than dimensions. Trade 
practices shall be followed in all cases. 

(2) Extracted Material. Where material is extracted from 
another standard, the context of the original material shall 
not be compromised or violated. Any editing of the 
extracted text shall be confined to making the style 
consistent with that of the NEC. 

(3) Industry Practice. Where industry practice is to 
express units in inch-pound units, the inclusion of SI units 
shall not be required. 

(4) Safety. Where a negative impact on safety would 
result, soft conversion shall be used. 

(D) Compliance. Conversion from inch-pound units to SI 
units shall be permitted to be an approximate conversion. 
Compliance with the numbers shown in either the SI 
system or the inch-pound system shall constitute 
compliance with this Code. 

FPN No. 1: Hard conversion is considered a change in 
dimensions or properties of an item into new sizes that 
might or might not be interchangeable with the sizes used in 
the original measurement. Soft conversion is considered a 
direct mathematical conversion and involves a change in the 
description of an existing measurement but not in the aclual 
dimension. 



FPN No. 2: SI conversions are based on lEEE/ASTM SI 10- 
1991 , Standard for the Use of the International System of 
Units (SI): The Modern Metric System. 



2010 California Electrical Code 



70-23 



CHAPTER 1 CALIFORNIA MATRIX ADOPTION TABLE 



• 




The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2. 
70-23.1 ■ \ 2010 California Electrical Code 



CHAPTER 1 CALIFORNIA MATRIX ADOPTION TABLE 



CHAPTER 1 - GENERAL 



Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


DPH 


1 


2 


AC 


SS 


ss/cc 


1 


2 


3 


4 




Adopt Entire Chapter 


X 


X 


X 


X 




X 


X 












Adopt Entire Chapter as amended 
(amended sections listed below) 
















X 


X 


X 


X 




Adopt only those articles / sections 
that are listed below 


























Article / Section 


100 / Coordination (Selective) 
















X 


X 


X 


X 




110.2 
















X 


X 


X 


X 




110.13(C) 
















X 


X 


X 


X 































The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is apphcable to structures subject to BCD 1 and/or HCD 2. 
2010 California Electrical Code 70-23.2 



CHAPTER 1 



ARTICLE 100 -DEFINITIONS 



Chapter 1 General 



Definitions 



Scope. This article contains only those definitions essential 
to the proper application of this Code. It is not intended to 
include conimonly defined general terms or commonly 
defined technical terms from related codes and standards. 
In general, only those terms that are used in two or more 
articles are defined in Article 100. Other definitions are 
included in the article in which they are used but may be 
referenced in Article 100. 

Part I of this article contains definitions intended to 
apply wherever the terms are used throughout this Code. 
Part II contains definitions applicable only to the parts of 
articles specifically covering installations and equipment 
operating at over 600 volts, nominal. 

I. General 

Accessible (as applied to equipment). Admitting close 
approach; not guarded by locked doors, elevation, or other 
effective means. 

Accessible (as applied to wiring methods). Capable of 
being removed or exposed without damaging the building 
structure or finish or not permanently closed in by the 
structure or finish of the building. 

Accessible, Readily (Readily Accessible). Capable of 
being reached quickly for operation, renewal, or 
inspections without requiring those to whom ready access 
is requisite to climb over or remove obstacles or to resort to 
portable ladders, and so forth. 

Ampacity. The current, in amperes, that a conductor can 
carry continuously under the conditions of use without 
exceeding its temperature rating. 

Appliance. Utilization equipment, generally other than 
industrial, that is normally built in standardized sizes or 
types and is installed or connected as a unit to perform one 
or more functions such as clothes washing, air 
conditioning, food mixing, deep frying, and so forth. 

Approved. Acceptable to the authority having jurisdiction. 

Askarel. A generic term for a group of nonflammable 
synthetic chlorinated hydrocarbons used as electrical 
insulating media. Askarels of various compositional types 
are used. Under arcing conditions, the gases produced, 
while consisting predominantly of noncombustible 



hydrogen chloride, can include varying amounts of 
combustible gases, depending on the askarel type. 

Attachment Plug (Plug Cap) (Plug). A device that, by 
insertion in a receptacle, establishes a connection between 
the conductors of the attached flexible cord and the 
conductors connected permanently to the receptacle. 

Authority Having Jurisdiction (AHJ). An organization, 
office, or individual responsible for enforcing the 
requirements of a code or standard, or for approving 
equipment, materials, an installation, or a procedure. 

FPN: The phrase "authority having jurisdiction," or its 
acronym AHJ, is used in NFPA documents in a broad 
manner, since jurisdictions and approval agencies vary, as 
do their responsibilities. Where public safety is primary, the 
authority having jurisdiction may be a federal, state, local, 
or other regional department or individual such as a fire 
chief; fire marshal; chief of a fire prevention bureau, labor 
department, or health department; building official; 
electrical inspector; or others having statutory authority. For 
insurance purposes, an insurance inspection department, 
rating bureau, or other insurance company representative 
may be the authority having jurisdiction. In many 
circumstances, the property owner or his or her designated 
agent assumes the role of the authority having jurisdiction; 
at government installations, the commanding officer or 
departmental official may be the authority having 
jurisdiction. 

Automatic. Self-acting, operating by its own mechanism 
when actuated by some impersonal influence, as, for 
example, a change in current, pressure, temperature, or 
mechanical configuration. 

Bathroom. An area including a basin with one or more of 
the following: a toilet, a tub, or a shower. 

Bonded ; (Bonding).: ponnected to- ^es^tablish ; electf ical 
<^ntinuity and coiidttCtiivity| 

Bonding Jumper. A reliable conductor to ensure the 
required electrical conductivity between metal parts 
required to be electrically connected. 

Bonding Jumper, Equipment. The cormection between 
two or more portions of the equipment grounding 
conductor. 

Bonding Jumper, Main. The connection between the 
grounded circuit conductor and the equipment grounding 
conductor at the service. 

Branch Circuit. The circuit conductors between the final 
overcurrent device protecting the circuit and the outlet(s). 

Branch Circuit, Appliance. A branch circuit that supplies 
energy to one or more outlets to which apphances are to be 
connected and that has no permanently connected 
luminaires that are not a part of an appliance. 



70-24 



2010 California Electrical Code 



ARTICLE 100 - DEFINITIONS 



CHAPTER 1 



Branch Circuit, General-Purpose. A branch circuit that 
supplies two or more receptacles or outlets for lighting and 
appliances. 

Branch Circuit, Individual. A branch circuit that supplies 
only one utilization equipment. 

Branch Circuit, Multiwire. A branch circuit that consists 
of two or more ungrounded conductors that have a voltage 
between them, and a grounded conductor that has equal 
voltage between it and each ungrounded conductor of the 
circuit and that is connected to the neutral or grounded 
conductor of the system. 

Bmiieh-C^lreiiit Ov^rctt'rre^^ Ajdeyioe ,cl[|)abie of 

jaad[eqiuipnietit bvcr the- Mtim^^pJ m^cuttjkxU i^^iwphi, 

its^mted current md kimtkmipMg ti^^^ 

bvf tciip-eit ptot^ctive , deyic^ ' A^^^^' JP^PYided with 

Building. A structure that stands alone or that is cut off 
from adjoining structures by fire walls with all openings 
therein protected by approved fire doors. 

Cabinet. An enclosure that is designed for either surface 
mounting or flush mounting and is provided with a frame, 
mat, or trim in which a swinging door or doors are or can 
be hung. 

Circuit Breaker. A device designed to open and close a 
circuit by nonautomatic means and to open the circuit 
automatically on a predetermined overcurrent without 
damage to itself when properly appHed within its rating. 

FPN: The automatic opening means can be integral, direct acting 
with the circuit breaker, or remote from the circuit breaker. 

Adjustable (as applied to circuit breakers). A qualifying 
term indicating that the circuit breaker can be set to trip at 
various values of current, time, or both, within a 
predetermined range. 

Instantaneous Trip (as applied to circuit breakers). A 
qualifying term indicating that no delay is purposely 
introduced in the tripping action of the circuit breaker. 

Inverse Time (as applied to circuit breakers), A qualifying 
term indicating that there is purposely introduced a delay in 
the tripping action of the circuit breaker, which delay 
decreases as the magnitude of the current increases. 

Nonadjustable (as applied to circuit breakers). A 
qualifying term indicating that the circuit breaker does not 
have any adjustment to alter the value of current at which it 
will trip or the time required for its operation. 



Setting (of circuit breakers). The value of current, time, or 
both, at which an adjustable circuit breaker is set to trip, 

jClc»^gS: Clmtt. Amii:^ roor^ or space jotfn4^4 

pritti&EY;forstq^ 

Communications Equipment. The electronic equipment 
that performs the telecommunications operations for the 
transmission of audio, video, and data, and includes power 
equipment (e.g., dc converters, inverters, and batteries) and 
technical support equipment (e.g., computers). 

Concealed. Rendered inaccessible by the structure or finish 
of the building. Wires in concealed raceways are 
considered concealed, even though they may become 
accessible by withdrawing them. 

Conductor, Bare. A conductor having no covering or 
electrical insulation whatsoever. 

Conductor, Covered. A conductor encased within material 
of composition or thickness that is not recognized by this 
Code as electrical insulation. 

Conductor, Insulated. A conductor encased within 
material of composition and thickness that is recognized by 
this Code as electrical insulation. 

Conduit Body. A separate portion of a conduit or tubing 
system that provides access through a removable cover(s) 
to the interior of the system at a junction of two or more 
sections of the system or at a terminal point of the system. 

Boxes such as FS and FD or larger cast or sheet metal 
boxes are not classified as conduit bodies. 

Connector, Pressure (Solderless). A device that establishes 
a connection between two or more conductors or between 
one or more conductors and a terminal by means of 
mechanical pressure and without the use of solder. 

Continuous Load. A load where the maximum current is 
expected to continue for 3 hours or more. 

Controller. A device or group of devices that serves to 
govern, in some predetermined manner, the electric power 
delivered to the apparatus to which it is connected. 

Cooking Unit, Counter-Mounted. A cooking appliance 
designed for mounting in or on a counter and consisting of 
one or more heating elements, internal wiring, and built-in 
or mountable controls. 

Coordination (Selective). Localization of an overcurrent 
condition to restrict outages to the circuit or equipment 
affected, accomplished by the choice of overcurrent 
protective devices and their ratings or settings, [OSHPD 1, 
2, 5, & 4] utilizing the 0.10 second level of the overcurrent 
protective device from the time current curve as the basis 
for the lower limit of the calculation method, 

Copper-Clad Aluminum Conductors. Conductors drawn 
from a copper-clad aluminum rod with the copper 
metallurgically bonded to an aluminum core. The copper 
forms a minimum of 10 percent of the cross-sectional area 
of a solid conductor or each strand of a stranded conductor. 



2010 California Electrical Code 



70-25 



CHAPTER 1 



ARTICLE 100 - DEFINITIONS 



Cutout Box. An enclosure designed for surface mounting 
that has swinging doors or covers secured directly to and 
telescoping with the walls of the box proper. 

Dead Front. Without live parts exposed to a person on the 
operating side of the equipment. 

Demand Factor. The ratio of the maximum demand of a 
system, or part of a system, to the total connected load of a 
system or the part of the system under consideration. 

Device. A unit of an electrical system that bames, or 
controls electric energy as its principal feriction. 

Disconnecting Means. A device, or group of devices, or 
other means by which the conductors of a circuit can be 
disconnected from their source of supply. 

Dusttight. Constructed so that dust will not enter the 
enclosing case under specified test conditions. 

Duty, Continuous. Operation at a substantially constant 
load for an indefinitely long time. 

Duty, Intermittent. Operation for altemate intervals of (1) load 
and no load; or (2) load and rest; or (3) load, no load, and rest. 

Duty, Periodic. Intermittent operation in which the load 
conditions are regularly recurrent. 

Duty, Short-Time. Operation at a substantially constant 
load for a short and definite, specified time. 

Duty, Varying. Operation at loads, and for intervals of 
time, both of which may be subject to wide variation. 

Dwelling, One-Family. A building that consists solely of 
one dwelling unit. 

Dwelling, Two-Family. A building that consists solely of 
two dwelling units. 

Dwelling, Multifamily. A building that contains three or 
more dwelling units. 

Dwelling Unit. A single unit, providing complete and 
independent Hving facilities for one or more persons, 
including permanent provisions for living, sleeping, 
cooking, and sanitation. 

Electric Sign. A fixed, stationary, or portable self- 
contained, electrically illuminated utilization equipment 
with words or symbols, designed to convey information or 
attract attention. 



■ ?9ii?M^^ont]K^M^ 

Enclosed. Surrounded by a case, housing, fence, or wall(s) 
that prevents persons from accidentally contacting 
energized parts. 



Enclosure. The case or housing of apparatus, or the fence 
or walls surrounding an installation to prevent personnel 
from accidentally contacting energized parts or to protect 
the equipment from physical damage. 

FPN: ^^eTabfe IJO.^ for examples of enclosure types. 

Energized. Electrically connected to, or is, a source of 
voltage. 

Equipment. A general term, including material, fittings, 
devices, appliances, luminaires, apparatus, m^cMj^ry; and 
the like used as a part of, or in connection with, an 
electrical installation. 

Explosionproof Apparatus. Apparatus enclosed in a case that 
is capable of withstanding an explosion of a specified gas or 
vapor that may occur within it and of preventing the ignition of 
a specified gas or vapor surrounding the enclosure by sparks, 
flashes, or explosion of the gas or vapor within, and that 
operates at such an external temperature that a surrounding 
flammable atmosphere will not be ignited thereby. 

FPN: For fiirther information, see ANSI/UL 1203-1999, 
Explosion-Proof and Dust-Ignition-Proof Electrical 
Equipment for Use in Hazardous (Classified) Locations. 

Exposed (as applied to live parts). Capable of being 
inadvertently touched or approached nearer than a safe 
distance by a person. It is applied to parts that are not 
suitably guarded, isolated, or insulated. 

Exposed (as appHed to wiring methods). On or attached to 
the surface or behind panels designed to allow access. 

Externally Operable. Capable of being operated without 
exposing the operator to contact with live parts. 

Feeder. All circuit conductors between the service 
equipment, the source of a separately derived system, or 
other power supply source and the final branch-circuit 
overcurrent device. 

Festoon Lighting. A string of outdoor lights that is 
suspended between two points. 

Fitting. An accessory such as a locknut, bushing, or other 
part of a wiring system that is intended primarily to 
perform a mechanical rather than an electrical fiinction. 

Garage. A building or portion of a building in which one 
or more self-propelled vehicles can be kept for use, sale, 
storage, rental, repair, exhibition, or demonstration purposes. 

FPN: For commercial garages, repair and storage, see 
Article 511. 

Ground. ^fefeartKj 

Grounded iGrmm^ng)] Connected (connecting) to 
ground or to a conductive body that e^tgaids f^^^^ 

Isi^iytioiiii 



70-26 



2010 California Electrical Code 



ARTICLE 100 - DEFINITIONS 



CHAPTER 1 



Grounded, Solidly. Connected to ground without inserting 
any resistor or impedance device. 

Grounded Conductor. A system or circuit conductor that 
is intentionally grounded. 

Ground-Fault Circuit Interrupter (GFCI). A device 
intended for the protection of personnel that functions to 
de-energize a circuit or portion thereof within an 
established period of time when a current to ground 
exceeds the values established for a Class A device. 

FPN: Class A ground- fault circuit interrupters trip when the 
current to ground i$;_|_mA or h%her'agd'^d^;not;5^^^ 
Iflie ejjirreilt to groujad is fes^ thaii 4 mSj For further 
information, see UL 943, Standard for Ground-Fault 
Circuit Interrupters. 

Ground-Fault Protection of Equipment. A system intended 
to provide protection of equipment from damaging line-to- 
ground fault currents by operating to cause a disconnecting 
means to open all ungrounded conductors of the fauhed 
circuit. This protection is provided at current levels less than 
those required to protect conductors from damage through the 
operation of a supply circuit overcurrent device. 

Grounding Conductor. A conductor used to connect 
equipment or the grounded circuit of a wiring system to a 
grounding electrode or electrodes. 

Grounding Conductor, Equipment ^GG|. The gotldpaSvi 

^ffijg^i|te| to connect Sapmi^R non-current-carrying metal 
parts of equipment pOj ^ief m ^ to the system grounded 
conductor or to the grounding electrode conductor, pr bolh. 

ijptAJ^Mr^a fe ,p etfonn^.bSn,togJ 

SfM.ift 2: 'See^ 2S0;-i I t,"fot i tet Wja^j^^He^^^^ 



gqpJittactoEs^ 
Grounding Electrode, Ik cqBjacffi|^^^^^ 

Grounding Electrode Conductor^ ^ eoBdiactor ^s^jy 
j^nnect Ae: system grbuided eoiidiictor or the ^^^ymmmi tB, 



Guarded. Covered, shielded, fenced, enclosed, or 
otherwise protected by means of suitable covers, casings, 
barriers, rails, screens, mats, or platforms to remove the 
likelihood of approach or contact by persons or objects to a 
point of danger. 

Guest Room. An accommodation combining living, 
sleeping, sanitary, and storage facilities within a 
compartment. 



Guest Suite. An accommodation with two or more 
contiguous rooms comprising a compartment, with or 
without doors between such rooms, that provides living, 
sleeping, sanitary, and storage facilities. 

Handhole Enclosure, An enclosure for use in underground 
systems, provided with an open or closed bottom, and sized 
to allow personnel to reach into, but not enter, for the 
purpose of installing, operating, or maintaining equipment 
or wiring or both. 

Hoistway. Any shaflway, hatchway, well hole, or other 
vertical opening or space in which an elevator or 
dumbwaiter is designed to operate. 

Identified (as applied to equipment). Recognizable as 
suitable for the specific purpose, function, use, 
environment, application, and so forth, where described in 
a particular Code requirement. 

FPN: Some examples of ways to determine suitability of 
equipment for a specific purpose, environment, or 
appHcation include investigations by a qualified testing 
laboratory (listing and labeling), an inspection agency, or 
other organizations concemed with product evaluation. 

In Sight From (Within Sight From, Within Sight). Where 
this Code specifies that one equipment shall be "in sight 
from," "within sight from," or "within sight of," and so forth, 
another equipment, the specified equipment is to be visible 
and not more than 1 5 m (50 ft) distant from the other. 

Interactive System. An electric power production system 
that is operating in parallel with and capable of delivering 
energy to an electric primary source supply system. 

Interrupting Rating. The highest current at rated voltage that 
a device is intended to interrupt under standard test conditions. 

FPN: Equipment intended to interrupt current at other than 
fault levels may have its interrupting rating implied in other 
ratings, such as horsepower or locked rotor current. 

^ovMjss ame^ans^for conEe<^|g comBjwcations systeS(s) 
groundilxg mndmtpi^d) and bpndiiig conductor{s) at tto 
keryice equipment or _ ^ ^J^q Am^^ „.8l^^^ „ fo| 

ftmldings/or ^^ktoctures^, §t^^ byj;"a_'Jeedet,'orJ;fe 
bircuiti 

Isolated (as applied to location). Not readily accessible to 
persons unless special means for access are used. 

Kilclieri^ Ail' ar^a with a^sffik and penMnent facjlilies for 
ifoodpcejjaratioi^^ 

Labeled. Equipment or materials to which has been 
attached a label, symbol, or other identifying mark of an 
organization that is acceptable to the authority having 
jurisdiction and concemed with product evaluation, that 



2010 California Electrical Code 



70-27 



CHAPTER 1 



ARTICLE 100 - DEFINITIONS 



maintains periodic inspection of production of labeled 
equipment or materials, and by whose labeling the 
manufacturer indicates compliance with appropriate 
standards or performance in a specified manner. 

Lighting Outlet, An outlet intended for the direct 
connection of a lampholder or luminaire. 

Listed. Equipment, materials, or services included in a list 
published by an organization that is acceptable to the authority 
having jurisdiction and concerned with evaluation of products 
or services, that maintains periodic inspection of production of 
listed equipment or materials or periodic evaluation of 
services, and whose listing states that either the equipment, 
material, or service meets appropriate designated standards or 
has been tested and found suitable for a specified purpose. 

FPN: The means for identifying listed equipment may vary 
for each organization concemed with product evaluation, 
some of which do not recognize equipment as listed unless 
it is also labeled. Use of the system employed by the listing 
organization allows the authority having jurisdiction to 
identify a listed product. 

Live Parts. Energized conductive components. 

Location, Damp. Locations protected from weather and 
not subject to saturation with water or other liquids but 
subject to moderate degrees of moisture. Examples of such 
locations include partially protected locations under 
canopies, marquees, roofed open porches, and like 
locations, and interior locations subject to moderate 
degrees of moisture, such is some basements, some bams, 
and some cold-storage warehouses. 

Location, Dry. A location not normally subject to 
danipness or wetness. A location classified as dry may be 
temporarily subject to dampness or wetness, as in the case 
of a building under construction. 

Locatioii, Wet. Installations underground or in concrete 
slabs or masonry in direct contact with the earth; in 
locations subject to saturation with water or other liquids, 
such as vehicle washing areas; and in unprotected locations 
exposed to weather. 



Luminaire. 'A;MJ^^^!:ltm^:^WM: 




10 gmitibftfte ^smm'^^^j^j^'^^'^ %i^'p*??^.^^%f, ^ 



Metal-Enclosed Power Switchgear. A switchgear 
assembly completely enclosed on all sides and top with 
sheet metal (except for ventilating openings and inspection 
windows) and containing primary power circuit switching, 
interrupting devices, or both, with buses and connections. 
The assembly may include control and auxiliary devices. 



Access to the interior of the enclosure is provided by doors, 
removable covers, or both. Mpt£h^mlq^J/jpqw 
^^t^g_^^w^^^^ 

Motor Control Center. An assembly of one or more 
enclosed sections having a conomon power bus and 
principally containing motor control units. 
Multioutlet Assembly. A type of surface, flush, or 
freestanding raceway designed to hold conductors and 
receptacles, assembled in the field or at the factory. 



dgfa;sysiein,^ot4ffl#^tetl';3^ 
b| ;,§|'iJiSi%^ '§om W^^ 

'^M^lsmrq: potoiWlil 
Nonautomatic. Action requiring personal intervention for 
its control. As applied to an electric controller, 
nonautomatic control does not necessarily imply a manual 
controller, but only that personal intervention is necessary. 
Nonlinear Load. A load where the wave shape of the 
steady-state current does not follow the wave shape of the 
applied voltage. 

FPN: Electronic equipment, electronic/electric-discharge 

lighting, adjustable-speed drive systems, and similar 

equipment may be nonlinear loads. 

Outlet. A point on the wiring system at which current is 
taken to supply utilization equipment. 

Outline Lighting. An arrangement of incandescent lamps, 
electric-discharge lighting, or other electrically powered light 
sources to outline or call attention to certain features such as 
the shape of a building or the decoration of a window. 

Overcurrent. Any current in excess of the rated current of 
equipment or the ampacity of a conductor. It may result 
from overload, short circuit, or ground fault. 

FPN: A current in excess of rating may be accommodated 
by certain equipment and conductors for a given set of 
conditions. Therefore, the rules for overcurrent protection 
are specific for particular situations. 

Overload. Operation of equipment in excess of normal, 
full-load rating, or of a conductor in excess of rated ampacity 
that, when it persists for a sufficient length of time, would 
cause damage or dangerous overheating. A fault, such as a 
short circuit or ground fault, is not an overload. 



70-28 



2010 California Electrical Code 



ARTICLE 100 - DEFINITIONS 



CHAPTER 1 



Panelboard. A single panel or group of panel units 
designed for assembly in the form of a single panel, 
including buses and automatic overcurrent devices, and 
equipped with or without switches for the control of light, 
heat, or power circuits; designed to be placed in a cabinet 
or cutout box placed in or against a wall, partition, or other 
support; and accessible only from the front. 

Plenum. A compartment or chamber to which one or more 
air ducts are connected and that forms part of the air 
distribution system. 

Power Outlet. An enclosed assembly that may include 
receptacles, circuit breakers, fiiseholders, fused switches, 
buses, and watt-hour meter mounting means; intended to 
supply and control power to mobile homes, recreational 
vehicles, park trailers, or boats or to serve as a means for 
distributing power required to operate mobile or 
temporarily installed equipment. 

Premises Wiring (System). Interior and exterior wiring, 
including power, lighting, control, and signal circuit wiring 
together with all their associated hardware, fittings, and 
wiring devices, both permanently and temporarily installed. 



^oujccert^!!tfte outfets or ft) wiring Mmjm^ iBcliidtafi'tfi^. 

Such wiring does not include wiring internal to 
appliances, luminaires, motors, controllers, motor control 
centers, and similar equipment. 

Qualified Person. One who has skills and knowledge 
related to the construction and operation of the electrical 
equipment and installations and has received safety training 
|^r&o§ii?e^a §y<33 the hazards involved. 

FPN: Refer to NFPA 70E®-2004, Standard for Electrical 
Safety in the Workplace, for electrical safety training 
requirements. 

Raceway. An enclosed channel of metal or nonmetallic 
materials designed expressly for holding wires, cables, or 
busbars, with additional functions as permitted in this 
Code. Raceways include, but are not limited to, rigid metal 
conduit, rigid nonmetallic conduit, intermediate metal 
conduit, liquidtight flexible conduit, flexible metallic 
tubing, flexible metal conduit, electrical nonmetallic 
tubing, electrical metallic tubing, underfloor raceways, 
cellular concrete floor raceways, cellular metal floor 
raceways, surface raceways, wireways, and busways. 

Rainproof. Constructed, protected, or treated so as to 
prevent rain from interfering with the successful operation 
of the apparatus under specified test conditions. 

Raintight. Constructed or protected so that exposure to a 
beating rain will not result in the entrance of water under 
specified test conditions. 



Receptacle. A receptacle is a contact device installed at the 
outlet for the connection of an attachment plug. A single 
receptacle is a single contact device with no other contact 
device on the same yoke. A multiple receptacle is two or 
more contact devices on the same yoke. 

Receptacle Outlet. An outlet where one or more 
receptacles are installed. 

Remote-Control Circuit. Any electrical circuit that 
controls any other circuit through a relay or an equivalent 
device. 

Sealable Equipment. Equipment enclosed in a case or 
cabinet that is provided with a means of sealing or locking 
so that live parts cannot be made accessible without 
opening the enclosure. The equipment may or may not be 
operable without opening the enclosure. 

Separately Derived System. A premises wiring system 
whose power is derived from a source of electric energy or 
equipment other than a service. Such systems have no 
direct electrical connection, including a solidly connected 
grounded circuit conductor, to supply conductors 
originating in another system. 

Service. The conductors and equipment for delivering 
electric energy from the serving utility to the wiring system 
of the premises served. 

Service Cable. Service conductors made up in the form of 
a cable. 

Service Conductors. The conductors from the service 
point to the service disconnecting means. 

Service Drop. The overhead service conductors from the 
last pole or other aerial support to and including the splices, 
if any, connecting to the service-entrance conductors at the 
building or other structure. 

Service-Entrance Conductors, Overhead System. The 

service conductors between the terminals of the service 
equipment and a point usually outside the building, clear of 
building walls, where joined by tap or splice to the service drop. 

Service-Entrance Conductors, Underground System. 

The service conductors between the terminals of the service 
equipment and the point of connection to the service lateral. 

FPN: Where service equipment is located outside the 
building walls, there may be no service-entrance conductors 
or they may be entirely outside the building. 

Service Equipment. The necessary equipment, usually 
consisting of a circuit breaker(s) or switch(es) and fuse(s) 
and their accessories, connected to the load end of service 
conductors to a building or other structure, or an otherwise 
designated area, and intended to constitute the main control 
and cutoff of the supply. 



2010 California Electrical Code 



70-29 



CHAPTER 1 



ARTICLE 100 -DEFINITIONS 



Service Lateral. The underground service conductors 
between the street main, including any risers at a pole or 
other structure or from transformers, and the first point of 
connection to the service -entrance conductors in a terminal 
box or meter or other enclosure, inside or outside the 
building wall. Where there is no terminal box, meter, or 
other enclosure, the point of connection is considered to be 
the point of entrance of the service conductors into the 
building. 

Service Point, The point of connection between the 
facilities of the serving utility and the premises wiring. 

Short-Circuit ^ Current _^_^RaBiig._^_T^^ j^rostpectiyd 

jsymmetrical fault curreat at a nominal voltage to ^ich an 
apparatus or systern is abie tg Idc cqmecte^^^^ 
sustaining damage exceeding denned acceptance ctiteriaJ 

Show Window. Any window used or designed to be used 
for the display of goods or advertising material, whether it 
is fully or partly enclosed or entirely open at the rear and 
whether or not it has a platform raised higher than the street 
floor level. 

Signaling Circuit. Any electrical circuit that energizes 
signaling equipment. 

Solar Photovoltaic System. The total components and 
subsystems that, in combination, convert solar energy into 
electric energy suitable for connection to a utilization load. 

Special Permission. The written consent of the authority 
having jurisdiction. 

Structure. That which is built or constructed. 

Supplementary Overcurrent Protective Device. A device 
intended to provide limited overcurrent protection for 
specific applications and utilization equipment such as 
luminaires and appliances. This limited protection is in 
addition to the protection provided in the required branch 
circuit by the branch circuit overcurrent protective device. 

Surge Arrester* A prqtecSve device fo^ 
voltages by discharging or bypassing surge current; it also 
l>revents continued flow of follow current wMlerema^^^^ 
capable of repeating tiiese functions.; 

Surge-Protective Device (SPD)* A protective device fot 
limiting transient voltages by divertmg or limiting sur^^ 
current; it also prevents continued flow of follow cnrrenti 
while remaining capable of repeating these fimctions and J^ 
designated as follows: 

Type 1: Permanently connected SPDs intended Jd 
installation between the secondary of the service; 
transformer and the line side of the service disconnect 
overcurrent device. 



Ty;^p^J.l^^QtmmtM^ jntended |ot 

installatiotL,i?^. , ii^ ^^M^j}^.,^^, '^^APV^i^^ ''Ay?^99V^^i 

bvercun:e^t_ deyice,^ inc|udiag^SPD^§ Jocate^ tli?.bl^[^K 

panel; 

Type 3: Point of ftlFzationSPDs] 

„ _ £??? "- i*.-~~,!?^W^Mi-^SIS-^ ..5^^lldmg^_ discrete! 
bpinponentSj as well as IssemWiesJ 

FFN:',Fpr Slither infopnatiqfi;on Typ^, ,1, T>^e 2,; Type 3J 

'Protective Devices. 

Switch, Bypass Isolation. A manually operated device 
used in conjunction with a transfer switch to provide a 
means of directly connecting load conductors to a power 
source and of disconnecting the transfer switch. 

Switch, General-Use. A switch intended for use in 
general distribution and branch circuits. It is rated in 
amperes, and it is capable of interrupting its rated current at 
its rated voltage. 

Switch, General-Use Snap. A form of general-use switch 
constructed so that it can be installed in device boxes or on 
box covers, or otherwise used in conjunction with wiring 
systems recognized by this Code. 

Switch, Isolating. A switch intended for isolating an 
electrical circuit from the source of power. It has no 
interrupting rating, and it is intended to be operated only 
after the circuit has been opened by some other means. 

Switch, Motor-Circuit. A switch rated in horsepower that 
is capable of interrupting the maximum operating overload 
current of a motor of the same horsepower rating as the 
switch at the rated voltage. 

Switch, Transfer. An automatic or nonautomatic device 
for transferring one or more load conductor connections 
from one power source to another. 

Switchboard. A large single panel, frame, or assembly of 
panels on which are mounted on the face, back, or both, 
switches, overcurrent and other protective devices, buses, 
and usually instruments. Switchboards are generally 
accessible from the rear as well as from the front and are 
not intended to be installed in cabinets. 

Thermally Protected (as applied to motors). The words 
Thermally Protected appearing on the nameplate of a motor 
or motor-compressor indicate that the motor is provided 
with a thermal protector. 

Thermal Protector (as applied to motors). A protective 
device for assembly as an integral part of a motor or motor- 
compressor that, when properly applied, protects the motor 
against dangerous overheating due to overload and failure 
to start. 



• 



70-30 



2010 California Electrical Code 



ARTICLE 100 - DEFINITIONS 



CHAPTER 1 



FPN: The thermal protector may consist of one or more 
sensing elements integral with the motor or motor- 
compressor and an external control device. 



jbo&y thai :€^xtettds tlie p'oimd cbm^otioil 



^ki^^^ehyerpoyimttQ the utilityJ 

Utilization Equipment. Equipment that utilizes electric 
energy for electronic, electromechanical, chemical, heating, 
lighting, or similar purposes. 

Ventilated. Provided with a means to permit circulation of 
air sufficient to remove an excess of heat, fumes, or vapors. 

Volatile Flammable Liquid. A flammable liquid having a 
flash point below 38°C (100°F), or a flammable liquid 
whose temperature is above its flash point, or a Class II 
combustible liquid that has a vapor pressure not exceeding 
276 kPa (40 psia) at 38°C (100°F) and whose temperature 
is above its flash point. 

Voltage (of a circuit). The greatest root-mean-square 
(rms) (effective) difference of potential between any two 
conductors of the circuit concerned. 

FPN: Some systems, such as 3 -phase 4-wire, single-phase 
3-wire, and 3 -wire direct current, may have various circuits 
of various voltages. 

Voltage, Nominal. A nominal value assigned to a circuit 
or system for the purpose of conveniently designating its 
voltage class (e.g., 120/240 volts, 480Y/277 volts, 600 
volts). The actual voltage at which a circuit operates can 
vary from the nominal within a range that permits 
satisfactory operation of equipment. 

FPN: See ANSI C84. 1-2006, Voltage Ratings for Electric 
Power Systems and Equipment (60 Hz), 

Voltage to Ground. For grounded circuits, the voltage 
between the given conductor and that point or conductor of 
the circuit that is grounded; for ungrounded circuits, the 
greatest voltage between the given conductor and any other 
conductor of the circuit. 

Watertight. Constructed so that moisture will not enter 
the enclosure under specified test conditions. 

Weatherproof. Constructed or protected so that exposure 
to the weather will not interfere with successful operation. 

FPN: Rainproof, raintight, or watertight equipment can 
fulfill the requirements for weatherproof where varying 
weather conditions other than wetness, such as snow, ice, 
dust, or temperature extremes, are not a factor. 



II. Over 600 Volts, Nominal 

Whereas the preceding definitions are intended to apply 
wherever the terms are used throughout this Code, the 
following definitions are applicable only to parts of the 
article specifically covering installations and equipment 
operating at over 600 volts, nominal. 

Electronically Actuated Fuse, An overcurrent protective 
device that generally consists of a control module that 
provides current sensing, electronically derived time- 
current characteristics, energy to initiate tripping, and an 
interrupting module that interrupts current when an 
overcurrent occurs. Electronically actuated fuses may or 
may not operate in a current-limiting fashion, depending on 
the type of control selected. 

Fuse. An overcurrent protective device with a circuit- 
opening fusible part that is heated and severed by the 
passage of overcurrent through it. 

FPN: A fuse comprises all the parts that form a unit capable 
of performing the prescribed functions. It may or may not 
be the complete device necessary to connect it into an 
electrical circuit. 

Controlled Vented Power Fuse. A fuse with provision for 
controlling discharge circuit interruption such that no solid 
material may be exhausted into the surrounding atmosphere. 

FPN: The fiise is designed so that discharged gases will not 
ignite or damage insulation in the path of the discharge or 
propagate a flashover to or between grounded members or 
conduction members in the path of the discharge where the 
distance between the vent and such insulation or conduction 
members conforms to manufacturer's recommendations. 

Expulsion Fuse Unit (Expulsion Fuse). A vented fuse unit 
in which the expulsion effect of gases produced by the arc 
and lining of the fuseholder, either alone or aided by a 
spring, extinguishes the arc. 

Nonvented Power Fuse. A fuse without intentional 
provision for the escape of arc gases, liquids, or solid 
particles to the atmosphere during circuit interruption. 

Power Fuse Unit. A vented, nonvented, or controlled 
vented fuse unit in which the arc is extinguished by being 
drawn through solid material, granular material, or liquid, 
either alone or aided by a spring. 

Vented Power Fuse. A fuse with provision for the escape of 
arc gases, liquids, or solid particles to the surrounding 
atmosphere during circuit interruption. 



2010 California Electrical Code 



70-31 



110.1 



ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS 



Multiple Fuse. An assembly of two or more single-pole 

fuses. 

Switching Device. A device designed to close, open, or 
both, one or more electrical circuits. 

Circuit Breaker, A switching device capable of making, 
carrying, and interrupting currents under normal circuit 
conditions, and also of making, carrying for a specified time, 
and interrupting currents under specified abnormal circuit 
conditions, such as those of short circuit. 

Cutout. An assembly of a fuse support with either a 
fuseholder, fuse carrier, or disconnecting blade. The 
fUseholder or fuse carrier may include a conducting element 
(fuse link) or may act as the disconnecting blade by the 
inclusion of a nonfusible member. 

Disconnecting Means. A device, group of devices, or other 
means whereby the conductors of a circuit can be 
disconnected from their source of supply. 

Disconnecting (or Isolating) Switch (Disconnector, Isolator), 
A mechanical switching device used for isolating a circuit or 
equipment from a source of power. 

Interrupter Switch. A switch capable of making, carrying, 
and interrupting specified currents. 

Oil Cutout (Oil-Filled Cutout). A cutout in which all or part 
of the fuse support and its fuse link or disconnecting blade is 
mounted in oil with complete immersion of the contacts and 
the fusible portion of the conducting element (fuse link) so 
that arc interruption by severing of the fuse link or by 
opening of the contacts will occur under oil. 

Oil Switch. A switch having contacts that operate under oil 
(or askarel or other suitable liquid). 

Regulator Bypass Switch. A specific device or combination 
of devices designed to bypass a regulator. 



Requireiiieii4^$ for pectrical ItistaUatioiis 



I. General 

11 0.1 Scope. This article covers general requirements for 
the examination and approval, installation and use, access 
to and spaces about electrical conductors and equipment; 
enclosures intended for personnel entry; and tunnel 
installations. 

110.2 Approval. The conductors and equipment required or 
permitted by this Code shall be acceptable only if approved. 

C [OSHPD 1, 2, 3 dt 4] Equipment shall be approvable if it is 
A listed, labeled or certified for its use by a Nationally 
C Recognized Testing Laboratory (NRTL) as recognized by the 



U.S. Department of Labor, Occupational Safety and Health 
Administration. 

FPN: See 90.7, Examination of Equipment for Safety, and 
110.3, Examination, Identification, Installation, and Use of 
Equipment. See definitions of Approved, Identified, Labeled, 
and Listed. 

110.3 Examination, Identification, Installation, and Use 
of Equipment 

(A) Examination. In judging equipment, considerations 
such as the following shall be evaluated: 

(1) Suitability for installation and use in conformity with the 
provisions of this Code 

FPN: Suitability of equipment use may be identified by a 
description marked on or provided with a product to identify 
the suitability of the product for a specific purpose, 
environment, or application. Suitability of equipment may be 
evidenced by listing or labeling. 

(2) Mechanical strength and durability, including, for parts 

designed to enclose and protect other equipment, the 
adequacy of the protection thus provided 

(3) Wire-bending and connection space 

(4) Electrical insulation 

(5) Heating effects under normal conditions of use and also 
under abnormal conditions likely to arise in service 

(6) Arcing effects 

(7) Classification by type, size, voltage, current capacity, and 

specific use 

(8) Other factors that contribute to the practical safeguarding 

of persons using or likely to come in contact with the 
equipment 

(B) Installation and Use. Listed or labeled equipment shall be 

installed and used in accordance with any instructions 
included in the hsting or labeling. 

110.4 Voltages. Throughout this Code, the voltage 
considered shall be that at which the circuit operates. The 
voltage rating of electrical equipment shall not be less than the 
nominal voltage of a circuit to which it is connected. 

110.5 Conductors. Conductors normally used to carry 
current shall be of copper unless otherwise provided in this 
Code. Where the conductor material is not specified, the 
material and the sizes given in this Code shall apply to copper 
conductors. Where other materials are used, the size shall be 
changed accordingly. 

FPN: For aluminum and copper-clad aluminum conductors, see 
310.15. 

110.6 Conductor Sizes. Conductor sizes are expressed in 
American Wire Gage (AWG) or in circular mils. 

110.7 Wtefiif Integrity. Completed wiring installations shall be 



G 
A 



70-32 



2010 California Electrical Code 



ARTICLE 1 10 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS 



110.14 



free from short circuits, grogSl^jfeS^^ 

110.8 Wiring Methods. Only wiring methods recognized as 
suitable are included in this Code. The recognized methods of 
wiring shall be permitted to be installed in any type of 
building or occupancy, except as otherwise provided in this 
Code. 

110.9 Interrupting Rating. Equipment intended to interrupt 
current at fault levels shall have an interrupting rating 
sufficient for the nominal circuit voltage and the current that is 
available at the line terminals of the equipment. 

Equipment intended to interrupt current at other than fault 
levels shall have an interrupting rating at nominal circuit 
voltage sufficient for the current that must be interrupted. 

110.10 Circuit Impedance and Other Characteristics. The 

overcurrent protective devices, the total impedance, the 
component short-circuit current ratings, and other 
characteristics of the circuit to be protected shall be selected 
and coordinated to permit the circuit-protective devices used 
to clear a fauh to do so without extensive damage to the 
electrical components of the circuit. This fault shall be 
assumed to be either between two or more of the circuit 
conductors or between any circuit conductor and the 
grounding conductor or enclosing metal raceway. Listed 
products applied in accordance with their listing shall be 
considered to meet the requirements of this section. 

110.11 Deteriorating Agents. Unless identified for use in the 
operating environment, no conductors or equipment shall be 
located in damp or wet locations; where exposed to gases, 
fiimes, vapors, liquids, or other agents that have a deteriorating 
effect on the conductors or equipment; or where exposed to 
excessive temperatures. 

FPN No. 1 ; See 300.6 for protection against corrosion. 

FPN No. 2: Some cleaning and lubricating compounds can 
cause severe deterioration of many plastic materials used for 
insulating and structural applications in equipment. 

Eqxaipment bot identified for oiit4obru>e^a^^ 

idimM^^i&y !& indop^^ iise,; sucfi a$;"te h^9^^'L''3^<>M 

^^]QA^M&tAh shall be protected against permanent damage 
firom the weather during building construction. 



FPN: Accepted industry practices are described in 
ANSI/NECA l#06i', Standard Practices for Good 
Workmanship in Electrical Contracting, and other ANSI- 
approved installation standards. 

(A) Unused Openings. Unused op^M^j ote 

totetided fot the bpemticm of ^Uipmepj fli^^ fox 

'^^^X.^^^¥^M!^^ shall be closed to afford protection 
substantially equivalent to the wall of the equipment. Where 
metallic plugs or plates are used with nonmetallic enclosures, 
they shall be recessed at least 6 mm (Va in.) from the outer 
surface of the enclosure. 



(B) Integrity of Electrical Equipment and Connections. 

Internal parts of electrical equipment, including busbars, 
wiring terminals, insulators, and other surfaces, shall not be 
damaged or contaminated by foreign materials such as paint, 
plaster, cleaners, abrasives, or corrosive residues. There shall 
be no damaged parts that may adversely affect safe operation 
or mechanical strength of the equipment such as parts that are 
broken; bent; cut; or/ deteriorated by corrosion, chemical 
action, or overheating. 

110.13 Mounting and Cooling of Equipment. 

(A) Mounting. Electrical equipment shall be frnnly secured to 
the surface on which it is mounted. Wooden plugs driven into 
holes in masonry, concrete, plaster, or similar materials shall 
not be used. 

(B) Cooling. Electrical equipment that depends on the natural 
circulation of air and convection principles for cooling of 
exposed surfaces shall be installed so that room airflow over 
such surfaces is not prevented by walls or by adjacent installed 
equipment. For equipment designed for floor mounting, 
clearance between top surfaces and adjacent surfaces shall be 
provided to dissipate rising warm air. 

Electrical equipment provided with ventilating openings 
shall be installed so that walls or other obstructions do not 
prevent the free circulation of air through the equipment. 

(C) fOSHPD ly 2y 3 & 4] Hospitals. Electrical equipment C 
and its supporting structure installed in hospital buildings ^ 



shall be anchored and braced to withstand the lateral 



A 



110.12 Mechanical Execution of Work. Electrical 
equipment shall be installed in a neat and workmanlike 
manner. 



forces, and shall accommodate calculated displacements as q 
required by Part 2, Title 24, C CR. A 

110.14 Electrical Connections. Because of different 
characteristics of dissimilar metals, devices such as pressure 
terminal or pressure splicing connectors and soldering lugs 
shall be identified for the material of the conductor and shall 
be properly installed and used. Conductors of dissimilar 



2010 California Electrical Code 



70-33 



110.15 



ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS 



metals shall not be intermixed in a terminal or splicing 
connector where physical contact occurs between dissimilar 
conductors (such as copper and aluminum, copper and 
copper-clad aluminum, or aluminum and copper-clad 
aluminum), unless the device is identified for the purpose 
and conditions of use. Materials such as solder, fluxes, 
inhibitors, and compounds, where employed, shall be 
suitable for the use and shall be of a type that will not 
adversely affect the conductors, installation, or equipment. 

FPN: Many terminations and equipment are marked with a 

tightening torque. 

(A) Terminals. Connection of conductors to terminal parts shall 
ensure a thoroughly good connection without damaging the 
conductors and shall be made by means of pressure connectors 
(including set-screw type), solder lugs, or splices to flexible 
leads. Connection by means of wire-binding screws or studs and 
nuts that have upturned lugs or the equivalent shall be permitted 
for 10 AWG or smaller conductors. 

Terminals for more than one conductor and terminals used 
to connect aluminum shall be so identified. 

(B) Splices. Conductors shall be spliced or joined with splicing 
devices identified for the use or by brazing, welding, or 
soldering with a fiisible metal or alloy. Soldered splices shall 
first be spliced or joined so as to be mechanically and 
electrically secure without solder and then be soldered. Ail 
spUces and joints and the free ends of conductors shall be 
covered with an insulation equivalent to that of the conductors 
or with an insulating device identified for the purpose. 

Wire connectors or splicing means installed on conductors 
for direct burial shall be hsted for such use. 

(C) Temperature Limitations. The temperature rating 
associated with the ampacity of a conductor shall be selected 
and coordinated so as not to exceed the lowest temperature 
rating of any connected termination, conductor, or device. 
Conductors with temperature ratings higher than specified for 
terminations shall be permitted to be used for ampacity 
adjustment, correction, or both. 

(1) Equipment Provisions. The determination of termination 
provisions of equipment shall be based on 110.14(C)(1)(a) or 
(C)(1)(b). Unless the equipment is listed and marked otherwise, 
conductor ampacities used in determining equipment 
termination provisions shall be based on Table 310.16 as 
appropriately modified by 3 1 0. 1 5(B)(6). 

(a) Termination provisions of equipment for circuits rated 
100 amperes or less, or marked for 14 AWG through 1 AWG 
conductors, shall be used only for one of the following: 

(1) Conductors rated 60°C(140°F). 

(2) Conductors with higher temperature ratings, provided the 

ampacity of such conductors is determined based on the 
60°C (140°F) ampacity of the conductor size used. 

(3) Conductors with higher temperature ratings if the equipment 

is listed and identified for use with such conductors. 

(4) For motors marked with design letters B, C, or D, 
conductors having an insulation rating of 75°C (167°F) 
or higher shall be permitted to be used, provided the 
ampacity of such conductors does not exceed the 75'^C 
(167°F) ampacity. 



(b) Termination provisions of equipment for circuits 
rated over 100 amperes, or marked for conductors larger 
than 1 AWG, shall be used only for one of the following: 

(1) Conductors rated 75 °C (167°F) 

(2) Conductors with higher temperature ratings, provided 
the ampacity of such conductors does not exceed the 
75°C (167°F) ampacity of the conductor size used, or 
up to their ampacity if the equipment is listed and 
identified for use with such conductors 

(2) Separate Connector Provisions. Separately installed 
pressure connectors shall be used with conductors at the 
ampacities not exceeding the ampacity at the listed and 
identified temperature rating of the connector. 

FPN: With respect to 110.14(C)(1) and (C)(2), equipment 
markings or listing information may additionally restrict the 
sizing and temperature ratings of connected conductors. 

110.15 Higii-Leg Marking. On a 4-wire, delta-connected 
system where the midpoint of one phase winding is 
grounded, only the conductor or busbar having the higher 
phase voltage to ground shall be durably and permanently 
marked by an outer finish that is orange in color or by other 
effective means. Such identification shall be placed at each 
point on the system where a connection is made if the 
grounded conductor is also present. 

110.16 Flash Protection. EleclMcal equipment 
switchboards, panelboards, industrial control panels, meter 
socket enclosures, and motor control centers, that are in 
other than dwelling occupancies, and are likely to require 
examination, adjustment, servicing, or maintenance while 
energized shall be field marked to warn qualified persons 
of potential electric arc flash hazards. The marking shall be 
located so as to be clearly visible to qualified persons 
before examination, adjustment, servicing, or maintenance 
of the equipment. 

FPN No. 1 : NFPA 70E-2004, Standard for Electrical Safety 
in the Workplace, provides assistance in determining 
severity of potential exposure, planning safe work practices, 
and selecting personal protective equipment. 

FPN No. 2: ANSI Z535.4-1998, Product Safety Signs and 
Labels, provides guidelines for the design of safety signs 
and labels for application to products. 

110.18 Arcing Parts. Parts of electrical equipment that in 
ordinary operation produce arcs, sparks, flames, or molten 
metal shall be enclosed or separated and isolated from all 
combustible material. 

FPN: For hazardous (classified) locations, see Articles 500 
through 517. For motors, see 430.14. 

110.19 Liglit and Power from Railway Conductors. 

Circuits for lighting and power shall not be connected to 
any system that contains trolley wires with a ground return. 

Exception: Such circuit connections shall be permitted in 
car houses, power houses, or passenger and freight 
stations operated in connection with electric railways. 



70-34 



2010 California Electrical Code 



ARTICLE no - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS 



110.21 















110,21 Marking. The manufacturer's name, trademark, or 
other descriptive marking by which the organization 
responsible for the product can be identified shall be placed 
on all electrical equipment. Other markings that indicate 
voltage, current, wattage, or other ratings shall be provided 
as specified elsewhere in this Code. The marking shall be of 
sufficient durability to withstand the environment involved. 



Table 110.20 Enclosure Selection 



Provides a Degree of Protection Against 
the Following Environmental Conditions 












For Outdoor Use 


















Enclosure-Type Number 










3 




3R 


3S 


3X 


3RX 


3SX 


4 


4X 


6 


6P 


Incidental contact with the enclosed 
equipment 


X 




X 


X 


X 


X 


X 


X 


X 


X 


X 


Rain, snow, and sleet 


X 




X 


X 


X 


X 


X 


X 


X 


X 


X 


Sleet* 


— 




— 


X 


-— 


— 


X 


— 


— 


— 


— 


Windblown dust 


X 




— 


X 


X 


— 


X 


X 


X 


X 


X 


Hosedown 


— 




— 


— 


— 


— 


— 


X 


X 


X 


X 


Corrosive agents 


— 




— 


— 


X 


X 


X 


— 


X 


— 


X 


Temporary submersion 


— 




— 


— 


~ 


— 


— 


— 


— 


X 


X 


Prolonged submersion 


— 




— 


— 


— 


— 


— 


— 


— 


— 


X 


Provides a Degree of Protection Against 
the Following Environmental Conditions 












For Indoor Use 


















Enclosure Type Number 










1 




2 


4 


4X 


5 


6 


6P 


12 


12K 


13 


Incidental contact with the enclosed 
equipment 


X 




X 


X 


X 


X 


X 


X 


X 


X 


X 


Falling dirt 


X 




X 


X 


X 


X 


X 


X 


X 


X 


X 


Falling liquids and light splashing 


— 




X 


X 


X 


X 


X 


X 


X 


X 


X 


Circulating dust, lint, fibers, and flyings 


— 




— 


X 


X 


— 


X 


X 


X 


X 


X 


Settling airborne dust, lint, fibers, and 
flyings 


— 




— 


X 


X 


X 


X 


X 


X 


X 


X 


Hosedown and splashing water 


— 




— 


X 


X 


— 


X 


X 


— 


— 


— 


Oil and coolant seepage 


— 




— 


— 


— 


— 


— 


— 


X 


X 


X 


Oil or coolant spraying and splashing 


— 




— 


— 


— 


— 


— 


— 


— 


— 


X 


Corrosive agents 


— 




— 


— 


X 


— 


-- 


X 


— 


— 


— 


Temporary submersion 


— 




— 


— 


— 


— 


X 


X 


— 


— 


— 


Prolonged submersion 


— 




— 


— 


— 


— 


— 


X 


— 


— 


— 


♦Mechanism shall be operable when ice covered. 






















FPN: The term raintight is typically used in conjunction with Enclosure Types 3, 3S, 3SX, 3X, 4, 4X, 6, and 6P. The term rainproof is 
typically used in conjunction with Enclosure Types 3R, and 3RX. The term watertight is typically used in conjunction with Enclosure 
Types 4, 4X, 6, 6P. The term driptight is typically used in conjunction with Enclosure Types 2, 5, 12, 12K, and 13. The term dusttight is 
typically used in conjunction with Enclosure Types 3, 3S, 3SX, 3X, 5, 12, 12K, and 13. 



2010 California Electrical Code 



70-35 



110.22 



ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS 



110.22 Identification of Disconnecting Means. 

(A) GeneraL Each disconnecting means shall be legibly 
marked to indicate its purpose unless located and arranged 
so the purpose is evident. The marking shall be of 
sufficient durability to withstand the environment involved. 

(B) Engineered Series Combiiialdan Sysfems/ Where; 
circuit breakers or fuses are applied in coniplianc^ witH 
relies :combinrtion iratings selected vmder engineering 
isupervision ; and marked : on the equipment as directed h^i 
the engineer, the equipnient enclbsure(s) shall be legibly 
marked in the field to indicate tteeqiiipin^nt has H^^^^ 
applied with a series combiiiaddii ratmg;=Th;elM^i1d 

be readily visible and state; tlie follo^dng: 

CAimoN. ■■ :''™-''~- -■■■^■iNGiMlMo'^ 

CQMBiNATIDN SYSTEM RAXED AMPERES^ 

identified ; replacement l^omponejnts 
requiMdI 

FPN: 'See '24d.86(A)^,fet;i^^ngme^ 
systems, 

(C) Tested , Series Coinbihatto^ Where circuit 
breakers or fuses are applied in compliance with the series 
combination ratings marked on the equipment by the 
manufacturer, the equipment enclosure(s) shall be legibly 
marked in the field to indicate the equipment has been 
applied with a series combination rating. The marking shall 
be readily visible and state the following: 

CAUTION — SERIES COMBINATION SYSTEM 

RATED AMPERES. IDENTIFIED 

REPLACEMENT COMPONENTS REQUIRED. 
FPN: See 240.86(B) for fested seriesxomto 

110.23 Current Transformers. Unused current 
transformers associated with potentially energized circuits 
shall be short-circuited. 

II. 600 Volts, Nominal, or Less 

110.26 Spaces About Electrical Equipment. Sufficient 
access and working space shall be provided and maintained 
about all electrical equipment to permit ready and safe 
operation and maintenance of such equipment. 

(A) Working Space. Working space for equipment 
operating at 600 volts, nominal, or less to ground and likely 
to require examination, adjustment, servicing, or 
maintenance while energized shall comply with the 
dimensions of 110.26(A)(1), (A)(2), and (A)(3) or as 
required or permitted elsewhere in this Code, 

(1) Depth of Working Space. The depth of the working 
space in the direction of live parts shall not be less than that 
specified in Table 110.26(A)(1) unless the requirements of 
110.26(A)(1)(a), (A)(1)(b), or (A)(1)(c) are met. Distances 
shall be measured from the exposed live parts or from the 
enclosure or opening if the live parts are enclosed. 



Table 110.26(A)(1) Working Spaces 





Minimum Clear Distance 


Nominal 

Voltage to 

Ground 


Condition 1 Condition 2 Condition 3 


0-150 
151-600 


:9:M mm (3 ft) W4 mm (3 ft) Wi mm (3 ft) 
|l4mm(3ft) |:^m(3ft6in.) I22m(4ft) 



Note: Where the conditions are as follows: 
Condition 1 — Exposed live parts on one side of the working 
space and no live or grounded parts on the other side of the 
working space, or exposed live parts on both sides of the working 
space that are effectively guarded by insulating materials. 
Condition 2 — Exposed live parts on one side of the working 
space and grounded parts on the other side of the working space. 
Concrete, brick, or tile walls shall be considered as grounded. 
Condition 3 — Exposed live parts on both sides of the working 
space. 

(a) Dead-Front Assemblies. Working space shall not be 
required in the back or sides of assemblies, such as dead-front 
switchboards or motor control centers, where all connections 
and all renewable or adjustable parts, such as fuses or switches, 
are accessible from locations other than the back or sides. 
Where rear access is required to work on nonelectrical parts on 
the back of enclosed equipment, a minimum horizontal working 
space of 762 mm (30 in.) shall be provided. 

(b) Low Voltage. By special permission, smaller 
working spaces shall be permitted where all exposed live 
parts operate at not greater than 30 volts rms, 42 volts peak, 
or 60 volts dc. 

(c) Existing Buildings. In existing buildings where 
electrical equipment is being replaced. Condition 2 
working clearance shall be permitted between dead-front 
switchboards, panelboards, or motor control centers located 
across the aisle from each other where conditions of 
maintenance and supervision ensure that written procedures 
have been adopted to prohibh equipment on both sides of 
the aisle from being open at the same time and qualified 
persons who are authorized will service the installation. 

(2) Width of Working Space. The width of the working 
space in front of the electrical equipment shall be the width 
of the equipment or |j6l mm (30 in.), whichever is greater. 
In all cases, the work space shall permit at least a 90 degree 
opening of equipment doors or hinged panels. 

(3) Height of Working Space. The work space shall be clear 
and extend from the grade, floor, or platform to the height 
required by 110.26(E). Within the height requirements of this 
section, other equipment that is associated with the electrical 
installation and is located above or below the electrical 
equipment shall be permitted to extend not more than 150 mm 
(6 in.) beyond the front of the electrical equipment. 

(B) Clear Spaces. Working space required by this section 
shall not be used for storage. When normally enclosed live 
parts are exposed for inspection or servicing, the working 
space, if in a passageway or general open space, shall be 
suitably guarded. 



70-36 



20 1 California Electrical Code 



ARTICLE 1 10 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS 



110.26 



(C) Entrance to ind Egifieflfroilj Working Space. 

(1) Minimum Required. At least one entrance of 
sufficient area shall be provided to give access to ffitj 
|e^#e'ss;fr$iq working space about electrical equipment. 

(2) Large EqmgmentJ^ rated 1200 amperes 
or more SgJOTer::3tg:^=^^^ that contains 
overcurrent devices, switching devices^or control devices, 
there shall be one entrance to ind ;0ff<^ss|fe the required 
working space not less than 610 mm (24 in.) wide and 2.0 
m (6V2 ft) high at each end of the working space. 

A single entrance to gS^igress Jfroimi the required 
working space shall be permitted where either of the 
conditions in 1 10.26(C)(2)(a) or (C)(2)(b) is met. 

(a) Unobstructed Egress. WhevQ the location permits a 
continuous and unobstructed way of iep^ssj travel, a single 
entrance to the working space shall be permitted. 

(b) Extra Working Space. Where the depth of the working 
space is twice that required by 110.26(A)(1), a single entrance 
shall be permitted. It shall be located such that the distance from 
the equipment to the nearest edge of the entrance is not less than 
the minimum clear distance specified in Table 1 10.26(A)(1) for 
equipment operating at that voltage and in that condition. 

i:3)[:r/PW|omiei; 'ipi^^^^ 

mote that contiM ^Witching! devices, oi 

oonprp\Myic€^:miM^ is a ;pers<>imerdpor(s) 

^n^rided for;eiite to atid: egress, ^oinJtheJwbfkiagspa^^^ 
less than 17.6; m (25;fl:); firpm the nearest edge of the working- 



feat ar^ ijprmally latched but open under Simple pressureJ 

(D) Illumination. Illumination shall be provided for all 

working spaces about service equipment, switchboards, 
panelboards, or motor control centers installed indoors. 
Additional lighting outlets shall not be required where the 
work space is illuminated by an adjacent light source or as 
permitted by 210.70(A)(1), Exception No. I, for switched 
receptacles. In electrical equipment rooms, the illumination 
shall not be controlled by automatic means only. 

(E) Headroom. The minimum headroom of working 
spaces about service equipment, switchboards, 
panelboards, or motor control centers shall be 2.0 m (6V2 
ft). Where the electrical equipment exceeds 2.0 m (6V2 ft) 
in height, the minimum headroom shall not be less than the 
height of the equipment. 

Exception: In existing dwelling units, service equipment or 
panelboards that do not exceed 200 amperes shall be 
permitted in spaces where the headroom is less than 2.0 m 
(6'Aft). 

(F) Dedicated Equipment Space. All switchboards, 
panelboards, distribution boards, and motor control centers 
shall be located in dedicated spaces and protected from 
damage. 



Exception: Control equipment that by its very nature or 
because of other rules of the Code must be adjacent to or 
within sight of its operating machinery shall be permitted 
in those locations. 

(1) Indoor. Indoor installations shall comply with 
1 10.26(F)(1)(a) through (F)(1)(d). 

(a) Dedicated Electrical Space. The space equal to the 
width and depth of the equipment and extending from the 
floor to a height of 1.8 m (6 ft) above the equipment or to 
the structural ceiling, whichever is lower, shall be 
dedicated to the electrical installation. No piping, ducts, 
leak protection apparatus, or other equipment foreign to the 
electrical installation shall be located in this zone. 

Exception: Suspended ceilings with removable panels 
shall be permitted within the 1.8-m (6-ft) zone. 

(b) Foreign Systems. The area above the dedicated 
space required by 110.26(F)(1)(a) shall be permitted to 
contain foreign systems, provided protection is installed to 
avoid damage to the electrical equipment from 
condensation, leaks, or breaks in such foreign systems. 

(c) Sprinkler Protection. Sprinkler protection shall be 
permitted for the dedicated space where the piping 
complies with this section. 

(d) Suspended Ceilings. A dropped, suspended, or 
similar ceiling that does not add strength to the building 
structure shall not be considered a structural ceiling. 

(2) Outdoor. Outdoor electrical equipment shall be 
installed in suitable enclosures and shall be protected from 
accidental contact by unauthorized personnel, or by 
vehicular traffic, or by accidental spillage or leakage from 
piping systems. The working clearance space shall include 
the zone described in 1 10.26(A). No architectural 
appurtenance or other equipment shall be located in this 
zone. 

p&)''iLocked lilecirtcaf iEqiiip or .Enclosures^ 

fel^trie^l equipment x^^ housing electrical 

^araWi^ ■ that; ; ^ei :cc«iiiix)lted ; : l^y a lock;(s) shall bd 

110.27 Guarding of Live Parts. 

(A) Live Parts Guarded Against Accidental Contact. 

Except as elsewhere required or permitted by this Code, 
live parts of electrical equipment operating at 50 volts or 
more shall be guarded against accidental contact by 
approved enclosures or by any of the following means: 

(1) By location in a room, vault, or similar enclosure that 
is accessible only to qualified persons. 

(2) By suitable permanent, substantial partitions or screens 
arranged so that only qualified persons have access to 
the space within reach of the live parts. Any openings 
in such partitions or screens shall be sized and located 
so that persons are not likely to come into accidental 



2010 California Electrical Code 



70™37 



110.27 



ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS 



contact with the live parts or to bring conducting 
objects into contact with them. 

(3) By location on a suitable balcony, gallery, or platform 
elevated and arranged so as to exclude unqualified 
persons. 

(4) By elevation of 2.5 m (8 ft) or more above the floor or 
other working surface. 

(B) Prevent Physical Damage. In locations where 
electrical equipment is likely to be exposed to physical 
damage, enclosures or guards shall be so arranged and of 
such strength as to prevent such damage. 

(C) Warning Signs. Entrances to rooms and other guarded 
locations that contain exposed live parts shall be marked 
with conspicuous warning signs forbidding unqualified 
persons to enter. 

FPN: For motors, see 430.232 and 430.233. For over 600 
volts, see 110.34. 



III. Over 600 Volts, Nominal 

110.30 General. Conductors and equipment used on 
circuits over 600 volts, nominal, shall comply with Part I of 
this article and with 110,30 through 110.40, which 
supplement or modify Part I. In no case shall the provisions 
of this part apply to equipment on the supply side of the 
service point. 

110.31 Enclosure for Electrical Installations. Electrical 
installations in a vault, room, or closet or in an area 
surrounded by a wall, screen, or fence, access to which is 
controlled by a lock(s) or other approved means, shall be 
considered to be accessible to qualified persons only. The 
type of enclosure used in a given case shall be designed 
and constructed according to the nature and degree of the 
hazard(s) associated with the installation. 

For installations other than equipment as described in 
1 10.31(D), a wall, screen, or fence shall be used to enclose 
an outdoor electrical installation to deter access by persons 
who are not qualified, or a combination of 1.8 m (6 ft) or 
more of fence fabric and a 300-mm (1-ft) or more 
extension utilizing three or more strands of barbed wire or 
equivalent. The distance from the fence to live parts shall 
be not less than given in Table 1 10.3 1 . 



Table 110.31 Minimum Distance from Fence to Live Parts 



Nominal Voltage 



Minimum Distance to Live Parts 



ft 



601-13,799 


3.05 


10 


13,800-230,000 


4.57 


15 


Over 230,000 


5.49 


18 



Note: For clearances of conductors for specific system voltages 
and typical BIL ratings, see ANSI C2-2007, National Electrical 
Safety Code. 

FPN: See Article 450 for construction requirements for 
transformer vaults. 

(A) Fire Resiis^iied of Electrical Vaults. The walls, roof, 
floors, and doorways of vaults containing conductors and 
equipment over 600 volts, nominal, shall be constructed of 
materials that have adequate structural strength for the 
conditions, with a minimum fire rating of 3 hours. 

For the purpose of this section, studs and wallboards shall 
not be considered acceptable. 

(B) Indoor Installations. 

(1) In Places Accessible to Unqualified Persons. Indoor 
electrical installations that are accessible to unqualified 
persons shall be made with metal-enclosed equipment. 
Metal-enclosed switchgear, unit substations, transformers, 
pull boxes, connection boxes, and other similar associated 
equipment shall be marked with appropriate caution signs. 
Openings in ventilated dry-type transformers or similar 
openings in other equipment shall be designed so that 
foreign objects inserted through these openings are 
deflected from energized parts. 

(2) In Places Accessible to Qualified Persons Only. 

Indoor electrical installations considered accessible only to 
qualified persons in accordance with this section shall 
comply with 1 10.34, 1 10.36, and 490.24. 

(C) Outdoor Installations. 

(1) In Places Accessible to Unqualified Persons. 

Outdoor electrical installations that are open to unqualified 
persons shall comply with Parts I, II, and III of Article 225. 



(2) In Places Accessible to Qualified Persons Only. 

Outdoor electrical installations that have exposed live parts 
shall be accessible to qualified persons only in accordance 
with the first paragraph of this section and shall comply 
with 110.34, 110.36, and 490.24. 



70-38 



2010 California Electrical Code 



ARTICLE 1 10 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS 



110.34 



(D) Enclosed Equipment Accessible to Unqualified 
Persons. Ventilating or similar openings in equipment 
shall be designed such that foreign objects inserted through 
these openings are deflected from energized parts. Where 
exposed to physical damage from vehicular traffic, suitable 
guards shall be provided. Nonmetallic or metal-enclosed 
equipment located outdoors and accessible to the general 
public shall be designed such that exposed nuts or bolts 
cannot be readily removed, permitting access to live parts. 
Where nonmetallic or metal-enclosed equipment is 
accessible to the general public and the bottom of the 
enclosure is less than 2.5 m (8 ft) above the floor or grade 
level, the enclosure door or hinged cover shall be kept 
locked. Doors and covers of enclosures used solely as pull 
boxes, splice boxes, or junction boxes shall be locked, 
bolted, or screwed on. Underground box covers that weigh 
over 45.4 kg (100 lb) shall be considered as meeting this 
requirement. 

110.32 Work Space About Equipment. Sufficient space 
shall be provided and maintained about electrical 
equipment to permit ready and safe operation and 
maintenance of such equipment. Where energized parts are 
exposed, the minimum clear work space shall be not less 
than 2.0 m (6V2 ft) high (measured vertically from the floor 
or platform) or not less than 9|3 mm (3 ft) wide (measured 
parallel to the equipment). The depth shall be as required in 
1 10.34(A). In all cases, the work space shall permit at least 
a 90 degree opening of doors or hinged panels. 



11033 Entrance p Enclosuresl and Access to WoiMtg Space. 

(A) Entrance. At least one entrance to eiiqiqswes f4^ 
?l??!ri<^§I|s?^?il§*i<>^^^ ^ d^^^ribed in 1 103| 

(1) Large Equipment. On switchboard and control panels 
exceeding 1.8 m (6 ft) in width, there shall be one entrance 
at each end of the equipment. A single entrance to the 
required working space shall be permitted where either of 
the conditions in 1 10.33(A)(1)(a) or (A)(1)(b) is met. 

(a) Unobstructed Exit. Where the location permits a 
continuous and unobstructed way of exit travel, a single 
entrance to the working space shall be permitted. 

(b) Extra Working Space. Where the depth of the working 
space is twice that required by 1 10.34(A), a single entrance shall 
be permitted. It shall be located so that the distance from the 
equipment to the nearest edge of the entrance is not less than the 
minimum clear distance specified in Table 110.34(A) for 
equipment operating at that voltage and in that condition. 

(2) Guarding. Where bare energized parts at any voltage 
or insulated energized parts above 600 vohs, nominal, to 
ground are located adjacent to such entrance, they shall be 
suitably guarded. 



(|>; ;:|ers6Mel;;P^or^^ ;W}iare ,th^re is;a:|>erspmerdooi;(s) 
mtm^^§\ for ~ ^nikmce. to '' ani egress , ftpm' Ihe :w6tMh^^ space 
fes jtHan tT^sSII.,^ .§9^: ^^ ^f^?,®?f.?dge;of ;thej w^ 
|pac4j|edop^|);^ 

l^m^ped wW^ 1^ tes^pres^ej plates, or other devites 
iMt £e nonmlJb^ Hohc^^^ opoi tmder shnple pres^urei^ 
(B) Access. Permanent ladders or stairways shall be 
provided to give safe access to the working space around 
electrical equipment installed on platforms, balconies, or 
mezzanine floors or in attic or roof rooms or spaces. 
110.34 Work Space and Guarding. 

(A) Worldng Space. Except as elsewhere required or 
permitted in this Code, Sqip^||it^{ jSj^^^^^^ 

la^gize^ ;sh§]^aye clear working space in the direction of 
access to live parts of ilia electrical equipment md shall be 
not less than specified in Table 110.34(A). Distances shall 
be measured fi-om the live parts, if such are exposed, or 
fi-om the enclosure firont or opening if such are enclosed. 

Exception: Working space shall not be required in back of 
equipment such as dead-front switchboards or control 
assemblies where there are no renewable or adjustable parts 
(such as fuses or switches) on the back and where all 
connections are accessible from locations other than the back. 

Table 110.34(A) Minimum Depth of Clear Working Space at 
Electrical Equipment 

Minimum Clear Distance 

Nominal Voltage 

to Ground Condition 1 Condition 2 Condition 3 

601-2500 V 900 mm (3 ft) 1 .2 m (4 ft) 1.5 m (5 ft) 
2501-9000 V 1.2 m (4 ft) 1.5 m (5 ft) 1.8 m (6 ft) 

9001-25,000 V 1.5 m (5 ft) 1.8 m (6 ft) 2.8 m (9 ft) 
25,001 V-75kV 1.8 m (6 ft) 2.5 m (8 ft) 3.0 m (10 ft) 
Above 75 kV 2.5 m (8 ft) 3.0 m (10 ft) 3.7 m (12 ft) 

Note: Where the conditions are as follows: 
Condition 1 — Exposed live parts on one side of the working 
space and no live or grounded parts on the other side of the 
working space, or exposed live parts on both sides of the working 
space that are effectively guarded by insulating materials. 
Condition 2 — Exposed live parts on one side of the working 
space and grounded parts on the other side of the working space. 
Concrete, brick, or tile walls shall be considered as grounded. 
Condition 3 — Exposed live parts on both sides of the working 
space. 

(B) Separation from Low-Voltage Equipment. Where 
sv^itches, cutouts, or other equipment operating at 600 
volts, nominal, or less are installed in a vault, room, or 
enclosure v^here there are exposed live parts or exposed 
wiring operating at over 600 vohs, nominal, the high- 
voltage equipment shall be effectively separated from the 
space occupied by the lov^-voltage equipment by a suitable 
partition, fence, or screen. 



2010 California Electrical Code 



70-39 



110.36 



ARTICLE 1 10 - REQUIREMENTS FOR ELCTRICAL INSTALLATIONS 



Exception: Switches or other equipment operating at 600 
volts, nominal, or less and serving only equipment within 
the high-voltage vault, room, or enclosure shall be 
permitted to be installed in the high-voltage vault, room, or 
enclosure without a partition, fence, or screen if accessible 
to qualified persons only. 

(C) Locked Rooms or Enclosures. The entrance to all 
buildings, vaults, rooms, or enclosures containing exposed 
live parts or exposed conductors operating at over 600 
volts, nominal, shall be kept locked unless such entrances 
are under the observation of a qualified person at all times. 

Where the voltage exceeds 600 volts, nominal, 
permanent and conspicuous warning signs shall be 
provided, reading as follows: 

DANGER — HIGH VOLTAGE — KEEP OUT 

(D) Illumination. Illumination shall be provided for all 
working spaces about electrical equipment. The lighting 
outlets shall be arranged so that persons changing lamps or 
making repairs on the lighting system are not endangered 
by live parts or other equipment. 

The points of control shall be located so that persons 
are not likely to come in contact with any live part or 
moving part of the equipment while turning on the lights. 

(E) Elevation of Unguarded Live Parts. Unguarded Hve 
parts above working space shall be maintained at elevations 
not less than required by Table 1 10.34(E). 



Table 110.34(E) Elevation of Unguarded Live Parts Above 
Working Space 



Elevation 


Nominal Voltage 
Between Phases 




m 


ft 


601-7500 V 




2.8 


9 


7501-35,000 V 




2.9 


9 ft 6 in. 


Over 35 kV 


2.9 


m + 9.5 mm/kV 
above 35 


9ft6in.+0.37 
in./kV above 35 



(F) Protection of Service Equipment, Metal-Enclosed 
Power Switchgear, and Industrial Control Assemblies. 

Pipes or ducts foreign to the electrical installation and 
requiring periodic maintenance or whose malfunction would 
endanger the operation of the electrical system shall not be 
located in the vicinity of the service equipment, metal- 
enclosed power switchgear, or mdustrial control assemblies. 
Protection shall be provided where necessary to avoid damage 
from condensation leaks and breaks in such foreign systems. 
Piping and other facilities shall not be considered foreign if 
provided for fire protection of the electrical installation. 

110.36 Circuit Conductors. Circuit conductors shall be 
permitted to be installed in raceways; in cable trays; as 
metal-clad cable, as bare wire, cable, and busbars; or as 



Type MV cables or conductors as provided in 300.37, 
300.39, 300.40, and 300.50. Bare live conductors shall 
comply with 490.24. 

Insulators, together with their mounting and conductor 
attachments, where used as supports for wires, single- 
conductor cables, or busbars, shall be capable of safely 
withstanding the maximum magnetic forces that would 
prevail if two or more conductors of a circuit were 
subjected to short-circuit current. 

Exposed runs of insulated wires and cables that have a 
bare lead sheath or a braided outer covering shall be 
supported in a manner designed to prevent physical damage 
to the braid or sheath. Supports for lead-covered cables 
shall be designed to prevent electrolysis of the sheath. 

110.40 Temperature Limitations at Terminations. 

Conductors shall be permitted to be terminated based on 
the 90°C (194°F) temperature rating and ampacity as 
given in Table 310.67 through Table 310.86, unless 
otherwise identified. 

IV. Tunnel Installations over 600 Volts, Nominal 

110.51 General. 

(A) Covered. The provisions of this part shall apply to the 
installation and use of high-voltage power distribution and 
utilization equipment that is portable, mobile, or both, such 
as substations, trailers, cars, mobile shovels, draglines, 
hoists, drills, dredges, compressors, pumps, conveyors, 
underground excavators, and the like. 

(B) Other Articles, The requirements of this part shall be 
additional to, or amendatory of, those prescribed in Articles 
100 through 490 of this Code. 

(C) Protection Against Physical Damage. Conductors and 
cables in tunnels shall be located above the tunnel floor and 
so placed or guarded to protect them from physical damage. 

110.52 Overcurrent Protection. Motor-operated 
equipment shall be protected from overcurrent in 
accordance with Parts III, IV, and V of Article 430. 
Transformers shall be protected from overcurrent in 
accordance with 450.3. 

110.53 Conductors. High- voltage conductors in tunnels 
shall be installed in metal conduit or other metal raceway, 
Type MC cable, or other approved multiconductor cable. 
Multiconductor portable cable shall be permitted to supply 
mobile equipment. 

110.54 Bonding and Equipment Grounding 
Conductors. 

(A) Grounded and Bonded. All non-current-carrying 
metal parts of electrical equipment and all metal raceways 
and cable sheaths shall be soiidl3^ grounded and bonded to 
all metal pipes and rails at the portal and at intervals not 
exceeding 300 m (1000 ft) throughout the tunnel. 



• 



70-40 



2010 California Electrical Code 



ARTICLE 1 10 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS 



110.72 



(B) Equipment Grounding Conductors. An equipment 
grounding conductor shall be run with circuit conductors 
inside the metal raceway or inside the multiconductor cable 
jacket. The equipment grounding conductor shall be 
permitted to be insulated or bare. 

110.55 Transformers, Switches, and Electrical 
Equipment. All transformers, switches, motor controllers, 
motors, rectifiers, and other equipment installed 
belowground shall be protected from physical damage by 
location or guarding. 

110.56 Energized Parts. Bare terminals of transformers, 
switches, motor controllers, and other equipment shall be 
enclosed to prevent accidental contact with energized parts. 

110.57 Ventilation System Controls. Electrical controls 
for the ventilation system shall be arranged so that the 
airflow can be reversed. 

110.58 Disconnecting Means. A switch or circuit breaker 
that simultaneously opens all ungrounded conductors of the 
circuit shall be installed within sight of each transformer or 
motor location for disconnecting the transformer or motor. 
The switch or circuit breaker for a transformer shall have 
an ampere rating not less than the ampacity of the 
transformer supply conductors. The switch or circuit 
breaker for a motor shall comply with the applicable 
requirements of Article 430. 

110.59 Enclosures. Enclosures for use in tunnels shall be 
dripproof, weatherproof, or submersible as required by the 
environmental conditions. Switch or contactor enclosures 
shall not be used as junction boxes or as raceways for 
conductors feeding through or tapping off to other 
switches, unless the enclosures comply with 312.8. 



V. Manholes and Other Electrical Enclosures Intended 
for Personnel Entry, All Voltages 

110.70 General. Electrical enclosures intended for 
personnel entry and specifically fabricated for this purpose 
shall be of sufficient size to provide safe work space about 
electrical equipment with live parts that is likely to require 
examination, adjustment, servicing, or maintenance while 
energized. Such enclosures shall have sufficient size to 
permit ready installation or withdrawal of the conductors 
employed without damage to the conductors or to their 
insulation. They shall comply with the provisions of this 
part. 



Exception: Where electrical enclosures covered by Part V 
of this article are part of an industrial wiring system 
operating under conditions of maintenance and supervision 
that ensure that only qualified persons monitor and 
supervise the system, they shall be permitted to be designed 
and installed in accordance with appropriate engineering 
practice. If required by the authority having jurisdiction, 
design documentation shall be provided. 

110.71 Strength. Manholes, vaults, and their means of 
access shall be designed under qualified engineering 
supervision and shall withstand all loads likely to be 
imposed on the structures. 

FPN: See ANSI C2-2007, National Electrical Safety Code, 
for additional information on the loading that can be 
expected to bear on underground enclosures. 

110.72 Cabling Work Space. A clear work space not less 
than 900 mm (3 ft) wide shall be provided where cables are 
located on both sides, and not less than 750 mm {IVi ft) 
where cables are only on one side. The vertical headroom 
shall be not less than 1.8 m (6 ft) unless the opening is 
within 300 mm (1 ft), measured horizontally, of the 
adjacent interior side wall of the enclosure. 

Exception: A manhole containing only one or more of the 
following shall be permitted to have one of the horizontal 
work space dimensions reduced to 600 mm (2 ft) where the 
other horizontal clear work space is increased so the sum 
of the two dimensions is not less than 1.8 m (6 ft): 

(1) Optical fiber cables as covered in Article 770 

(2) Power-limited fire alarm circuits supplied in 
accordance with 760lftii 

(3) Class 2 or Class 3 remote-control and signaling 
circuits, or both, supplied in accordance with 72^:121 

110.73 Equipment Work Space. Where electrical 
equipment with live parts that is likely to require 
examination, adjustment, servicing, or maintenance while 
energized is installed in a manhole, vault, or other 
enclosure designed for personnel access, the work space 
and associated requirements in 110.26 shall be met for 
installations operating at 600 volts or less. Where the 
installation is over 600 volts, the work space and associated 
requirements in 110.34 shall be met. A manhole access 
cover that weighs over 45 kg (100 lb) shall be considered 
as meeting the requirements of 1 10.34(C). 



2010 California Electrical Code 



70-41 



110.73 



ARTICLE 110- REQUIREMENTS FOR ELCTRICAL INSTALLATIONS 



110.74 Bending Space for Conductors. Bending space for 
conductors operating at 600 volts or below shall be provided 
in accordance with the requirements of 314.28. Conductors 
operating at over 600 volts shall be provided with bending 
space in accordance with 314.71(A) and 314.71(B), as 
applicable. All conductors shall be cabled, racked up, or 
arranged in an approved manner that provides ready and safe 
access for persons to enter for installation and maintenance. 

Exception: Where 314.71(B) applies, each row or column 
of ducts on one wall of the enclosure shall be calculated 
individually, and the single row or column that provides 
the maximum distance shall be used. 

110.75 Access to Manholes. 

(A) Dimensions. Rectangular access openings shall not be 
less than 650 mm x 550 mm (26 in. x 22 in.). Round access 
openings in a manhole shall be not less than 650 mm (26 
in.) in diameter. 

Exception: A manhole that has a fixed ladder that does not 
obstruct the opening or that contains only one or more of 
the following shall be permitted to reduce the minimum 
cover diameter to 600 mm (2 ft): 

(1) Optical fiber cables as covered in Article 770 

(2) Power-limited fire alarm circuits supplied in 
accordance with 760:l2l\ 

(3) Class 2 or Class 3 remote-control and signaling 
circuits, or both, supplied in accordance with '/25J2i 

(B) Obstructions. Manhole openings shall be free of 
protrusions that could injure personnel or prevent ready 
egress. 

(C) Location. Manhole openings for personnel shall be 
located where they are not directly above electrical equipment 
or conductors in the enclosure. Where this is not practicable, 
either a protective barrier or a fixed ladder shall be provided. 

(D) Covers. Covers shall be over 45 kg (100 lb) or 
otherwise designed to require the use of tools to open. They 
shall be designed or restrained so they cannot fall into the 
manhole or protrude sufficiently to contact electrical 
conductors or equipment within the manhole. 



(E) Marking. Manhole covers shall have an identifying 
mark or logo that prominently indicates their function, such 
as "electric." 

110.76 Access to Vaults and Tunnels. 

(A) Location. Access openings for personnel shall be 
located where they are not directly above electrical 
equipment or conductors in the enclosure. Other openings 
shall be permitted over equipment to facilitate installation, 
maintenance, or replacement of equipment. 

(B) Locks. In addition to compliance with the requirements 
of 1 10.34, if applicable, access openings for personnel shall 
be arranged such that a person on the inside can exit when 
the access door is locked from the outside, or in the case of 
normally locking by padlock, the locking arrangement shall 
be such that the padlock can be closed on the locking 
system to prevent locking from the outside. 

110.77 Ventilation. Where manholes, tunnels, and vaults 
have communicating openings into enclosed areas used by 
the public, ventilation to open air shall be provided 
wherever practicable. 

110.78 Guarding. Where conductors or equipment, or 
both, could be contacted by objects falling or being pushed 
through a ventilating grating, both conductors and live 
parts shall be protected in accordance with the 
requirements of 110.27(A)(2) or 110.31(B)(1), depending 
on the voltage, 

110.79 Fixed Ladders. Fixed ladders shall be corrosion resistant. 



70^2 



2010 California Electrical Code 



CHAPTER 2 CALIFORNIA MATRIX ADOPTION TABLE 



CHAPTER 2 - WIRING AND PROTECTION 



Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


DPH 


1 


2 


AC 


SS 


ss/cc 


1 


2 


3 


4 


Adopt Entire Chapter 


X 


X 


X 


X 




X 


X 




X 


X 


X 


X 


Adopt Entire Chapter as amended 
(amended sections listed below) 
















X 










Adopt only those articles / sections that 
are listed below 


























Article / Section 


210.50(D). (E) 
























X 


220 / Table 220.42 
















X 





































The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2. 



2010 California Electrical Code 



70-42.1 



CHAPTER 2 CALIFORNIA MATRIX ADOPTION TABLE 




The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2. 
'^^■^^'^ 2010 California Electrical Code 



ARTICLE 200 - USE AND IDENTIFICATION OF GROUNDED CONDUCTORS 



200.6 



Chapter 2 Wiring and Protection 



iJie and Idgntipeation 0f Grounded 



200.1 Scope. 

following: 



This article provides requirements for the 



(1) Identification of terminals 

(2) Grounded conductors in premises wiring systems 

(3) Identification of grounded conductors 

FPN: See Article 100 for definitions of Grounded 
Conductor and Grounding Conductor. 

200,2 General. All premises wiring systems, other than 
circuits and systems exempted or prohibited by 210.10, 
215.7, 250.21, 250.22, 250.162, 503.155, 517.63, 668.11, 
668.21, and 690.41, Exception, shall have a grounded 
conductor that is identified in accordance with 200.6. |p|^ 



^gr^dedtqadjacto^^ and (B). 

(S) JDttiul|ti0it. The grounded conductor, where insulated, 
shall have insulation that is (1) suitable, other than color, 
for any ungrounded conductor of the same circuit on 
circuits of less than 1000 volts or impedance grounded 
neutral systems of 1 kV and over, or (2) rated not less than 
600 volts for solidly grounded neutral systems of 1 kV and 
over as described in 250.184(A). 



(9) C^OT^»uity.;Tfe Qpntiiimty of a gi:0^hjded ooncluctoij 

shall"; laot &p^d: ^OB^a', <?'o^ 

200.3 Connection to Grounded System. Premises wiring 
shall not be electrically connected to a supply system 
unless the latter contains, for any grounded conductor of 
the interior system, a corresponding conductor that is 
grounded. For the purpose of this section, electrically 
connected shall mean connected so as to be capable of 
carrying current, as distinguished from connection through 
electromagnetic induction. 



Exception: tfytedmHUi^tr0^m^^ 

m^9m'\dMrikui)^d'\ rksomt^i ^^<^^mfion[ tsyMkini such ; as 

ph^iqv(:>ltdi0 anafiie-l c0]^pi^: s^iems:^ ^H^U \Q0^etfhiited 

h^h^tm wfi^re ' the [ (x^nmci^'jpr'em^^ '.W-^.^& W. V^'Wty^ 
■§yit0minplu<^l-agr0tmd^^^^ 

200.6 Means of Identifying Grounded Conductors. 

(A) Sizes 6 AWG or Smaller. An insulated grounded 
conductor of 6 AWG or smaller shall be identified by a 
continuous white or gray outer finish or by three 



continuous white stripes on other than green insulation 
along its entire length. Wires that have their outer covering 
finished to show a white or gray color but have colored 
tracer threads in the braid identifying the source of 
manufacture shall be considered as meeting the provisions 
of this section. Insulated grounded conductors shall also be 
permitted to be identified as follows: 

(1) The grounded conductor of a mineral-insulated, metal- 
sheathed cable shall be identified at the time of 
installation by distinctive marking at its terminations. 

(2) A single-conductor, sunlight-resistant, outdoor-rated 
cable used as a grounded conductor in photovoltaic 
power systems as permitted by 690.31 shall be 
identified at the time of installation by distinctive 
white marking at all terminations. 

(3) Fixture wire shall comply with the requirements for 
groxmded conductor identification as specified in 
402.8. 

(4) For aerial cable, the identification shall be as above, or 
by means of a ridge located on the exterior of the cable 
so as to identify it. 

(B) Sizes Larger Than 6 AWG. An insulated grounded 
conductor larger than 6 AWG shall be identified by one of 
the following means: 

(1) By a continuous white or gray outer finish. 

(2) By three continuous white stripes along its entire 
length on other than green insulation. 

(3) At the time of installation, by a distinctive white or 
gray marking at its terminations. This marking shall 
encircle the conductor or insulation. 

(C) Flexible Cords. An insulated conductor that is 
intended for use as a grounded conductor, where contained 
within a flexible cord, shall be identified by a white or gray 
outer finish or by methods permitted by 400.22. 

(D) Grounded Conductors of Different Systems. Where 

grounded conductors of different systems are installed in the 
same raceway, cable, box, auxiliary gutter, or other type of 
enclosure, each grounded conductor shall be identified by 
system. Identification that distinguishes each system grounded 
conductor shall be permitted by one of the following means: 

(1) One system grounded conductor shall have an outer 
covering conforming to 200,6(A) or (B). 

(2) The grounded conductor(s) of other systems shall have 
a different outer covering conforming to 200.6(A) or 
200.6(B) or by an outer covering of white or gray with 
a readily distinguishable colored stripe other than 
green running along the insulation. 



2010 California Electrical Code 



70-43 



200.7 



ARTICLE 200 - USE AND IDENTIFICATION OF GROUNDED CONDUCTORS 



(3) Other and different means of identification as allowed by 
200.6(A) or (B) that will distinguish each system 
grounded conductor. This means of identification shall 
be permanently posted at each branch-circuit panelboard. 

(E) Grounded Conductors of Multiconductor Cables. 

The insulated grounded conductors in a multiconductor cable 
shall be identified by a continuous white or gray outer finish 
or by three continuous white stripes on other than green 
insulation along its entire length. Multiconductor flat cable 4 
AWG or larger shall be permitted to employ an external 
ridge on the grounded conductor. 

Exception No. 1: Where the conditions of maintenance and 
supervision ensure that only qualified persons service the 
installation, grounded conductors in multiconductor cables 
shall be permitted to be permanently identified at their 
terminations at the time of installation by a distinctive 
white marking or other equally effective means. 

Exception No. 2: The grounded conductor of a 
multiconductor varnished-cloth-insulated cable shall be 
permitted to be identified at its terminations at the time of 
installation by a distinctive white marking or other equally 
effective means. 

FPN: The color gray may have been used in the past as an 
ungrounded conductor. Care should be taken when working 
on existing systems. 

200.7 Use of Insulation of a White or Gray Color or 
with Three Continuous White Stripes. 

(A) General. The following shall be used only for the 
grounded circuit conductor, unless otherwise permitted in 
200.7(B) and (C): 

(1) A conductor with continuous white or gray covering 

(2) A conductor with tfu-ee continuous white stripes on 
other than green insulation 

(3) A marking of white or gray color at the termination 

(B) Circuits of Less Than 50 Volts. A conductor with 
white or gray color insulation or three continuous white 
stripes or having a marking of white or gray at the 
termination for circuits of less than 50 volts shall be 
required to be grounded only as required by 250.20(A). 

(C) Circuits of 50 Volts or More. The use of insulation that 
is white or gray or that has three continuous white stripes for 
other than a grounded conductor for circuits of 50 volts or 
more shall be permitted only as in (1) through (3). 

(I) If part of a cable assembly and where the insulation is 
permanently reidentified to indicate its use as an 
ungrounded conductor, by painting or other effective 
means at its termination, and at each location where 
the conductor is visible and accessible. Identification 
shall encircle the insulation and shall be a color other 
than white, gray, or green. 



(2) Where a cable assembly contains an insulated 
conductor for single-pole, 3 -way or 4-way switch 
loops and the conductor with white or gray insulation 
or a marking of three continuous white stripes is used 
for the supply to the switch but not as a return 
conductor fi*om the switch to the switched outlet. In 
these applications, the conductor with white or gray 
insulation or with three continuous white stripes shall 
be permanently reidentified to indicate its use by 
painting or other effective means at its terminations 
and at each location where the conductor is visible and 
accessible. 

(3) Where a flexible cord, having one conductor identified 
by a white or gray outer finish or three continuous white 
stripes or by any other means permitted by 400.22, is 
used for connecting an appliance or equipment 
permitted by 400.7. This shall apply to flexible cords 
connected to outlets whether or not the outlet is supplied 
by a circuit that has a grounded conductor. 

FPN: The color gray may have been used in the past as an 
ungrounded conductor. Care should be taken when working 
on existing systems. 

200.9 Means of Identification of Terminals. The 

identification of terminals to which a grounded conductor 
is to be connected shall be substantially white in color. The 
identification of other terminals shall be of a readily 
distinguishable different color. 

Exception: Where the conditions of maintenance and 
supervision ensure that only qualified persons service the 
installations, terminals for grounded conductors shall be 
permitted to be permanently identified at the time of installation 
by a distinctive white marking or other equally effective means. 

200.10 Identification of Terminals. 

(A) Device Terminals. All devices, excluding panelboards, 
provided with terminals for the attachment of conductors 
and intended for connection to more than one side of the 
circuit shall have terminals properly marked for 
identification, unless the electrical connection of the 
terminal intended to be connected to the grounded 
conductor is clearly evident. 

Exception: Terminal identification shall not be required for 
devices that have a normal current rating of over 30 amperes, 
other than polarized attachment plugs and polarized 
receptacles for attachment plugs as required in 200.10(B). 

(B) Receptacles, Plugs, and Connectors. Receptacles, 
polarized attachment plugs, and cord connectors for plugs 
and polarized plugs shall have the terminal intended for 
connection to the grounded conductor identified as follows: 

(1) Identification shall be by a metal or metal coating that 
is substantially white in color or by the word white or 
the letter ^located adjacent to the identified terminal. 



70-44 



2010 California Electrical Code 



ARTICLE 2 1 - BRANCH CIRCUITS 



210.4 



(2) If the terminal is not visible, the conductor entrance 
hole for the connection shall be colored white or 
marked with the word white or the letter W. 

FPN: See 250.126 for identification of wiring device 
equipment grounding conductor terminals. 

(C) Screw Shells. For devices with screw shells, the 
terminal for the grounded conductor shall be the one 
connected to the screw shell. 

(D) Screw Shell Devices with Leads. For screw shell 
devices with attached leads, the conductor attached to the 
screw shell shall have a white or gray finish. The outer 
finish of the other conductor shall be of a solid color that 
will not be confused with the white or gray finish used to 
identify the grounded conductor. 

FPN: The color gray may have been used in the past as an 
ungrounded conductor. Care should be taken when working 
on existing systems. 

(E) Appliances. Appliances that have a single-pole switch 
or a single-pole overcurrent device in the line or any line- 
connected screw shell lampholders, and that are to be 
connected by (1) a permanent wiring method or (2) field- 
installed attachment plugs and cords with three or more 
wires (including the equipment grounding conductor), shall 
have means to identify the terminal for the grounded circuit 
conductor (if any). 

200.11 Polarity of Connections. No grounded conductor 
shall be attached to any terminal or lead so as to reverse the 
designated polarity. 



Bi*a;iich Circiiits^ 



I. General Provisions 

210.1 Scope. This article covers branch circuits except for 
branch circuits that supply only motor loads, which are 
covered in Article 430. Provisions of this article and Article 
430 apply to branch circuits with combination loads. 

210.2 Other Articles for Specific-Purpose Branch 
Circuits. Branch circuits shall comply with this article and 
also with the applicable provisions of other articles of this 
Code. The provisions for branch circuits supplying 
equipment listed in Table 210.2 amend or supplement the 
provisions in this article and shall apply to branch circuits 
referred to therein. 



210.3 Rating. Branch circuits recognized by this article 
shall be rated in accordance with the maximum permitted 
ampere rating or setting of the overcurrent device. The 
rating for other than individual branch circuits shall be 15, 
20, 30, 40, and 50 amperes. Where conductors of higher 
ampacity are used for any reason, the ampere rating or 
setting of the specified overcurrent device shall determine 
the circuit rating. 

Exception: Multioutlet branch circuits greater than 50 
amperes shall be permitted to supply nonlighting outlet 
loads on industrial premises where conditions of 
maintenance and supervision ensure that only qualified 
persons service the equipment 

210.4 Multiwire Branch Circuits. 

(A) General. Branch circuits recognized by this article 
shall be permitted as multiwire circuits. A multiwire circuit 
shall be permitted to be considered as multiple circuits. All 
conductors ^JaN jmjBijyjffe ^m^:\s^<^ shall originate 
from the same panelboard or similar distribution 
equipment. 

FPN: A 3 -phase, 4- wire, wye-connected power system used 
to supply power to nonlinear loads may necessitate that the 
power system design allow for the possibility of high 
harmonic ^^^tf^S:ofiJi|eJg£^ 

(B) pis^ttii<^ri|g^^^^^ mtiltiwire feraach.citcui| 
sliafi ' tfe : provide^ witli ^ m^wm tfisi^ will 's^nlimm'^i: 

(C) Line-to-Neutral Loads. Multiwire branch circuits 
shall supply only line-to-neutral loads. 

Exception No. 1: A multiwire branch circuit that supplies 
only one utilization equipment. 

Exception No. 2: Where all ungrounded conductors of the 
multiwire branch circuit are opened simultaneously by the 
branch-circuit overcurrent device. 

FPN: See 300.13(B) for continuity of grounded conductor 
on multiwire circuits. 






Exception: ffe£^^E^^?!;^^rS^H^?J^(M»^^.^^/ MtPMib^ji 
the circuit fJl^^^o^ a cable or mcewgy unique tp 'thi 
''circuit ihaimake^ the grouping, obvi<>m: 



2010 California Electrical Code 



70™45 



210.5 



ARTICLE 210 - BRANCH CIRCUITS 



Table 210.2 Specific-Purpose Branch Circuits 



Equipment 


Article 


Section 


Air-conditioning and 




440.6,440.31, 


refrigerating equipment 




440.32 


Audio signal processing, 




640.8 


amplification, and 






reproduction equipment 






Busways 




368.17 


Circuits and equipment 


720 




operating at less than 50 volts 






Central heating equipment 




422.12 


other than fixed electric 






space-heating equipment 






Class 1, Class 2, and Class 3 


725 




remote-control, signaling, 






and power-limited circuits 






Cranes and hoists 




610.42 


Electric signs and outline 




600.6 


lighting 






Electric welders 


630 




Blectnified JSck parjg|ig;^pace 


* w. 





Elevators, dumbwaiters, 

escalators, moving walks, 

wheelchair lifts, and 

stairway chair lifts 
Fire alarm systems 760 

Fixed electric heating equipment 

for pipelines and vessels 
Fixed electric space-heating 

equipment 
Fixed outdoor electrical deicing 

and snow-melting equipment 
Information technology 

equipment 
Infrared lamp industrial 

heating equipment 

Induction and dielectric 665 

heating equipment 
Marinas and boatyards 

Mobile homes, manufactured 550 

homes, and mobile home 

parks 
Motion picture and television 530 

studios and similar locations 
Motors, motor circuits, and 430 

controllers 
Pipe organs 

Recreational vehicles and 551 

recreational vehicle parks 
Switchboards and panelboards 

Theaters, audience areas of 

motion picture and television 

studios, and similar locations 
X-ray equipment 



620.61 



427.4 
424.3 
426.4 
645.5 
422.48, 424.3 

555.19 



650.7 



408.52 

520.41,520.52, 
520.62 

660.2,517.73 



210.5 Identification for Branch Circuits. 

(A) Grounded Conductor. The grounded conductor of a 
branch circuit shall be identified in accordance with 200.6. 

(B) Equipment Grounding Conductor. The equipment 
grounding conductor shall be identified in accordance with 
250.119. 

(C) Ungrounded Conductors. Where the premises wiring 
system has branch circuits suppHed from more than one 
nominal voltage system, each ungrounded conductor of a 
branch circuit shall be identified by pMseor line/^d 
is>^tem; aL^iall: :term^ conaectioa; and sjjice ftbititsJ 
The means of identification shall be permitted to be by 
separate color coding, marking tape, tagging, or other 
approved means. ;fte; mefe^^ "u^iztd. for conductors 
originating withiri eachfcraihch-citcu skmlat 
branch-oircui^^^^ equipment shall be documented 
in a mamer thaH^^^^^ shall be permanently 
posted at each branch-circuit panelboard or similar branch- 
circuit distribution equipment. 

210.6 Branch-Circuit Voltage Limitations. The nominal 
voltage of branch circuits shall not exceed the values 
permitted by 210.6(A) through (E). 

(A) Occupancy Limitation, hi dwelling units and guest 
rooms or guest suites of hotels, motels, and similar 
occupancies, the voltage shall not exceed 120 volts, nominal, 
between conductors that supply the terminals of the following: 

(1) Luminaires 

(2) Cord-and-plug-connected loads 1440 volt-amperes, 
nominal, or less or less than % hp 

(B) 120 Volts Between Conductors. Circuits not exceeding 
120 volts, nominal, between conductors shall be permitted to 
supply the following: 

(1) The terminals of lampholders apphed within their 
voltage ratings 

(2) Auxiliary equipment of electric-discharge lamps 

(3) Cord-and-plug-connected or permanently connected 
utilization equipment 

(C) 277 Volts to Ground. Circuits exceeding 120 volts, 
nominal, between conductors and not exceeding 277 volts, 
nominal, to ground shall be permitted to supply the 
following: 

(1) Listed electric-discharge luminaires 

(2) Listed incandescent luminaires, where supplied at 120 
volts or less from the output of a stepdown 
autotransformer that is an integral component of the 
luminaire and the outer shell terminal is electrically 
connected to a grounded conductor of the branch circuit 



# 



70^6 



2010 California Electrical Code 



ARTICLE 210 - BRANCH CIRCUITS 



210.8 



(3) Luminaires equipped with mogul-base screw shell 
lampholders 

(4) Lampholders, other than the screw shell type, applied 
within their voltage ratings 

(5) Auxiliary equipment of electric-discharge lamps 

(6) Cord-and-plug-connected or permanently connected 
utilization equipment 

(D) 600 Volts Between Conductors. Circuits exceeding 
277 volts, nominal, to ground and not exceeding 600 volts, 
nominal, between conductors shall be permitted to supply 
the following: 

(1) The auxiliary equipment of electric-discharge lamps 
mounted in permanently installed luminaires where the 
luminaires are mounted in accordance with one of the 

following: 

a. Not less than a height of 6.7 m (22 ft) on poles or 

similar structures for the illumination of outdoor 
areas such as highways, roads, bridges, athletic 
fields, or parking lots 

b. Not less than a height of 5.5 m (18 ft) on other 

structures such as tunnels 

(2) Cord-and-plug-connected or permanently connected 
utilization equipment other than luminaires 

l%^-^§mmkm |c^rate'd; teU^t .tfii£| 

§^^^ isblatipn J)^!^^ the 4e power souro^ " aii3 

FPN: See 410.l3| for auxiliary equipment limitations. 

Exception No. I to (B), (C), and (D): For lampholders of 
infrared industrial heating appliances as provided in 

422.14. 

Exception No. 2 to (B), (C), and (D): For railway 
properties as described in 110.19. 

(E) Over 600 Volts Between Conductors. Circuits 
exceeding 600 volts, nominal, between conductors shall be 
permitted to supply utilization equipment in installations 
where conditions of maintenance and supervision ensure 
that only qualified persons service the installation. 

210.7 Branch-Circuit Requirements tor ;Deyic^ 

(A) Receptacle Outlet Location. Receptacle outlets shall 
be located in branch circuits in accordance with Part III of 
Article 210. 

(B) Multiple Branch Circuits. Where two or more branch 
circuits supply devices or equipment on the same yoke, a 



means to simultaneously disconnect the ungrounded 
conductors supplying those devices shall be provided at the 
point at which the branch circuits originate. 

210.8 Ground-Fault Circuit-Interrupter Protection for 
Personnel. 

FPN: See 215.9 for ground-fault circuit-interrupter 
protection for personnel on feeders. 

(A) Dwelling Units. All 125-volt, single-phase, 15- and 
20-ampere receptacles installed in the locations specified in 
(1) through (8) shall have ground- fault circuit-interrupter 
protection for personnel. 

(1) Bathrooms 

(2) Garages, and also accessory buildings that have a floor 
located at or below grade level not intended as 
habitable rooms and limited to storage areas, work 
areas, and areas of similar use 

(3) Outdoors 

Exception to (3): Receptacles that are not readily 
accessible and are supplied by a dedicated branch circuit 
for electric snow-melting or deicing equipment shall be 
permitted to be installed in accordance with 426.28. 

(4) Crawl spaces — at or below grade level 

(5) Unfinished basements — for purposes of this section, 
unfinished basements are defined as portions or areas 
of the basement not intended as habitable rooms and 
limited to storage areas, work areas, and the like 

# 

Exception to (5): A receptacle supplying only a 
permanently installed fire alarm or burglar alarm system 
shall not be required to have ground-fault circuit- 
interrupter protection. 

pPN: Sed^ 760)1 i(F) and 760.iI2i(B) fik' powrjiiipply 
requi^menk for fire alarm systc^J 

Receptacles installed under the exception to 
210.8(A)(5) shall not be considered as meeting the 
requirements of 210.52(G). 

(6) Kitchens — where the receptacles are installed to serve 
the countertop surfaces 

(7) Laundry, utility, and wet bar sinks — where the 
receptacles are installed within 1.8 m (6 ft) of the 
outside edge of the sink 

(8) Boathouses 

(B) Other Than Dwelling Units. All 125-voh, single- 
phase, 15- and 20-ampere receptacles installed in the 
locations specified in (1) through (5) shall have ground- 
fault circuit-interrupter protection for personnel: 

(1) Bathrooms 

(2) Kitchegg 

(3) Rooftops 

(4) iOffiSrl 



2010 California Electrical Code 



70^^7 



210.9 



ARTICLE 210 - BRANCH CIRCUITS 



Exception No. 1 to (3) and (4): Receptacles that are not 
readily accessible and are supplied from a dedicated 
branch circuit for electric snow-melting or deicing 
equipment shall be permitted to be installed mthoulGFCJ. 
protectiml 

lBxceplion{Na:'f£ 'ip'- 0):-'0: ifidusMdl '^stMUhmerits only;. 

'asmre'(i_ eqmpfnent' M9^p4}f^K,. !^^)^^^^MK: M^M^^Hj(i 
specified in "590j^'(B)J2}^ shafl be permitted fp^ only those 
receptacle outlets used to supply equipment that, would 
create a greater hazard ^ power 'is interrupted or having d, 
design thahs not compatible with GFCt prqtectioni 

(5) Siiiks — where, rece|)tacles are installed within 1.8 m 
(6 ft) pf the outride edge^^ sidk.^ 

Exception N& I:,J<>_(5}:-^\ In if^mtrial laboratories, 
receptacles ^^ used to supply equipm^^ removal of 

power would inp;pdHce a greater hazard shall be permitted 

to berins tailed yf^MputOFCl^ 

Exception No '2/tq (5): :fPpr receptacles located in 

care areas of he^^^ than those covered 

(C) Boat Hoists. ^FC| protection shall be provided for 
outlets ]|#leicee^^ that supply boat hoists 

installed in dwelling unit locations. 

210.9 Circuits Derived from Autotransformers. Branch 
circuits shall not be derived from autotransformers unless 
the circuit supplied has a grounded conductor that is 
electrically connected to a grounded conductor of the 
system supplying the autotransformer. 

Exception No. I: An autotransformer shall be permitted 
without the connection to a grounded conductor where 
transforming from a nominal 208 volts to a nominal 240- 
volt supply or similarly from 240 volts to 208 volts. 

Exception No. 2: In industrial occupancies, where 
conditions of maintenance and supervision ensure that only 
qualified persons service the installation, autotransformers 
shall be permitted to supply nominal 600-volt loads from 
nominal 480-volt systems, and 480-volt loads from nominal 
600-volt systems, without the connection to a similar 
grounded conductor. 

210.10 Ungrounded Conductors Tapped from Grounded 
Systems. Two-wire dc circuits and ac circuits of two or 
more ungrounded conductors shall be permitted to be tapped 
from the ungrounded conductors of circuits that have a 
grounded neutral conductor. Switching devices in each 
tapped circuit shall have a pole in each ungrounded 
conductor. All poles of multipole switching devices shall 



manually switch together where such switching devices also 
serve as a disconnecting means as required by the following: 

(1) 4 10. H for double-pole switched lampholders 

(2) 410.|^(B) for electric-discharge lamp auxiliary 

equipment switching devices 

(3) 422.31(B) for an apphance 

(4) 424.20 for a fixed electric space-heating unit 

(5) 426.51 for electric deicing and snow-melting equipment 

(6) 430.85 for a motor controller 

(7) 430.103 for a motor 

210.11 Branch Circuits Required. Branch circuits for 
hghting and for apphances, including motor-operated 
appliances, shall be provided to supply the loads calculated 
in accordance with 220.10. In addition, branch circuits 
shall be provided for specific loads not covered by 220.10 
where required elsewhere in this Code and for dwelling 
unit loads as specified in 210.1 1(C). 

(A) Number of Branch Circuits. The minimum number 
of branch circuits shall be determined from the total 
calculated load and the size or rating of the circuits used. In 
all installations, the number of circuits shall be sufficient to 
supply the load served. In no case shall the load on any 
circuit exceed the maximum specified by 220.18. 

(B) Load Evenly Proportioned Among Branch Circuits, 

Where the load is calculated on the basis of volt-amperes 
per square meter or per square foot, the wiring system up to 
and including the branch-circuit panelboard(s) shall be 
provided to serve not less than the calculated load. This 
load shall be evenly proportioned among multioutlet 
branch circuits within the panelboard(s). Branch-circuit 
overcurrent devices and circuits shall be required to be 
installed only to serve the connected load. 

(C) Dwelling Units. 

(1) Small-Appliance Branch Circuits. In addition to the 
number of branch circuits required by other parts of this section, 
two or more 20-ampere small-appliance branch circuits shall be 
provided for all receptacle outlets specified by 210.52(B). 

(2) Laundry Branch Circuits. In addition to the number 
of branch circuits required by other parts of this section, at 
least one additional 20-ampere branch circuit shall be 
provided to supply the laundry receptacle outlet(s) required 
by 210.52(F). This circuit shall have no other outlets. 

(3) Bathroom Branch Circuits. In addition to the number 
of branch circuits required by other parts of this section, at 
least one 20-ampere branch circuit shall be provided to 
supply bathroom receptacle outlet(s). Such circuits shall 
have no other outlets. 



70-48 



2010 California Electrical Code 



ARTICLE 210 - BRANCH CIRCUITS 



210.19 



Exception: Where the 20-ampere circuit supplies a single 
bathroom, outlets for other equipment within the same 
bathroom shall be permitted to be supplied in accordance 
with 210.23(A)(1) and (A)(2). 

FPN: See Examples Dl(a), Dl(b), D2(b), and D4(a) in 
Annex D. 

210.12 Arc-Fault Circuit-Interrupter Protection. 

(A) Definition: Arc-Fault Circuit Interrupter (AFCI). A 

device intended to provide protection from the effects of 
arc faults by recognizing characteristics unique to arcing 
and by functioning to de-energize the circuit when an arc 
fault is detected. 

(B) DwelUng fSite. All 120-volt, single phase, 15- and 20- 
ampere branch circuits supplying outlets installed in dwelling 
unit jfami V. rooms, dmiug rooms, living rooms, parlors] 
ibrari^^^sJ&etooms^^ recr^ti^T<>oi^,^lose^^ 
SkHMyiL&:^?(M^(^,.^^ shall be protected by a 
listed arc-fault circuit interrupter, combination-type, installed 
to provide protection of the branch circuit. 

llSjSiESl FoJ" information on t5T>es of arc-fault circuit 
interrupters, see UL 1699-1999, Standard for Arc-Fault 
Circuit Interrupters . 

WM:S>^^M^M^MM and 760.121(1) for power- 
supply requirements for fire alarm systems. 

Exception No. 1: 'Where^RMQlMQMl^ 

^et^^Su^fmdjunAion-' boxes- m\ tj^i^MpSi^A^i^P^^M^^ 
%e:3f:dricMcifhJ0rie(^^ 

^ombJmii§h:]iF€I dtjh^j§rst outlet 'toJiTQ^jde prdte^tfp^^t 

Exception No. 2: 'Where^^i hramh^c^^ 

'^fyslem^J^tdled^^ ;with ;^ 76pJl(Bjj, and 

kirmhred .'^abh^ type' AC, meeting, the requirements of 
WiOjlM, \viih metal qutlet and jmctian bpx^Sjl Ap'Ct 
''pmhckod.shaUhe^ to be^pmiiiedl 

210.18 Guest Rooms and Guest Suites. Guest rooms and 
guest suites that are provided with permanent provisions 
for cooking shall have branch circuits installed to meet the 
rules for dwelling units. 

II. Branch-Circuit Ratings 

210.19 Conductors — Minimum Ampacity and Size. 
(A) Branch Circuits Not More Than 600 Volts. 

(1) General Branch-circuit conductors shall have an 



ampacity not less than the maximum load to be served. Where 
a branch circuit supplies continuous loads or any combination 
of continuous and noncontinuous loads, the minimum branch- 
circuit conductor size, before the application of any 
adjustment or correction factors, shall have an allowable 
ampacity not less than the noncontinuous load plus 125 
percent of the continuous load. Exception No. 1: Where the 
assembly, including the overcurrent devices protecting the 
branch circuit(s), is listed for operation at 100 percent of its 
rating, the allowable ampacity of the branch circuit 
conductors shall be permitted to be not less than the sum of 
the continuous load plus the noncontinuous load. 
Exception No, 2: XStpu^4^;i^^fi^^ 
, g^ei6i0 p[€^-^^^ 'be 

FPN No. 1: See 3 10.15 for ampacity ratings of conductors. 
FPN No. 2: See Part II of Article 430 for minimum rating of 
motor branch-circuit conductors. 

FPN No. 3: See 310.10 for temperature limitation of 
conductors. 

FPN No. 4: Conductors for branch circuits as defined in 
Article 100, sized to prevent a voltage drop exceeding 3 
percent at the farthest outlet of power, heating, and lighting 
loads, or combinations of such loads, and where the 
maximum total voltage drop on both feeders and branch 
circuits to the farthest outlet does not exceed 5 percent, 
provide reasonable efficiency of operation. See FPN No. 2 of 
215.2(A)(3) for voltage drop on feeder conductors. 

(2) Multioutlet Branch Circuits. Conductors of branch 
circuits supplying more than one receptacle for cord-and- 
plug-connected portable loads shall have an ampacity of not 
less than the rating of the branch circuit. 

(3) Household Ranges and Cooking Appliances. Branch- 
circuit conductors supplying household ranges, wall- 
mounted ovens, counter-mounted cooking units, and other 
household cooking appliances shall have an ampacity not 
less than the rating of the branch circuit and not less than the 
maximum load to be served. For ranges of %Va kW or more 
rating, the minimum branch-circuit rating shall be 40 
amperes. 

Exception No. 1: Conductors p^^|?^]§ig»i= «■ SQ-ampete 
W0f0^{;icim4& supplying electric ranges, wall-mounted 
electric ovens, and counter-mounted electric cooking units 
shall have an ampacity of not less than 20 d^^af^ and shall 
be sufficient for the load to be served. These tap conductors 
include any conductors that are apart of the leads supplied 
with the appliance that are smaller than the branch-circuit 
conductors. The taps shall not be longer than necessary for 
servicing the appliance. 



2010 California Electrical Code 



70-49 



210,20 



ARTICLE 210 - BRANCH CIRCUITS 



Exception No. 2: The neutral conductor of a 3-wire branch 
circuit supplying a household electric range, a wall-mounted 
oven, or a counter-mounted cooking unit shall be permitted 
to be smaller than the ungrounded conductors where the 
maximum demand of a range of8V4-kW or more rating has 
been calculated according to Column C of Table 220.55, but 
such conductor shall have an ampacity of not less than 70 
percent of the branch-circuit rating and shall not be smaller 
thanlOAWG. 

(4) Other Loads. Branch-circuit conductors that supply 
loads other than those specified in 210.2 and other than 
cooking appliances as covered in 210.19(A)(3) shall have an 
ampacity sufficient for the loads served and shall not be 
smaller than 

Exception No. 1 : Tap conductors shall have an ampacity 
sufficient for the load served. In addition, they shall have 
an ampacity of not less than 15 for circuits rated less than 
40 amperes and not less than 20 for circuits rated at 40 or 
50 amperes and only where these tap conductors supply 
any of the following loads: 

(a) Individual lampholders or luminaires with taps 
extending not longer than 450 mm (18 in.) beyond any 
portion of the lampholder or luminaire. 

(b) A luminaire having tap conductors as provided in 
410.117. 

(c) Individual outlets, other than receptacle outlets, 
with taps not over 450 mm (18 in.) long. 

(d) Infrared lamp industrial heating appliances. 

(e) Nonheating leads of deicing and snow-melting 
cables and mats. 

Exception No. 2: Fixture wires and flexible cords shall be 
permitted to be smaller than 14 A WG as permitted by 240.5. 

(B) Branch Circuits Over 600 Volts. The ampacity of 
conductors shall be in accordance with 310.15 and 310,60, 
as applicable. Branch-circuit conductors over 600 volts 
shall be sized in accordance with 210.19(B)(1) or (B)(2), 

(1) General. The ampacity of branch-circuit conductors 
shall not be less than 125 percent of the designed potential 
load of utilization equipment that will be operated 
simultaneously. 

(2) Supervised Installations. For supervised installations, 
branch-circuit conductor sizing shall be permitted to be 
determined by qualified persons under engineering 
supervision. Supervised installations are defined as those 
portions of a facility where both of the following 
conditions are met: 

(1) Conditions of design and installation are provided 
under engineering supervision. 

(2) Qualified persons with documented training and 
experience in over 600-voh systems provide 
maintenance, monitoring, and servicing of the system. 



210.20 Overcurrent Protection. Branch-circuit 
conductors and equipment shall be protected by 
overcurrent protective devices that have a rating or setting 
that complies with 210.20(A) through (D). 

(A) Continuous and Noncontinuous Loads. Where a 
branch circuit supplies continuous loads or any combination 
of continuous and noncontinuous loads, the rating of the 
overcurrent device shall not be less than the noncontinuous 
load plus 125 percent of the continuous load. 

Exception: Where the assembly, including the overcurrent 
devices protecting the branch circuit(s), is listed for 
operation at 100 percent of its rating, the ampere rating of 
the overcurrent device shall be permitted to be not less 
than the sum of the continuous load plus the noncontinuous 
load. 

(B) Conductor Protection. Conductors shall be protected 
in accordance with 240.4. Flexible cords and fixture wires 
shall be protected in accordance with 240.5. 

(C) Equipment. The rating or setting of the overcurrent 
protective device shall not exceed that specified in the 
applicable articles referenced in Table 240.3 for equipment. 

(D) Outlet Devices. The rating or setting shall not exceed 
that specified in 210.21 for outlet devices. 

210.21 Outlet Devices. Outlet devices shall have an 
ampere rating that is not less than the load to be served and 
shall comply with 210.21(A) and (B). 

(A) Lampholders. Where connected to a branch circuit 
having a rating in excess of 20 amperes, lampholders shall 
be of the heavy-duty type. A heavy-duty lampholder shall 
have a rating of not less than 660 watts if of the admedium 
type, or not less than 750 watts if of any other type. 

(B) Receptacles. 

(1) Single Receptacle on an Individual Branch Circuit. 

A single receptacle installed on an individual branch circuit 
shall have an ampere rating not less than that of the branch 
circuit. 

Exception No. 1: A receptacle installed in accordance with 
430.81(B). 

Exception No. 2: A receptacle installed exclusively for the 
use of a cord-and-plug-connected arc welder shall be 
permitted to have an ampere rating not less than the 
minimum branch-circuit conductor ampacity determined by 
630.11 (A) for arc welders. 

FPN: See the definition of receptacle in Article 100. 

(2) Total Cord-and-Plug-Connected Load. Where connected 
to a branch circuit supplying two or more receptacles or 
outlets, a receptacle shall not supply a total cord-and- 
plug-connected load in excess of the maximum specified 
in Table 210.21(B)(2). 



70-50 



2010 California Electrical Code 



ARTICLE 210- BRANCH CIRCUITS 



210.25 



Table 210.21(B)(2) 


Maximum Cord-and-Plug-Connected 


Load to Receptacle 






Circuit Rating 


Receptacle Rating 


Maximum Load 


(Amperes) 


(Amperes) 


(Amperes) 


15 or 20 


15 


12 


20 


20 


16 


30 


30 


24 



(3) Receptacle Ratings. Where connected to a branch circuit 
supplying two or more receptacles or outlets, receptacle 
ratings shall conform to the values listed in Table 
210.21(B)(3), or where larger than 50 amperes, the receptacle 
rating shall not be less than the branch-circuit rating. 

Exception No. 1: Receptacles for one or more cord-and- 
plug-connected arc welders shall be permitted to have 
ampere ratings not less than the minimum branch-circuit 
conductor' ampacity permitted by 630.11(A) or (B) as 
applicable for arc welders. 

Exception No. 2: The ampere rating of a receptacle 
installed for electric discharge lighting shall be permitted 
to be based on 410.62(C). 

Table 210.21(B)(3) Receptacle Ratings for Various Size Circuits 



Circuit Rating 


Receptacle Rating 


(Amperes) 


(Amperes) 


15 


Not over 1 5 


20 


15 or 20 


30 


30 


40 


40 or 50 


50 


50 



(4) Range Receptacle Rating. The ampere rating of a 
range receptacle shall be permitted to be based on a single 
range demand load as specified in Table 220.55. 

210.23 Permissible Loads. In no case shall the load 
exceed the branch-circuit ampere rating. An individual 
branch circuit shall be permitted to supply any load for 
which it is rated. A branch circuit supplying two or more 
outlets or receptacles shall supply only the loads specified 
according to its size as specified in 210.23(A) through (D) 
and as summarized in 210.24 and Table 210.24. 

(A) 15- and 20-Ampere Branch Circuits. A 15- or 20- 

ampere branch circuit shall be permitted to supply lighting 
units or other utilization equipment, or a combination of 
both, and shall comply with 210.23(A)(1) and (A)(2). 



Exception: The small-appliance branch circuits, laundry 
branch circuits, and bathroom branch circuits required in 
a dwelling unit(s) by 210.11(C)(1), (C)(2), and (C)(3) shall 
supply only the receptacle outlets specified in that section. 

(1) Cord-and-Plug-Connected Equipment Not Fastened 
in Place. The rating of any one cord-and-plug-connected 
utilization equipment not fastened in place shall not exceed 
80 percent of the branch-circuit ampere rating. 

(2) Utilization Equipment Fastened in Place. The total rating 
of utilization equipment fastened in place, other than luminaires, 
shall not exceed 50 percent of the branch-circuit ampere rating 
where lighting units, cord-and-plug-connected utilization 
equipment not fastened in place, or both, are also supplied. 

(B) 30-Ampere Branch Circuits. A 30-ampere branch 
circuit. shall be permitted to supply fixed lighting units with 
heavy-duty lampholders in other than a dwelling unit(s) or 
utilization equipment in any occupancy. A rating of any 
one cord-and-plug-connected utilization equipment shall 
not exceed 80 percent of the branch-circuit ampere rating. 

(C) 40- and 50-Ampere Branch Circuits. A 40- or 50- 
ampere branch circuit shall be permitted to supply cooking 
appliances that are fastened in place in any occupancy. In 
other than dwelling units, such circuits shall be permitted to 
supply fixed lighting units with heavy-duty lampholders, 
infrared heating units, or other utilization equipment. 

(D) Branch Circuits Larger Than 50 Amperes. Branch 
circuits larger than 50 amperes shall supply only 
nonlighting outlet loads. 

210.24 Branch-Circuit Requirements — Summary. The 

requirements for circuits that have two or more outlets or 
receptacles, other than the receptacle circuits of 
210.11(C)(1) and (C)(2), are summarized in Table 210.24. 
This table provides only a summary of minimum 
requirements. See 210.19, 210.20, and 210.21 for the 
specific requirements applying to branch circuits. 

210.25 Branch Circuits ji^ufld^^^ Than 
One Occupancy. 



(A) BweUlag Unit Branch Circuit!^. Branch circuits in each 
dwelling ]unjt shall supply only loads within that dwelling 

unit or loads associated only with that dwelling unit. 

IB) Go^inrnpn j^rea jBraiicfe^j O Branch circuits 

required for the purpose of lighting, central alarm, signal, 
communications, or otherjieed[s for public or common areas 
of ajtwo-family jdweiling, j^multifamjlY:d^ or a multi- 

jc^cupancy building shall not be supplied from equipment 
that supplies an individual dwelling unit or tenagt space. 



2010 California Electrical Code 



70-51 



210.50 



ARTICLE 210 - BRANCH CIRCUITS 



Table 210.24 Summary of Branch-Circuit Requirements 


Circuit Rating 


15 A 


20 A 


30 A 


40 A 


50 A 


Conductors (min. size): 

Circuit wires 
Taps 
Fixture wires and cords — 


see 240.5 


12 

14 


10 


8 
12 


6 

12 


Overcurrent Protection 


15 A 


20 A 


30 A 


40 A 


50 A 


Outlet devices: 
Lampholders permitted 

Receptacle rating 


Any type 
15 max. A 


Any type 

15 or 20 A 


Heavy duty 
30 A 


Heavy duty 
40 or 50 A 


Heavy duty 
50 A 


Maximum Load 


15 A 


20 A 


30 A 


40 A 


50 A 


Permissible load 


See 210.23(A) 


See 210.23(A) 


See 210.23(B) 


See 210.23(C) 


See 210.23(C) 



These gauges are for copper conductors. 

2 

For receptacle rating of cord-connected electric-discharge luminaires (hghting fixtures), see 410.30(C). 



c 

A 
C 
A 
C 
A 
C 
A 



III. Required Outlets 

210.50 General. Receptacle outlets shall be installed as 

specified in 210.52 through 210.63. 

(A) Cord Pendants. A cord connector that is supplied by a 
permanently connected cord pendant shall be considered a 
receptacle outlet. 

(B) Cord Connections. A receptacle outlet shall be installed 
wherever flexible cords with attachment plugs are used. Where 
flexible cords are permitted to be permanently connected, 
receptacles shall be permitted to be omitted for such cords. 

(C) Appliance |leceptocle Outlets. Appliance receptacle 
outlets installed in a dweUing unit for specific appliances, 
such as laundry equipment, shall be installed within 1.8 m 
(6 ft) of the intended location of the appliance. 

(D) fDPHJ Commissary Service Outlet A commissary which 
services food preparation units shall provide one outlet for each 
vehicle requiring electrical power for mechanical refrigeration, 

(E) [DPH w/ exceptions] Installation Height The center of 15-, 
20-, and 30-ampere receptacle outlets required by sections 210- 
52(A), (B), and (C) shall be installed not less than 12 inches 
above the floor or working platform. 

Exception No. 1: Receptacle outlets installed as part of 
permanently installed baseboard heaters are exempt. 
Exception No. 2: Required receptacle outlets shall be permitted in 
floors when adjacent to sliding panels or walls. 
Exception No. 3: Baseboard electrical outlets used in relocatable 
partitions, window walls or other electrical convenience floor 
outlets are not subject to the minimum height requirements. 
210.52 Dwelling Unit Receptacle Outlets. This section 
provides requirements for 125-volt, 15- and 20-ampere 
receptacle outlets. Jhejreceptade^ required by this section 
shall be in addition to anj; recepjtacle that is: 

(2) |Gpiitr6iled:';by :' a - ; -wall swife;}i^ in ; &cprto wltfi 

(3) tocated \Htliiii cabine^^^ _ 

(4) ^Located more thanj.7^^ (SJ/^ft) abqv^ th^ftol? 

Permanently installed electric baseboard heaters equipped 



with factory-installed receptacle outlets or outlets provided as 
a separate assembly by the manufacturer shall be permitted as 
the required outlet or outlets for the wall space utilized by such 
permanently installed heaters. Such receptacle outlets shall not 
be connected to the heater circuits. 

FPN: Listed baseboard heaters include instructions that may 
not permit their installation below receptacle outlets. 

(A) General Provisions, In every kitchen, family room, dining 
room, living room, parlor, library, den, sunroom, bedroom, 
recreation room, or similar room or area of dwelling units, 
receptacle outlets shall be installed in accordance with the 
general provisions specified in 210.52(A)(1) through (A)(3). 

(1) Spacing. Receptacles shall be installed such that no 
point measured horizontally along the floor line in any wall 
space is more than 1.8 m (6 ft) from a receptacle outlet. 

(2) Wall Space. As used in this section, a wall space shall 
include the following: 

(1) Any space 600 mm (2 ft) or more in width (including 
space measured around comers) and unbroken along the 
floor line by doorways, fireplaces, and similar openings 

(2) The space occupied by fixed panels in exterior walls, 
excluding sliding panels 

(3) The space afforded by fixed room dividers such as 
freestanding bar-type counters or railings 

(3) Floor Receptacles. Receptacle outlets in floors shall 
not be counted as part of the required number of receptacle 
outlets unless located within 450 mm (18 in.) of the wall. 

(B) Small Appliances. 

(1) Receptacle Outlets Served. In the kitchen, pantry, 
breakfast room, dining room, or similar area of a dwelling 
unit, the two or more 20-ampere small-appliance branch 
circuits required by 210.11(C)(1) shall serve all wall and 
floor receptacle outlets covered by 210.52(A), all 
countertop outlets covered by 210.52(C), and receptacle 
outlets for refrigeration equipment. 



70-52 



2010 California Electrical Code 



ARTICLE 210 - BRANCH CIRCUITS 



210.52 



Exception No. 1: In addition to the required receptacles 
specified by 210.52, switched receptacles supplied from a 
general-purpose branch circuit as defined in 210.70(A)(1), 
Exception No. 1, shall be permitted. 

Exception No. 2: The receptacle outlet for refrigeration 
equipment shall be permitted to be supplied from an 
individual branch circuit rated 15 amperes or greater. 

(2) No Other Outlets. The two or more small-appliance 
branch circuits specified in 210.52(B)(1) shall have no 
other outlets. 

Exception No. 1: A receptacle installed solely for the 
electrical supply to and support of an electric clock in any 
of the rooms specified in 210.52(B)(1). 

Exception No. 2: Receptacles installed to provide power 
for supplemental equipment and lighting on gasfired 
ranges, ovens, or counter-mounted cooking units. 

(3) Kitchen Receptacle Requirements. Receptacles 
installed in a kitchen to serve countertop surfaces shall be 
supplied by not fewer than two small-appliance branch 
circuits, either or both of which shall also be permitted to 
supply receptacle outlets in the same kitchen and in other 
rooms specified in 210.52(B)(1). Additional small- 
appliance branch circuits shall be permitted to supply 
receptacle outlets in the kitchen and other rooms specified 
in 210.52(B)(1). No small-appliance branch circuit shall 
serve more than one kitchen. 



(C) Countertops. In kitchens, ^^^^S^^^^^^M^mI 
BjBjmg rooms, aiid; siniilajc areas of dwelling units, 
receptacle outlets for countertop spaces shall be installed in 
accordance with 210.52(C)(1) through (C)(5). 

^^ iWher^ a range, ;cou|lt^r-ii^p|tM \i 

kf^eStetoBIand'^^^ 



jto|'j 



^bemndi ji^ ,,^i#i';;'M^^^i:feL^^Ml^ 




^uiitelppl ^p^'^^iafe J two ' ' si^imt^'; ' ,goi5Wqp" siages ; "fi 
defined mM^4%i£&r &?ii,„?^^^l?.i<M^^ 
iqondply Mftt&;^plcabie t^m^ms^M'^^Mi®. 

(1) Wall jEoupteit^i Spaces. A receptacle outlet shall be 
installed at each wall ^W§^^ space that is 300 mm (12 
in.) or wider. Receptacle outlets shall be installed so that no 
point along the wall line is more than 600 mm (24 in.) 
measured horizontally from a receptacle outlet in that space. 

Exception: Receptacle outlets shall not be required on a 

wall directly behind a range, ^^pMnter^momh^^ 

or sink in the installation described in W^K^iMSi^MI^MQi 



Outlet within 
'^0mm(24in.r 


Space exempt from wall 
line if X< 300 mm (12 in.) 


^ 


Outlet within 
600 mm (24 inj^ 




T 

X 

\ t 




r 'V 

V J ^ J , ^j^^„^^ J 





















Range^ counter-mounted cooking unit extending 
from face of counter 



Space exempt from wall line 
If X< 450 mm (18 in.) 



Oullet within 
600 mm 

(24 in.) 



-Outlet within 600 mm (24 in.) - 




Ranqe, counter-mounted cookinq unit mounted in corner 

Figure 210.52(C)(1) Determination of Area Behind a Range, 
or Counter-Mounted Cooking Unit or Sink. 



(2) Island ^oujjitfftgjl Spaces. At least one receptacle 
shall be installed at each island 'm^ttip^ space with a 
long dimension of 600 mm (24 in.) or greater and a short 
dimension of 300 mm (12 in.) or greater. 

(3) Peninsular ^Qiijitejlgii Spaces. At least one receptacle 
outlet shall be installed at, each peninsular countertop space 
with a long dimension of 600 mm (24 in.) or greater and a 
short dimension of 300 mm (12 m.) or greater. A peninsular 
countertop is measured from the connecting edge. 

(4) Separate Spaces. Countertop spaces separated by 
rangetops, refrigerators, or sinks shall be considered as 
separate countertop spaces in applying the requirements of 
210.52(C)(1), (C)(2), and (C)(3). 

(5) Receptacle Outlet Location. Receptacle outlets shall 
be located above, but not more than 500 mm (20 in.) above, 
the countertop. Receptacle outlets rendered not readily 



2010 California Electrical Code 



70-53 



210.60 



ARTICLE 210 - BRANCH CIRCUITS 



accessible by appliances fastened in place, appliance 
garages, sinks, or rangetops as covered in 210.52(C)(1), 
Exception, or appliances occupying dedicated space shall 
not be considered as these required outlets. 

Exception to (5): To comply with the conditions specified in 
(1) or (2), receptacle outlets shall be permitted to be mounted 
not more than 300 mm (12 in.) below the countertop. 
Receptacles mounted below a countertop in accordance with 
this exception shall not be located where the countertop 
extends more than 150 mm (6 in.) beyond its support base. 

(1) Construction fi)r the physically impaired 

(2) On island and peninsular countertops where the 
countertop is flat across its entire surface (no 
backsplashes, dividers, etc.) and there are no means to 
mount a receptacle within 500 mm (20 in.) above the 
countertop, such as an overhead cabinet 

(D) Bathrooms. In dwelling units, at least one receptacle 
outlet shall be installed in bathrooms within 900 mm (3 ft) of 
the outside edge of each basin. The receptacle outlet shall be 
located on a wall or partition that is adjacent to the basin or 
basin countertop, ox instiled on tbe side or face of the basin 
Eabinet not more than 300 mm (12 in.) below tiie cpratertop*; 

(E) Outdoor Outlets. Outdoor teceptacle outlets shall be 
installed in accordanqe with (E)(1) tlffough (E){3}. [See 

liiMm)-] "^ 2"" 

(1) One-Famiiy and TwO'Faniiiy Dwellii5^3 For a one- 
family dwelling and each unit of a two-family dwelling that 
is at grade level, at least one receptacle outlet accessible 
^^le standing at grade level and located not more than 2.0 
m {6V2 ft) above grade shall be installed at the front and 
back of the dwelling. 



i^lJJNfiilrtlafldJX For each dwelling unit of a 

multifamily dwelling where the dwelling unit is located at 
grade level and provided with individual exterior 
entrance/egress, at least one receptacle outlet accessible 
from grade level and not more than 2.0 m {6V2 ft) above 
grade shall be installed. 

(5) ■ BalcoiiieSj^Decli^^ Bdcqmes^^ d^^ks, and 

poaches that are acj^ssiW^^ inside &/dw^^^ 



Ifoli have at least ori^ 

perimetei of the bal^y, B^ck^ or porcii. The red^y^t^le 
;$JW1; BOt^be locjrted;'Hra;e;&a§, 2.0 mX6Y2.:'M:^^oye^&€f 
balcony, deck, or porch surfaced 

Exception to (3): Balconies, decks, or porches with a 

usable area of less than 1.86 m^ (20 ft^) are not required 
to have a receptacle installed. 



(F) Laundry Areas. In dwelling units, at least one 
receptacle outlet shall be installed for the laundry. 

Exception No. 1: In a dwelling unit that is an apartment or 
living area in a multifamily building where laundry 
facilities are provided on the premises and are available to 
all building occupants, a laundry receptacle shall not be 
required. 

Exception No. 2: In other than one-family dwellings where 
laundry facilities are not to be installed or permitted, a 
laundry receptacle shall not be required. 

(G) Basements and Garages. For a one-family dwelling, 
|he fpllowihg prbvisiois shall apply: 



(1) At least one receptacle outlet, |ii:Mditi£ri2t£;;thds^^ 

l^cific ei^urgiSliitT shall be installed in each 
basement, in each attached garage, and in each 
detached garage with electric power. 

(2) Where a portion of the basement is finished into one or 
more habitable rooms, each separate unfinished 
portion shall have a receptacle outlet installed in 
accordance with this section. 

(H) Hallways. In dwelling units, hallways of 3.0 m (10 ft) 
or more in length shall have at least one receptacle outlet. 

As used in this subsection, the hall length shall be 
considered the length along the centerline of the hall 
without passing through a doorway. 

210.60 Guest Rooms, Guest Suites, t^'iiTM^^^h^h^. 
SlmMLSccttpaii^ 

(A) General. Guest rooms or guest suites in hotels, motels, 

sleepmg tqop:^ to and similar occupancies 

shall have receptacle outlets installed in accordance with 
210.52(A) and 210.52(D). Guest rooms or guest suites 
provided with permanent provisions for cooking shall have 
receptacle outlets installed in accordance with all of the 
applicable rules in 210.52. 

(B) Receptacle Placement. In applying the provisions of 
210.52(A), the total number of receptacle outlets shall not 
be less than the minimum number that would comply with 
the provisions of that section. These receptacle outlets shall 
be permitted to be located conveniently for permanent 
ftirniture layout. At least two receptacle outlets shall be 
readily accessible. Where receptacles are installed behind 
the bed, the receptacle shall be located to prevent the bed 
from contacting any attachment plug that may be installed 
or the receptacle shall be provided with a suitable guard. 



• 



70-54 



2010 California Electrical Code 



ARTICLE 2 1 5 - FEEDERS 



215.1 



210.62 Show Windows. At least one receptacle outlet 
shall be installed ^^^^iOm^ 

show window for each 3.7 linear m (12 linear ft) or major 
fraction thereof of show window area measured 
horizontally at its maximum width. 

210.63 Heating, Air-Conditioning, and Refrigeration 
Equipment Outlet. A 125-volt, single-phase, 15- or 20- 
ampere-rated receptacle outlet shall be installed at an 
accessible location for the servicing of heating, air- 
conditioning, and refrigeration equipment. The receptacle 
shall be located on the same level and within 7.5 m (25 ft) 
of the heating, air-conditioning, ^nd refrigeration 
equipment. The receptacle outlet shall not be connected to 
the load side of the equipment disconnecting means. 

Exception: A receptacle outlet shall not be required at 
one- and two-family dwellings for the service of 
evaporative coolers. 

FPN: See 210.8 for ground- fault circuit-interrupter 
requirements. 

210.70 Lighting Outlets Required. Lighting outlets shall 
be installed where specified in 210.70(A), (B), and (C). 

(A) Dwelling Units. In dwelling units, lighting outlets shall 
be installed in accordance with 210.70(A)(1), (A)(2), and 
(A)(3). 

(1) Habitable Rooms. At least one wall switch-controlled 
lighting outlet shall be installed in every habitable room 
and bathroom. 

Exception No. 1: In other than kitchens and bathrooms, 
one or more receptacles controlled by a wall switch shall 
be permitted in lieu of lighting outlets. 

Exception No. 2: Lighting outlets shall be permitted to be 
controlled by occupancy sensors that are (I) in addition to 
wall switches or (2) located at a customary wall switch 
location and equipped with a manual override that will 
allow the sensor to function as a wall switch. 

(2) Additional Locations. Additional lighting outlets shall be 
installed in accordance with (A)(2)(a), (A)(2)(b), and (A)(2)(c). 

(a) At least one wall switch-controlled lighting outlet shall 
be installed in hallways, stairways, attached garages, and 
detached garages with electric power. 

(b) For dwelling units, attached garages, and detached 
garages with electric power, at least one wall sv^tch-controlled 
lighting outlet shall be installed to provide illumination on the 
exterior side of outdoor entrances or exits with grade level 
access. A vehicle door in a garage shall not be considered as an 
outdoor entrance or exit. 



(c) Where one or more lighting outlet(s) are installed 
for interior stairways, there shall be a wall switch at each 
floor level, and landing level that includes an entryway, to 
control the lighting outlet(s) where the stairway between 
floor levels has six risers or more. 

Exception to (A)(2)(a), (A)(2)(b), and (A)(2)(c): In 
hallways, in stairways, and at outdoor entrances, remote, 
central, or automatic control of lighting shall be 
permitted. 

(3) Storage or Equipment Spaces. For attics, underiloor 
spaces, utility rooms, and basements, at least one lighting 
outlet containing a switch or controlled by a wall switch 
shall be installed where these spaces are used for storage 
or contain equipment requiring servicing. At least one 
point of control shall be at the usual point of entry to 
these spaces. The lighting outlet shall be provided at or 
near the equipment requiring servicing. 

(B) Guest Rooms or Guest Suites. In hotels, motels, or 
similar occupancies, guest rooms or guest suites shall 
have at least one wall switch-controlled lighting outlet 
installed in every habitable room and bathroom. 

Exception No. 1: In other than bathrooms and kitchens 
where provided, one or more receptacles controlled by a 
wall switch shall be permitted in lieu of lighting outlets. 

Exception No. 2: Lighting outlets shall be permitted to be 
controlled by occupancy sensors that are (I) in addition 
to wall switches or (2) located at a customary wall switch 
location and equipped with a manual override that allows 
the sensor to function as a wall switch. 

(C) Other Than Dwelling Units. For attics and underiloor 
spaces containing equipment requiring servicing, such as 
heating, air-conditioning, and refrigeration equipment, at 
least one lighting outlet containing a switch or controlled 
by a wall switch shall be installed in such spaces. At least 
one point of control shall be at the usual point of entry to 
these spaces. The lighting outlet shall be provided at or 
near the equipment requiring servicing. / 



ARTICLE 215 



215.1 Scope. This article covers the installation 

requirements, overcurrent protection requirements, 
minimum size, and ampacity of conductors for feeders 
supplying branch-circuit loads. 

Exception: Feeders for electrolytic cells as covered in 
668.3(C)(1) and (C)(4). 



2010 California Electrical Code 



70-55 



215.2 



ARTICLE 215 - FEEDERS 



215.2 Minimum Rating and Size. 

(A) Feeders Not More Tlian 600 Volts. 

(1) General. Feeder conductors shall have an ampacity 
not less than required to supply the load as calculated in 
Parts III, IV, and V of Article 220. The minimum feeder- 
circuit conductor size, before the application of any 
adjustment or correction factors, shall have an allowable 
ampacity not less than the noncontinuous load plus 125 
percent of the continuous load. 

Exception No. 1: Where the assembly, including the 
overcurrent devices protecting the feeder(s), is listed for 
operation at 100 percent of its rating, the allowable 
ampacity of the feeder conductors shall be permitted to be 
not less than the sum of the continuous load plus the 
noncontinuous load. 
Exception No. 2: ^r^im^S^mS^ 

The size of the feeder circuit grounded conductor shall 
not be smaller than that required by 250.122, except that 
250.122(F) shall not apply where grounded conductors are 
run in parallel. 

Additional minimum sizes shall be as specified in 
215.2(A)(2) and (A)(3) under the conditions stipulated. 

(2) Ampacity Relative to Service Conductors. The 
feeder conductor ampacity shall not be less than that of the 
service conductors where the feeder conductors carry the 
total load supplied by service conductors with an ampacity 
of 55 amperes or less. 

(3) Individual Dwelling Unit or Mobile Home Conductors. 
Feeder conductors for individual dwelling units or mobile 
homes need not be larger than service conductors. 
Paragraph 310.15(B)(6) shall be permitted to be used for 
conductor size. 

FPN No. 1 : See Examples Dl through Dl 1 in Annex D. 
FPN No. 2: Condiictors for feeders as defined in Article 
100, sized to prevent a voltage drop exceeding 3 percent at 
the farthest outlet of power, heating, and lighting loads, or 
combinations of such loads, and where the maximum total 
voltage drop on both feeders and branch circuits to the 
farthest outlet does not exceed 5 percent, will provide 
reasonable efficiency of operation. 

(B) Feeders over 600 Volts. The ampacity of conductors 
shall be in accordance with 310.15 and 310.60 as 
applicable. Where installed, the size of the feeder-circuit 
grounded conductor shall not be smaller than that required 
by 250.122, except that 250.122(F) shall not apply where 
grounded conductors are run in parallel. Feeder conductors 
over 600 vohs shall be sized in accordance with 
215.2(B)(1), (B)(2), or (B)(3). 

(1) Feeders Supplying Transformers. The ampacity of 
feeder conductors shall not be less than the sum of the 
nameplate ratings of the transformers supplied when only 
transformers are supplied. 



(2) Feeders Supplying Transformers and Utilization 
Equipment. The ampacity of feeders supplying a 
combination of transformers and utilization equipment 
shall not be less than the sum of the nameplate ratings of 
the transformers and 125 percent of the designed potential 
load of the utilization equipment that will be operated 
simultaneously. 

(3) Supervised Installations. For supervised installations, 
feeder conductor sizing shall be permitted to be determined 
by qualified persons under engineering supervision. 
Supervised installations are defined as those portions of a 
facility where all of the following conditions are met: 

(1) Conditions of design and installation are provided under 
engineering supervision. 

(2) Qualified persons with documented training and experience 

in over 600-volt systems provide maintenance, 
monitoring, and servicing of the system. 

215.3 Overcurrent Protection. Feeders shall be protected 
against overcurrent in accordance with the provisions of 
Part I of Article 240. Where a feeder supplies continuous 
loads or any combination of continuous and noncontinuous 
loads, the rating of the overcurrent device shall not be less 
than the noncontinuous load plus 125 percent of the 
continuous load. 

Exception No. 1: Where the assembly, including the 
overcurrent devices protecting the feeder(s), is listed for 
operation at 100 percent of its rating, the ampere rating of 
the overcurrent device shall be permitted to be not less than 
the sum of the continuous load plus the noncontinuous load. 
Exception No. 2: Overcurrent protection for feeders over 
600 volts, nominal, shall comply with Part XI of Article 240. 

215.4 Feeders with Common Neutral p^Siliol. 

(A) Feeders with Common Neutral. HfejJ^ three sets of 3- 
wire feeders or two sets of 4-wire or 5 -wire feeders shall be 
permitted to utilize a common neutral. 

(B) In Metal Raceway or Enclosure. Where installed in a 
metal raceway or other metal enclosure, all conductors of 
all feeders using a common neutral |afl[49it<g shall be 
enclosed within the same raceway or other enclosure as 
required in 300.20. 

215.5 Diagrams of Feeders. If required by the authority 
having jurisdiction, a diagram showing feeder details shall 
be provided prior to the installation of the feeders. Such a 
diagram shall show the area in square feet of the building or 
other structure supplied by each feeder, the total calculated 
load before applying demand factors, the demand factors 
used, the calculated load after applying demand factors, and 
the size and type of conductors to be used. 

215.6 Feeder gg^^^g Grounding W^^^^^. Where a 
feeder supplies branch circuits in which equipment 
grounding conductors are required, the feeder shall include 
or provide |]^^u|^^ grounding 'c^^SctjS in accordance 
with the provisions of 250.134, to which the equipment 
grounding conductors of the branch circuits shall be 



70-56 



2010 California Electrical Code 



ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



220.3 



connected Wt^re fe feeder $uppHes a separate bui}& 
stocture;,:tih;e re^mtemefib p|^250,32^^ sM apjlyj 

215.7 Ungrounded Conductors Tapped from Grounded 
Systems. Two-wire dc circuits and ac circuits of two or more 
ungrounded conductors shall be permitted to be tapped from 
the ungrounded conductors of circuits having a grounded 
neutral conductor. Switching devices in each tapped circuit 
shall have a pole in each ungrounded conductor. 

215.9 Ground-Fault Circuit-Interrupter Protection for 
Personnel. Feeders supplying 15- and 20-ampere receptacle 
branch circuits shall be permitted to be protected by a 
ground-fault circuit interrupter in lieu of the provisions for 
such interrupters as specified in 210.8 and 590.6(A). 

215.10 Ground-Fault Protection of Equipment. Each 
feeder disconnect rated 1000 amperes or more and installed 
on solidly grounded wye electrical systems of more than 
150 vohs to ground, but not exceeding 600 volts phase-to- 
phase, shall be provided with ground-fault protection of 
equipment in accordance with the provisions of 230.95. 

FPN: For buildings that contain health care occupancies, see 
the requirements of 5 1 7 . 1 7 . 

Exception No. 1: The provisions of this section shall not 
apply to a disconnecting means for a continuous industrial 
process where a nonorderly shutdown will introduce 
additional or increased hazards. 



215.12 Identificatipn for Feeders. 

(A) Grounded Conductor. The grounded conductor of a 
feeder shall be identified in accordance with 200.6. 

(B) Equipment Grounding Conductor. The equipment 
grounding conductor shall be identified in accordance with 
250,119. 

(C) Ungrounded Conductors. Where the premises wiring 
system has feeders supplied from more than one nominal 
voltage system, each ungrounded conductor of a feeder 
shall be identified by jphase , pr Jm^^^^ 

[termination, conilection^ aSd splice points, The means of 
identification shall be permitted to be by separate color 
coding, marking tape, tagging, or other approved means. 
JrheJ~^ethod;utUiz^^ origmating wit§B each 

peder panelboard or sirmJar feeder dtstFibutionequipmenf 
khajj feidoctoenteid in a maimer ftiat is readily available or 
shall be permanently posted at each feeder panelboard or 
similar feeder distribution equipment. 



Braii€K-€irciiit9 Feeder^ and Service 



Exception No. 2: The provisions of this section shall Mot 
apply if ground fault protection of equipment is provided 
on the supply side of the feeder hnS on iHeload side of dm 
tramfqhr^^r su^ the feeder^-. 

215.11 Circuits Derived from Autotransformers. 

Feeders shall not be derived from autotransformers unless 
the system supplied has a grounded conductor that is 
electrically connected to a grounded conductor of the 
system supplying the autotransformer. 

Exception No. J: An autotransformer shall be permitted 
without the connection to a grounded conductor where 
transforming from a nominal 208 volts to a nominal 240- 
volt supply or similarly from 240 volts to 208 volts. 

Exception No. 2: In industrial occupancies, where conditions of 
maintenance and supervision ensure that only qualified persons 
service the installation, autotransformers shall be permitted to 
supply nominal 600-volt loads fi-om nominal 480-volt systems, 
and 480-volt loads from nominal 600-volt systems, without the 
connection to a similar grounded conductor 



I. General 

220.1 Scope. This article provides requirements for 
calculating branch-circuit, feeder, and service loads. Part I 
provides for general requirements for calculation methods. 
Part II provides calculation methods for branch-circuit loads. 
Parts III and IV provide calculation methods for feeders and 
services. Part V provides calculation methods for farms. 

FPN: See Figure 220. 1 for information on the organization 
of Article 220. 

220.3 Application of Otiier Articles. In other articles 
applying to the calculation of loads in specialized 
applications, there are requirements provided in Table 
220.3 that are in addition to, or modifications of, those 
within this article. 



2010 California Electrical Code 



70-57 



220.5 



ARTICLE 220 -BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



fart I General 



Part li Branch-circuit load calculations 



Part Hi 
Feeder and 
service load 
calculations 



220.61 

Neutral 
Loads 



Part IV 

Optional 

feeder and 

service load 

calculations 



Farm dwellings 
only 



Farm dwellings 

only 



Part V Farm load calculations 



Figure 220.1 Branch-Circuit, Feeder, and Service 



Calculation Methods. 
220.5 Calculations. 

(A) Voltages. Unless other voltages are specified, for purposes 
of calculating branch-circuit and feeder loads, nominal system 
voltages of 120, 120/240, 208Y/120, 240, 347, 480Y/277, 480, 
600Y/347, and 600 volts shall be used. 

(B) Fractions of an Ampere. Where calculations result in a 
fraction of an ampere that is less than 0.5, such fractions shall 
be permitted to be dropped. 

n. Branch-Circuit Load Calculations 

220.10 General. Branch-circuit loads shall be calculated as 

shown in 220.12, 220.14, and 220.16. 

220.12 Lighting Load for Specified Occupancies. A unit 

load of not less than that specified in Table 220.12 for 

occupancies specified therein shall constitute the minimum 

lighting load, area involved. For dweUing units, the calculated 

floor area shall not include open porches, garages, or unused 

or unfinished spaces not adaptable for future use. 



• 



Table 220.3 Additional Load Calculation References 



Calculation 


Article 


Section (or Part) 


Air-Conditioning and Refrigerating Equipment, Branch-Circuit 


440 


PartrV 


Conductor Sizing 






Cranes and Hoists, Rating and Size of Conductors 


610 


610.14 


Electric Welders, ampacity calculations 


630 


630.11,630.31 


Electrically Driven or Controlled Irrigation Machines 


675 


675.7(A), 675.22(A) 


Elk^filledimpkpSrkiiig '$pac| 


l?| 




Electrolytic Cell Lines 


668 


668.3(C) 


Electroplating, Branch-Circuit Conductor Sizing 


669 


669.5 


Elevator Feeder Demand Factors 


620 


620.14 


Fire Pumps, Voltage Drop (mandatory calculation) 


695 


695.7 


Fixed Electric Heating Equipment for Pipelines and Vessels, Branch- 


427 


427.4 


Circuit Sizing 






Fixed Electric Space Heating Equipment, Branch-Circuit Sizing 


424 


424.3 


Fixed Outdoor Electric Deicing and Snow-Mehing Equipment, 


426 


426.4 


Branch-Circuit Sizing 






Industrial Machinery, Supply Conductor Sizing 


670 


670.4(A) 


Marinas and Boatyards, Feeder and Service Load Calculations 


555 


555.12 


Mobile Homes, Manufactured Homes, and Mobile Home Parks, Total 


550 


550.18(B) 


Load for Determining Power Supply 






Mobile Homes, Manufactured Homes, and Mobile Home Parks, 


550 


550.31 


Allowable Demand Factors for Park Electrical Wiring Systems 






Motion Picture and Television Studios and Similar Locations - Sizing 


530 


530.19 


of Feeder Conductors for Television Studio Sets 






Motors, Feeder Demand Factor 


430 


430.26 


Motors, Multimotor and Combination-Load Equipment 


430 


430.25 


Motors, Several Motors or a Motor(s) and Other Load(s) 


430 


430.24 


Over 600 Volt Branch Circuit Calculations 


210 


210.19(B) 


Over 600 Volt Feeder Calculations 


215 


215.2(B) 


Phase Converters, Conductors 


455 


455.6 


Recreational Vehicle Parks, Basis of Calculations 


551 


551.73(A) 


Sensitive Electrical Equipment, Voltage Drop (mandatory calculation) 


647 


647.4(D) 


Solar Photovoltaic Systems, Circuit Sizing and Current 


690 


690.8 


Storage-Type Water Heaters 


422 


422.11(E) 


Theaters, Stage Switchboard Feeders 


520 


520.27 




70-58 



2010 California Electrical Code 



ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



220.14 



FPN: The unit values herein are based on minimum load 
conditions and 100 percent power factor and may not 
provide sufficient capacity for the installation contemplated. 

Table 220.12 General Lighting Loads by Occupancy 





Unit Load 




Volt-Amperes 


Volt-Amperes 




per Square 


per Square 


Type of Occupancy 


Meter 


Foot 


Armories and auditoriums 


11 


1 


Banks 


39b 


^Vih 


Barber shops and beauty 


33 


3 


parlors 






Churches 


11 


1 


Clubs 


22 


2 


Court rooms 


22 


2 


Dvi^elling unitsa 


33 


3 


Garages — commercial 


6 


V2 


(storage) 






Hospitals 


22 


2 


Hotels and motels, including 


22 


2 


apartment houses without 






provision for cooking by 






tenants^ 






Industrial commercial (loft) 


22 


2 


buildings 






Lodge rooms 


17 


\V2 


Office buildings 


39b 


3V^ 


Restaurants 


22 


2 


Schools 


33 


3 


Stores 


33 


3 


Warehouses (storage) 


3 


Va 


In any of the preceding 






occupancies except one- 






family dwellings and 






individual dwelling units 






of two-family and 






muhifamily dwellings: 






Assembly halls and 


11 


1 


auditoriums 






Halls, corridors, closets, 


6 


Vi 


stairways 






Storage spaces 


3 


% 



aSee220.14(J). 
bSee220.14(K). 

Exception: The loads of outlets serving switchboards and 
switching frames in telephone exchanges shall be waived 
from the calculations. 

(A) Specific Appliances or Loads. An outlet for a specific 
appliance or other load not covered in 220.14(B) through 
(L) shall be calculated based on the ampere rating of the 
appliance or load served. 



(B) Electric Dryers and Household Electric Cooking 
Appliances. Load calculations shall be permitted as 
specified in 220.54 for electric dryers and in 220.55 for 
electric ranges and other cooking appliances. 

(C) Motor Loads. Outlets for motor loads shall be 
calculated in accordance with the requirements in 430,22, 
430.24, and 440.6. 

(D) Luminaires. An outlet supplying luminaire(s) shall be 
calculated based on the maximum volt-ampere rating of the 
equipment and lamps for vv^hich the luminaire(s) is rated. 

(E) Heavy-Duty Lampholders. Outlets for heavy-duty 
lampholders shall be calculated at a minimum of 600 volt- 
amperes. 

(F) Sign and Outline Lighting. Sign and outline lighting 
outlets shall be calculated at a minimum of 1200 volt- 
amperes for each required branch circuit specified in 
600.5(A). 

(G) Show Windows. Shov^ windows shall be calculated in 
accordance with either of the following: 

(1) The unit load per outlet as required in other provisions 

of this section 

(2) At 200 volt-amperes per 300 mm (1 ft) of show window 

(H) Fixed Multioutlet Assemblies. Fixed multioutlet 
assemblies used in other than dwelling units or the guest 
rooms or guest suites of hotels or motels shall be calculated 
in accordance with (H)(1) or (H)(2). For the purposes of 
this section, the calculation shall be permitted to be based 
on the portion that contains receptacle outlets. 

(1) Where apphances are unlikely to be used simultaneously, 

each 1.5 m (5 ft) or fi-action thereof of each separate and 
continuous length shall be considered as one outlet of not 
less than 180 volt-amperes. 

(2) Where apphances are likely to be used simultaneously, each 

300 mm (1 ft) or fraction thereof shall be considered as an 
outlet of not less than 180 volt-amperes. 

(I) Receptacle Outlets. Except as covered in 220.14(J) and 
(K), receptacle outlets shall be calculated at not less than 
180 volt-amperes for each single or for each multiple 
receptacle on one yoke. A single piece of equipment 
consisting of a multiple receptacle comprised of four or 
more receptacles shall be calculated at not less than 90 
volt-amperes per receptacle. This provision shall not be 
applicable to the receptacle outlets specified in 
210.11(C)(1) and (C)(2). 

(J) Dwelling Occupancies. In one-family, two-family, and 
multifamily dwellings and in guest rooms or guest suites of 
hotels and motels, the outlets specified in (J)(l), (J)(2), and 
(J)(3) are included in the general hghting load calculations 
of 220.12. No additional load calculations shall be required 
for such outlets. 



2010 California Electrical Code 



70-59 



220.16 



ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



(1) All general-use receptacle outlets of 20-ampere rating 
or less, including receptacles connected to the circuits 

in 210.11(C)(3) 

(2) The receptacle outlets specified in 210.52(E) and (G) 

(3) The lighting outlets specified in 210.70(A) and (B) 

(K) Banks and Office Buildings. In banks or office 
buildings, the receptacle loads shall be calculated to be the 
largerof(l)or(2): 

(1) The calculate load from 220. 14(1) 

(2) 1 1 volt-amperes/m2 or 1 volt-ampere/ft2 

(L) Other Outlets. Other outlets not covered in 220.14(A) 

through (K) shall be calculated based on 1 80 volt-amperes 
per outlet. 

220.16 Loads for Additions to Existing Installations. 

(A) Dwelling Units. Loads added to an existing dwelling 
unit(s) shall comply with the following as applicable: 

(1) Loads for structural additions to an existing dwelling 
unit or for a previously un wired portion of an existing 
dwelling unit, either of which exceeds 46.5 m2 (500 
ft2), shall be calculated in accordance with 220.12 and 
220.14. 

(2) Loads for new circuits or extended circuits in 
previously wired dwelling units shall be calculated in 
accordance with either 220.12 or 220.14, as applicable. 

(B) Other Than Dwelling Units. Loads for new circuits or 

extended circuits in other than dwelling units shall be 
calculated in accordance with either 220.12 or 220.14, as 
applicable. 

220.18 Maximum Loads. The total load shall not exceed 
the rating of the branch circuit, and it shall not exceed the 
maximum loads specified in 220.18(A) through (C) under 
the conditions specified therein. 

(A) Motor-Operated and Combination Loads. Where a 

circuit supplies only motor-operated loads, Article 430 
shall apply. Where a circuit supphes only air-conditioning 
equipment, refrigerating equipment, or both, Article 440 
shall apply. For circuits supplying loads consisting of 
motor-operated utilization equipment that is fastened in 
place and has a motor larger than 1/8 hp in combination 
with other loads, the total calculated load shall be based on 
125 percent of the largest motor load plus the sum of the 
other loads. 



(B) Inductive Lighting Loads. For circuits supplying 
Hghting units that have ballasts, transformers, or 
autotransformers, the calculated load shall be based on the 
total ampere ratings of such units and not on the total watts 
of the lamps. 

(C) Range Loads. It shall be permissible to apply demand 
factors for range loads in accordance with Table 220.55, 
including Note 4. 

III. Feeder and Service Load Calculations 

220.40 General. The calculated load of a feeder or service 
shall not be less than the sum of the loads on the branch 
circuits supplied, as determined by Part II of this article, 
after any applicable demand factors permitted by Part III or 
IV or required by Part V have been appHed. 

FPN: See Examples Dl(a) through DIG in Annex D. See 
220.18(B) for the maximum load in amperes permitted for 
lighting units operating at less than 100 percent power 
factor. 

220.42 General Lighting. The demand factors specified in 
Table 220.42 shall apply to that portion of the total branch- 
circuit load calculated for general illumination. They shall 
not be applied in determining the number of branch circuits 
for general illumination. 

220.43 Show-window and Track Lighting. 

(A) Show Windows. For show-window lighting, a load of 
not less than 660 volt-amperes/linear meter or 200 volt- 
amperes/linear foot shall be included for a show window, 
measured horizontally along its base. 

FPN: See 220.14(G) for branch circuits supplying show 
windows. 

(B) Track Lighting. For track hghting in other than 
dwelling units or guest rooms or guest suites of hotels or 
motels, an additional load of 150 voh-amperes shall be 
included for every 600 mm (2 ft) of lighting track or 
fraction thereof Where multicircuit track is installed, the 
load shall be considered to be divided equally between the 
track circuits. 

220.44 Receptacle Loads — Other Than Dwelling Units. 

Receptacle loads calculated in accordance with 220.14(H) 
and (I) shall be permitted to be made subject to the demand 
factors given in Table 220.42 or Table 220.44. 



70-60 



2010 California Electrical Code 



ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



220.55 



Table 220.42 Lighting Load Demand Factors 



m 





Portion of Lighting 






Load to Which 






Demand Factor 


Demand Factor 


Type of Occupancy 


Applies 
(Volt-Amperes) 


(%) 


Dwelling units 


First 3000 or less at 


100 




From 3001 to 


35 




120,000 at 






Remainder over 


25 




120,000 at 




Hospitals* 


First 50,000 or less at 


40 




Remainder over 


20 




50,000 at 




Hotels and motels, 


First 20,000 or less at 


50 


including 


From 20,001 to 


40 


apartment houses 


100,000 at 




without provision 


Remainder over 


30 


for cooking by 


100,000 at 




tenants* 






Warehouses 


First 12,500 or less at 


100 


(storage) 


Remainder over 
12,500 at 


50 


All others 


Total volt-amperes 


100 



The demand factors of this table shall not apply to the calculated 
load of feeders or services supplying areas in hospitals, hotels, 
and motels where the entire lighting is likely to be used at one 
time, as in operating rooms, ballrooms, or dining rooms. [OSHPD 
1] The factors of Table 220.42 shall not be applied in the 
following areas: surgery suite, including recovery; emergency 
department, kitchen, food service, dining, critical care areas as 
defined in Article 517, elevator lobbies, corridors, inpatient nurse 
stations, and loads connected to the life safety branch or the 
critical branch of the emergency system. Administrative areas 
shall be included in "All others " Type of Occupancy. 



Table 220.44 Demand Factors for Non-Dwelling Receptacle 
Loads 



Portion of Receptacle Load to 
Which Demand Factor Applies 
(Volt-Amperes) 



Demand Factor W^ 



First 10 kVA or less at 
Remainder over 10 kVA at 



100 

50 



220.50 Motors. Motor loads shall be calculated in 
accordance with 430.24, 430.25, and 430.26 and v^ith 440.6 
for hermetic refrigerant motor compressors. 

220.51 Fixed Electric Space Heating. Fixed electric 
space-heating loads shall be calculated at 100 percent of 
the total connected load. However, in no case shall a feeder 
or service load current rating be less than the rating of the 
largest branch circuit supplied. 

Exception: Where reduced loading of the conductors 
results from units operating on duty-cycle, intermittently, 
or from all units not operating at the same time, the 
authority having jurisdiction may grant permission for 
feeder and service conductors to have an ampacity less 



than 100 percent, provided the conductors have an 
ampacity for the load so determined. 

220.52 Small-Appliance and Laundry Loads — 
Dwelling Unit. 

(A) Small-Appliance Circuit Load. In each dwelling unit, 
the load shall be calculated at 1500 volt-amperes for each 
2-wire small-appliance branch circuit las ,^C0Yere<| by 
2 10. 11 (C)(1). Where the load is subdivided through two or 
more feeders, the calculated load for each shall include not 
less than 1500 volt-amperes for each 2-wire small- 
appliance branch circuit. These loads shall be permitted to 
be included with the general lighting load and subjected to 
the demand factors provided in Table 220.42. 
Exception: The individual branch circuit permitted by 
210.52(B)(1), Exception No. 2, shall be permitted to be 
excluded from the calculation required by 220. 52. 

(B) Laundry Circuit Load. A load of not less than 1500 
volt-amperes shall be included for each 2-wire laundry 
branch circuit installed as covered by 210.11(C)(2). This 
load shall be permitted to be included with the general 
lighting load and subjected to the demand factors provided 
in Table 220.42. 

220.53 Appliance Load — Dwelling Unit(s). 

It shall be permissible to apply a demand factor of 75 
percent to the nameplate rating load of four or more 
appliances fastened in place, other than electric ranges, 
clothes dryers, space-heating equipment, or air- 
conditioning equipment, that are served by the same feeder 
or service in a one-family, two-family, or multifamily 
dwelling. 

220.54 Electric Clothes Dryers — Dwelling Unit(s). 
The load for household electric clothes dryers in a dwelling 
unit(s) shall be either 5000 watts (volt-amperes) or the 
nameplate rating, whichever is larger, for each dryer 
served. The use of the demand factors in Table 220.54 shall 
be permitted. Where two or more single-phase dryers are 
supplied by a 3 -phase, 4- wire feeder or service, the total 
load shall be calculated on the basis of twice the maximum 
number connected between any two phases. Kiloyglt^^ 
'amperes (kV A) shall be coBsidered equivalent to kilowatts! 
ji^W) for loads caiculated in this section; 

220.55 Electric Ranges and Other Cooking Appliances — 
Dwelling Unit(s). The load for household electric ranges, 
wall-mounted ovens, counter-mounted cooking units, and 
other household cooking appliances individually rated in 
excess of VA kW shall be permitted to be calculated in 
accordance with Table 220.55. Kilo volt-amperes (kVA) 
shall be considered equivalent to kilowatts (kW) for loads 
calculated under this section. 



2010 California Electrical Code 



70-61 



220.56 



ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



Table 220.54 Demand Factors for Household Electric Clothes 
Dryers 





Number of Demand Factor 




Dryers (%) 




1^ . 100 




5 85 




6 75 




7 65 




8 60 




9 55 




10 50 




11 47 




- "'- -' t2-23; ' '' '4^Al^S¥/i§t'ikh^'^^iik&eii^^ 11] 


24-42 immtM'&A iotm(ii^m:^tm^u0i 


43 and over 25%. 



Where two or more single-phase ranges are supplied 
by a 3 -phase, 4-wire feeder or service, the total load shall 
be calculated on the basis of tw^ice the maximum number 
connected between any two phases. 

FPN No. 1 : See Example D5(A) in Annex D. 

FPN No. 2: See Table 220.56 for commercial cooking 
equipment. 

FPN No. 3: See the examples in Annex D. 

220.56 Kitchen Equipment — Other Than Dwelling 
Unit(s). 

It shall be permissible to calculate the load for commercial 
electric cooking equipment, dishwasher booster heaters, 
water heaters, and other kitchen equipment in accordance 
with Table 220.56. These demand factors shall be applied 
to all equipment that has either thermostatic control or 
intermittent use as kitchen equipment. These demand 
factors shall not apply to space-heating, ventilating, or air- 
conditioning equipment. 

However, in no case shall the feeder or service 
calculated load be less than the sum of the largest two 
kitchen equipment loads. 

Table 220.56 Demand Factors for Kitchen Equipment — Other 
Than Dwelling Unit(s) 



Number of Units of 


Demand Factor 


Equipment 


■ 


1 


100 


2 


100 


3 


90 


4 


80 


5 


70 


6 and over 


65 



220.60 Noncoincident Loads. Where it is unlikely that 
two or more noncoincident loads will be in use 
simultaneously, it shall be permissible to use only the 
largest load(s) that will be used at one time for calculating 
the total load of a feeder or service. 

220.61 Feeder or Service Neutral Load. 

(A) Basic Calculation. The feeder or service neutral load 
shall be the maximum unbalance of the load determined by 
this article. The maximum unbalanced load shall be the 
maximum net calculated load between the neutral 
i<>litt?Mi ^^^ ^^y ^^^ ungrounded conductor. 
Exception: For 3 -wire, 2-phase or 5 -wire, 2 -phase 
systems, the maximum unbalanced load shall be the 
maximum net calculated load between the neutral 
pmdujdtgfjm^^ any one ungrounded conductor multiplied 
by 140 percent. 

(B) Permitted Reductions. A service or feeder supplying 
the following loads shall be permitted to have an additional 
demand factor of 70 percent applied to the amount in 
220.61(B)(1) or portion of the amount in 220.61(B)(2) 
determined by the basic calculation: 

(1) A feeder or service supplying household electric ranges, 
wall-mounted oyens, counter-mounted cooking units, 
and electric dryers, where the maximum unbalanced 
load has been determined in accordance with Table 
220.55 for ranges and Table 220.54 for dryers 

(2) That portion of the unbalanced load in excess of 200 
amperes where the feeder or service is supplied from a 
3 -wire dc or single-phase ac system; or a 4-wire, 3- 
phase, 3-wire, 2-phase system; or a 5-wire, 2-phase 
system 

(C) Prohibited Reductions. There shall be no reduction of 
the neutral or grounded conductor capacity applied to the 
amount in 220.61(C)(1), or portion of the amount in (C)(2), 
from that determined by the basic calculation: 

(1) Any portion of a 3-wire circuit consisting of 2 tMgr||tt]^^ 
|gSdi|?fe^g and the neutral jcjoStc^ of a 4-wire, 3-phase, 
wye-connected system 

(2) That portion consisting of nonlinear loads supplied from a 
4-wire, v^e-connected, 3-phase system 

FPN No. 1 : See Examples Dl(a), Dl(b), D2(b), D4(a), and D5(a) 
in Annex D. 

FPN No. 2: A 3-phase, 4-wire, wye-connected power 
system used to supply power to nonlinear loads may 
necessitate that the power system design allow for the 



possibility of high harmonic neutral-^j 



currents. 



IV. Optional Feeder and Service Load Calculations 
220.80 General. Optional feeder and service load 
calculations shall be permitted in accordance with Part IV. 



70-62 



2010 California Electrical Code 



ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 220.80 



Table 220.55 Demand Factors and Loads for Household Electric Ranges, Wall-Mounted Ovens, Counter-Mounted Cooking Units, and 
Other Household Cooking Appliances over P/i kW Rating (Column C to be used in all cases except as otherwise permitted in Note 3.) 

Demand Factor (%) (See Notes) 

Column C 
Column A Column B Maximum Demand (kW) 

Number of Appliances (Less than 3^2 kW Rating) (3!/2 kW |fi5iipi'^j3 kW Rating) (See Notes) (Not over 12 kW Rating) 

1 80 80 8 

2 75 65 • 11 

3 70 55 14 

4 66 50 17 

5 62 45 20 

6 59 43 21 

7 56 40 22 

8 53 36 23 

9 51 35 24 

10 49 34 - 25 

11 .47 32 26 

12 45 32 27 

13 43 32 28 

14 41 32 29 

15 _40 32 30 

16 39 28 31 

17 38 28 32 

18 37 28 33 

19 36 28 34 

20 35 28 35 

21 34 26 36 

22 33 26 37 

23 32 26 38 

24 31 26 39 

25 30 26 40 

26-30 30 24 1 5 kW + 1 kW for each range 

31-40 30 22 

41-50 30 20 25 kW + y4 kW for each range 

51-60 .30 18 

61 and over 30 16 

Notes: 

1. Over 12 kW through 27 kW ranges all of same rating. For ranges individually rated more than 12 kW but not more than 27 kW, the 
maximum demand in Column C shall be increased 5 percent for each additional kilowatt of rating or major fraction thereof by which the 
rating of individual ranges exceeds 12 kW. 

2. Over 8% kW through 27 kW ranges of unequal ratings. For ranges individually rated more than %Ya kW and of different ratings, but none 
exceeding 27 kW, an average value of rating shall be calculated by adding together the ratings of all ranges to obtain the total connected 
load (using 12 kW for any range rated less than 12 kW) and dividing by the total number of ranges. Then the maximum demand in Column 
C shall be increased 5 percent for each kilowatt or major fraction thereof by which this average value exceeds 12 kW. 

3. Over VA kW through ^V^ kW. In Heu of the method provided in Column C, it shall be permissible to add the nameplate ratings of all 
household cooking appliances rated more than W^ kW but not more than %Va kW and multiply the sum by the demand factors specified in 
Column A or Column B for the given number of appliances. Where the rating of cooking appliances falls under both Column A and 
Column B, the demand factors for each column shall be applied to the appliances for that column, and the results added together. 

4. Branch-Circuit Load. It shall be permissible to calculate the branch-circuit load for one range in accordance with Table 220.55. The 
branch-circuit load for one wall-mounted oven or one counter-mounted cooking unit shall be the nameplate rating of the appliance. The 
branch-circuit load for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch 
circuit and located in the same room, shall be calculated by adding the nameplate rating of the individual appHances and treating this total 
as equivalent to one range. 

5. This table shall also apply to household cooking appliances rated over VA kW and used in instructional programs. 



20 1 California Electrical Code 70—63 



220.82 



ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



220.82 Dwelling Unit. 

(A) Feeder and Service Load. This section applies to a 
dwelling unit having the total connected load served by a 
single 120/240-volt or 208Y/120-voh set of 3-wire service 
or feeder conductors with an ampacity of 100 or greater. It 
shall be permissible to calculate the feeder and service 
loads in accordance with this section instead of the method 
specified in Part III of this article. The calculated load shall 
be the resuk of adding the loads from 220.82(B) and (C). 
Feeder and service-entrance conductors whose calculated 
load is determined by this optional calculation shall be 
permitted to have the neutral load determined by 220.6 1 . 

(B) General Loads. The general calculated load shall be 
not less than 100 percent of the first 10 kVA plus 40 
percent of the remainder of the following loads: 

(1) 33 volt-amperes/m2 or 3 volt-amperes/ft2 for general 
lighting and general-use receptacles. The floor area for 
each floor shall be calculated from the outside 
dimensions of the dwelling unit. The calculated floor 
area shall not include open porches, garages, or unused 
or unfinished spaces not adaptable for fiiture use. 

(2) 1500 volt-amperes for each 2-wire, 20-ampere small- 
appliance branch circuit and each laundry branch 
circuit covered j&21(hii(CIl^ 

(3) The nameplate rating of the foiiowing: 

iJ All apphances that are fastened in place, permanently 
connected, or located to be on a specific circuit 

J Ranges, wall-mounted ovens, counter-mounted cooking 
units 



jl Clothes dryers Siat am ti^ftconnect^^ 
branch circuii specified m item (2) 

4^ Water heaters 

(4) The nameplate ampere or kVA rating of all permanently 
connected motors not included in item (3). 

(C) Heating and Air-Conditioning Load. The largest of 
the following six selections (load in kVA) shall be 
included: 

(1) 100 percent of the nameplate rating(s) of the air 
conditioning and cooling. 

(2) 100 percent of the nameplate rating(s) of the h^^t:gumfi 
when the heat pump is used without any supplemental 
electric heating. 

(3) 100 percent of the nameplate rating(s) of the heat pump 
compressor and 65 percent of the supplemental electric 
heating for central electric space-heating systems. If 
the heat pump compressor is prevented from operating 
at the same time as the supplementary heat, it does not 
need to be added to the supplementary heat for the 
total central space heating load. 

(4) 65 percent of the nameplate rating(s) of electric space 
heating if less than four separately controlled units. 



(5) 40 percent of the nameplate rating(s) of electric space 
heating if four or more separately controlled units. 

(6) 100 percent of the nameplate ratings of electric thermal 
storage and other heating systems where the usual load 
is expected to be continuous at the frill nameplate 
value. Systems qualifying under this selection shall not 
be calculated under any other selection in 220.82(C). 

220.83 Existing Dwelling Unit. This section shall be 
permitted to be used to determine if the existing service or 
feeder is of sufficient capacity to serve additional loads. 
Where the dwelling unit is served by a 120/240-volt or 
208Y/120-volt, 3-wire service, it shall be permissible to 
calculate the total load in accordance with 220.83(A) or (B). 

(A) Where Additional Air-Conditioning Equipment or 
Electric Space-Heating Equipment Is Not to Be 
Installed. The following formula shall be used for existing 
and additional new loads. 



Load (kVA) 



Percent of Load 



First 8 kVA of load at 
Remainder of load at 



100 
40 



Load calculations shall include the following: 

(1) General lighting and general-use receptacles at 33 volt- 
amperes/m2 or 3 volt-ampere s/ft2 as determined by 

220.12 

(2) 1500 volt-amperes for each 2-wire, 20-ampere small- 
appliance branch circuit and each laundry branch 
circuit goyer^K2l£il|Q 

(3) ithi^mmepUt€ i^^ 

aj; All appliances that ai*© fastened in place,' permanently 
Iccraiected, or located fe> fee cm a specific circuit 

J>;^Rmiges^ waJtmouM 

f:i jCfoth*^ ^er$ liikt tfe not; comiected ; to the^^ M 
bitocii cjrcmtspeyfi^ m 

(i Water teatSrs 

(B) Where Additional Air-Conditioning Equipment or 
Electric Space-Heating Equipment Is to Be Installed. 

The following formula shall be used for existing and 
additional new loads. The larger connected load of air- 
conditioning or space-heating, but not both, shall be used. 



Load 


Percent of Load 


Air-conditioning equipment 


100 


Central electric space heating 


100 


Less than four separately controlled 


100 


space-heating units 




First 8 kVA of all other loads 


100 


Remainder of all other loads 


40 



70-64 



2010 California Electrical Code 



ARTICLE 220 - BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



220.86 



Other loads shall include the following: 

(1) General lighting and general-use receptacles at 33 volt- 
amperes/m2 or 3 volt-amperes/ft2 as determined by 
220.12 

(2) 1500 volt-amperes for each 2-wire, 20-ampere small- 
appliance branch circuit and each laundry branch 
circuit coygt^ iii 2 10, ll(C^I)?B03^ (JS)(^ 

(3) TheVna£eplpirafi%rf 

a/ AiJpappiiaiices '&# mc^W^m4¥WpTmpl_^^^^ 
pefmaidtatttly pdniectedv #;'loca|f di|o/ba;'^^^ 
Si^cific^ircmt 

jeooldEg uirits 
C.J ei|thas jky^m &dX^&JX0(^^p^^^^^SM^^ 

i/;W^ejheatfS 
220.84 Multifamily Dwelling. 

(A) Feeder or Service Load. It shall be permissible to 
calculate the load of a feeder or service that supplies three 
or more dwelling units of a multifamily dwelling in 
accordance with Table 220.84 instead of Part III of this 
article if all the following conditions are met: 

(1) No dwelling unit is suppUed by more than one feeder. 

(2) Each dwelling unit is equipped with electric cooking 
equipment. 

Exception: When the calculated load for multifamily 
dwellings without electric cooking in Part III of this article 
exceeds that calculated under Part IV for the identical load 
plus electric cooking (based on 8 kWper unit), the lesser of 
the two loads shall be permitted to be used. 

(3) Each dwelling unit is equipped with either electric 
space heating or air conditioning, or both. Feeders and 
service conductors whose calculated load is 
determined by this optional calculation shall be 
permitted to have the neutral load determined by 
220.61. 

(B) House Loads. House loads shall be calculated in 
accordance with Part III of this article and shall be in 
addition to the dwelling unit loads calculated in accordance 
with Table 220.84. 

(C) Connected Loads. The calculated load to which the 
demand factors of Table 220.84 apply shall include the 
following: 

(1) 33 volt-amperes/m2 or 3 volt-amperes/ft2 for general 
lighting and general-use receptacles 

(2) 1500 volt-amperes for each 2-wire, 20-ampere small- 
appliance branch circujt and each laundry branch 

circuit )^^\xxmMMxyMM)&i 

(3) The nameplate rating oi\%^:t(Mo^^m^^^ 

a: All appliances that are fastened in place, permanently 
connected, or located to be on a specific circuit 



Table 220.84 Optional 


Calculations 


— Demand Factors for 


Three or More Multifamily Dwelling 


Units 




Number of 




Demand Factor 


Dwelling Units 






i%) 


3-5 






45 


6-7 






44 


8-10 






43 



11 

12-13 
14-15 
16-17 
18-20 



42 
41 
40 
39 
38 



21 

22-23 
24-25 
26-27 
28-30 



37 
36 
35 
34 
33 



31 
32-33 
34-36 
37-38 
39^2 



32 
31 
30 
29 
28 



43^5 
46-50 
51-55 
56-61 
62 and over 



27 
26 

25 
24 
23 



y Ranges, wall-mounted ovens, counter-mounted cooldng 

units 
y Clothes ^[ryersjbat aire npt cpimecfed to j&e Jautidry 

Ij Water heaters 
(4) The nameplate ampere or kVi§ rating of all 
t^emanentlyc^ motors not included in item (3) 



(5) Thejarger of the air-conditioning load or the Hied 
gleetn3 space-heating load 

220.85 Two Dwelling Units. Where two dwelling units 
are supplied by a single feeder and the calculated load 
under Part III of this article exceeds that for three identical 
units calculated under 220.84, the lesser of the two loads 
shall be permitted to be used. 

220.86 Schools. The calculation of a feeder or service 
load for schools shall be permitted in accordance with 
Table 220.86 in lieu of Part III of this article where 
equipped with electric space heating, air conditioning, or 
both. The connected load to which the demand factors of 
Table 220.86 apply shall include all of the interior and 
exterior lighting, power, water heating, cooking, other 
loads, and the larger of the air-conditioning load or spcice- 
heating load within the building or structure. 



2010 California Electrical Code 



70-65 



220.87 



ARTICLE 220 -BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCULATIONS 



Feeders and service conductors whose calculated load 
is determined by this optional calculation shall be permitted 
to have the neutral load determined by 220.61. Where the 
building or structure load is calculated by this optional 
method, feeders within the building or structure shall have 
ampacity as permitted in Part III of this article; however, 
the ampacity of an individual feeder shall not be required to 
be larger than the ampacity for the entire building. 

This section shall not apply to portable classroom 
buildings. 

Table 220.86 Optional Method — Demand Factors for 
Feeders and Service Conductors for Schools 



Connected Load 


Demand Factor 

(%) 


First 33 VA/m2 
Plus, 




(3 VA/ft2) at 


100 


Over 33 to 220 

VA/m'Plus, 




(3 to 20 VA/ft2) at 


75 


Remainder over 

VA/m^ 


220 


(20 VA/ft2) at 


25 



other loads that may be periodic in nature due to seasonal 
or similar conditions. 

(2) The maximum demand at 125 percent plus the new 
load does not exceed the ampacity of the feeder or 
rating of the service. 

(3) The feeder has overcurrent protection in accordance 
with 240.4, and the service has overload protection in 
accordance with 230.90. 

220.88 New Restaurants. Calculation of a service or 
feeder load, where the feeder serves the total load, for a 
new restaurant shall be permitted in accordance with Table 
220.88 in lieu of Part III of this article. 

The overload protection of the service conductors shall 
be in accordance with 230.90 and 240.4. 

Feeder conductors shall not be required to be of greater 
ampacity than the service conductors. 

Service or feeder conductors whose calculated load is 
determined by this optional calculation shall be permitted 
to have the neutral load determined by 220.61. 



220.87 Determining Existing Loads. The calculation of 
a feeder or service load for existing installations shall be 
permitted to use actual maximum demand to determine the 
existing load under all of the following conditions: 

(1) The maximum demand data is available for a 1-year 
period. 

Exception: If the maximum demand data for a 1-year 
period is not available, the calculated load shall be 
permitted to be based on the maximum demand (measure of 
average power demand over a IS-minute period) 
continuously recorded over a minimum SO-day period 
using a recording ammeter or power meter connected to 
the highest loaded phase of the feeder or service, based on 
the initial loading at the start of the recording. The 
recording shall reflect the maximum demand of the feeder 
or service by being taken when the building or space is 
occupied and shall include by measurement or calculation 
the larger of the heating or cooling equipment load, and 



V. Farm Load Calculations 

220.100 General. Farm loads shall be calculated in 
accordance with Part V. 

220.102 Farm Loads — Buildings and Other Loads. 

(A) Dwelling Unit. The feeder or service load of a farm 
dwelling unit shall be calculated in accordance with the 
provisions for dwellings in Part III or IV of this article. 
Where the dwelling has electric heat and the farm has 
electric grain-drying systems, Part IV of this article shall 
not be used to calculate the dwelling load where the 
dwelling and farm loads are supplied by a common service. 

(B) Other Than Dwelling Unit. Where a feeder or service 
supplies a farm building or other load having two or more 
separate branch circuits, the load for feeders, service 
conductors, and service equipment shall be calculated in 
accordance with demand factors not less than indicated in 
Table 220.102. 



Table 220.88 Optional Method — Permitted Load Calculations for Service and Feeder Conductors for New Restaurants 



Total Connected 
Load (kVA) 



All Electric Restaurant 
Calculated Loads (kVA) 



Not All Electric Restaurant 
Calculated Loads (kVA) 



0-200 
201-325 
326-800 
Over 800 



80% 
10% (amount over 200) + 160.0 
50% (amount over 325) + 172.5 
50% (amount over 800) + 410.0 



100% 
50% (amount over 200) + 200.0 
45% (amount over 325) + 262.5 
20% (amount over 800) + 476.3 



Note: Add all electrical loads, including both heating and cooling loads, to calculate the total connected load. Select the one demand facto: 
applies from the table, then multiply the total connected load by this single demand factor. 



• 



70-66 



2010 California Electrical Code 



ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS 



225.4 



Table 220.102 Method for Calculating Farm Loads for Other 
Than Dwelling Unit 



Table 225,2 Other Articles 



Ampere Load at 240 Volts 
Maximum 


Demand Factor 

(%) 


Loads expected to operate 

simultaneously, but not less than 
125 percent full-load current of 
the largest motor and not less 
than the first 60 amperes of load 

Next 60 amperes of all other loads 

Remainder of other load 


100 

50 
25 



Equipment/Conductors 



Article 



220.103 Farm Loads — Total. Where supplied by a 
common service, the total load of the farm for service 
conductors and service equipment shall be calculated in 
accordance with the farm dwelling unit load and demand 
factors specified in Table 220.103. Where there is 
equipment in two or more farm equipment buildings or for 
loads having the same function, such loads shall be 
calculated in accordance with Table 220.102 and shall be 
permitted to be combined as a single load in Table 220.103 
for calculating the total load. 

Table 220.103 Method for Calculating Total Farm Load 



Individual Loads Calculated in 




Accordance with Table 220.102 


Demand Factor (%) 


Largest load 


100 


Second largest load 


75 


Third largest load 


65 


Remaining loads 


50 



Note: To this total load, add the load of the farm dwelling unit 
calculated in accordance with Part III or IV of this article. 
Where the dwelling has electric heat and the farm has electric 
grain-drying systems, Part IV of this article shall not be used 
to calculate the dwelling load. 



Oiitside Branch Circuits and Feedm 



225.1 Scope. This article covers requirements for outside 
branch circuits and feeders run on or between buildings, 
structures, or poles on the premises; and electrical 
equipment and wiring for the supply of utilization 
equipment that is located on or attached to the outside of 
buildings, structures, or poles. 

FPN: For additional information on wiring over 600 volts, 
see ANSI C2-2007, National Electrical Safety Code. 

225.2 Other Articles. Application of other articles, 
including additional requirements to specific cases of 
equipment and conductors, is shown in Table 225.2. 



Branch circuits 


210 


Class 1, Class 2, and Class 3 remote- 
control, signaling, and power- 
limited circuits 


725 


Communications circuits 


800 


Community antenna television and 
radio distribution systems 


820 


Conductors for general wiring 


310 


Electrically driven or controlled 
irrigation machines 


675 


Electric signs and outhne lighting 


600 


Feeders 


215 


Fire alarm systems 


760 


Fixed outdoor electric deicing and 
snow-melting equipment 


426 


Floating buildings 


553 


Grounding 


250 


Hazardous (classified) locations 


500 


Hazardous (classified) locations — 
specific 


510 


Marinas and boatyards 


555 


Messenger supported wiring 


396 


Mobile homes, manufactured homes, 
and mobile home parks 


550 


Open wiring on insulators 


398 


Over 600 volts, general 


490 


Overcurrent protection 


240 


Radio and television equipment 


810 


Services 


230 


Solar photovoltaic systems 


690 


Swimming pools, fountains, and 
similar installations 


680 


Use and identification of grounded 
conductors 


200 



I. General 

225.3 Calculation of Loads 600 Volts, Nominal, or Less. 

(A) Branch Circuits. The load on outdoor branch circuits 
shall be as determined by 220.10. 

(B) Feeders. The load on outdoor feeders shall be as 
determined by Part III of Article 220. 

225.4 Conductor Covering. Where within 3.0 m (10 ft) of 

any building or structure other than supporting poles or 
towers, open individual (aerial) overhead conductors shall 
be insulated or covered. Conductors in cables or raceways, 
except Type MI cable, shall be of the rubber-covered type 
or thermoplastic type and, in wet locations, shall comply 
with 310.8. Conductors for festoon lighting shall be of the 
rubber-covered or thermoplastic type. 



2010 California Electrical Code 



70-67 



225.5 



ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS 



Exception: Equipment grounding conductors and 
grounded circuit conductors shall be permitted to be bare 
or covered as specifically permitted elsewhere in this Code, 

225.5 Size of Conductors 600 Volts, Nominal, or Less. 

The ampacity of outdoor branch-circuit and feeder 
conductors shall be in accordance with 310.15 based on 
loads as determined under 220.10 and Part III of Article 
220. 

225.6 Conductor Size and Support. 

(A) Overhead Spans. Open individual conductors shall 
not be smaller than the following: 

(1) For 600 volts, nominal, or less, 10 AWG copper or 8 
AWG aluminum for spans up to 15 m (50 ft) in length, 
and 8 AWG copper or 6 AWG aluminum for a longer 
span unless supported by a messenger wire 

(2) For over 600 volts, nominal, 6 AWG copper or 4 AWG 
aluminum where open individual conductors, and 8 
AWG copper or 6 AWG aluminum where in cable 

(B) Festoon Lighting. Overhead conductors for festoon 
Hghting shall not be smaller than 12 AWG unless the 
conductors are supported by messenger wires. In all spans 
exceeding 12 m (40 ft), the conductors shall be supported 
by messenger wire. The messenger wire shall be supported 
by strain insulators. Conductors or messenger wires shall 
not be attached to any fire escape, downspout, or plumbing 
equipment. 

225.7 Lighting Equipment Installed Outdoors. 

(A) General. For the supply of lighting equipment installed 
outdoors, the branch circuits shall comply with Article 210 
and 225.7(B) through (D). 

(B) Common Neutral. The ampacity of the neutral 
conductor shall not be less than the maximum net 
computed load current between the neutral Jc^dW<)| and 
all ungrounded conductors connected to any one phase of 
the circuit. 

(C) 277 Volts to Ground. Circuits exceeding 120 volts, 
nominal, between conductors and not exceeding 277 volts, 
nominal, to ground shall be permitted to supply luminaires 
for illumination of outdoor areas of industrial 
establishments, office buildings, schools, stores, and other 
commercial or public buildings where the luminaires are 
not less than 900 mm (3 ft) from windows, platforms, fire 
escapes, and the like. 

(D) 600 Volts Between Conductors. Circuits exceeding 
277 volts, nominal, to ground and not exceeding 600 volts, 
nominal, between conductors shall be permitted to supply 
the auxiliary equipment of electric-discharge lamps in 
accordance with 210.6(D)(1). 



225.10 Wiring on Buildings. The installation of outside 
wiring on surfaces of buildings shall be permitted for circuits 
of not over 600 volts Volts, nominal, as open wiring on 
insulators, as multiconductor cable, as Type MC cable, as 
IHilfJSJsSij ^s Type MI cable, as messenger-supported 
wiring, in rigid metal conduit, in intermediate metal conduit, 
in rigid nonmetallic conduit, in cable trays, as cablebus, in 
wireways, in auxiliary gutters, in electrical metallic tubing, 
in flexible metal conduit, in hquidtight flexible metal 
conduit, in liquidtight flexible nonmetallic conduit, and in 
busways. Circuits of over 600 volts, nominal, shall be 
installed as provided in 300.37. 

225.11 Circuit Exits and Entrances. 

225.12 Open-Conductor Supports. Open conductors shall 
be supported on glass or porcelain knobs, racks, brackets, or 
strain insulators. 

225.14 Open-Conductor Spacings. 

(A) 600 Volts, Nominal, or Less. Conductors of 600 volts, 
nominal, or less, shall comply with the spacings provided in 
Table 230.51(C). 

(B) Over 600 Volts, Nominal. Conductors of over 600 
volts, nominal, shall comply with the spacings provided in 
110.36 and 490.24. 

(C) Separation from Other Circuits. Open conductors 
shall be separated from open conductors of other circuits or 
systems by not less than 100 mm (4 in.). 

(D) Conductors on Poles. Conductors on poles shall have a 
separation of not less than 300 mm (1 ft) where not placed 
on racks or brackets. Conductors supported on poles shall 
provide a horizontal climbing space not less than the 
following: 

(1) Power conductors below communications conductors — 
750 mm (30 in.) 

(2) Power conductors alone or above communications 
conductors: 

a. 300 volts or less — 600 mm (24 in.) 

b. Over 300 volts — 750 mm (30 in.) 

(3) Communications conductors below power conductors — 
same as power conductors 

(4) Communications conductors alone — no requirement 

225.15 Supports over Buildings. Supports over a building 
shall be in accordance with 230.29. 

225.16 Attachment to Buildings. 

(A) Point of Attachment. The point of attachment to a 
building shall be in accordance with 230.26. 



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2010 California Electrical Code 



ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS 



225.20 



(B) Means of Attachment. The means of attachment to a 
building shall be in accordance with 230.27. 

225.17 Masts as Supports. Where a mast is used for the 
support of final spans of feeders or branch circuits, it shall be 
of adequate strength or be supported by braces or guys to 
withstand safely the strain imposed by the overhead drop 

Where raceway-type masts are used, all raceway fittings shall be 
identified for use with masts. Only the feeder or branch- 
circuit conductors specified within this section shall be 
permitted to be attached to the feeder and/or branch-circuit 
mast. 



225.18 Clearance IgrjO^^fijfe^^ 

Overhead spans of open conductors and open 
multiconductor cables of not over 600 volts, nominal, shall 
have a clearance of not less than the following: 

(1) 3.0m(10ft) — above finished grade, sidewalks, or fi"om 
any platform or projection fi'om which they might be 
reached where the voltage does not exceed 150 volts to 
ground and accessible to pedestrians only 

(2) 3.7 m (12 ft) — over residential property and driveways, 
and those commercial areas not subject to truck traffic 
where the voltage does not exceed 300 volts to ground 

(3) 4.5 m (15 ft) — for those areas Hsted in the 3.7-m (12-ft) 
classification where the voltage exceeds 300 volts to 
ground 

(4) 5.5 m (18 ft) — over public streets, alleys, roads, parking 
areas subject to truck traffic, driveways on other than 
residential property, and other land traversed by vehicles, 
such as cultivated, grazing, forest, and orchard 

225.19 Clearances from Buildings for Conductors of 
Not over 600 Volts, Nominal. 

(A) Above Roofs. Overhead spans of open conductors and 
open multiconductor cables shall have a vertical clearance 
of not less than 2.5 m (8 ft) above the roof surface. The 
vertical clearance above the roof level shall be maintained 
for a distance not less than 900 mm (3 ft) in all directions 
from the edge of the roof 

Exception No. I: The area above a roof surface subject to 
pedestrian or vehicular traffic shall have a vertical 
clearance from the roof surface in accordance with the 
clearance requirements of 225.18. 

Exception No. 2: Where the voltage between conductors 
does not exceed 300, and the roof has a slope of 100 mm in 
300 mm (4 in. in 12 in.) or greater, a reduction in 
clearance to 900 mm (3 ft) shall be permitted. 



Exception No. 3: Where the voltage between conductors 
does not exceed 300, a reduction in clearance above only 
the overhanging portion of the roof to not less than 450 mm 
(18 in.) shall be permitted if (1) not more than 1.8 m (6 ft) 
of the conductors, 1.2 m (4 ft) horizontally, pass above the 
roof overhang and (2) they are terminated at a through- 
the-roof raceway or approved support. 

Exception No. 4: The requirement for maintaining the 
vertical clearance 900 mm (3 ft) from the edge of the roof 
shall not apply to the final conductor span where the 
conductors are attached to the side of a building. 

(B) From Nonbuilding or Nonbridge Structures. From 
signs, chimneys, radio and television antennas, tanks, and 
other nonbuilding or nonbridge structures, clearances — 
vertical, diagonal, and horizontal — shall not be less than 
900 mm (3 ft). 

(C) Horizontal Clearances. Clearances shall not be less 
than 900 mm (3 ft). 

(D) Final Spans. Final spans of feeders or branch circuits 
shall comply with 225.19(D)(1), (D)(2), and (D)(3). 

(1) Clearance from Windows. Final spans to the building 
they supply, or fi-om which they are fed, shall be permitted 
to be attached to the building, but they shall be kept not 
less than 900 mm (3 ft) fi-om windows that are designed to 
be opened, and fi-om doors, porches, balconies, ladders, 
stairs, fire escapes, or similar locations. 

Exception: Conductors run above the top level of a 
window shall be permitted to be less than the 900-mm (3 -ft) 
requirement. 

(2) Vertical Clearance. The vertical clearance of final 
spans above, or within 900 mm (3 ft) measured 
horizontally of, platforms, projections, or surfaces fi"om 
which they might be reached shall be maintained in 
accordance with 225. 1 8. 

(3) BuUding Openings. The overhead branch-circuit and 
feeder conductors shall not be installed beneath openings 
through which materials may be moved, such as openings in 
farm and commercial buildings, and shall not be installed 
where they obstruct entrance to these buildings' openings. 

(E) Zone for Fire Ladders. Where buildings exceed three 
stories or 15 m (50 ft) in height, overhead lines shall be 
arranged, where practicable, so that a clear space (or zone) 
at least 1.8 m (6 ft) wide will be left either adjacent to the 
buildings or beginning not over 2.5 m (8 ft) fi-om them to 
facilitate the raising of ladders when necessary for fire 
fighting. 

225.20 Mechanical Protection of Conductors. 

Mechanical protection of conductors on buildings, 
structures, or poles shall be as provided for services in 
230.50. 



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70-69 



225.21 



ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS 



225.21 Multiconductor Cables on Exterior Surfaces of 
Buildings. Supports for multiconductor cables on exterior 
surfaces of buildings shall be as provided in 230.51. 

225.22 Raceways on Exterior Surfaces of Buildings or 
Otiier Structures. Raceways on exteriors of buildings or 
other structures shall be arranged to drain and shall be 
raintight in wet locations. 

225.24 Outdoor Lampliolders. Where outdoor 
lampholders are attached as pendants, the connections to 
the circuit wires shall be staggered. Where such 
lampholders have terminals of a type that puncture the 
insulation and make contact with the conductors, they shall 
be attached only to conductors of the stranded type. 

225.25 Location of Outdoor Lamps. Locations of lamps 
for outdoor lighting shall be below all energized 
conductors, transformers, or other electric utilization 
equipment, unless either of the following apply: 

(1) Clearances or other safeguards are provided for 
relamping operations. 

(2) Equipment is controlled by a disconnecting means that 
can be locked in the open position. 

225.26 Vegetation as Support. Vegetation such as trees 
shall not be used for support of overhead conductor spans. 

IL More Than One Building or Other Structure 

225.30 Number of Supplies. Where more than one building 
or other structure is on the same property and under single 
management, each additional building or other structure that 
is served by a branch circuit or feeder on the load side of the 
service disconnecting means shall be supplied by only one 
feeder or branch circuit unless permitted in 225.30(A) 
through (E). For the purpose of this section, a multiwire 
branch circuit shall be considered a single circuit. 

(A) Special Conditions. Additional feeders or branch 
circuits shall be permitted to supply the following: 

(1) Fire pumps 

(2) Emergency systems 

(3) Legally required standby systems 

(4) Optional standby systems 

(5) Parallel power production systems 

(6) Systems designed for connection to multiple sources 
of supply for the purpose of enhanced rehability 

(B) Special Occupancies. By special permission, 

additional feeders or branch circuits shall be permitted for 
either of the following: 

(1) Muhiple-occupancy buildings where there is no space 
available for supply equipment accessible to all 
occupants 



(2) A single building or other structure sufficiently large to 
make two or more supplies necessary 

(C) Capacity Requirements. Additional feeders or branch 
circuits shall be permitted where the capacity requirements 
are in excess of 2000 amperes at a supply voltage of 600 
volts or less. 

(D) Different Characteristics. Additional feeders or 
branch circuits shall be permitted for different voltages, 
frequencies, or phases or for different uses, such as control 
of outside lighting from multiple locations. 

(E) Documented Switching Procedures. Additional 
feeders or branch circuits shall be permitted to supply 
installations under single management where documented 
safe switching procedures are established and maintained 
for disconnection. 

225.31 Disconnecting Means. Means shall be provided 
for disconnecting all ungrounded conductors that supply or 
pass through the building or structure. 

225.32 Location. The disconnecting means shall be 
installed either inside or outside of the building or structure 
served or where the conductors pass through the building 
or structure. The disconnecting means shall be at a readily 
accessible location nearest the point of entrance of the 
conductors. For the purposes of this section, the 
requirements in 230.6 shall be utilized. 

Exception No. 1: For installations under single 
management, where documented safe switching procedures 
are established and maintained for disconnection, and 
where the installation is monitored by qualified 
individuals, the disconnecting means shall be permitted to 
be located elsewhere on the premises. 

Exception No. 2: For buildings or other structures 
qualifying under the provisions of Article 685, the 
disconnecting means shall be permitted to be located 
elsewhere on the premises. 

Exception No. 3: For towers or poles used as lighting 
standards, the disconnecting means shall be permitted to 
be located elsewhere on the premises. 

Exception No. 4: For poles or similar structures used only 
for support of signs installed in accordance with Article 
600, the disconnecting means shall be permitted to be 
located elsewhere on the premises. 

225.33 Maximum Number of Disconnects. 

(A) General. The disconnecting means for each supply 
permitted by 225.30 shall consist of not more than six 
switches or six circuit breakers mounted in a single 
enclosure, in a group of separate enclosures, or in or on a 
switchboard. There shall bie no more than six disconnects 
per supply grouped in any one location. 



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2010 California Electrical Code 



ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS 



225.39 



Exception: For the purposes of this section, disconnecting 
means used solely for the control circuit of the ground-fault 
protection system, or the control circuit of the power- 
operated supply disconnecting means, installed as part of 
the listed equipment, shall not be considered a supply 
disconnecting means. 

(B) Single-Pole Units. Two or three single-pole switches 
or breakers capable of individual operation shall be 
permitted on multiwire circuits, one pole for each 
ungrounded conductor, as one multipole disconnect, 
provided they are equipped with ^^mtl§|i| handle ties or a 
master handle to disconnect all ungrounded conductors 
with no more than six operations of the hand. 

225.34 Grouping of Disconnects. 

(A) General. The two to six disconnects as permitted in 
225.33 shall be grouped. Each disconnect shall be marked 
to indicate the load served. 

Exception: One of the two to six disconnecting means 
permitted in 225.33, where used only for a water pump 
also intended to provide fire protection, shall be permitted 
to be located remote from the other disconnecting means. 

(B) Additional Disconnecting Means. The one or more 
additional disconnecting means for fire pumps or for 
emergency, legally required standby or optional standby 
system permitted by 225.30 shall be installed sufficiently 
remote from the one to six disconnecting means for normal 
supply to minimize the possibility of simultaneous 
interruption of supply. 

225.35 Access to Occupants. In a multiple-occupancy 
building, each occupant shall have access to the occupant's 
supply disconnecting means. 

Exception: In a multiple-occupancy building where 
electric supply and electrical maintenance are provided by 
the building management and where these are under 
continuous building management supervision, the supply 
disconnecting means supplying more than one occupancy 
shall be permitted to be accessible to authorized 
management personnel only. 

225.36 Suitable for Service Equipment. The 

disconnecting means specified in 225.31 shall be suitable 
for use as service equipment 

Exception: For garages and outbuildings on residential 
property, a snap switch or a set of 3-way or 4-way snap 
switches shall be permitted as the disconnecting means. 

225.37 Identification. Where a building or structure has 
any combination of feeders, branch circuits, or services 
passing through it or supplying it, a permanent plaque or 
directory shall be installed at each feeder and branch-circuit 



disconnect location denoting all other services, feeders, or 
branch circuits supplying that building or structure or 
passing through that building or structure and the area 
served by each. 

Exception No. I: A plaque or directory shall not be 
required for large-capacity multibuilding industrial 
installations under single management, where it is ensured 
that disconnection can be accomplished by establishing 
and maintaining safe switching procedures. 

Exception No. 2: This identification shall not be required 
for branch circuits installed from a dwelling unit to a 
second building or structure. 

225.38 Disconnect Construction. Disconnecting means 
shall meet the requirements of 225.38(A) through (D). 

Exception: For garages and outbuildings on residential 
property, snap switches or sets of 3-way or 4-way snap 
switches shall be permitted as the disconnecting means. 

(A) Manually or Power Operable. The disconnecting 
means shall consist of either (1) a manually operable 
switch or a circuit breaker equipped with a handle or other 
suitable operating means or (2) a power-operable switch or 
circuit breaker, provided the switch or circuit breaker can 
be opened by hand in the event of a power failure. 

(B) Simultaneous Opening of Poles. Each building or 
structure disconnecting means shall simultaneously 
disconnect all ungrounded supply conductors that it 
controls from the building or structure wiring system. 

(C) Disconnection of Grounded Conductor. Where the 
building or structure disconnecting means does not 
disconnect the grounded conductor from the grounded 
conductors in the building or structure wiring, other means 
shall be provided for this purpose at the location of 
disconnecting means. A terminal or bus to which all 
grounded conductors can be attached by means of pressure 
connectors shall be permitted for this purpose. 

In a multisection switchboard, disconnects for the 
grounded conductor shall be permitted to be in any section 
of the switchboard, provided any such switchboard section 
is marked. 

(D) Indicating. The building or structure disconnecting 
means shall plainly indicate whether it is in the open or 
closed position. 

225.39 Rating of Disconnect. The feeder or branch-circuit 
disconnecting means shall have a rating of not less than the 
SSiliMi 1^^*^ to be suppHed, determined in accordance 
with Parts I and II of Article 220 for branch circuits, Part 
III or IV of Article 220 for feeders, or Part V of Article 220 
for farm loads. [pS^e;^^.^|^?2%fflSL3^1il^ 



2010 California Electrical Code 



70-71 



225.40 



ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS 



discoimectmg mean^^ 

circuit breaker, as permitted by 22l33, combmmg the! 

ratmgs of ail the switches or circuit breakers for 

deteitnimng the rating of the disconnecting means shall be; 

germitteA In no case shaU the tat^^ 

spSdiiecl in 22539{A)r(BI ^^ 

(A) One-Circuit Installation. For installations to supply 
only limited loads of a single branch circuit, the branch 
circuit disconnecting means shall have a rating of not less 
than 15 amperes. 

(B) Two-Circuit Installations. For installations consisting 
of not more than two 2-wire branch circuits, the feeder or 
branch-circuit disconnecting means shall have a rating of 
not less than 30 amperes. 

(C) One-Family Dwelling. For a one-family dwelling, the 
feeder disconnecting means shall have a rating of not less 
than 100 amperes, 3-wire. 

(D) All Others. For all other installations, the feeder or 
branch-circuit disconnecting means shall have a rating of 
not less than 60 amperes. 

225.40 Access to Overcurrent Protective Devices. 

Where a feeder overcurrent device is not readily accessible, 
branch-circuit overcurrent devices shall be installed on the 
load side, shall be mounted in a readily accessible location, 
and shall be of a lower ampere rating than the feeder 
overcurrent device. 



III. Over 600 Volts 

225.50 Sizing of Conductors. The sizing of conductors 
over 600 volts shall be in accordance with 210.19(B) for 
branch circuits and 215.2(B) for feeders. 

225.51 Isolating Switches. Where oil switches or air, oil, 
vacuum, or sulfur hexafluoride circuit breakers constitute a 
building disconnecting means, an isolating switch with 
visible break contacts and meeting the requirements of 
230.204(B), (C), and (D) shall be installed on the supply 
side of the disconnecting means and all associated 
equipment. 

Exception: The isolating switch shall not be required 
where the disconnecting means is mounted on removable 
truck panels or metal-enclosed switchgear units that 
cannot be opened unless the circuit is disconnected and 
that, when removed from the normal operating position, 
automatically disconnect the circuit breaker or switch from 
all energized parts. 



225.52 Location. A building or structure disconnecting 
means shall be located in accordance with 225.32, or it 
shall be electrically operated by a similarly located remote- 
control device. 

225.53 Type. Each building or structure disconnect shall 
simultaneously disconnect all ungrounded supply 
conductors it controls and shall have a fault-closing rating 
not less than the maximum available short-circuit current 
available at its supply terminals. 

Where fused switches or separately mounted fuses are 
installed, the fuse characteristics shall be permitted to 
contribute to the fault closing rating of the disconnecting 
means. 

225.60 Clearances over Roadways, Walkways, Rail, 
Water, and Open Land. 

(A) 22 kV, Nominal, to Ground or Less. The clearances 
over roadways, walkways, rail, water, and open land for 
conductors and Hve parts up to 22 kV, nominal, to ground 
or less shall be not less than the values shown in Table 
225.60. 

Table 225.60 Clearances over Roadways, Walkways, Rail, 
Water, and Open Land 



Clearance 


Location 


m 


ft 


Open land subject to vehicles, 
cultivation, or grazing 


5.6 


18.5 


Roadways, driveways, parking lots, 
and alleys 


5.6 


18.5 


Walkways 


4.1 


13.5 


Rails 


8.1 


26.5 


Spaces and ways for pedestrians and 
restricted traffic 


4.4 


14.5 


Water areas not suitable for boating 


5.2 


17.0 



(B) Over 22 kV Nominal to Ground. Clearances for the 
categories shown in Table 225.60 shall be increased by 10 
mm (0.4 in.) per kV above 22,000 volts. 

(C) Special Cases. For special cases, such as where 
crossings will be made over lakes, rivers, or areas using 
large vehicles such as mining operations, specific designs 
shall be engineered considering the special circumstances 
and shall be approved by the authority having jurisdiction. 

FPN: For additional information, see ANSI C2-2007, 
National Electrical Safety Code. 

225.61 Clearances over Buildings and Other Structures. 

(A) 22 kV Nominal to Ground or Less. The clearances 
over buildings and other structures for conductors and live 
parts up to 22 kV, nominal, to ground or less shall be not 
less than the values shown in Table 225.61 . 



70-72 



2010 California Electrical Code 



ARTICLE 230 - SERVICES 



230.2 



Table 225.61 Clearances over Buildings and Other Structures 



Clearance from 

Conductors or Live 

Parts from: 



Horizontal 



Vertical 



m 



ft 



m 



Building walls, 2.3 7.5 — — 

projections, and 
windows 

Balconies, catwalks, 2.3 7.5 4.1 13.5 

and similar areas 
accessible to 
people 

Over or under roofs or — — 3.8 12.5 

projections not 
readily accessible 
to people 

Over roofs accessible — — 4.1 13.5 

to vehicles but not 
trucks 

Over roofs accessible — — 5.6 18.5 

to trucks 

Other structures 2.3 7.5 — — 



(B) Over 22 kV Nominal to Ground. Clearances for the 
categories shown in Table 225.61 shall be increased by 10 
mm (0.4 in.) per kV above 22,000 volts. 

FPN: For additional information, see ANSI C2-2007, 
National Electrical Safety Code. 






230.1 Scope. This article covers service conductors and 
equipment for control and protection of services and their 
installation requirements. 

FPN: See F^fmjl 

I. General 

230.2 Number of Services. A building or other structure 
served shall be supplied by only one service unless 
permitted in 230.2(A) through (D). For the purpose of 
230.40, Exception No. 2 only, underground sets of 
conductors, 1/0 AWG and larger, running to the same 
location and connected together at their supply end but not 
connected together at their load end shall be considered to 
be supplying one service. 

(A) Special Conditions. Additional services shall be 
permitted to supply the following: 

(1) Fire pumps 

(2) Emergency systems 

(3) Legally required standby systems 



General Part \ 

Overhead Service-Drop Conductors Part tl 

Underground Service-Lateral Conductors Part III 

Service-Entrance Conductors Part iV 

Service Equipment— General Part V 

Ser^^ce Equipment— Disconnecting Means Part VI 

Service Equipment — Overcurrent Protection Part VI I 

Services Exceeding BOO Volts, Nominal Part VIII 

Source 



Overhead 
last pole 






Underground 
Street main 


Part 11 Service drop 
230.24 Clearances 

Service head 




Service lateral Part ill 

Depth of burial 230.49 
and protection 

Terminal box, 
meter, or other 










enclosure 











Service-entrance 
conductors 


Part IV 


Service equipment— general 
Grounding and bonding 


c 


s 


PartV 
Article 250 



Disconnecting means 


\ 




Part VI 


Overcurrent protection 




Pail Vli 










Branch circuits 
Feeders 


Articles 210, 225 
Articles 215. 225 











iigure 230,1 ServicesJ 

(4) Optional standby systems 

(5) Parallel power production systems 

(6) Systems designed for connection to multiple sources of 
supply for the purpose of enhanced rehability 

(B) Special Occupancies. By special permission, 
additional services shall be permitted for either of the 
following: 

(1) Multiple-occupancy buildings where there is no 
available space for service equipment accessible to all 
occupants 

(2) A single building or other structure sufficiently large to 
make two or more services necessary 

(C) Capacity Requirements. Additional services shall be 
permitted under any of the following: 

(1) Where the capacity requirements are in excess of 2000 
amperes at a supply voltage of 600 volts or less 

(2) Where the load requirements of a single-phase 
installation are greater than the serving agency 
normally supplies through one service 

(3) By special permission 



2010 California Electrical Code 



70-73 



230.3 



ARTICLE 230 - SERVICES 



(D) Different Characteristics. Additional services shall be 
permitted for different voltages, frequencies, or phases, or 
for different uses, such as for different rate schedules. 

(E) Identification. Where a building or structure is 
supplied by more than one service, or any combination of 
branch circuits, feeders, and services, a permanent plaque 
or directory shall be installed at each service disconnect 
location denoting all other services, feeders, and branch 
circuits supplying that building or structure and the area 
served by each. See 225.37. 

230.3 One Building or Other Structure Not to Be 
Supplied Through Another. Service conductors 
supplying a building or other structure shall not pass 
through the interior of another building or other structure. 

230.6 Conductors Considered Outside the Building. 

Conductors shall be considered outside of a building or 
other structure under any of the following conditions: 

(1) Where installed under not less than 50 mm (2 in.) of 
concrete beneath a building or other structure 

(2) Where installed within a building or other structure in a 
raceway that is encased in concrete or brick not less 
than 50mm (2 in.) thick ' 

(3) Where installed in any vault that meets the construction 
requirements of Article 450, Part III 

(4) Where installed in conduit and under not less than 450 
mm (18 in.) of earth beneath a building or other 
structure 

230.7 Other Conductors in Raceway or Cable. 

Conductors other than service conductors shall not be 
installed in the same service raceway or service cable. 

Exception No. 1: Grounding conductors and bonding 
jumpers. 

Exception No. 2: Load management control conductors 
having overcurrent protection. 

230.8 Raceway Seal. Where a service raceway enters a 
building or structure from an underground distribution 
system, it shall be sealed in accordance with 300.5(G). 
Spare or unused raceways shall also be sealed. Sealants 
shall be identified for use with the cable insulation, shield, 
or other components. 

230.9 Clearances on Buildings. Service conductors and 
final spans shall comply with 230.9(A), (B), and (C). 

(A) Clearances. Service conductors installed as open 
conductors or multiconductor cable without an overall 
outer jacket shall have a clearance of not less than 900 mm 
(3 ft) from windows that are designed to be opened, doors, 
porches, balconies, ladders, stairs, fire escapes, or similar 
locations. 



Exception: Conductors run above the top level of a 
window shall be permitted to be less than the 900-mm (3-ft) 
requirement. 

(B) Vertical Clearance. The vertical clearance of final 
spans above, or within 900 mm (3 ft) measured 
horizontally of, platforms, projections, or surfaces from 
which they might be reached shall be maintained in 
accordance with 230.24(B). 

(C) Building Openings. Overhead service conductors shall 
not be installed beneath openings through which materials 
may be moved, such as openings in farm and commercial 
buildings, and shall not be installed where they obstruct 
entrance to these building openings. 

230.10 Vegetation as Support. Vegetation such as trees 
shall not be used for support of overhead service conductors. 



II. Overhead Service-Drop Conductors 

Individual conductors 



230.22 Insulation or Covering. 

shall be insulated or covered. 



Exception: The grounded conductor of a multiconductor 
cable shall be permitted to be bare. 

230.23 Size and Rating. 

(A) General. Conductors shall have sufficient ampacity to 
carry the current for the load as calculated in accordance 
with Article 220 and shall have adequate mechanical 
strength. 

(B) Minimum Size. The conductors shall not be smaller 
than 8 AWG copper or 6 AWG aluminum or copper-clad 
aluminum. 

Exception: Conductors supplying only limited loads of a 
single branch circuit — such as small polyphase power, 
controlled water heaters, and similar loads — shall not be 
smaller than 12 A WG hard-drawn copper or equivalent. 

(C) Grounded Conductors. The grounded conductor shall 
not be less than the minimum size as required by 
250.24(C). 

230.24 Clearances. Service-drop conductors shall not be 
readily accessible and shall comply with 230.24(A) through 

(D) for services not over 600 volts, nominal. 

(A) Above Roofs. Conductors shall have a vertical 
clearance of not less than 2.5 m (8 ft) above the roof 
surface. The vertical clearance above the roof level shall be 
maintained for a distance of not less than 900 mm (3 ft) in 
all directions from the edge of the roof 



• 



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ARTICLE 230 - SERVICES 



230.33 



Exception No. I: The area above a roof surface subject to 
pedestrian or vehicular traffic shall have a vertical 
clearance from the roof surface in accordance with the 
clearance requirements of 230.24(B). 

Exception No. 2: Where the voltage between conductors 
does not exceed 300 and the roof has a slope of 100 mm in 
300 mm (4 in. in 12 in.) or greater, a reduction in 
clearance to 900 mm (3 ft) shall be permitted. 

Exception No. 3: Where the voltage between conductors 
does not exceed 300, a reduction in clearance above only 
the overhanging portion of the roof to not less than 450 mm 
(18 in.) shall be permitted if (1) not more than 1.8 m (6 ft) 
of service-drop conductors, 1.2 m (4 ft) horizontally, pass 
above the roof overhang, and (2) they are terminated at a 
through- the-roof raceway or approved support. 

FPN: See 230.28 for mast supports. 

Exception No. 4: The requirement for maintaining the 
vertical clearance 900 mm (3 ft) from the edge of the roof 
shall not apply to the final conductor span where the 
service drop is attached to the side of a building. 

(B) Vertical Clearance for Servlce-Brop CpnduC 

Service-drop conductors, where not in excess of 600 volts, 
nominal, shall have the following minimum clearance from 
final grade: 

(1) 3.0 m (10 ft) — at the electrical service entrance to 
buildings, also at the lowest point of the drip loop of 
the building electrical entrance, and above areas or 
sidewalks accessible only to pedestrians, measured 
from final grade or other accessible surface only for 
service-drop cables supported on and cabled together 
with a grounded bare messenger where the voltage 
does not exceed 1 50 vohs to ground 

(2) 3.7 m (12 ft) — over residential property and 
driveways, and those commercial areas not subject to 
truck traffic where the vohage does not exceed 300 
volts to ground 

(3) 4.5 m (15 ft) — for those areas hsted in the 3.7-m (12- 
ft) classification where the voltage exceeds 300 volts 
to ground 

(4) 5.5 m (18 ft) — over public streets, alleys, roads, 
parking areas subject to truck traffic, driveways on 
other than residential property, and other land such as 
cuhivated, grazing, forest, and orchard 

(C) Clearance from Building Openings. See 230.9. 

(D) Clearance from Swimming Pools. See 680.8. 

230.26 Point of Attachment. The point of attachment of 
the service-drop conductors to a building or other structure 
shall provide the minimum clearances as specified in 230.9 
and 230.24. In no case shall this point of attachment be less 
than 3.0 m (10 ft) above finished grade. 



230.27 Means of Attachment. Multiconductor cables 
used for service drops shall be attached to buildings or 
other structures by fittings identified for use with service 
conductors. Open conductors shall be attached to fittings 
identified for use with service conductors or to 
noncombustible, nonabsorbent insulators securely attached 
to the building or other structure. 

230.28 Service Masts as Supports. Where a service mast 
is used for the support of service-drop conductors, it shall 
be of adequate strength or be supported by braces or guys 
to withstand safely the strain imposed by the service drop. 
Where raceway-type service masts are used, all raceway 
fittings shall be identified for use with service masts. Only 
power service-drop conductors shall be permitted to be 
attached to a service mast. 

230.29 Supports over Buildings. Service-drop conductors 
passing over a roof shall be securely supported by 
substantial structures. Where pracficable, such supports 
shall be independent of the building. 

III. Underground Service-Lateral Conductors 

230.30 Insulation. Service-lateral conductors shall be 
insulated for the applied voltage. 

Exception: A grounded conductor shall be permitted to be 
uninsulated as follows: 

(1) Bare copper used in a raceway. 

(2) Bare copper for direct burial where bare copper is 
judged to be suitable for the soil conditions. 

(3) Bare copper for direct burial without regard to soil 
conditions where part of a cable assembly identified for 
underground use. 

(4) Aluminum or copper-clad aluminum without individual 
insulation or covering where part of a cable assembly identified 
for underground use in a raceway or for direct burial 

230.31 Size and Rating. 

(A) General. Service-lateral conductors shall have 
sufficient ampacity to carry the current for the load as 
calculated in accordance with Article 220 and shall have 
adequate mechanical strength. 

(C) Grounded Conductors. The grounded conductor shall 
not be less than the minimum size required by 250.24(C). 

230.32 Protection Against Damage. Underground 
service-lateral conductors shall be protected against 
damage in accordance with 300.5. Service-lateral 
conductors entering a building shall be installed in 
accordance with 230.6 or protected by a raceway wiring 
method identified in 230.43. 

230.33 Spliced Conductors. Service-lateral conductors 
shall be permitted to be spliced or tapped in accordance 
with 110.14, 300.5(E), 300.13, and 300.15. 



2010 California Electrical Code 



70-75 



230.40 



ARTICLE 230 - SERVICES 



be determined from 310.15. The maximum allowable 
current of busways shall be that value for which the 
busway has been listed or labeled. 

(1) The sum of the noncontinuous loads plus 125 percent 
of continuous loads 

(2) The sum of the noncontinuous load plus the 
continuous load if the service-entrance conductors 
terminate in an overcurrent device where both the 
overcurrent device and its assembly are listed for 
operation at 1 00 percent of their rating 

(B) Specific Installations. In addition to the requirements 
of 230.42(A), the minimum ampacity for ungrounded 
conductors for specific installations shall not be less than 
the rating of the service disconnecting means specified in 
230.79(A) through (D). 

(C) Grounded Conductors. The grounded conductor shall 
not be smaller: than the minimum size as required by 

250.24(C). 

230.43 Wiring Methods for 600 Volts, Nominal, or Less. 

Service-entrance conductors shall be installed in 
accordance with the applicable requirements of this Code 
covering the type of wiring method used and shall be 
imited to the following methods: 

1) Open wiring on insulators 

2) Type IGS cable 

3) Rigid metal conduit 

4) Intermediate metal conduit 

5) Electrical metallic tubing 

6) Electrical nonmetaUic tubing (ENT) 

7) Service-entrance cables 

8) Wireways 

9) Busways 

10) Auxiliary gutters 

1 1) Rigid nonmetallic conduit 

12) Cablebus 

13) Type MC cable 

14) Mineral-insulated, metal-sheathed cable 

15) Flexible metal conduit not over 1.8 m (6 ft) long or 
liquidtight flexible metal conduit not over 1.8 m (6 ft) 
long between raceways, or between raceway and 
service equipment, with equipment bonding jumper 
routed with the flexible metal conduit or the liquidtight 
flexible metal conduit according to the provisions of 
250.102(A), (B),(C), and (E) 

I^ W, driV,;o|:iitoic^ Ampacity shall (16) Liquidtight flexible nonmetallic conduit 



IV. Service-Entrance Conductors 

230.40 Number of Service-Entrance Conductor Sets. 

Each service drop or lateral shall supply only one set of 
service-entrance conductors. 

Exception No. 1: A building mth /more than one 
occupancy shall be permitted to have one set of service- 
entrance conductors for each service, as defined in 230.2, 
run to each occupancy or group of occupancies. 

Exception No. 2: Where two to six service disconnecting 
means in separate enclosures are grouped at one location 
and supply separate loads from one service drop or lateral, 
one set of service- entrance conductors shall be permitted to 
supply each or several such service equipment enclosures. 

Exception No. 3: A single-family dwelling unit and a 
separate structure shall be permitted to have one set of 
service-entrance conductors run to each from a single 
service drop or lateral. 

Exception No. 4: A two-family dwelling or a multifamily 
dwelling shall be permitted to have one set of service- 
entrance conductors installed to supply the circuits covered 
in 210.25. 

Exception No. 5: One set of service-entrance conductors 
connected to the supply side of the normal service 
disconnecting means shall be permitted to supply each or 
several systems covered by 230.82(5) or 230.82(6). 

230.41 Insulation of Service-Entrance Conductors. 

Service-entrance conductors entering or on the exterior of 
buildings or other structures shall be insulated. 

Exception: A grounded conductor shall be permitted to be 
uninsulated as follows: 

(!) Bare copper used in a raceway or part of a service 
cable assembly. 

(2) Bare copper for direct burial where bare copper is 
Judged to be suitable for the soil conditions. 

(3) Bare copper for direct burial without regard to soil 
conditions where part of a cable assembly identified for 
underground use. 

(4) Aluminum or copper-clad aluminum without 
individual insulation or covering where part of a cable 
assembly or identified for underground use in a raceway, or 
for direct burial. 

(5) Bare conductors used in an auxiliary gutter. 

230.42 Minimum Size and Rating. 

(A) General. The ampacity of the service-entrance 
conductors before the application of any adjustment or 
correction factors shall not be less than either (A)(1) or 
Loads shall be determined in accordance with Part 



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ARTICLE 230 - SERVICES 



230.51 



230.44 Cable Trays. Cable tray systems shall be 
permitted to support service-entrance conductors. Cable 
trays used to support service-entrance conductors shall 
contain only service -entrance conductors. 

Exception: Conductors, other than service-entrance 
conductors, shall be permitted to be installed in a cable 
tray with service-entrance conductors, provided a solid 
fixed barrier of a material compatible with the cable tray is 
installed to separate the service-entrance conductors from 
other conductors installed in the cable tray. Cable trays, 
shall beMeniified with permanently affixed labels with the 
}yprdingj";Seiyice-Entrance Cdnduci6rs,f The labels shall 
be located so as to be visible after instdlidtibn and placea 
'sa thai the service^entrance conductors may be readily 
trqcedfi^iqugh the entire length of the cjahle^h^ 

230.46 Spliced Conductors. Service-entrance conductors 
shall be permitted to be spHced or tapped in accordance 
with 1 10.14, 300.5(E), 300.13, and 300.15. 

230.50 Protection Against Physical Damage. 

|(A)j Underground Seryic e-Entrajtfee: CondnfetQ t%. 
Underground service-entrance conductors shall be 
protected against physical damage in accordance with 
300.5. 



(Bll^^iWI; ;;fJ^Ii^»' \Service-p»traiie^: idoMiic^^ oth^ 

^er^i!D*6refito^ conduct^irs;^^; ;.^igl|^;3!3^ 
&ftj^(&j]jlDJ^^ shall be protected against 

physical damage as specified in '§M^:^^^MkMM)i?)\ 

(1) Service Cables. Service cables, where subject to 
physical, damage, shall be protected by any of the 
following: 

(1) Rigid metal conduit 

(2) Intermediate metal conduit 

(3) Schedule 80 Pf q conduit 

(4) Electrical metallic tubing 

(5) Other approved means 

(2) Other Than Service Cable. Individual open 
conductors and cables, other than service cables, shall not 
be installed within 3.0 m (10 ft) of grade level or where 
exposed to physical damage. 



Exception: Type MI and Type MC cable shall be permitted 
within 3,0 m (10 ft) of grade level where not exposed to 
physical damage or where protected in accordance with 
300, 5(D), 

230.51 Mounting Supports. Cables or individual open 
service conductors shall be supported as specified in 
230.51(A), (B), or (C). 

(A) Service Cables. Service cables shall be supported by 
straps or other approved means within 300 mm (12 in.) of 
every service head, gooseneck, or connection to a raceway 
or enclosure and at intervals not exceeding 750 mm (30 
in.). 

(B) Other Cables. Cables that are not approved for 
mounting in contact with a building or other structure shall 
be mounted on insulating supports installed at intervals not 
exceeding 4.5 m (15 ft) and in a manner that maintains a 
clearance of not less than 50 mm (2 in.) from the surface 
over which they pass. 

(C) Individual Open Conductors. Individual open 
conductors shall be installed in accordance with Table 
230.51(C). Where exposed to the weather, the conductors 
shall be mounted on insulators or on insulating supports 
attached to racks, brackets, or other approved means. 
Where not exposed to the weather, the conductors shall be 
mounted on glass or porcelain knobs. 

230.52 Individual Conductors Entering Buildings or Other 
Structures. Where individual open conductors enter a 
building or other structure, they shall enter through roof 
bushings or through the wall in an upward slant through 
individual, noncombustible, nonabsorbent insulating tubes. 
Drip loops shall be formed on the conductors before they enter 
the tubes. 

230.53 Raceways to Drain. Where exposed to the weather, 
raceways enclosing service-entrance conductors shall be 
^m^la for i|se in w and arranged to drain. Where 
embedded in masonry, raceways shall be arranged to drain. 

m 

230.54 Overhead Service Locations. 

(A) Service Head. Service raceways shall be equipped with a 
service head at jthe point of connection to ^ervice-drop 
conductors. [The -service head sMl Spmply;: \^^ the 



20 1 California Electrical Code 



70-77 



230.56 



ARTICLE 230 - SERVICES 



Table 230.51(C) Supports 





Maximum Distance Between Supports 
m ft 




Minimum Clearance 




Between Conductors 


From Surface 


Maximum Volts 


mm 


in. 


mm in. 


600 


2.7 


9 


150 


6 


50 2 


600 


4.5 


15 


300 


12 


50 2 


300 


1.4 


4'/2 


75 


3 


50 2 


600* 


1.4* 


4^2* 


65* 


2^/2* 


25* 1* 



*Where not exposed to weather. 

(B) Service Cable Equipped with Service Head or 
Gooseneck. Service cables shall be equipped with a 
service head; the service head shall comply :m^ 
reqiairement for fittings in 314. 1 5, 

Exception: Type SE cable shall be permitted to be formed 
in a gooseneck and taped with a self-sealing weather- 
resistant thermoplastic, 

(C) Service Heads and Goosenecks Above Service- 
Drop Attachment. Service heads and goosenecks in 
service-entrance cables shall be located above the point of 
attachment of the service-drop conductors to the building 
or other structure. 

Exception: Where it is impracticable to locate the service 
head or gooseneck above the point of attachment, the 
service head or gooseneck location shall be permitted not 
farther than 600 mm (24 in.) from the point of attachment. 

(D) Secured. Service cables shall be held securely in 
place. 

(E) Separately Bushed Openings. Service heads shall 
have conductors of different potential brought out through 
separately bushed openings. 

Exception: For jacketed multiconductor service cable 
without splice. 

(F) Drip Loops. Drip loops shall be formed on individual 
conductors. To prevent the entrance of moisture, service- 
entrance conductors shall be connected to the service- 
drop conductors either (1) below the level of the service 
head or (2) below the level of the termination of the 
service-entrance cable sheath. 

(G) Arranged That Water Will Not Enter Service 
Raceway or Equipment. Service-drop conductors and 
service-entrance conductors shall be arranged so that 
water will not enter service raceway or equipment. 

230.56 Service Conductor with the Higher Voltage to 
Ground. On a 4-wire, deha-connected service where the 
midpoint of one phase winding is grounded, the service 
conductor having the higher phase voltage to ground shall 
be durably and permanently marked by an outer finish 



that is orange in color, or by other effective means, at 
each termination or junction point. 

V. Service Equipment — General 

230.62 Service Equipment — Enclosed or Guarded. 

Energized parts of service equipment shall be enclosed 
as specified in 230.62(A) or guarded as specified in 
230.62(B). 

(A) Enclosed. Energized parts shall be enclosed so that 
they will not be exposed to accidental contact or shall 
be guarded as in 230.62(B). 

(B) Guarded. Energized parts that are not enclosed 
shall be installed on a switchboard, panelboard, or 
control board and guarded in accordance with 110.18 
and 110.27. Where energized parts are guarded as 
provided in 110.27(A)(1) and (A)(2), a means for 
locking or sealing doors providing access to energized 
parts shall be provided. 

230.66 Marking. Service equipment rated at 600 volts 
or less shall be marked to identify it as being suitable 
for use as service equipment. Individual meter socket 
enclosures shall not be considered service equipment. 

VI. Service Equipment — Disconnecting Means 

230.70 General. Means shall be provided to 
disconnect all conductors in a building or other 
structure from the service-entrance conductors. 

(A) Location. The service disconnecting means shall 
be installed in accordance with 230.70(A)(1), (A)(2), 
and (A)(3). 

(1) Readily Accessible Location. The service 
disconnecting means shall be installed at a readily 
accessible location either outside of a building or 
structure or inside nearest the point of entrance of the 
service conductors. 



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ARTICLE 230 - SERVICES 



230.79 



(2) Bathrooms. Service disconnecting means shall not be 
installed in bathrooms. 

(3) Remote Control. Where a remote control device(s) is 
used to actuate the service disconnecting means, the service 
disconnecting means shall be located in accordance with 
230.70(A)(1). 

(B) Marking. Each service disconnect shall be 
permanently marked to identify it as a service disconnect. 

(C) Suitable for Use. Each service disconnecting means 
shall be suitable for the prevailing conditions. Service 
equipment installed in hazardous (classified) locations shall 
comply v^ith the requirements of Articles 500 through 517. 

230.71 Maximum Number of Disconnects. 

(A) General. The service disconnecting means for each 
service permitted by 230.2, or for each set of service- 
entrance conductors permitted by 230.40, Exception No. 1, 
3, 4, or 5, shall consist of not more than six switches or sets 
of circuit breakers, or a combination of not more than six 
switches and sets of circuit breakers, mounted in a single 
enclosure, in a group of separate enclosures, or in or on a 
switchboard. There shall be not more than six sets of 
disconnects per service grouped in any one location. 

For the purpose of this section, disconnecting means 
ittstalfed^ part of listed eqiiipment a used solely for the 
fpnowmg shall iiot be comidered a service discdimectirig 

(1) Power monitoring equipment 

(2) Surge-protective device(s) 

(3) Control circuit of the ground-fault protection system 

(4) Power-operable service disconnecting means 

(B) Single-Pole Units. Two or three single-pole switches 
or breakers, capable of individual operation, shall be 
permitted on multiwire circuits, one pole for each 
ungrounded conductor, as one multipole disconnect, 
provided they are equipped with ideatified handle ties or a 
master handle to disconnect all conductors of the service 
with no more than six operations of the hand. 

FPN: See 408.36, £xcepti<m Ho. 1 and Bxception Ho. 3, for 

service equipment in certain panelboards, and see 430.95 
for service equipment in motor control centers. 

230.72 Grouping of Disconnects. 

(A) General. The two to six disconnects as permitted in 
230.71 shall be grouped. Each disconnect shall be marked 
to indicate the load served. 

Exception: One of the two to six service disconnecting means 
permitted in 230.71, where used only for a water pump also 
intended to provide fire protection, shall be permitted to he 
located remote from the other disconnecting means. 



(B) Additional Service Disconnecting Means. The one or 

more additional service disconnecting means for fire 
pumps, emergency systems, legally required standby, or 
optional standby services permitted by 230.2 shall be 
installed remote from the one to six service disconnecting 
means for normal service to minimize the possibility of 
simultaneous interruption of supply, 

(C) Access to Occupants. In a multiple-occupancy 
building, each occupant shall have access to the occupant's 
service disconnecting means. 

Exception: In a multiple-occupancy building where 
electric service and electrical maintenance are provided by 
the building management and where these are under 
continuous building management supervision, the service 
disconnecting means supplying more than one occupancy 
shall be permitted to be accessible to authorized 
management personnel only. 

230.74 Simultaneous Opening of Poles. Each service 
disconnect shall simultaneously disconnect all ungrounded 
service conductors that it controls from the premises wiring 
system. 

230.75 Disconnection of Grounded Conductor. Where 
the service disconnecting means does not disconnect the 
grounded conductor from the premises wiring, other means 
shall be provided for this purpose in the service equipment. 
A terminal or bus to which all grounded conductors can be 
attached by means of pressure connectors shall be 
permitted for this purpose. In a multisection switchboard, 
disconnects for the grounded conductor shall be permitted 
to be in any section of the switchboard, provided any such 
switchboard section is marked. 

230.76 Manually or Power Operable. The service 
disconnecting means for ungrounded service conductors 
shall consist of one of the following: 

(1) A manually operable switch or circuit breaker equipped 
with a handle or other suitable operating means 

(2) A power-operated switch or circuit breaker, provided 
the switch or circuit breaker can be opened by hand in 
the event of a power supply failure 

230.77 Indicating. The service disconnecting means shall 
plainly indicate whether it is in the open or closed position. 

230.79 Rating of Service Disconnecting Means. The 

service disconnecting means shall have a rating not less 
than the calculated load to be carried, determined in 
accordance with Part ID, IVi or V of Article 220, as 
applicable; In no case shall the rating be lower than 
specified in 230.79(A), (B), (C), or (D). 

(A) One-Circuit Installations. For installations to 
supply only limited loads of a single branch circuit, the 
service disconnecting means shall have a rating of not 
less than 15 amperes^ 



2010 California Electrical Code 



70-79 



230.80 



ARTICLE 230 - SERVICES 



(B) Two-Circuit Installations. For installations 
consisting of not more than two 2-wire branch circuits, 
the service disconnecting means shall have a rating of 
not less than 30 amperes. 

(C) One-Family Dwellings. For a one-family dwelling, 
the service disconnecting means shall have a rating of 
not less than 100 amperes, 3 -wire. 

(D) All Others. For all other installations, the service 
disconnecting means shall have a rating of not less than 
60 amperes. 

230.80 Combined Rating of Disconnects. Where the 

service disconnecting means consists of more than one 
switch or circuit breaker, as permitted by 230.71, the 
combined ratings of all the switches or circuit breakers 
used shall not be less than the rating required by 230.79. 

230.81 Connection to Terminals. The service 
conductors shall be connected to the service 
disconnecting means by pressure connectors, clamps, or 
other approved means. Connections that depend on 
solder shall not be used. 

230.82 Equipment Connected to the Supply Side of 
Service Disconnect. Only the following equipment 
shall be permitted to be connected to the supply side of 
the service disconnecting means: 

(1) Cable limiters or other current-limiting devices. 

(2) Meters and meter sockets nominally rated not in excess of 
600 volts, provided all metal housings and service 
enclosures are grounded k m:cardance witii Part VH and 
bonded in accoixjancc with Part V of Article 250; 

(3) Meter disconnect switches nominally rated not in excess of 
600 volts that have a short-circuit current rating equal to or 
greater than the available short-circuit current, provided all 
metal housings and service enclosures are grounded in 
accordance with Part VH and bonded in aca)rda2ice m&i 
Part V of Articte 250. A met^ disconnect switch diall Ije 
capable of intem^tkig the load servedi 

(4) Instrument transformers (current and voltage), impedance 
shunts, load management devices, mtgQ arresters, md 
Type 1 surge-protective device^, 

(5) Taps used only to supply load management devices, 
circuits for standby power systems, fire pump equipment, 
and fire and sprinkler alarms, if provided with service 
equipment and installed in accordance with requirements 
for service-entrance conductors. 

(6) Solar photovoltaic systems, fuel cell systems, or 
interconnected electric power production sources. 

(7) Control circuits for power-operable service disconnecting 

means, if suitable overcurrent protection and disconnecting 
means are provided. 



(8) Ground-fault protection systems or Type 2 surge- 
protective devices, where installed as part of listed 
equipment, if suitable overcurrent protection and 
disconnecting means are provided. 



VIL Service Equipment — Overcurrent Protection 

230.90 Where Required. Each ungrounded service 
conductor shall have overload protection. 

(A) Ungrounded Conductor. Such protection shall be 
provided by an overcurrent device in series with each 
ungrounded service conductor that has a rating or setting 
not higher than the allowable ampacity of the conductor. A 
set of fuses shall be considered all the fuses required to 
protect all the ungrounded conductors of a circuit. Single- 
pole circuit breakers, grouped in accordance with 
230.71(B), shall be considered as one protective device. 

Exception No. 1: For motor-starting currents, ratings that 
comply with 430.52, 430.62, and 430.63 shall be permitted. 

Exception No. 2: Fuses and circuit breakers with a rating 
or setting that complies with 240.4(B) or (C) and 240.6 
shall be permitted. 

Exception No. 3: Two to six circuit breakers or sets of 
fuses shall be permitted as the overcurrent device to 
provide the overload protection. The sum of the ratings of 
the circuit breakers or fuses shall be permitted to exceed 
the ampacity of the service conductors, provided the 
calculated load does not exceed the ampacity of the service 
conductors. 

Exception No. 4: Overload protection for fire pump supply 
conductors shall comply with 695.4(B)(1). 

Exception No. 5: Overload protection for 120/240-volt, 3- 
wire, single-phase dwelling services shall be permitted in 
accordance with the requirements of 310.15(B)(6). 

(B) Not in Grounded Conductor. No overcurrent device 
shall be inserted in a grounded service conductor except a 
circuit breaker that simultaneously opens all conductors of 
the circuit. 

230.91 Location. The service overcurrent device shall be 
an integral part of the service disconnecting means or shall 
be located immediately adjacent thereto. 

230.92 Loclied Service Overcurrent Devices. Where the 

service overcurrent devices are locked or sealed or are not 
readily accessible to the occupant, branch-circuit 
overcurrent devices shall be installed on the load side, shall 
be mounted in a readily accessible location, and shall be of 
lower ampere rating than the service overcurrent device. 



70-80 



2010 California Electrical Code 



ARTICLE 230 - SERVICES 



230.200 



230.93 Protection of Specific Circuits. Where necessary 
to prevent tampering, an automatic overcurrent device that 
protects service conductors supplying only a specific load, 
such as a water heater, shall be permitted to be locked or 
sealed where located so as to be accessible. 

230.94 Relative Location of Overcurrent Device and 
Other Service Equipment. The overcurrent device shall 
protect all circuits and devices. 

Exception No. 1 : The service switch shall be permitted on 
the supply side. 

Exception No. 2: High-impedance shunt circuits, surge 
arresters] Jypel^surge-protecUve devices, surge-protective 
capacitors, and instrument transformers (current and 
voltage) shall be permitted to be connected and installed 
on the supply side of the service disconnecting means as 
permitted by 230,82. 

Exception No. 3: Circuits for load management devices 
shall be permitted to be connected on the supply side of the 
service overcurrent device where separately provided with 
overcurrent protection. 

Exception No. 4: Circuits used only for the operation of 
fire alarm, other protective signaling systems, or the supply 
to fire pump equipment shall be permitted to be connected 
on the supply side of the service overcurrent device where 
separately provided with overcurrent protection. 

Exception No. 5: Meters nominally rated not in excess of 
600 volts shall be permitted, provided all metal housings 
and service enclosures are grounded. 

Exception No. 6: Where service equipment is power 
operable, the control circuit shall be permitted to be 
connected ahead of the service equipment if suitable 
overcurrent protection and disconnecting means are 
provided. 

230.95 Ground-Fault Protection of Equipment. 

Ground-fault protection of equipment shall be provided for 
solidly grounded wye electric services of more than 150 
volts to ground but not exceeding 600 volts phase-to-phase 
for each service disconnect rated 1000 amperes or more. 
The grounded conductor for the solidly grounded wye 
system shall be connected directly to ground througJ^Cta^ 
'j^oundSg eiectrod^^ system, a^ specifietfin 250 JOJ without 
inserting any resistor or impedance device. 

The rating of the service disconnect shall be 
considered to be the rating of the largest fuse that can be 
installed or the highest continuous current trip setting for 
which the actual overcurrent device installed in a circuit 
breaker is rated or can be adjusted. 



Exception: The ground-fault protection provisions of this 
section shall not apply to a service disconnect for a 
continuous industrial process where a nonorderly 
shutdown will introduce additional or increased hazards. 



(A) Setting. The ground-fault protection system shall 
operate to cause the service disconnect to open all 
ungrounded conductors of the faulted circuit. The 
maximum setting of the ground-fault protection shall be 
1200 amperes, and the maximum time delay shall be one 
second for ground-fault currents equal to or greater than 
3000 amperes. 

(B) Fuses. If a switch and fuse combination is used, the 
fuses employed shall be capable of interrupting any current 
higher than the interrupting capacity of the switch during a 
time that the ground-fault protective system will not cause 
the switch to open. 

(C) Performance Testing. The ground-fault protection 
system shall be performance tested when first installed on 
site. The test shall be conducted in accordance with 
instructions that shall be provided with the equipment. A 
written record of this test shall be made and shall be 
available to the authority having jurisdiction. 

FPN No. 1 : Ground-fauh protection that functions to open 
the service disconnect affords no protection from faults on 
the line side of the protective element. It serves only to limit 
damage to conductors and equipment on the load side in the 
event of an arcing ground fault on the load side of the 
protective element. 

FPN No. 2: This added protective equipment at the service 
equipment may make it necessary to review the overall 
wiring system for proper selective overcurrent protection 
coordination. Additional installations of ground-fault 
protective equipment may be needed on feeders and branch 
circuits where maximum continuity of electric service is 
necessary. 

FPN No. 3: Where ground- fault protection is provided for 
the service disconnect and interconnection is made with 
another supply system by a transfer device, means or 
devices may be needed to ensure proper ground-fault 
sensing by the ground-fault protection equipment. 

FPN No. 4: See 517.17(A) for information on where an 
additional step of ground-fault protection is required for 
hospitals and other buildings with critical areas or life 
support equipment. 

VIII. Services Exceeding 600 Volts, Nominal 

230.200 General. Service conductors and equipment used 
on circuits exceeding 600 volts, nominal, shall comply with 
all the applicable provisions of the preceding sections of 



2010 California Electrical Code 



70-81 



230.202 



ARTICLE 230 - SERVICES 



this article and with the following sections that supplement 
or modify the preceding sections. In no case shall the 
provisions of Part VIII apply to equipment on the supply 
side of the service point. 

FPN: For clearances of conductors of over 600 volts, 
nominal, see ANSI C2-2007, National Electrical Safety 
Code. 

230.202 Service-Entrance Conductors. Service-entrance 
conductors to buildings or enclosures shall be installed to 
conform to 230.202(A) and (B). 

(A) Conductor Size. Service-entrance conductors shall not 
be smaller than 6 AWG unless in multiconductor cable. 
Multiconductor cable shall not be smaller than 8 AWG. 
(B) Wiring Methods. Service-entrance conductors shall 
be installed by one of the wiring methods covered in 
300.37 and 300.50. 

230.204 Isolating Switches. 

(A) Where Required. Where oil switches or air, oil, 
vacuum, or sulfur hexafluoride circuit breakers constitute 
the service disconnecting means, an isolating switch with 
visible break contacts shall be installed on the supply side 
of the disconnecting means and all associated service 
equipment. 

Exception: An isolating switch shall not be required where 
the circuit breaker or switch is mounted on removable 
truck panels or metal-enclosed switchgear units where both 
of the following conditions apply: 

(1) Cannot be opened unless the circuit is disconnected. 

(2) Where all energized parts are automatically 
disconnected when the circuit breaker or switch is removed 
from the normal operating position. 

(B) Fuses as Isolating Switch. Where fuses are of the type 
that can be operated as a disconnecting switch, a set of such 
fuses shall be permitted as the isolating switch. 

(C) Accessible to Qualified Persons Only. The isolating 
switch shall be accessible to qualified persons only. 

(D) Connection to Ground, Isolating switches shall be 
provided with a nieans for readily connecting the load side 
conductors to a grounding electrode system, equipmenj 
^ound busbar, ; or grounded steel structure when 
disconnected from the source of supply. 

A means for grounding the load side conductors to a 
gro^mdittg electrode system^ eqgipmeiit groutiditig busbatj^ 
ot^ow^^ shall not be required for any 

duplicate isolating switch installed and maintained by the 
electric supply company. 

230.205 Disconnecting Means. 

(A) Location. The service disconnecting means shall be 
located in accordance with 230.70. 

For eitiijet ; ;6vei&ad or undetgnyutid primar>| 
Bftliibutioii : s)^stem$;: on private ■ property, the seryicd 
(dftcomect : shk^ii :l>^ ■ i^miitted to be JcMcated^^^^^^ a loc^m 
|hM is |K>t ^^^'^}iyi^^^^]^\^i 



(B) Type. Each service disconnect shall simultaneously 
disconnect all ungrounded service conductors that it 
controls and shall have a fault-closing rating that is not less 
than the maximum short-circuit current available at its 
supply terminals. 

Where fused switches or separately mounted fuses are 
installed, the fuse characteristics shall be permitted to 
contribute to the fault-closing rating of the disconnecting 
means. 

(C) Remote Control. For multibuilding, industrial 
installations under single management, the service 
disconnecting means shall be permitted to be located at a 
separate building or structure. In such cases, the service 
disconnecting means shall be permitted to be electrically 
operated by a readily accessible, remote-control device. 
230.206 Overcurrent Devices as Disconnecting Means. 
Where the circuit breaker or alternative for it, as specified 
in 230.208 for service overcurrent devices, meets the 
requirements specified in 230.205, they shall constitute the 
service disconnecting means. 

230.208 Protection Requirements. A short-circuit 
protective device shall be provided on the load side of, or 
as an integral part of, the service disconnect, and shall 
protect all ungrounded conductors that it suppHes. The 
protective device shall be capable of detecting and 
interrupting all values of current, in excess of its trip setting 
or melting point, that can occur at its location. A fuse rated 
in continuous amperes not to exceed three times the 
ampacity of the conductor, or a circuit breaker with a trip 
setting of not more than six times the ampacity of the 
conductors, shall be considered as providing the required 
short-circuit protection. 

FPN: See Table 310.67 through Table 310.86 for 
ampacities of conductors rated 2001 volts and above. 
Overcurrent devices shall conform to 230.208(A) and (B). 

(A) Equipment Type. Equipment used to protect service- 
entrance conductors shall meet the requirements of Article 
490, Part II. 

(B) Enclosed Overcurrent Devices. The restriction to 80 
percent of the rating for an enclosed overcurrent device for 
continuous loads shall not apply to overcurrent devices 
installed in systems operating at over 600 volts. 

230.209 Surge Arresters (Lightning Arresters). 

Surge arresters installed in accordance with the 
requirements of Article 280 shall be permitted on each 
ungrounded overhead service conductor. 

230.210 Service Equipment — General Provisions. 
Service equipment, including instrument transformers, 
shall conform to Article 490, Part I. 

230.211 Metal-Enclosed Switchgear. Metal-enclosed 
switchgear shall consist of a substantial metal structure and 
a sheet metal enclosure. Where installed over a 
combustible floor, suitable protection thereto shall be 
provided. 



70-82 



2010 California Electrical Code 



ARTICLE 240 - OVERCURRENT PROTECTION 



240.4 



230.212 Over 35,000 Volts. Where the voltage exceeds 
35,000 volts between conductors that enter a building, they 
shall terminate in a metal-enclosed switchgear 
compartment or a vault conforming to the requirements of 
450.41 through 450.48. 



ARTICLE 240 

Overcttrrent Protection 



I. General 

240.1 Scope. Parts I through VII of this article provide 
the general requirements for overcurrent protection and 
overcurrent protective devices not more than 600 volts, 
nominal. Part VIII covers overcurrent protection for those 
portions of supervised industrial installations operating at 
voltages of not more than 600 volts, nominal. Part IX 
covers overcurrent protection over 600 volts, nominal. 

FPN: Overcurrent protection for conductors and 
equipment is provided to open the circuit if the current 
reaches a value that will cause an excessive or dangerous 
temperature in conductors or conductor insulation. See 
also 110.9 for requirements for interrupting ratings and 
110.10 for requirements for protection against fault 
currents. 

240.2 Definitions. 

Current-Limiting Overcurrent Protective Device. A 

device that, when interrupting currents in its current- 
limiting range, reduces the current flowing in the faulted 
circuit to a magnitude substantially less than that 
obtainable in the same circuit if the device were replaced 
with a solid conductor having comparable impedance. 

Supervised Industrial Installation. For the purposes of 
Part VIII, the industrial portions of a facility where all of 
the following conditions are met: 

(1) Conditions of maintenance and engineering supervision 

ensure that only qualified persons monitor and service the 
system. 

(2) The premises wiring system has 2500 kVA or greater of 
load used in industrial process(es), manufacturing 
activities, or both, as calculated in accordance with 
Article 220. 

(3) The premises has at least one service or feeder that is 
more than 150 volts to ground and more than 300 volts 
phase-to-phase. 



This definition excludes installations in buildings 
used by the industrial facility for offices, warehouses, 
garages, machine shops, and recreational facilities that are 
not an integral part of the industrial plant, substation, or 
control center. 

Tap Conductors. As used in this article, a tap 
conductor is defined as a conductor, other than a 
service conductor, that has overcurrent protection 
ahead of its point of supply that exceeds the value 
permitted for similar conductors that are protected as 
described elsewhere in 240.4. 

240.3 Other Articles. Equipment shall be protected 
against overcurrent in accordance with the article in 
this Code that covers the type of equipment specified 
in Table 240.3. 

240.4 Protection of Conductors. Conductors, other than 
flexible cords, flexible cables, and fixture wires, shall be 
protected against overcurrent in accordance with their 
ampacities specified in 310.15, unless otherwise 
permitted or required in 240.4(A) through (G). 

(A) Power Loss Hazard. Conductor overload protection 
shall not be required where the interruption of the circuit 
would create a hazard, such as in a material-handling 
magnet circuit or fire pump circuit. Short-circuit 
protection shall be provided. 

FPN: See NFPA 20-2007, Standard for the Installation of 
Stationary Pumps for Fire Protection. 

(B) Devices Rated 800 Amperes or Less. The next 
higher standard overcurrent device rating (above the 
ampacity of the conductors being protected) shall be 
permitted to be used, provided all of the following 
conditions are met: 

(1) The conductors being protected are not part of a 
multioutlet branch circuit supplying receptacles for 
cord-and-p lug-connected portable loads. 

(2) The ampacity of the conductors does not correspond 
with the standard ampere rating of a fuse or a circuit 
breaker without overload trip adjustments above its 
rating (but that shall be permitted to have other trip or 
rating adjustments). 

(3) The next higher standard rating selected does not 
exceed 800 amperes. 



2010 California Electrical Code 



70-83 



240.4 



ARTICLE 240 - OVERCURRENT PROTECTION 



Table 240.3 Other Articles 



Equipment 


Article 


Air-conditioning and refrigerating 


440 


equipment 




Appliances 


422 


Assembly occupancies 


518 


Audio signal processing, amplification, 


640 


and reproduction equipment 




Branch circuits 


210 


Busways 


368 


Capacitors 


460 


Class 1, Class 2, and Class 3 remote- 


725 


control, signaling, and power-limited 




circuits 




Closed-loop and programmed power 


780 


distribution 




Cranes and hoists 


610 


Electric signs and outhne lighting 


600 


Electric welders 


630 


Electrolytic cells 


668 


Elevators, dumbwaiters, escalators. 


620 


moving walks, wheelchair lifts, and 




stairway chair lifts 




Emergency systems 


700 


Fire alarm systems 


760 


Fire pumps 


695 


Fixed electric heating equipment for 


427 


pipelines and vessels 




Fixed electric space-heating equipment 


424 


Fixed outdoor electric deicing and snow- 


426 


melting equipment 




Generators 


445 


Health care facilities 


517 


Induction and dielectric heating equipment 


665 


Industrial machinery 


670 


Luminaires (lighting fixtures), 


410 


lampholders, and lamps 




Motion picture and television studios and 


530 


similar locations 




Motors, motor circuits, and controllers 


430 


Phase converters 


455 


Pipe organs 


650 


Receptacles 


406 


Services 


230 


Solar photovoltaic systems 


690 


Switchboards and panelboards 


408 


Theaters, audience areas of motion picture 


520 


and television studios, and similar 




locations 




Transformers and transformer vaults 


450 


X-ray equipment 


660 



(C) Devices Rated over 800 Amperes. Where the 

overcurrent device is rated over 800 amperes, the ampacity 



of the conductors it protects shall be equal to or greater 
than the rating of the overcurrent device defined in 240.6. 

(D) Small Conductors. Unless specifically permitted in 
240.4(E) or (G), the overcurrent protection^hall not exceed 
that required by (D)(1) through (D)(7) after aay correction 
factors for ambient tjei33|)eratoe a§d nianber of conductors 
have been appliedJ 

(i) iSAWG Copilen 7 ampereSj provided all the 

( 1 ) '^mtinuom}^^ 

(2) < Ovaciidrent l>ro^cifo|tis|ffOvid^^^ following: 

a; BranchH^ircuit-latfed circuit breakers listed and 

rnarkedforus|w^^ 1 8; AWG copper w^ 
b: feanch-circuit-rated fiises listed and marked for use 

jiyith;18;AWG|p^^^^^ 
cl ^ Giass_ GC;,^^ Gjass|[,; or' ClassT fiised 
p),7 '1.6' aWG; Goppln'TITamgires,,;^]^^ ^all the 
foilowin^';cqttdi^^^ 

( 1 ) jCpntii^upUjs, Iba'ds, ||) not exceed i athperes. 

(2) pverciiront piptec& of & following: 

a. VBi^anchncirciiit-Jiatea , VckcMit bi;eakers listed 2 and 

m^ked; for[us^ W'][th - l:$:;AW6icbpper wfe 
b^;®ranch-citcmt-ISfe5^ listM^^and^inarked fcr'use 

g^'jCSs^GglJiasil?^ 

0j i2^' AWG/Alumn^ .Qoiigei^Giad Ainmimm*^ 

15 amperes; 

(6) iO AV^AJurBdi^^ 

25 amperes 

(E) Tap Conductors. Tap conductors shall be permitted to be 
protected against overcurrent in accordance with the following: 

(1) 210.19(A)(3) and (A)(4), Household Ranges and 
Cooking Appliances and Other Loads 

(2) 240.5(B)(2), Fixture Wire 

(3) 240.21, Location in Circuit 

(4) 368.17(B), Reduction in Ampacity Size of Busway 

(5) 368.17(C), Feeder or Branch Circuits (busway taps) 

(6) 430.53(D), Single Motor Taps 

(F) Transformer Secondary Conductors. Single-phase (other 
than 2-wire) and multiphase (other than delta-delta, 3-wire) 
transformer secondary conductors shall not be considered to be 
protected by the primary overcurrent protective device. 
Conductors supplied by the secondary side of a single-phase 
transformer having a 2-wire (single-voltage) secondary, or a 
three-phase, delta-delta connected transformer having a 3-wire 
(single- voltage) secondary, shall be permitted to be protected by 
overcurrent protection provided on the primary (supply) side of 
the transformer, provided this protection is in accordance with 
450.3 and does not exceed the value determined by multiplying 



70-84 



2010 California Electrical Code 



ARTICLE 240 - OVERCURRENT PROTECTION 



240.6 



the secondary conductor ampacity by the secondary-to-primary 

transformer voltage ratio. 

(G) Overcurrent Protection for Specific Conductor 

Applications. Overcurrent protection for the specific 

conductors shall be permitted to be provided as referenced 

in Table 240.4(G). 

Table 240.4(G) Specific Conductor Applications 



Conductor 


Article 


Section 


Air-conditioning and 
refrigeration 
equipment circuit 
conductors 


440, Parts III, VI 




Capacitor circuit 
conductors 


460 


460.8(B) and 
460.25(A)-(D) 


Control and 

instrumentation 
circuit conductors 
(TypelTC) 


727 


727.9 


Electric welder circuit 
conductors 


630 


630.12 and 630.32 


Fire alarm system circuit 
conductors 


760 


760.23, 760.24, 

760.41, and 
Chapter 9, Tables 
12(A) and 12(B) 


Motor-operated 
appliance circuit 
conductors 


422, Part II 




Motor and motor-control 
circuit conductors 


430, Parts III, IV, 
V, VI, VII 




Phase converter supply 
conductors 


455 


455.7 


Remote-control, 

signaling, and power- 
limited circuit 
conductors 


725 


725.23, 725.24, 

725.41, and 
Chapter 9, Tables 
11(A) and 11(B) 


Secondary tie conductors 


450 


450.6 



240.5 Protection of Flexible Cords, Flexible Cables, and 
Fixture Wires. Flexible cord and flexible cable, including 
tinsel cord and extension cords, and fixture wires shall be 
protected against overcurrent by either 240.5(A) or (B). 

(A) Ampacities. Flexible cord and flexible cable shall be 
protected by an overcurrent device in accordance with their 
ampacity as specified in Table 400.5(A) and Table 
400.5(B). Fixture wire shall be protected against 
overcurrent in accordance with its ampacity as specified in 
Table 402.5. Supplementary overcurrent protection, as 
covered in 240.10, shall be permitted to be an acceptable 
means for providing this protection. 

(B) Branch-Circuit Overcurrent Device. Flexible cord 
shall be protected, where supplied by a branch circuit, in 
accordance with one of the methods described in 

240.5(B)(1), (B)(3), or (B)(4). RxtiJ^: w^ 



jsrQtected, where supplied by a branch ciri^uit, in 
bi:cord4icewithi240^^^ 

(1) Supply Cord of Listed Appliance or Ltimiiiaire.; 

Where flexible cord or tinsel cord is approved for and used 
with a specific listed appliance or luminaire^^ it shall be 
considered to be protected when applied within the 
appliance or liiminaire listing requirements. For the 
jpurposes of this section, a iuminaire may be either portable 
orpemianent; 

(2) Fixture Wire. Fixture wire shall be permitted to be 
tapped to the branch-circuit conductor of a branch circuit in 
accordance with the following: 

(1) 20-ampere circuits — 18 AWG, up to 15 m (50 ft) of 
run length 

(2) 20-ampere circuits — 16 AWG, up to 30 m (100 ft) of 
run length 

(3) 20-ampere circuits — 14 AWG and larger 

(4) 30-ampere circuits — 14 AWG and larger 

(5) 40-ampere circuits — 12 AWG and larger 

(6) 50-ampere circuits — 12 AWG and larger 

(3) Extension Cord Sets. Flexible cord used in listed 
extension cord sets shall be considered to be protected 
when applied within the extension cord listing 
requirements. 

(4) Field Assembled Extension Cord Sets. Flexible cord 
used in extension cords made with separately listed and 
installed components shall be permitted to be suppHed by a 
branch circuit in accordance with the following: 

20-ampere circuits — 16 AWG and larger 

240.6 Standard Ampere Ratings. 

(A) Fuses and Fixed-Trip Circuit Breakers. The 

standard ampere ratings for fuses and inverse time circuit 
breakers shall be considered 15, 20, 25, 30, 35, 40, 45, 50, 
60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 
350, 400, 450, 500, 600, 700, 800, 1000, 1200, 1600, 2000, 
2500, 3000, 4000, 5000, and 6000 amperes. Additional 
standard ampere ratings for fuses shall be I, 3, 6, 10, and 
601. The use of fuses and inverse time circuit breakers with 
nonstandard ampere ratings shall be permitted. 

(B) Adjustable-Trip Circuit Breakers. The rating of 
adjustable-trip circuit breakers having external means for 
adjusting the current setting (long-time pickup setting), not 
meeting the requirements of 240.6(C), shall be the 
maximum setting possible. 

(C) Restricted Access Adjustable-Trip Circuit 
Breakers. A circuit breaker(s) that has restricted access to 
the adjusting means shall be permitted to have an ampere 
rating(s) that is equal to the adjusted current setting (long- 
time pickup setting). Restricted access shall be defined as 
located behind one of the following: 



20 1 California Electrical Code 



70-85 



240.8 



ARTICLE 240 - OVERCURRENT PROTECTION 



(1) Removable and scalable covers over the adjusting means 

(2) Bolted equipment enclosure doors 

(3) Locked doors accessible only to qualified personnel 

240.8 Fuses or Circuit Breakers in Parallel. Fuses and 
circuit breakers shall be permitted to be connected in parallel 
where they are factory assembled in parallel and listed as a 
unit. Individual fuses, circuit breakers, or combinations 
thereof shall not otherwise be connected in parallel. 

240.9 Thermal Devices. Thermal relays and other devices 
not designed to open short circuits or ground faults shall 
not be used for the protection of conductors against 
overcurrent due to short circuits or ground faults, but the 
use of such devices shall be permitted to protect motor 
branch-circuit conductors from overload if protected in 
accordance with 430.40. 

240.10 Supplementary Overcurrent Protection. Where 
supplementary overcurrent protection is used for 
luminaires, appliances, and other equipment or for internal 
circuits and components of equipment, it shall not be used 
as a substitute for required branch-circuit overcurrent 
devices or in place of the required branch-circuit 
protection. Supplementary overcurrent devices shall not be 
required to be readily accessible. 

240.12 Electrical System Coordination. 

Where an orderly shutdown is required to minimize the 
hazard(s) to personnel and equipment, a system of 
coordination based on the following two conditions shall 
be permitted: 

(1) Coordinated short-circuit protection 

(2) Overload indication based on monitoring systems or 
devices 

FPN: The monitoring system may cause the condition 
to go to alarm, allowing corrective action or an orderly 
shutdown, thereby minimizing personnel hazard and 
equipment damage. 

240.13 Ground-Fault Protection of Equipment. 

Ground-fault protection of equipment shall be provided in 
accordance with the provisions of 230.95 for soHdly 
grounded wye electrical systems of more than 150 volts to 
ground but not exceeding 600 volts phase-to-phase for each 
individual device used as a building or structure main 
disconnecting means rated 1000 amperes or more. 

The provisions of this section shall not apply to the 
disconnecting means for the following: 

(1) Continuous industrial processes where a nonorderly 
shutdown will introduce additional or increased 
hazards 

(2) Installations where ground- fault protection is provided 
by other requirements for services or feeders 



(3) Fire pumps 

240jl§ Ungrounded Conductors. 

(A) Overcurrent Device Required. A fuse or an 
overcurrent trip unit of a circuit breaker shall be connected 
in series with each ungrounded conductor. A combination 
of a current transformer and overcurrent relay shall be 
considered equivalent to an overcurrent trip unit. 

FPN: For motor circuits, see Parts III, IV, V, and XI of 
Article 430. 

(B) Circuit Breaker as Overcurrent Device. Circuit 
breakers shall open all ungrounded conductors of the 
circuit both manually and automatically unless otherwise 
permitted in |4pVl^(B)(l), (B)(2), and (B)(3). 

(1) Multiwire Branch Circuit. Except where limited by 
210.4(B), individual single-pole circuit breakers, with or 
without identified handle ties, shall be permitted as the 
protection for each ungrounded conductor of multiwire 
branch circuits that serve only single-phase line-to -neutral 
loads. 

(2) Grounded Single-Phase and 3-Wire dc Circuits. In 

grounded systems, individual single-pole circuit breakers 
with identified handle ties shall be permitted as the 
protection for each ungrounded conductor for line-to-line 
connected loads for single-phase circuits or 3 -wire, direct- 
current circuits. 

(3) 3-Phase and 2-Phase Systems. For line-to-line loads 
in 4-wire, 3-phase systems or 5-wire, 2-phase systems 
having a grounded neutral |0Mt and no conductor 
operating at a voltage greater than permitted in 210.6, 
individual single-pole circuit breakers with identified 
handle ties shall be permitted as the protection for each 
ungrounded conductor. 

(C) Closed-Loop Power Distribution Systems. Listed 
devices that provide equivalent overcurrent protection in 
closed-loop power distribution systems shall be permitted 
as a substitute for fuses or circuit breakers. 



240.21 Location in Circuit. Overcurrent protection shall be 
provided in each ungrotmded circuit conductor and shall be 
located at the point where the conductors receive their supply 
except as specified in 240.21(A) through (H). CoBdWctSri 
supplied under the provisions of 240.21(A) through (H) shall 
no^ supply another conductor except through an overcurrent 
protective device meeting the requu-ements of 240.4. 
(A) Branch-Circuit Conductors. Branch-circuit tap 
conductors meeting the requirements specified in 210.19 
shall be permitted to have overcurrent protection as 
specified in M&JZOl 



70-86 



2010 California Electrical Code 



ARTICLE 240 - OVERCURRENT PROTECTION 



240.21 



(B) Feeder Taps. Conductors shall be permitted to be 
tapped, without overcurrent protection at the tap, to a feeder 
as specified in 240.21(B)(1) through (B)(5). The provisions 
of 240.4(B) shall not be permitted for tap conductors. 

(1) Taps Not over 3 m (10 ft) Long. Where the length of 
the tap conductors does not exceed 3 m (10 ft) and the tap 
conductors comply with all of the following: 

(1) The ampacity of the tap conductors is 

a. Not less than the combined calculated loads on the 

circuits supplied by the tap conductors, and 

b. Not less than the rating of the device supplied by 

the tap conductors or not less than the rating of the 
overcurrent protective device at the termination of 
the tap conductors. 

(2) The tap conductors do not extend beyond the 
switchboard, panelboard, disconnecting means, or 
control devices they supply. 

(3) Except at the point of connection to the feeder, the tap 
conductors are enclosed in a raceway, which shall 
extend from the tap to the enclosure of an enclosed 
switchboard, panelboard, or control devices, or to the 
back of an open switchboard. 

(4) For field installations where the tap conductors leave 
the enclosure or vault in which the tap is made, the 
rating of the overcurrent device on the line side of the 
tap conductors shall not exceed 10 times the ampacity 
of the tap conductor. 

FPN: For overcurrent protection requirements for 
panelboards, see ffp836J 

(2) Taps Not over 7.5 m (25 ft) Long. Where the length 
of the tap conductors does not exceed 7.5 m (25 ft) and the 
tap conductors comply with all the following: 

(1) The ampacity of the tap conductors is not less than 
one-third of the rating of the overcurrent device 
protecting the feeder conductors. 

(2) The tap conductors terminate in a single circuit breaker 
or a single set of fuses that Hmit the load to the 
ampacity of the tap conductors. This device shall be 
permitted to supply any number of additional 
overcurrent devices on its load side. 

(3) The tap conductors are protected from physical damage 
by being enclosed in an approved raceway or by other 
approved means. 

(3) Taps Supplying a Transformer [Primary Plus 
Secondary Not over 7.5 m (25 ft) Long]. Where the tap 
conductors supply a transformer and comply with all the 
following conditions: 

(1) The conductors supplying the primary of a transformer 
have an ampacity at least one-third the rating of the 
overcurrent device protecting the feeder conductors. 

(2) The conductors supplied by the secondary of the 



transformer shall have an ampacity that is not less than 
the value of the primary-to-secondary voltage ratio 
multiplied by one-third of the rating of the overcurrent 
device protecting the feeder conductors. 

(3) The total length of one primary plus one secondary 
conductor, excluding any portion of the primary conductor 
that is protected at its ampacity, is not over 7.5 m (25 ft). 

(4) The primary and secondary conductors are protected 
from physical damage by being enclosed in an 
approved raceway or by other approved means. 

(5) The secondary conductors terminate in a single circuit 
breaker or set of fuses that limit the load current to not 
more than the conductor ampacity that is permitted by 
310.15. 

(4) Taps over 7.5 m (25 ft) Long. Where the feeder is in a high 
bay manufacturing building over 1 1 m (35 ft) high at walls and 
the installation complies with all the following conditions: 

(1) Conditions of maintenance and supervision ensure that 
only qualified persons service the systems. 

(2) The tap conductors are not over 7.5 m (25 ft) long 
horizontally and not over 30 m (100 ft) total length. 

(3) The ampacity of the tap conductors is not less than 
one-third the rating of the overcurrent device 
protecting the feeder conductors. 

(4) The tap conductors terminate at a single circuit breaker 
or a single set of fiises that limit the load to the 
ampacity of the tap conductors. This single overcurrent 
device shall be permitted to supply any number of 
additional overcurrent devices on its load side. 

(5) The tap conductors are protected from physical damage 
by being enclosed in an approved raceway or by other 
approved means, 

(6) The tap conductors are continuous from end-to-end and 
contain no sphces. 

(7) The tap conductors are sized 6 AWG copper or 4 AWG 
aluminum or larger. 

(8) The tap conductors do not penetrate walls, floors, or 
ceilings. 

(9) The tap is made no less than 9 m (30 ft) from the floor. 

(5) Outside Taps of Unlimited Length. Where the 
conductors are located outdoors of a building or structure, 
except at the point of load termination, and comply with all 
of the following conditions: 

( 1 ) The conductors are protected from physical damage in 
an approved manner. 

(2) The conductors terminate at a single circuit breaker or 
a single set of ftises that limit the load to the ampacity 
of the conductors. This single overcurrent device shall 
be permitted to supply any number of additional 
overcurrent devices on its load side. 



2010 California Electrical Code 



70-87 



240.21 



ARTICLE 240 - OVERCURRENT PROTECTION 



(3) The overcurrent device for the conductors is an integral 
part of a disconnecting means or shall be located 
immediately adjacent thereto. 

(4) The disconnecting means for the conductors is installed 
at a readily accessible location complying with one of 
the following: 

a. Outside of a building or structure 

b. Inside, nearest the point of entrance of the 

conductors 

c. Where installed in accordance with 230.6, nearest 

the point of entrance of the conductors 

(C) Transformer Secondary Conductors. A s^t of 
Conductors feeding a singie lo^d; or each set of conductors 
feeding separate loads, shall be permitted to be connected 
to a transformer secondary, without overcurrent protection 
at the secondary, as specified in 240.21(C)(1) through 
(C)(6). The provisions of 240.4(B) shall not be permitted 
for transformer secondary conductors. 

FPN: For overcurrent protection requirements for 
transformers, see 450.3. 

(1) Protection by Primary Overcurrent Device. 

Conductors supplied by the secondary side of a single- 
phase transformer having a 2 -wire (single- voltage) 
secondary, or a three-phase, delta-delta coimected 
transformer having a 3-wire (single-voltage) secondary, 
shall be permitted to be protected by overcurrent protection 
provided on the primary (supply) side of the transformer, 
provided this protection is in accordance with 450.3 and 
does not exceed the value determined by multiplying the 
secondary conductor ampacity by the secondary-to-primary 
transformer voltage ratio. 

Single-phase (other than 2-wire) and multiphase (other 
than delta-delta, 3-wire) transformer secondary conductors 
are not considered to be protected by the primary 
overcurrent protective device. 

(2) Transformer Secondary Conductors Not over 3 m 
(10 ft) Long. Where the length of secondary conductor 
does not exceed 3 m (10 ft) and complies with all of the 
following: 

(1) The ampacity of the secondary conductors is 

a. Not less than the combined calculated loads on the 

circuits supplied by the secondary conductors, and 

b. Not less than the rating of the device supplied by 

the secondary conductors or not less than the 
rating of the overcurrent-protective device at the 
termination of the secondary conductors 

(2) The secondary conductors do not extend beyond the 
switchboard, panelboard, disconnecting means, or 
control devices they supply. 

(3) The secondary conductors are enclosed in a raceway, 
which shall extend from the transformer to the 
enclosure of an enclosed switchboard, panelboard, or 
control devices or to the back of an open switchboard. 



(4) For field; installatidpswl^^^ th^ secondary conductors 
lea;ve-;/tlie enclospf e or yatilt in which: the supply 
b|Di^ecti^Qh;/ is;^:^m^ ;J;he; ^rating of the overcurrent 



dpvi66: ■protecting 
nit^tiiplied By -t^ 

|&it^ge5jtaii|>^,^iii4l; 



tiije^,:{)|nrnary of the transformer, 
prirnai^:' to; sec^ transformer 

i6t exqeefljpjim the ampacity of 

FPN: For overcurrent protection requirements for 
panelboards, see |083,|> 

(3) Industrial Installation Secondary Conductors Not 
over 7.5 m (25 ft) Long. For industrial installations only, 
where the length of the secondary conductors does not 
exceed 7.5 m (25 ft) and compHes with all of the following: 

(1) Conditions of mairif^nance and supervisioE ensure that 
only qualified pers|ns service the systems j 

(2) The ampacity of the secondary conductors is not less 
than the secondary current rating of the transformer, and 
the sum of the ratings of the overcurrent devices does 
not exceed the ampacity of the secondary conductors. 

(3) All overcurrent devices are grouped. 

(4) The secondary conductors are protected from physical 
damage by being enclosed in an approved raceway or 
by other approved means. 

(4) Outside Secondary Conductors. Where the 
conductors are located outdoors of a building or structure, 
except at the point of load termination, and comply with all 
of the following conditions: 

(1) The conductors are protected from physical damage in 
an approved manner. 

(2) The conductors terminate at a single circuit breaker or 
a single set of frises that limit the load to the ampacity 
of the conductors. This single overcurrent device shall 
be permitted to supply any number of additional 
overcurrent devices on its load side. 

(3) The overcurrent device for the conductors is an integral 
part of a disconnecting means or shall be located 
immediately adjacent thereto. 

(4) The disconnecting means for the conductors is installed 
at a readily accessible location complying with one of 
the following: 

a. Outside of a building or structure 

b. Inside, nearest the point of entrance of the 
conductors 

c. Where installed in accordance with 230.6, nearest 

the point of entrance of the conductors 

(5) Secondary Conductors from a Feeder Tapped 
Transformer. Transformer secondary conductors installed 
in accordance with 240.21(B)(3) shall be permitted to have 
overcurrent protection as specified in that section. 

(6) Secondary Conductors Not over 7.5 m (25 ft) Long. 

Where the length of secondary conductor does not exceed 
7.5 m (25 ft) and complies with all of the following: 



70-88 



2010 California Electrical Code 



ARTICLE 240 - OVERCURRENT PROTECTION 



240.24 



(1) The secondary conductors shall have an ampacity that is not 

less than the value of the primary-to-secondary voltage 
ratio multiplied by one-third of the rating of the overcurrent 
device protecting the primary of the transformer. 

(2) The secondary conductors terminate in a single circuit 
breaker or set of fuses that limit the load current to not 
more than the conductor ampacity that is permitted by 
310.15. 

(3) The secondary conductors are protected from physical 
damage by being enclosed in an approved raceway or 
by other approved means. 

(D) Service Conductors. Service conductors shall be 
permitted to be protected by overcurrent devices in 
accordance with 230.91. 

(E) Busway Taps. Busways and busway taps shall be 
permitted to be protected against overcurrent in accordance 

with 368.17. 

(F) Motor Circuit Taps. Motor-feeder and branch-circuit 
conductors shall be permitted to be protected against 
overcurrent in accordance with 430.28 and 430.53, 
respectively. 

(G) Conductors from Generator Terminals. Conductors 
from generator terminals that meet the size requirement in 
445.13 shall be permitted to be protected against overload by 
the generator overload protective device(s) required by 445. 12. 

(H) Battery Conductors^ pVerciiiTerifproteQtipn shall be 

permiited[ to be ijaslalied as c}ose_a|^practicabie jo_ the 
stomgc^^ttpty-^ tettt)^als_^m^ a___J[0^^ 
imt^^4^_iof ^ the ^^y^rcmrpnt ^jotectjoii wiffi|a^^:: j 
hazardoiJjb^ be peri^edl 

240.22 Grounded Conductor. No overcurrent device 
shall be connected in series with any conductor that is 
intentionally grounded, unless one of the following two 
conditions is met: 

(1) The overcurrent device opens all conductors of the 
circuit, including the grounded conductor, and is 
designed so that no pole can operate independently. 

(2) Where required by 430.36 or 430.37 for motor 
overload protection. 

240.23 Change in Size of Grounded Conductor. Where 
a change occurs in the size of the ungrounded conductor, a 
similar change shall be permitted to be made in the size of 
the grounded conductor. 

240.24 Location in or on Premises. 



(A) Accessibility. Overcurrent devices shall be readily 
accessible and shall be installed so that the center of the grip of 
the operating handle of the switch or circuit breaker, when in its 
highest position, is not more than 2.0 m (6 ft 7 in.) above the 
floor or working platform, unless one of the following applies: 

(1) For busways, as provided in 368.17(C). 

(2) For supplementary overcurrent protection, as described in 
240.10. 

(3) For overcurrent devices, as described in 225.40 and 230.92. 

(4) For overcurrent devices adjacent to utilization equipment 
that they supply, access shall be permitted to be by portable 
means. 

(B) Occupancy. Each occupant shall have ready access to all 
overcurrent devices protecting the conductors supplying that 
occupancy, unless oSerwise permiged in 246.2|(B5(1} and 



(if) Service aiid Feeder Overcuireiit Devices* Where electric 
service and electrical maintenance are provided by the building 
management and where these are under continuous building 
management supervision, the service overcurrent devices and 
feeder overcurrent devices supplying more than one occupancy 
shall be permitted to be accessible only to authorized 
management personnel in the following: 

(1) Multiple-occupancy buildmgs 

(2) Guest rooms or guest suites 



(2)'^^Branch*C^cirft Ove^^ Where electric 

service and electrical maintenance are provided by the building 
management and where these are under continuous building 
management supervision, the branch-circuit overcurrent devices 
supplying any guest rooms or guest suites withQUt penBikiedt 
ptpvisions for cookkig shall be permitted to be accessible only 
to authorized management personnel. 

(C) Not Exposed to Physical Damage. Overcurrent devices 
shall be located where they will not be exposed to physical 
damage. 

FPN: See 1 10.1 1, Deteriorating Agents. 

(D) Not in Vicinity of Easily Ignitible Material. Overcurrent 
devices shall not be located in the vicinity of easily ignitible 
material, such as in clothes closets. 

(E) Not Located in Bathrooms. In dwelling units and guest 
rooms or guest suites of hotels and motels, overcurrent devices, 
other than supplementary overcurrent protection, shall not be 
located in bathrooms. 

(E) Not Located <^^^^ Steps. Oye|cuiteiit <fevices shajl oot be 
legated over stepsj>f a staii;wayl 



2010 California Electrical Code 



70-89 



240.30 



ARTICLE 240 - OVERCURRENT PROTECTION 



III. Enclosures 
240.30 General. 

(A) Protection from Physical Damage. Overcurrent 
devices shall be protected from physical damage by one of 
the following: 

(1) Installation in enclosures, cabinets, cutout boxes, or 
equipment assembhes 

(2) Mounting on open-type switchboards, panelboards, or 
control boards that are in rooms or enclosures free 
from dampness and easily ignitible material and are 
accessible only to qualified personnel 

(B) Operating Handle. The operating handle of a circuit 
breaker shall be permitted to be accessible without opening 
a door or cover. 

240.32 Damp or Wet Locations. Enclosures for overcurrent 
devices in damp or wet locations shall comply with 312.2. 

240.33 Vertical Position. Enclosures for overcurrent 
devices shall be mounted in a vertical position unless that is 
shown to be impracticable. Circuit breaker enclosures shall 
be permitted to be installed horizontally where the circuit 
breaker is installed in accordance with 240.81. Listed 
busway plug-in units shall be permitted to be mounted in 
orientations corresponding to the busway mounting position. 

IV. Disconnecting and Guarding 

240.40 Disconnecting Means for Fuses. Cartridge fuses 
in circuits of any voltage where accessible to other than 
quahfied persons, and all fuses in circuits over 150 volts to 
ground, shall be provided with a disconnecting means on 
their supply side so that each circuit containing fuses can 
be independently disconnected from the source of power. A 
cxirrent-limiting device without a disconnecting means shall 
be permitted on the supply side of the service 
disconnecting means as permitted by 230.82. A single 
disconnecting means shall be permitted on the supply side 
of more than one set of fiises as permitted by 430.112, 
Exception, for group operation of motors and 424.22(C) for 
fixed electric space-heating equipment. 

240.41 Arcing or Suddenly Moving Parts. Arcing or 
suddenly moving parts shall comply with 240.41(A) and (B). 

(A) Location. Fuses and circuit breakers shall be located or 
shielded so that persons will not be burned or otherwise 
injured by their operation. 

(B) Suddenly Moving Parts. Handles or levers of circuit 
breakers, and similar parts that may move suddenly in such 
a way that persons in the vicinity are Hkely to be injured by 
being struck by them, shall be guarded or isolated. 



V. Plug Fuses, Fuseholders, and Adapters 

240.50 General. 

(A) Maximum Voltage. Plug fuses shall be permitted to be 
used in the following circuits: 

(1) Circuits not exceeding 125 voUs between conductors 

(2) Circuits supplied by a system having a grounded neutral 
point where the line-to-neutral voltage does not exceed 
150 volts 

(B) Marking. Each fuse, fuseholder, and adapter shall be 
marked with its ampere rating. 

(C) Hexagonal Configuration. Plug fuses of 15 -ampere 
and lower rating shall be identified by a hexagonal 
configuration of the window, cap, or other prominent part 
to distinguish them from fuses of higher ampere ratings. 

(D) No Energized Parts. Plug fuses, fuseholders, and 
adapters shall have no exposed energized parts after fuses 
or fuses and adapters have been installed. 

(E) Screw Shell. The screw shell of a plug-type fuseholder 
shall be connected to the load side of the circuit. 

240.51 Edison-Base Fuses. 

(A) Classification. Plug fuses of the Edison-base type shall be 
classified at not over 125 volts and 30 amperes and below. 

(B) Replacement Only. Plug fuses of the Edison-base type 
shall be used only for replacements in existing installations 
where there is no evidence of overfusing or tampering. 

240.52 Edison-Base Fuseholders. Fuseholders of the 
Edison-base type shall be installed only where they are 
made to accept Type S fuses by the use of adapters. 

240.53 Type S Fuses. Type S fuses shall be of the plug 
type and shall comply with 240.53(A) and (B). 

(A) Classification. Type S fuses shall be classified at not 
over 125 volts and to 15 amperes, 16 to 20 amperes, and 
21 to 30 amperes. 

(B) Noninterchangeable. Type S fuses of an ampere 
classification as specified in 240.53(A) shall not be 
interchangeable with a lower ampere classification. They 
shall be designed so that they cannot be used in any 
fuseholder other than a Type S fuseholder or a fuseholder 
with a Type S adapter inserted. 

240.54 Type S Fuses, Adapters, and Fuseholders. 

(A) To Fit Edison-Base Fuseholders. Type S adapters 
shall fit Edison-base fuseholders. 

(B) To Fit Type S Fuses Only. Type S fuseholders and 
adapters shall be designed so that either the fuseholder 
itself or the fuseholder with a Type S adapter inserted 
cannot be used for any fuse other than a Type S fuse. 



70-90 



2010 California Electrical Code 



ARTICLE 240 - OVERCURRENT PROTECTION 



240.85 



(C) Nonremovable. Type S adapters shall be designed so 
that once inserted in a fuseholder, they cannot be removed. 

(D) Nontamperable. Type S fuses, fuseholders, and 
adapters shall be designed so that tampering or shunting 
(bridging) would be difficult. 

(E) Interchangeability. Dimensions of Type S fuses, 
fuseholders, and adapters shall be standardized to permit 
interchangeabihty regardless of the manufacturer. 

VI. Cartridge Fuses and Fuseholders 

240.60 General. 

(A) Maximum Voltage — 300-Volt Type. Cartridge fuses 
and fuseholders of the 300-volt type shall be permitted to 
be used in the following circuits: 

(1) Circuits not exceeding 300 volts between conductors 

(2) Single-phase line-to-neutral circuits supplied from a 3- 
phase, 4-wire, solidly grounded neutral source where 
the line- to-neutral voltage does not exceed 300 volts 

(B) Noninterchangeable — 0-6000-Ampere Cartridge 
Fuseholders. Fuseholders shall be designed so that it will 
be difficult to put a fuse of any given class into a 
fuseholder that is designed for a current lower, or voltage 
higher, than that of the class to which the fuse belongs. 
Fuseholders for current-limiting fuses shall not permit 
insertion of fuses that are not current-Umiting. 

(C) Marking. Fuses shall be plainly marked, either by 
printing on the fuse barrel or by a label attached to the 
barrel showing the following: 

(1) Ampere rating 

(2) Voltage rating 

(3) Interrupting rating where other than 10,000 amperes 

(4) Current limiting where applicable 

(5) The name or trademark of the manufacturer 

The interrupting rating shall not be required to be 
marked on fuses used for supplementary protection. 

(D) Renewable Fuses. Class H cartridge fuses of the 
renewable type shall be permitted to be used only for 
replacement in existing installations where there is no 
evidence of overfusing or tampering. 

240.61 Classification. Cartridge fuses and fuseholders 
shall be classified according to voltage and amperage 
ranges. Fuses rated 600 volts, nominal, or less shall be 
permitted to be used for voltages at or below their ratings. 



VII. Circuit Breakers 

240.80 Method of Operation. Circuit breakers shall be 
trip fi*ee and capable of being closed and opened by manual 
operation. Their normal method of operation by other than 
manual means, such as electrical or pneumatic, shall be 
permitted if means for manual operation are also provided. 

240.81 Indicating. Circuit breakers shall clearly indicate 
whether they are in the open "off or closed "on" position. 

Where circuit breaker handles are operated vertically 
rather than rotationally or horizontally, the "up" position of 
the handle shall be the "on" position. 

240.82 Nontamperable. A circuit breaker shall be of such 
design that any alteration of its trip point (calibration) or the 
time required for its operation requires dismantling of the device 
or breaking of a seal for other than intended adjustments. 

240.83 Marking. 

(A) Durable and Visible. Circuit breakers shall be marked 
with their ampere rating in a manner that will be durable 
and visible after installation. Such marking shall be 
permitted to be made visible by removal of a trim or cover. 

(B) Location. Circuit breakers rated at 100 amperes or less 
and 600 volts or less shall have the ampere rating molded, 
stamped, etched, or similarly marked into their handles or 
escutcheon areas. 

(C) Interrupting Rating. Every circuit breaker having an 
interrupting rating other than 5000 amperes shall have its 
interrupting rating shown on the circuit breaker. The 
interrupting rating shall not be required to be marked on 
circuit breakers used for supplementary protection. 

(D) Used as Switches. Circuit breakers used as switches in 
120-volt and 277-volt fluorescent lighting circuits shall be 
listed and shall be marked SWD or HID. Circuit breakers 
used as switches in high-intensity discharge lighting 
circuits shall be listed and shall be marked as HID. 

(E) Voltage Marking. Circuit breakers shall be marked with a 
voltage rating not less than the nominal system voltage that is 
indicative of their capability to interrupt fault currents between 
phases or phase to ground. 

240.85 Applications. A circuit breaker with a straight voltage 
rating, such as 240V or 480V, shall be permitted to be applied in 
a circuit in which the nominal voltage between any two 
conductors does not exceed the circuit breaker *s voltage rating. 
A two-pole circuit breaker shall not be used for protecting a 3- 
phase, comer-grounded delta circuit unless the circuit breaker is 
marked 10-30 to indicate such suitability. 



2010 California Electrical Code 



70-91 



240.86 



ARTICLE 240 - OVERCURRENT PROTECTION 



A circuit breaker with a slash rating, such as 1 20/240 V or 
480Y/277V, shall be permitted to be applied in a soHdly 
grounded circuit where the nominal voltage of any conductor to 
ground does not exceed the lower of the two values of the 
circuit breaker's voltage rating and the nominal voltage between 
any two conductors does not exceed the higher value of the 
circuit breaker's voltage rating. 

FPN: Proper application of molded case circuit breakers 
on 3-phase systems, other than solidly grounded wye, 
particularly on comer grounded delta systems, considers 
the circuit breakers' individual pole-interrupting 
capability. 

240.86 Series Ratings. Where a circuit breaker is used on a 
circuit having an available fault current higher than the marked 
interrupting rating by being connected on the load side of an 
acceptable overcurrent protective device having a higher rating, 
the circuit breaker shall meet the requirements specified in (A) 
or(B),and(C). 

(A) Selected Under Engineering Supervision in Existing 
Installations. The series rated combination devices shall be 
selected by a licensed professional engineer engaged primarily 
in the design or maintenance of electrical installations. The 
selection shall be documented and stamped by the professional 
engineer. This documentation shall be available to those 
authorized to design, install, inspect, maintain, and operate the 
system. This series combination rating, including identification 
of the upstream device, shall be field marked on the end use 
equipment. 

For calculated M^lic?;tio|is,;l|ie engineer shall ensure fimi 
the downstream circuit breaker($) th at ai'e pait pfjie series 
combination remain passive during the interruption period of" 
tiie line sidQ &% rg^^ 

(B) Tested Combinations. The combination of line-side 
overcurrent device and load-side circuit breaker(s) is tested and 
marked on the end use equipment, such as switchboards and 
panelboards. 

5cgml)jn|^on: systSfe 

(C) Motor Contribution. Series ratings shall not be used where 

(1) Motors are connected on the load side of the higher-rated 
overcurrent device and on the line side of the lower-rated 
overcurrent device, and 

(2) The sum of the motor full-load currents exceeds 1 percent 
of the interrupting rating of the lower-rated circuit breaker. 



VIII. Supervised Industrial Installations 

240.90 General. Overcurrent protection in areas of 
supervised industrial installations shall comply with all of 
the other appHcable provisions of this article, except as 
provided in Part VIII. The provisions of Part VIII shall be 
permitted only to apply to those portions of the electrical 
system in the supervised industrial installation used 
exclusively for manufacturing or process control activities. 

240.92 Location in Circuit. An overcurrent device shall 
be connected in each ungrounded circuit conductor as 
required in 240.92(A) through (E). 

(A) Feeder and Branch-Circuit Conductors. Feeder and 
branch-circuit conductors shall be protected at the point the 
conductors receive their supply as permitted in 240.21 or as 
otherwise permitted in 240.92(B), (C), (D), or (E). 

g):lieaer 

(C) Transformer Secondary Conductors of Separately 
Derived Systems. Conductors shall be permitted to be 
connected to a transformer secondary of a separately derived 
system, without overcurrent protection at the connection, where 
the conditions of 240.92(C)(1), (C)(2), and (C)(3) are met 

(1) Short-Circuit and Ground-Fault Protection. The 

conductors shall be protected from short-circuit and 
ground-fault conditions by complying with one of the 
following conditions: 

(1) The length of the secondary conductors does not exceed 30 
m (100 ft) and the transformer primary overcurrent device 
has a rating or setting that does not exceed 150 percent of 
the value determined by multipl5dng the secondary 
conductor ampacity by the secondary-to-primary 
transformer voltage ratio. 

(2) The conductors are protected by a differential relay with a 
trip setting equal to or less than the conductor ampacity. 

FPN: A differential relay is connected to be sensitive only to 
short-circuit or fault currents within the protected zone and is 
normally set much lower than the conductor ampacity. The 
differential relay is connected to trip protective devices that 
de-energize the protected conductors if a short-circuit 
condition occurs. 

(3) The conductors shall be considered to be protected 
if calculations, made under engineering 
supervision, determine that the system overcurrent 
devices will protect the conductors within 
recognized time vs. current limits for all short- 
circuit and ground-fault conditions 



70-92 



2010 California Electrical Code 



ARTICLE 240 - OVERCURRENT PROTECTION 



240,100 



Table 240.92(B) Tap Conductor Short-Circuit Current Ratings. 



Tap conductors are considered to be protected under short-circuit 
conditions when their short-circuit temperature limit is not 
exceeded. Conductor heating under short-circuit conditions is 
determined by ( 1 ) or (2) : 



(1) Short-Circuit Formula for Copper Conductors 
{I2IA2)t = 0.0297 log,o [(7^2 + 2U)I{T^ + 234)] 

(2) Short-Circuit Formula for Aluminum Conductors 

(12/A2)t = 0.0125 logio [(^2 + 228)/(r, + 228)] 

where: 

/ = short-circuit current in amperes 

A = conductor area in circular mils 

t = time of short circuit in seconds (for times less than or equal to 
10 seconds) 

Ti = initial conductor temperature in degrees Celsius. 

T2 = final conductor temperature in degrees Celsius. 

Copper conductor with paper, rubber, varnished cloth insulation, 
T2 = 200 

Copper conductor with thermoplastic insulation, 72 = 150 

Copper conductor with cross-linked polyethylene insulation, T2 ^ 
250 

Copper conductor with ethylene propylene rubber insulation, T2 = 
250 

Aluminum conductor with paper, rubber, varnished cloth 
insulation, T2 = 200 

Aluminum conductor with thermoplastic insulation, T2- 150 

Aluminum conductor with cross-linked polyethylene insulation, 
T2 = 250 

Aluminum conductor with ethylene propylene rubber insulation, 
T2 = 250 



(2) Overload Protection. The conductors shall be 
protected against overload conditions by complying with 
one of the follow^ing: 

(1) The conductors terminate in a single overcurrent device that 
will hmit the load to the conductor ampacity. 

(2) The sum of the overcurrent devices at the conductor 
termination limits the load to the conductor ampacity. The 
overcurrent devices shall consist of not more than six 
circuit breakers or sets of fuses, mounted in a single 
enclosure, in a group of separate enclosures, or in or on a 
switchboard. There shall be no more than six overcurrent 
devices grouped in any one location. 

(3) Overcurrent relaying is connected [with a current 
transformer(s), if needed] to sense all of the secondary 
conductor current and limit the load to the conductor 



ampacity by opening upstream or downstream devices. 

(4) Conductors shall be considered to be protected if 
calculations, made under engineering supervision, 
determine that the system overcurrent devices will 
protect the conductors Irom overload conditions. 

(3) Physical Protection. The secondary conductors are 
protected fi"om physical damage by being enclosed in an 
approved raceway or by other approved means. 

(D) Outside Feeder Taps. Outside conductors shall be 
permitted to be tapped to a feeder or to be connected at a 
transformer secondary, without overcurrent protection at 
the tap or connection, where all the following conditions 
are met: 

(1) The conductors are protected from physical damage in 
an approved maimer. 

(2) The sum of the overcurrent devices at the conductor 
termination limits the load to the conductor ampacity. 
The overcurrent devices shall consist of not more than 
six circuit breakers or sets of fuses mounted in a single 
enclosure, in a group of separate enclosures, or in or 
on a switchboard. There shall be no more than six 
overcurrent devices grouped in any one location. 

(3) The tap conductors are installed outdoors of a building 
or structure except at the point of load termination. 

(4) The overcurrent device for the conductors is an integral 
part of a disconnecting means or shall be located 
immediately adjacent thereto. 

(5) The disconnecting means for the conductors are 
installed at a readily accessible location complying 
with one of the following: 

a. Outside of a building or structure 

b. Inside, nearest the point of entrance of the 

conductors 

c. Where installed in accordance with 230.6, nearest 

the point of entrance of the conductors 

(E) Protection by Primary Overcurrent Device. 

Conductors supplied by the secondary side of a transformer 
shall be permitted to be protected by overcurrent protection 
provided on the primary (supply) side of the transformer, 
provided the primary device time-current protection 
characteristic, multiplied by the maximum effective 
primary-to-secondary transformer voltage ratio, effectively 
protects the secondary conductors. 



IX. Overcurrent Protection over 600 Volts, Nominal 

240.100 Feeders and Branch Circuits. 

(A) Location and Type of Protection. Feeder and branch- 
circuit conductors shall have overcurrent protection in each 



2010 California Electrical Code 



70-93 



240.101 



ARTICLE 250 - GROUNDING AND BONDING 



ungrounded conductor located at the point where the 
conductor receives its supply or at an alternative location in 
the circuit when designed under engineering supervision 
that includes but is not limited to considering the 
appropriate fault studies and time-current coordination 
analysis of the protective devices and the conductor 
damage curves. The overcurrent protection shall be 
permitted to be provided by either 240.100(A)(1) or (A)(2). 

(1) Overcurrent Relays and Current Transformers. 

Circuit breakers used for overcurrent protection of 3-phase 
circuits shall have a minimum of three overcurrent relay 
elements operated from three current transformers. The 
separate overcurrent relay elements (or protective 
functions) shall be permitted to be part of a single 
electronic protective relay unit. 

On 3-phase, 3 -wire circuits, an overcurrent relay 
element in the residual circuit of the current transformers 
shall be permitted to replace one of the phase relay 
elements. 

An overcurrent relay element, operated from a current 
transformer that links all phases of a 3-phase, 3-wire 
circuit, shall be permitted to replace the residual relay 
element and one of the phase-conductor current 
transformers. Where the neutral gotldiictpi: is not 
regrounded on the load side of the circuit as permitted in 
250.184(B), the current transformer shall be permitted to 
link all 3-phase conductors and the grounded circuit 
conductor (neutral). 

(2) Fuses. A fuse shall be connected in series with each 
ungrounded conductor. 

(B) Protective Devices. The protective device(s) shall be 
capable of detecting and interrupting all values of current 
that can occur at their location in excess of their trip-setting 
or melting point. 

(C) Conductor Protection. The operating time of the 
protective device, the available short-circuit current, and 
the conductor used shall be coordinated to prevent 
damaging or dangerous temperatures in conductors or 
conductor insulation under short-circuit conditions. . 

240.101 Additional Requirements for Feeders. 

(A) Rating or Setting of Overcurrent Protective 
Devices. The continuous ampere rating of a fiise shall not 
exceed three times the ampacity of the conductors. The 
long-time trip element setting of a breaker or the minimum 
trip setting of an electronically actuated fuse shall not 
exceed six times the ampacity of the conductor. For fire 
pumps, conductors shall be permitted to be protected for 
overcurrent in accordance with 695.4(B). 

(B) Feeder Taps. Conductors tapped to a feeder shall be 
permitted to be protected by the feeder overcurrent device 
where that overcurrent device also protects the tap 
conductor. 



AM^ICLEISO 

Grounding and Bonding 



I. General 

250.1 Scope. This article covers general requirements for 
grounding and bonding of electrical installations, and the 
specific requirements in (1) through (6). 

(1) Systems, circuits, and equipment required, permitted, 
or not permitted to be grounded 

(2) Circuit conductor to be grounded on grounded systems 

(3) Location of grounding connections 

(4) Types and sizes of grounding and bonding conductors 
and electrodes 

(5) Methods of grounding and bonding 

(6) Conditions under which guards, isolation, or insulation 
may be substituted for grounding 

FPif:- See Figure 250.^; for infomiation on the organization 
of Article 250 A:ivenng _^mpding ^ 3M J^ 



Part i General 



Part li System 
grounding 



Part VI I! Direct-current 

systems 



Part X Grounding of 

systems md circuits of 

1 kV and over (high voltage) 




Part III Grounding electrode 

system and grounding 

electrode conductor 



Part iV Enclosure, 

raceway, and service 

cable grounding 



Part VI Equipment 

grounding and equipment 

grounding conductors 




Part V Bonding 



Part VII Methods of 

equipment grounding 



Part IX Instruments, 
meters, and relays 



Figure 2504 Grounding and Bonding. 



70-94 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.4 



250.2 Definitions. 



B0ndiii^£]fif mper^ Syslteni^ The connection between the 
grounded circuit conductor and the equipment grounding 
conductor at a separately derived system. 

Effective Ground-Fault Current Path. An intentionally 
constructed, low-impedance electrically conductive path 
designed and intended to carry current under ground-fault 
conditions from the point of a ground fault on a wiring 
system to the electrical supply source and that facilitates the 
operation of the overcurrent protective device or ground- 
fault detectors on high-impedance grounded systems. 

Ground Fault. An unintentional, electrically conducting 
connection between an ungrounded conductor of an 
electrical circuit and the normally non-current-carrying 
conductors, metallic enclosures, metallic raceways, 
metallic equipment, or earth. 

Ground-Fault Current Path. An electrically conductive path 
from the point of a ground fault on a wiring system through 
normally non-current-carrying conductors, equipment, or 
the earth to the electrical supply source. 

FPN: Examples of ground-fault current paths could consist 
of any combination of equipment grounding conductors, 
metallic raceways, metallic cable sheaths, electrical 
equipment, and any other electrically conductive material 
such as metal water and gas piping, steel framing members, 
stucco mesh, metal ducting, reinforcing steel, shields of 
communications cables, and the earth itself 

250.3 Application of Other Articles. For other articles 
applying to particular cases of installation of conductors 
and equipment, grounding and bonding requirements are 
identified in Table 250.3 that are in addition to, or 
modifications of, those of this article. 

250.4 General Requirements for Grounding and 
Bonding. The following general requirements identify 
what grounding and bonding of electrical systems are 
required to accomplish. The prescriptive methods 
contained in Article 250 shall be followed to comply with 
the performance requirements of this section. 

(A) Grounded Systems. 

(1) Electrical System Grounding. Electrical systems that 
are grounded shall be connected to earth in a manner that 
will limit the voltage imposed by lightning, line surges, or 
unintentional contact with higher-voltage lines and that will 
stabilize the voltage to earth during normal operation. 



FPN: : jAn itdportant tbtisideimtion for htbittiig; : the imposed 
yolt^^' is the ioutiiig of bdndirig and g^rounditig conductors sc> 
jhat ihjey are iK>t any Ibnger ■ than necess^ tp compjete thd 
conneciion without distiiibing ; ; the p^mahent paits of the 
JnstallatibhM so that umieces^ary bends and;toops are avoided.; 



(2) Grounding of Electrical Equipment. Normally non- 
current-carrying conductive materials enclosing electrical 
conductors or equipment, or forming part of such 
equipment, shall be connected to earth so as to limit the 
voltage to ground on these materials. 

(3) Bonding of Electrical Equipment. NpilBally non- 
current-carrying conductive materials enclosing electrical 
conductors or equipment, or forming part of such 
equipment, shall be connected together and to the electrical 
supply source in a manner that establishes an effective 
ground- fault current path. 

(4) Bonding of Electrically Conductive Materials and 
Other Equipment. Normally non-current-carrying 
electrically conductive materials that are likely to become 
energized shall be connected together and to the electrical 
supply source in a manner that establishes an effective 
ground- fault current path. 

(5) Effective Ground-Fault Current Path. Electrical 
equipment and wiring and other electrically conductive 
material likely to become energized shall be installed in a 
manner that creates a low-impedance circuit facilitating the 
operation of the overcurrent device or ground detector for 
high-impedance grounded systems. It shall be capable of 
safely carrying the maximum ground-fault current likely to 
be imposed on it from any point on the wiring system 
where a ground fault may occur to the electrical supply 
source. The earth shall not be considered as an effective 
ground-fault current path. 

(B) Ungrounded Systems. 

(1) Grounding Electrical Equipment. Non-current- 
carrying conductive materials enclosing electrical 
conductors or equipment, or forming part of such 
equipment, shall be connected to earth in a manner that will 
limit the voltage imposed by lightning or unintentional 
contact with higher-voltage lines and limit the voltage to 
ground on these materials. 

(2) Bonding of Electrical Equipment Non-current- 
carrying conductive materials enclosing electrical conductors 
or equipment, or forming part of such equipment, shall be 
connected together and to the supply system grounded 
equipment in a manner that creates a low-impedance path for 
ground- fault current that is capable of carrying the maximum 
fault current likely to be imposed on it. 

(3) Bonding of Electrically Conductive Materials and 
Other Equipment. Electrically conductive materials that 
are likely to become energized shall be connected together 
and to the supply system grounded equipment in a manner 
that creates a low-impedance path for ground-fault current 
that is capable of carrying the maximum fault current likely 
to be imposed on it. 



2010 California Electrical Code 



70-95 



250.4 



ARTICLE 250 - GROUNDING AND BONDING 



Table 250.3 Additional Grounding and Bonding Requirements 



Conductor/Equipment 



Article 



Section 



Agricultural buildings 

Audio signal processing, amplification, and reproduction 

equipment 
Branch circuits 
Cablebus 
Cable trays 
Capacitors 

Circuits and equipment operating at less than 50 volts 
Closed-loop and programmed power distribution 
Communications circuits 
Community antenna television and radio distribution 

systems 
Conductors for general wiring 
Cranes and hoists 

Electrically driven or controlled irrigation machines 
Electric signs and outline lighting 
Electrolytic cells 
Elevators, dumbwaiters, escalators, moving walks, 

wheelchair lifts, and stairway chair lifts 
Fire alarm systems 

Fixed electric heating equipment for pipelines and vessels 
Fixed outdoor electric deicing and snow-melting 

equipment 
Flexible cords and cables 
Floating buildings 
Grounding-type receptacles, adapters, cord connectors, 

and attachment plugs 
Hazardous (classified) locations 
Health care facilities 

Induction and dielectric heating equipment 
Industrial machinery 
Information technology equipment 
Intrinsically safe systems 

Luminaires (lighting fixtures) and lighting equipment 
Luminaires (fixtures), lampholders, and lamps 
Marinas and boatyards 
Mobile homes and mobile home park 
Motion picture -and television studios and similar 

locations 
Motors, motor cn-cuits, and controllers 
Natural ind artificially made bodies of water 
Outlet, device, pull, and junction boxes; conduit bodies; 

and fittings 
Over 600 volts, nominal, underground wiring methods 
Panelboards 
Pipe organs 

Radio and television equipment 
Receptacles and cord connectors 
Recreational vehicles and recreational vehicle parks 
Services 

Solar photovoltaic systems 

Swimming pools, fountains, and similar installations 
Switchboards and panelboards 
Switches 
Theaters, audience areas of motion picture and television 

studios, and similar locations 
Transformers and transformer vaults 
Use and identification of grounded conductors 
X-ray equipment 



392 
720 
800 



310 
610 

600 
668 
620 



547.9 and 547.10 
640.7 

210.5,210.6,406.3 

370.9 

392.3(C), 392.7 

460.10,460.27 

780.3 

820.93,820.100,820.103 



675.11(C), 675.12, 675.13, 675.14, 675.15 



760.9 

427.29, 427.48 

426.27 

400.22, 400.23 

553.8,553.10,553.11 

406.9 



500-517 
517 
665 
670 



410 
550 

430 




650 
810 

551 
230 

680 



200 
660 



645.15 

504.50 

410.17, 410.18, 410.20, 410.21, 410.105(B) 

555.15 

530.20, 530.64(B) 

314.4,314.25 

300.50(B) 
408.40 

406.3 



690.41, 690.42, 690.43, 690.45, 690.47 

408.3(D) 
404.12 
520.81 

450.10 

517.78 



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ARTICLE 250 - GROUNDING AND BONDING 



250.20 



(4) Path for Fault Current, Electrical equipment, wiring, 
and other electrically conductive material likely to become 
energized shall be installed in a manner that creates a low- 
impedance circuit from any point on the wiring system to 
the electrical supply source to facilitate the operation of 
overcurrent devices should a second ground fault fromVa 
diffemiit phase occur on the wiring system. The earth shall 
not be considered as an effective fault-current path. 

250.6 Objectionable Current. 

(A) Arrangement to Prevent Objectionable Current. 

The grounding of electrical systems, circuit conductors, 
surge arresters, siw^-^mfccti^v^; devices^ and conductive 
normally non-current-carrying metai paStS; of equipment 
shall be installed and arranged in a manner that will prevent 
objectionable current. 

(B) Alterations to Stop Objectionable Current. If the use 

of multiple grounding connections results in objectionable 
current, one or more of the following alterations shall be 
permitted to be made, provided that the requirements of 
250.4(A)(5) or (B)(4) are met: 

( 1 ) Discontinue one or more but not all of such grounding 
connections. 

(2) Change the locations of the grounding connections. 

(3) Interrupt the continuity of the conductor or conductive 
path causing the objectipliable currehti 

(4) Take other suitable remedial and approved action. 

(C) Temporary Currents Not Classified as Objectionable 
Currents. Temporary currents resulting from accidental 
conditions, such as ground faults, shall not be classified as 
objectionable current for the purposes specified in 250.6(A) 
and (B). 

(D) Limitations to Permissible Alterations. The provisions 
of this section shall not be considered as permitting 
electronic equipment from being operated on ac systems or 
branch circuits that are not cto^efed Jo^^^/^^^M^^ 
^^^^^^^c^y^^acfi:^ as required by this article. Currents 
that introduce noise or data errors in electronic equipment 
shall not be considered the objectionable currents 
addressed in this section. 

(E) Isolation of Objectionable Direct-Current Ground 
Currents. Where isolation of objectionable dc ground currents 
from cathodic protection systems is required, a listed ac 
coupling/dc isolating device shall be permitted in the equipment 
grounding BoilSl^tor path to provide an effective retum path for 
ac ground-fault current while blocking dc current. 



250.8 Connection of Grounding and Bonding 
Equipment. 

(A) Perimttedj M^ Groutidiiig conductors md 

t^ndmgjxmipei^ shall :b^^ by one of & 

folloWmg means: 

(1) psted |)!^ssu!;e opiine 

(2) Irjei&maito 

(3) l*re3S#e cojj^^ and bonding 
equipment 

(4) Exothemic weldM 

(5) Machine screwrtj^e fasteaers that engage not less than 
two Uireads or are secured: with a nut 

(6) Thread-forming imcjUne $cre^ that engage not lesfj 
than two threads in tiie enclosure 

(7) Connections ^Sat arejgaft of a ii$ted assemM^ 

(8) jOther listed meatis 

J(B);'. Methods . ■- Not ■ . l^i^rinitSed.;.; \ 'd^vicel;: ox 

itiSn^s that dependspleiy on soite shall riot be used! 

250.10 Protection of Ground Clamps and Fittings. 

Ground clamps or other fittings shall be approved for 
general use without protection or shall be protected from 
physical damage as indicated in (1) or (2) as follows: 

(1) In installations where they are not likely to be damaged 

(2) Where enclosed in metal, wood, or equivalent 
protective covering 

250.12 Clean Surfaces. Nonconductive coatings (such as 
paint, lacquer, and enamel) on equipment to be grounded 
shall be removed from threads and other contact surfaces to 
ensure good electrical continuity or be connected by means 
of fittings designed so as to make such removal unnecessary. 

II. System Grounding 

250.20 Alternating-Current Systems to Be Grounded. 

Alternating-current systems shall be grounded as provided 
for in 250.20(A), (B), (C), [pj,\6r: (E). Other systems shall 
be permitted to be grounded. If such systems are grounded, 
they shall comply with the applicable provisions of this 
article. 

FPN: An example of a system permitted to be grounded is a 
comer-grounded delta transformer connection. See 
250.26(4) for conductor to be grounded. 

(A) Alternating-Current Systems of Less Than 50 Volts. 

Ahernating-current systems of less than 50 volts shall be 
grounded under any of the following conditions: 

(1) Where supplied by transformers, if the transformer 
supply system exceeds 150 volts to ground 



2010 California Electrical Code 



70-97 



250.21 



ARTICLE 250 - GROUNDING AND BONDING 



(2) Where supplied by transformers, if the transformer 
supply system is ungrounded 

(3) Where installed outside as overhead conductors 

(B) Alternating-Current Systems of 50 Volts to 1000 
Volts. Alternating-current systems of 50 volts to 1000 volts 
that supply premises wiring and premises wiring systems 
shall be grounded under any of the following conditions: 

(1) Where the system can be grounded so that the 
maximum voltage to ground on the ungrounded 
conductors does not exceed 150 volts 

(2) Where the system is 3 -phase, 4- wire, wye connected in 
which the neutral conductor is used as a circuit 
conductor 

(3) Where the system is 3 -phase, 4-wire, delta connected 
in which the midpoint of one phase winding is used as 
a circuit conductor 

(C) Alternating-Current Systems of 1 kV and Over. 

Alternating-current systems supplying mobile or portable 
equipment shall be grounded as specified in 250.188. 
Where supplying other than mobile or portable equipment, 
such systems shall be permitted to be grounded. 

(D) Separately Derived Systems. Separately derived 
systems, as covered in 250.20(A) or (B), shall be grounded 
as specified in 250.30(A). Where ^^ttalterciate sotircje siichi 
^s:aii on-$ite generator is provided with traiisfer equiptnen^ 
that includes a grounded conductor that is BOt solidl}^ 
intetcotHiected to the seryice^supplied grounded conductor j 
ihe alter^iate source (deiiyed syst^) sha^^ 
k9£9£4i¥^cewkh 

FPN No. 1: An alternate ac power source such as an on-site 
generator is not a separately derived system if the grounded 
conductor is solidly interconnected to a service-supplied 
system grounded conductor. An .exan^ie of su^h situations 
is where alternate source transfer equipmerit does not 
include a switching action in tfe grounded coBductox: and 
allows it to remain splidly comi^e0te4 to the sorvice-sitppii^d 
gtbutded-C0nduotbr;whesn the alternate sou^e : is ppmtim^ 
and suj)piying the load served; 

FPN No. 2: For systems that are not separately derived and are 
not required to be grounded as specified in 250.30, see 445.13 
for minimum size of conductors that must carry fault current. 

(E) Impedance Grounded Neutral Systems. Impedance 
grounded neutral systems shall be grounded in accordance 
with 250.36 or 250.186. 

250.21 Alternating-Current Systems of 50 Volts to 1000 
Volts Not Required to Be Grounded. 

lAJ General* The folio w^ing ac systems of 50 volts to 1000 
volts shall be permitted to be grounded but shall not be 
required to be grounded: 

(1) Electrical systems used exclusively to supply industrial 
electric furnaces for melting, refining, tempering, and 
the like 



(2) Separately derived systems used exclusively for 
rectifiers that supply only adjustable-speed industrial 
drives 

(3) Separately derived systems suppHed by transformers 
that have a primary voltage rating less than 1000 volts, 
provided that all the following conditions are met: 

a. The system is used exclusively for control circuits. 

b. The conditions of maintenance and supervision 
ensure that only qualified persons service the 
installation. 

c. Continuity of control power is required. 
m 

(4) Other systems that are not required to be grounded in 
accordance with the requirements of 250.20(B) 

« 

P) GrouBd Detectors* tlngrounded alternating cuitent 
^sy^tems as permitted in 25Q.2lf A;)(l) through (A)(4:) 
^bperatingat iiot less thaii^l^ exceeding J 000 

!^Jts..y[iaH;h^ ;grou^^ the systemf 

250.22 Circuits Not to Be Grounded. The following 
circuits shall not be grounded: 

(1) Circuits for electric cranes operating over combustible 
fibers in Class III locations, as provided in 503.155 

(2) Circuits in health care facilities as provided in 517.61 
and 517.160 

(3) Circuits for equipment within electrolytic cell working 
zone as provided in Article 668 

(4) Secondary circuits of lighting systems as provided in 

411.5(A) 

(5) Secondary drciiy^fS lighting^ as providedjn 
||g,23(A)N(2)r "^^~ "^ 

250.24 Grounding Service-Supplied Alternating- 
Current Systems. 

(A) System Grounding Connections. A premises wiring 
system supplied by a grounded ac service shall have a 
grounding electrode conductor connected to the grounded 
service conductor, at each service, in accordance with 
250.24(A)(1) through (A)(5). 

(1) General. The gmmdrtigy ch^^^ conductor 
connection shall be made at any accessible point from the 
load end of the service drop or service lateral to and 
including the terminal or bus to which the grounded service 
conductor is connected at the service disconnecting means. 

FPN: See definitions of Service Drop and Service Lateral in 
Article 100. 

(2) Outdoor Transformer. Where the transformer 
supplying the service is located outside the building, at 
least one additional grounding connection shall be made 
from the grounded service conductor to a grounding 
electrode, either at the transformer or elsewhere outside the 
building. 



70-98 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.24 



Exception: The additional grounding plectrade condifCtQf^ 
connection shall not he made on high-impedance grounded 
neutral systems. The system shall meet the requirements of 
250.36. 

(3) Dual-Fed Services. For services that are dual fed 
(double ended) in a common enclosure or grouped together 
in separate enclosures and employing a secondary tie, a 
single grounding electrode feoncfaibtS^ connection to the tie 
point of the grounded conductor(s) from each power source 
shall be permitted. 

(4) Main Bonding Jumper as Wire or Busbar. Where 
the main bonding jumper specified in 250.28 is a wire or 
busbar and is installed from the grounded conductor 
terminal bar or bus to the equipment grounding terminal 
bar or bus in the service equipment, the grounding 
electrode conductor shall be permitted to be connected to 
the equipment grounding terminal, bar, or bus to which the 
main bonding jumper is connected. 

(5) Load-Side Grounding Connections. A grounded 
con&c£or|$haH not be^ conae'cte3j(£^g^ non-^impnU 
(caixying M^tal parts of equipment, tip equipment grounding 
conductors) J or be reconnected Jo ground on the load side 
of the service disconnecting means except as otherwise 
permitted in this article. 

FPN: See 250.30(A) for separately derived systems, 250.32 
for connections at separate buildings or structures, and 
250.142 for use of the grounded circuit conductor for 
grounding equipment. 

(B) Main Bonding Jumper. For a grounded system, an 
unspliced main bonding jumper shall be used to connect the 
equipment grounding conductor(s) and the service-disconnect 
enclosure to the grounded conductor within the enclosure for 
each service disconnect in accordance with 250.28. 
Exception No. J: Where more than one service 
disconnecting means is located in an assembly listed for 
use as service equipment, an unspliced main bonding 
jumper shall bond the grounded conductor(s) to the 
assembly enclosure. 

Exception No. 2: Impedance grounded neutral systems 
shall be permitted to be connected as provided in 250.36 
and 250.186. 

(C) Grounded Conductor Brougiit to Service Equipment. 
Where an ac system operating at less than 1000 volts is 
grounded at any point, the grounded conductor(s) shall be run 
to each service disconnecting means and shall be comect^td 
bacj discdinnectiBg means grounded conductor(s) terminal or 
bus. A main bonding jumper shall connect the grounded 
conductor(s) to each service disconnecting means enclosure. 
The grounded conductor(s) shall be installed in accordance 
with 250.24(C)(1) through (C)(3). 



Exception: Where more than one service disconnecting 
means are located in d;Smgl§ assembly listed for use as 
service equipment, it shall be permitted to run the 
grounded conductor(s) to the assembly common grounde<i 
hqndueipr(s). termiml -or^ bus-^.. 'The assembly shall '. include -d 
>fwmjbon^^ -Cimnecting the "g>:oiinde4 

Cpnductorfs) to the assembly enclosure. 

(1) Routing and Sizing. This conductor shall be routed with 
the phase conductors and shall not be smaller than the 
required grounding electrode conductor specified in Table 
250.66 but shall not be required to be larger than the largest 
ungrounded service-entrance phase conductor. In addition, 
for service-entrance phase conductors larger than 1 100 kcmil 
copper or 1750 kcmil aluminum, the grounded conductor 
shall not be smaller than I2V2 percent of the area of the 
largest service-entrance phase conductor. The grounded 
conductor of a 3 -phase, 3 -wire delta service shall have an 
ampacity not less than that of the ungrounded conductors. 

(2) Parallel Conductors. Where the service-entrance 
phase conductors are installed in parallel, the size of the 
grounded conductor shall be based on the total circular mil 
area of the parallel conductors as indicated in this section. 
Where installed in two or more raceways, the size of the 
grounded conductor in each raceway shall be based on the 
size of the ungrounded service-entrance conductor in the 
raceway but not smaller than I/O AWG. 

FPN: See 310.4 for grounded conductors connected in 
parallel. 

(3) High Impedance. The grounded conductor on a high- 
impedance grounded neutral system shall be grounded in 
accordance with 250.36. 

(D) Grounding Electrode Conductor. A grounding 
electrode conductor shall be used to connect the equipment 
grounding conductors, the service-equipment enclosures, 
and, where the system is grounded, the grounded service 
conductor to the grounding electrode(s) required by Part III 
of this article. [This j^o^Hu^ctec^ ^^w^d'm-BJC^:^c^^^ 

High-impedance grounded neutral system connections shall 
be made as covered in 250.36. 

FPN: See 250.24(A) for ac system grounding connections. 

(E) Ungrounded System Grounding Connections. A 
premises wiring system that is suppHed by an ac service 
that is ungrounded shall have, at each service, a grounding 
electrode conductor connected to the grounding 
electrode(s) required by Part III of this article. The 
grounding electrode conductor shall be connected to a 
metal enclosure of the service conductors at any accessible 
point from the load end of the service drop or service 
lateral to the service disconnecting means. 



2010 California Electrical Code 



70-99 



250.26 



ARTICLE 250 - GROUNDING AND BONDING 



250.26 Conductor to Be Grounded — Alternating- 
Current Systems. For ac premises wiring systems, the 
conductor to be grounded shall be as specified in the 
following: 

(1) Single-phase, 2-wire — one conductor 

(2) Single-phase, 3 -wire — the neutral conductor 

(3) Multiphase systems having one wire common to all 
phases — the common conductor 

(4) Multiphase systems where one phase is grounded — 
one phase conductor 

(5) Multiphase systems in which one phase is used as in 
(2) — the neutral conductor 

250.28 Main Bonding Juniper and System Bonding 
Jumper. For a grounded system, main bonding jumpers 
and system bonding jumpers shall be installed as follows: 

(A) Material. Main bonding jumpers and system bonding 
jumpers shall be of copper or other corrosion-resistant 
material. A main bonding jumper and a system bonding 
jumper shall be a wire, bus, screw, or similar suitable 
conductor. 

(B) Construction. Where a main bonding jumper or a 
system bonding jumper is a screw only, the screw shall be 
identified with a green finish that shall be visible with the 
screw installed. 

(C) Attachment. Main bonding jumpers and system 
bonding jumpers shall be connected in the manner 
specified by the applicable provisions of 250.8. 

(D) Size. Main bonding jtynp6rs and system bondktg 
jumpers shall be sized in accordance with 250.28(f>)(i) 
throu^(OX3): 

(1) General. Main bonding jumpers and system bonding 
jumpers shall not be smaller than the sizes shown in Table 
250.66. Where the supply conductors are larger than 1100 
kcmil copper or 1750 kcmil aluminum, the bonding jumper 
shall have an area that is not less than I2V2 percent of the 
area of the largest phase conductor except that, where the 
phase conductors and the bonding jumper are of different 
materials (copper or aluminum), the minimum size of the 
bonding jumper shall be based on the assumed use of phase 
conductors of the same material as the bonding jumper and 
with an ampacity equivalent to that of the installed phase 
conductors. 

(2)_ Mam Bonding Jumper for^Serw Thari 

bn|:J&5closiire, Where ^:spm(^[ consists of motia than a; 
^mglC; enclosure j as^^ PMmit|ei| ^jja;^^^^ the-/ mad 

hgndmBjumj>ct for^- each; jenc|pji^^ mmd^^M 

l^rcordance' ^ ^ , with \25B2^py0J$^ ;. on the , ^ largesl 
imgrounded service conduc^^ semng that enclosure. 



i[3)';fSe|jarately _ ^ More^ J]hatfl6'iiii 

tencios«re. Where ?^J^pp^tntQi£d^^ systeni supplies 
more than, a single eriplosure, the system bonding jumper 
for each enclosure shall be sized m accoi'dance with 
25p.28(D)(l) based |n , the largest ungroimded feedeii 
conductor serving th|t enclosure, or a single system 
jbonding jumper shall % installed at the source and sized in 
kccordance w^ 25().2|(r))(l) tes^ equiyalent size! 

joOhe^largest supj)ly 

fe&M: |h^, ^^P^P^^i ih|:5?ff4sp„^55(ngi conductors^'of .eacS 
bet: 

250.30 Grounding Separately Derived Alternating- 
Current Systems. 

(A) Grounded Systems. A separately derived ac system that 
is grounded shall comply with 250.30(A)(1) through (A)(8). 
Except as otherwise p^rmittey in this article, a pounded 
Conductor s^^ bejcormec^y to^^n^^ nonTHCurrerit:^ 

jCOTyiiig metal parts q^equipmen^^ grquaiditig 

bo^ductors, or be recqnnepted^ to^^qimd on the loa^^^^ 
jtheppint of grounding of a^ep^aratef>; derived system, 

FPN: See 250.32 for connections at separate buildings or 
structures, and 250.142 for use of the grounded circuit 
conductor for grounding equipment. 

Exception: Impedance grounded neutral system grounding 
connections shall be made as specified in 250.36 or 250.186. 
(1) System Bonding Jumper. An unspHced system 
bonding jumper in compliance with 250.28(A) through (D) 
that is sized based on the derived phase conductors shall be 
used to connect the equipment grounding conductors of the 
separately derived system to the grounded conductor. This 
connection shall be made at any single point on the 
separately derived system from the source to the first 
system disconnecting means or overcurrent device, or it 
shall be made at the source of a separately derived system 
that has no disconnecting means or overcurrent devices. 
Exception No. 1: For separately derived systems that are 
dual fed (double ended) in a common enclosure or grouped 
together in separate enclosures and employing a secondary 
tie, a single system bonding jumper connection to the tie 
point of the grounded circuit conductors from each power 
source shall be permitted. 

Exception No. 2: A system bonding jumper at both the 
source and the first disconnecting means shall be permitted 
where doing so does not establish a parallel path for the 
grounded conductor. Where a grounded conductor is used 
in this manner, it shall not be smaller than the size 
specified for the system bonding jumper but shall not be 
required to be larger than the ungrounded conductor (s). 
For the purposes of this exception, connection through the 
earth shall not be considered as providing a parallel path. 



70-100 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.30 



Exception No. 3: The size of the system bonding jumper 
for a system that supplies a Class 1, Class 2, or Class 3 
circuit, and is derived from a transformer rated not more 
than 1000 volt-amperes, shall not be smaller than the 
derived phase conductors and shall not be smaller than 14 
A WG copper or 12 A WG aluminum. 

(2) Equipment Bonding Jumper Size. Where %xi 
equipment bonding jumper of the wire type is run with the 
derived phase conductors from the source of a separately 
derived system to the first disconnecting means, it shall be 
sized in accordance with 250.102(C), based on the size of 
the derived phase conductors. 

(3) Grounding Electrode Conductor, Single Separately 
Derived System. A grounding electrode conductor for a single 
separately derived system shall be sized in accordance with 
250.66 for the derived phase conductors and shall be used to 
connect the grounded conductor of the derived system to the 
grounding electrode as specified in 250.30(A)(7). This 
connection shall be made at the same point on the separately 
derived system where the system bonding jumper is poimictedi 
Exception No. 1: Where the system bonding jumper 
specified in 250, 30(A)(1) is a wire or busbar, it shall be 
permitted to connect the grounding electrode conductor to 
the equipment grounding terminal, bar, or bus, provided 
the equipment grounding terminal, bar, or bus is of 
sufficient size for the separately derived system. 
Exception No, 2: Where a separately derived system 
originates in listed equipment suitable as service equipment, 
the grounding electrode conductor from the service or feeder 
equipment to the grounding electrode shall be permitted as 
the grounding electrode conductor for the separately derived 
system, provided the groimding electrode conductor is of 
sufficient size for the separately derived system. Where the 
equipment grounding bus internal to the equipment is not 
smaller than the required grounding electrode conductor for 
the separately derived system, the grounding electrode 
connection for the separately derived system shall be 
permitted to be made to the bus. 

Exception No. 3: A grounding electrode conductor shall 
not be required for a system that supplies a Class 1, Class 
2, or Class 3 circuit and is derived from a transformer 
rated not more than 1000 volt-amperes, provided the 
grounded conductor is bonded to the transformer frame or 
enclosure by a jumper sized in accordance with 
250.30(A)(1), Exception No. 3, and the transformer frame 
or enclosure is grounded by one of the means specified in 
250.134. 

(4) Grounding Electrode Conductor, Multiple 
Separately Derived Systems. Where more than one 
separately derived system is installed, it shall be 
permissible to connect a tap from each separately derived 
system to a common grounding electrode conductor. Each 
tap conductor shall connect the grounded conductor of the 
separately derived system to the common grounding 



electrode conductor. The grounding electrode conductors 

and taps shall comply with 250.30(A)(4)(a) through 

(A)(4)(c). This coxmectipn shall fei^^ 

pn the separately derived system where thie system bonding 

jumper is installed; 

Exception No. 1: Where the system bonding jumper 

specified in 250.30(A)(1) is a wire or busbar, it shall be 

permitted to connect the grounding electrode conductor to 

the equipment grounding terminal, bar, or bus, provided 

the equipment grounding terminal, bar, or bus is of 

sufficient size for the separately derived system. 

Exception No. 2: A grounding electrode conductor shall not 
be required for a system that supplies a Class 1, Class 2, or 
Class 3 circuit and is derived from a transformer rated not 
more than 1000 volt-amperes, provided the system grounded 
conductor is bonded to the transformer frame or enclosure 
by a jumper sized in accordance with 250.30(A)(1), 
Exception No. 3 and the transformer frame or enclosure is 
grounded by one of the means specified in 250.134. 

(a) Common Grounding Electrode Conductor Size. 
The common grounding electrode conductor shall not be 
smaller than 3/0 AWG copper or 250 kcmil aluminum. 

(b) Tap Conductor Size. Each tap conductor shall be 
sized in accordance with 250.66 based on the derived phase 
conductors of the separately derived system it serves. 

Exception: Where a separately derived system originates 
in listed equipment suitable as service equipment, the 
grounding electrode conductor from the service or feeder 
equipment to the grounding electrode shall be permitted as 
the grounding electrode conductor for the separately 
derived system, provided the grounding electrode 
conductor is of sufficient size for the separately derived 
system. Where the equipment ground bus internal to the 
equipment is not smaller than the required grounding 
electrode conductor for the separately derived system, the 
grounding electrode connection for the separately derived 
system shall be permitted to be made to the bus. 

(c) Connections. All tap connections to the common 
grounding electrode conductor shall be made at an 
accessible location by one of the following methods: 

(1) A listed connector. 

(2) Listed connections to aluminum or copper busbars not 
less than 6 mm x 50 mm (% in. x 2 in.). Where 
aluminum busbars are used, the installation shall 
comply with 250.64(A). 

(3) The exothermic welding process. 

Tap conductors shall be connected to the common 
grounding electrode conductor in such a manner that the 
common grounding electrode conductor remains without a 
splice or joint. 



2010 California Electrical Code 



70-101 



250.32 



ARTICLE 250 - GROUNDING AND BONDING 



(5) Installation. The installation of all grounding electrode 
conductors shall comply with 250.64(A), (B), (C), and (E). 

(6) Bonding. Structural steel and metal piping shall be 

derived system in accprdaace with 250/1 p4(p)i 

(7) Grounding Electrode. The grounding electrode shall 
be as near as practicable to and preferably in the same area 
as the grounding electrode conductor connection to the 
system. The grounding electrode shall be the nearest one of 
the following: 

(1) Metal water pipe grounding electrode as specified in 
250.52(A)(1) 

(2) Structural metal grounding electrode as specified in 

250.52(A)(2) 

Exception No, 1: Any of the other electrodes identified in 
250.52(A) shall be used where the electrodes specified by 
25030(A)(7) are not available. 

Exception No. 2 to (1) and (2): Where a separately derived 
system originates in listed equipment suitable for use as 
service equipment, the grounding electrode used for the 
service or feeder equipment shall be permitted as the 
grounding electrode for the separately derived system. 

FPN: See 250.104(D) for bonding requirements of interior 
metal water piping in the area served by separately derived 
systems. 

(8) Grounded Conductor. Where a grounded conductor 
is installed and the system bonding jumper connection is 
not located at the source of the separately derived system, 
250.30(A)(8)(a), (A)(8)(b), and (A)(8)(c) shall apply. 

(a) Routing and Sizing. This conductor shall be routed 
with the derived phase conductors and shall not be smaller 
than the required grounding electrode conductor specified 
in Table 250.66 but shall not be required to be larger than 
the largest ungrounded derived phase conductor. In 
addition, for phase conductors larger than 1100 kcmil 
copper or 1750 kcmil aluminum, the grounded conductor 
shall not be smaller than I2V2 percent of the area of the 
largest derived phase conductor. The grounded conductor 
of a 3 -phase, 3 -wire delta system shall have an ampacity 
not less than that of the ungrounded conductors. 

(b) Parallel Conductors. Where the derived phase 
conductors are installed in parallel, the size of the grounded 
conductor shall be based on the total circular mil area of 
the parallel conductors, as indicated in this section. Where 
installed in two or more raceways, the size of the grounded 
conductor in each raceway shall be based on the size of the 
ungrounded conductors in the raceway but not smaller than 
1/0 AWG. 



FPN: See 310.4 for grounded conductors connected in 
parallel. 

(c) Impedance Grounded System. The grounded 
conductor of an impedance grounded neutral system shall 
be installed in accordance with 250.36 or 250.186. 

(B) Ungrounded Systems. The equipment of an 
ungrounded separately derived system shall be grounded as 
specified in 250.30(B)(1) and (B)(2). 

(1) Grounding Electrode Conductor. A grounding 
electrode conductor, sized in accordance with 250.66 for 
the derived phase conductors, shall be used to connect the 
metal enclosures of the derived system to the grounding 
electrode as specified in 250.30(B)(2). This connection 
shall be made at any point on the separately derived system 
from the source to the first system disconnecting means. 

(2) Grounding Electrode. Except as permitted by 250.34 
for portable and vehicle-mounted generators, the grounding 
electrode shall comply with 250.30(A)(7). 

250.32 Buildings or Structures Supplied by a Feeder(s) 
or Branch Circuit(s). 

(A) Grounding Electrode. Building(s) or structure(s) 
supplied by feeder(s) or branch circuit(s) shall have a 
grounding electrode or grounding electrode system 
installed in accordance with part III prA^ 250, The 
grounding electrode conductor(s) shall be connected in 
accordance with 250.32(B) or (C). Where there is no 
existing grounding electrode, the grounding electrode(s) 
required in 250.50 shall be installed. 

Exception: A grounding electrode shall not be required 
where only a single branch circuit, mcluding pmult^^ 
Pl93<^h.£k£¥¥> supplies the building or structure and the 
branch circuit includes an equipment grounding conductor 
for grounding the normally non-current-carrying metal 
parts of equipment. 

(B) Grounded Systems. For a grounded system at the 
separate building or structure, ^ equipment grounding 
conductor as described in 250.118 shall be run with the 
supply conductors and § connected to the building or 
structure disconnecting means and to the grounding 
electrode(s). The equipment grounding conductor shall be 
used for grounding or bonding of equipment, structures, or 
frames required to be grounded or bonded. The equipment 
grounding conductor shall be sized in accordance with 
250.122, Any installed grounded conductor shall not be 
connected to the equipment grounding conductor or to the 
grounding electrode(s). 

Exceptionf For existing premUes^ wiring system^ = Qnly, \ the. 
grounded conductor run with fhe-Mppjy. to the buttding or 
stmcture shall be pefjnitted toh0€^ building 

0r stmctur^ disionnectingjineaps; and to the grounding 
eiectr€!de(s) andshdMbeiisedfor gm^ or bonding of 

equipment, structures^ or: fiames^t;eguired^^^^ be grounded 
or ponded where all ih^^requitemev^^ 
are met: 



70-102 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



i50J5 



(1) An equipment grounding conductor is not run with 
the supply to the building or structure. 

(2) There are no continuous metallic paths bonded to 
the grounding system in each building or structure 
involved. 

(3) Ground-fault protection of equipment has not been 
installed on the supply side of the feeder (s). 

^Where\ '-the; gromde(i condtdctor is -usedrfi^r gr0tmiing in 
accordmtSe with the provision of this exc^ptipn, the size of 
the grounded conductor shall not be smaller than the 
larger of either of the following: 

(1) That required by 220.61 

(2) That required by 250. 122 

(C) Ungrounded Systems. The grounding electrode(s) 
shall be connected to the building or structure 
disconnecting means. 

(D) Disconnecting Means Located in Separate Building 
or Structure on the Same Premises. Where one or more 
disconnecting means supply one or more additional 
buildings or structures under single management, and 
where these disconnecting means are located remote from 
those buildings or structures in accordance with the 
provisions of 225.32, Exception No. 1 and No. 2, 
760J2(B)(6);MLniB)(5). or 7011 i,^ all of the following 
conditions shall be met: 

(1) The connection of the grounded conductor to the 
grounding electrode, b nbrmaliyr&|i7ttCBipr 

rnetaij!. = pSrS; ; : iof r ^(^rpm^n% 1; or K;io K J|g^.i: :eqdpm^ 
grburi&g pohd^^ at a separate building or structure 
shall not be made. 

(2) An equipment grounding conductor for grounding and. 
bondmg any aomiallyi non-current-carrying metal 
part$' of equipment, interior metal piping systems, and 
building or structural metal frames is run with the 
circuit conductors to a separate building or structure 
and fe<>taieGteJ to existing grounding electrode(s) 
required in Part III of this article, or, where there are 
no existing electrodes, the grounding electrode(s) 
required in Part III of this article shall be installed 
where a separate building or structure is supplied by 
more than one branch circuit. 

(3) ilfe;: cogtgptito^;]^^ the equipment grounding 
conductor aM the grounding electrode at a separate 
building or structure shall be made in a junction box, 
panelboard, or similar enclosure located immediately 
inside or outside the separate building or structure. 

(E) Grounding Electrode Conductor. The size of the 

grounding electrode conductor to the grounding 
electrode(s) shall not be smaller than given in 250.66, 
based on the largest ungrounded supply conductor. The 
installation shall comply with Part III of this article. 



250.34 Portable and Vehicle-Mounted Generators. 

(A) Portable Generators. The frame of a portable 
generator shall not be required to be connected to a 
grounding electrode as defined in 250.52 for a system 
supplied by the generator under the following conditions: 

(1) The generator supplies only equipment mounted on the 
generator, cord-and-plug-connected equipment through 
receptacles mounted on the generator, or both, and 

(2) The normaiiy non-current-carrying metal parts of 
equipment and the equipment grounding conductor 
terminals of the receptacles are g<Hmecte<| to the 
generator frame. 

(B) Vehicle-Mounted Generators. The frame of a vehicle 
shall not be required to be connected to a grounding 
electrode as defined in 250.52 for a system supphed by a 
generator located on this vehicle under the following 
conditions: 

(1) The frame of the generator is bonded to the vehicle 
frame, and 

(2) The generator supplies only equipment located on the 
vehicle or cord-and-plug-connected equipment through 
receptacles mounted on the vehicle, or both equipment 
located on the vehicle and cord-and-plug-connected 
equipment through receptacles mounted on the vehicle 
or on the generator, and 

(3) The normal^ non-current-carrying metal parts of 
equipment and the equipment grounding conductor 
terminals of the receptacles are 'ppwdpipA to the 
generator frame. 

(C) Grounded Conductor Bonding. A system conductor 
that is required to be grounded by 250.26 shall be 
pqnnected to the generator frame where the generator is a 
component of a separately derived system. 

FPN: For grounding portable generators supplying fixed 
wiring systems, see 250.20(D). 

250.35 Pernaaaentiy liistBiled Generators. A conductor 
that provides an effqctive ground-fault current pa<ih shall be 
installed with the supply eondudors from a permanently 
installed gen€rator(s) to th^ fkst discpmiectm^^ 
;qicc0rdance with (A) or (B)J 

(A) ''Separately- derived ':Systeniv Where; ;Se';geaeratdr; i$ 
iristalledias a sepiaratelyjderived systera^ th^^^^^ 
m 25030 shall apply^ ' '^ 

i(P) Noiiseparately Derived System* Where the generator 
is ■ not installed as a separately dOTVedsystarrij an 
equipnaent bonding jmnper shall be mstalied between the 
generator equipment grotinding terminal; and the: equipnient 
^rbtmdiiig terminal or; bus of the; etM^loske: df jsupplied 
^dis connecting niean(s) in accbrda^^^ (B)( l;);;Qt £B)(2): 



2010 California Electrical Code 



70-103 



250.36 



ARTICLE 250 - GROUNDING AND BONDING 



(1) Supply Side of Geneirator Overcurrent Device* The 

equipment boeding jumper on the supply sid^ of each 
generator oyercurreiit device shall be sized in accordance 
with 250.102(C) based ori the size of the conductors 
isuppiied by the generator 

1(2) \ >Load Side of : (Jeneratbr Overcurrent ^ Device* ._ The 
eqiitpnieiit groimdiiig;;c^^^^ on the load side of each 

generator overcurrent device shall be sized in accordance 
with ,250J02(D) baged on the rating of the overcurrent 
device supplied: 

250.36 High-Impedance Grounded Neutral Systems. 

High-impedance grounded neutral systems in which a 
grounding impedance, usually a resistor, limits the ground- 
fault current to a low value shall be permitted for 3 -phase 
ac systems of 480 volts to 1000 volts where all the 
following conditions are met: 

(1) The conditions of maintenance and supervision ensure 
that only qualified persons service the installation. 



(2) Ground detectors are installed on the system. 

(3) Line- to-neutral loads are not served. 

High-impedance grounded neutral systems shall 
comply with the provisions of 250.36(A) through (G). 

(A) Grounding Impedance Location. The grounding 
impedance shall be installed between the grounding 
electrode conductor and the system neutral point. Where a 
neutral point is not available, the grounding impedance shall 
be installed between the grounding electrode conductor and 
the neutral point derived from a grounding transformer. 

(B) Grounded System Conductor. The grounded system 

conductor from the neutral point of the transformer or 
generator to its connection point to the grounding 
impedance shall be fully insulated. 

The grounded'^ systerri conductor shall have an 
ampacity of not less than the maximum current rating of 
the grounding impedance. In no case shall the pounded 
system conductor be smaller than 8 AWG copper or 6 
AWG aluminum or copper-clad aluminum. 

(C) System Groundiiig Connection. The system shall not 
be connected to ground except through the grounding 
impedance. 

FPN: The impedance is normally selected to limit the 
ground-fault current to a value slightly greater than or equal 
to the capacitive charging current of the system. This value 
of impedance will also limit transient overvoltages to safe 
values. For guidance, refer to criteria for limiting transient 
overvoltages in ANSI/IEEE 142-1991, Recommended 
Practice for Grounding of Industrial and Commercial 
Power Systems. 

(D) Neutral Point to Grounding Impedanci^ Conductor 
Routing. The conductor connecting the neutral point of the 
transformer or generator to the grounding impedance shall 



be permitted to be installed in a separate raceway frpm the 
ungrounded conductpifs J It shall not be required to run this 
conductor with the phase conductors to the first system 
disconnecting means or overcurrent device. 

(E) Equipment Bonding Jumper. The equipment bonding 
jumper (the connection between the equipment grounding 
conductors and the grounding impedance) shall be an 
unspliced conductor run from the first system 
disconnecting means or overcurrent device to the grounded 
side of the grounding impedance. 

(F) Grounding Electrode Conductor Location. The 

grounding electrode conductor shall be CQnnectedi at any 
point from the grounded side of the grounding impedance 
to the equipment grounding connection at the service 
equipment or first system disconnecting means. 

(G) Equipment Bonding Jumper Size. The equipment 
bonding jumper shall be sized in accordance with (1) or (2) 

as follows: 

(1) Where the grounding electrode conductor connection is 
made at the grounding impedance, the equipment 
bonding jumper shall be sized in accordance with 
250.66, based on the size of the service entrance 
conductors for a service or the derived phase 
conductors for a separately derived system. 

(2) Where the grounding electrode conductor is connected 
at the first system disconnecting means or overcurrent 
device, the equipment bonding jumper shall be sized 
the same as the neutral conductor in 250.36(B). 

III. Grounding Electrode System and Grounding 
Electrode Conductor 

250.50 Grounding Electrode System. All grounding 
electrodes as described in 250.52(A)(1) through (A)(7) that 
are present at each building or structure served shall be 
bonded together to form the grounding electrode system. 
Where none of these grounding electrodes exist, one or 
more of the grounding electrodes specified in 250.52(A)(4) 
through (A)(8) shall be installed and used. 

Exception: Concrete-encased electrodes of existing 
buildings or structures shall not be required to be part of 
the grounding electrode system where the steel reinforcing 
bars or rods are not accessible for use without disturbing 
the concrete. 

250.52 Grounding Electrodes. 

(A) Electrodes Permitted for Grounding. 

(1) Metal Underground Water Pipe. A metal underground 
water pipe in direct contact with the earth for 3.0 m (10 ft) 
or more (including any metal well casing bonded to the 
pipe) and electrically continuous (or made electrically 
continuous by bonding around insulating joints or 
insulating pipe) to the points of connection of the 
grounding electrode conductor and the bonding conductors. 



70-104 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.53 



Interior metal water piping located more than 1.52 m (5 ft) 
from the point of entrance to the building shall not be used 
as a part of the grounding electrode system or as a 
conductor to interconnect electrodes that are part of the 
grounding electrode system. 

Exception: In industrial, commercial, and institutional 
buildings or structures where conditions of maintenance 
and supervision ensure that only qualified persons service 
the installation, interior metal water piping located more 
than 1.52 m (5 ft) from the point of entrance to the building 
shall be permitted as a part of the grounding electrode 
system or as a conductor to interconnect electrodes that 
are part of the grounding electrode system, provided that 
the entire length, other than short sections passing 
perpendicularly through walls, floors, or ceilings, of the 
interior metal water pipe that is being used for the 
conductor is exposed. 

(2) Metal Frame of the Building or Structure. The metal 
frame of the building or structure tjc^ihmwmQi^AO: the 

earth by^fiJdfSie fol jewing m^hod$| 

(1) 3.0 m (10 ft) or more of a single structural metal 
member in direct contact with the earth or encased in 
concrete that is in direct contact with the earth 

(2) jCdmecting' the structural metal frame to the 
ranflrciBg: bars of a;„ concrete-encased d as 



25(K 

(3) Bond^ing the Srocturaj rnetal frame to one or moire of 
the glgunding electrodes as defined m250.52(^^^ or 
(AXi^Siat comply with 256,5^ 

(4) Other approved means of establishing a connection to 
earth 

(3) Concrete-Encased Electrode. An electrode encased 
by at least 50 mm (2 in.) of concrete, located jborizqntaily 
near the bottom pr verticaliy» and wiJiin that porttoij of a 
concrete foundation or footing that is in direct contact with 
the earth, consisting of at least 6.0 m (20 ft) of one or more 
bare or zinc galvanized or other electrically conductive 
coated steel reinforcing bars or rods of not less than 1 3 mm 
(V2 in.) in diameter, or consisting of at least 6.0 m (20 ft) of 
bare copper conductor not smaller than 4 AWG. 
Reinforcing bars shall be permitted to be bonded together 
by the usual steel tie wires or other effective means, jwfeg 

WldiBg:|f Supti^ .to:|)oiWi only 

bneip.t6;4ej^ouijd eleotxode^ §yste;m, 

(4) Ground Ring. A ground ring encircling the building or 
structure, in direct contact with the earth, consisting of at 



least 6.0 m (20 ft) of bare copper conductor not smaller 
than 2 AWG. 

(5) Rod and Pipe Electrodes. Rod and pipe electrodes 
shall not be less than 2.44 m (8 ft) in length and shall 
consist of the following materials. 

(a) jGxomdiiig elecfrodes of pipe or conduit shall not 
be smaller than metric designator 21 (trade size Va) and, 
where of steel, shall have the outer surface galvanized or 
otherwise metal-coated for corrosion protection. 



(b) Grounding eleqtodes of ^stmhles?- steel and coppe;? 
!or ziiiC coated steel shall be at least 15.87 mm (5/8 in.) in 
diameter, unless listed and not less than 12.70 mm (V2 in.) 
in diameter. 

|<|) ^ Other Listed J^^ groundinl 

Jdectrodes shall |)ei>ermtted.; 

(7) Plate Electrodes. Each plate electrode shall expose not 
less than 0.186 m2 (2 ft2) of surface to exterior soil. 
Electrodes of iron or steel plates shall be at least 6.4 mm QA 
in.) in thickness. Electrodes of nonferrous metal shall be at 
least 1.5 mm (0.06 in.) in thickness. 

(8) Other Local Metal Underground Systems or 
Structures. Other local metal underground systems or 
structures such as piping systems, underground tanks, and 
underground metal well casings that are not bonded to a 
metal water pipe. 

(B) Not Permitted for lUse as Grounding EleciroSi^ The 
following systems and materials shall not be used as 
grounding electrodes: 

(1) Metal underground gas piping systemf 

(2) Aluminum 

FPN: See 250.104(B) for bonding requirements of gas piping. 

250.53 Grounding Electrode System Installation. FPN: 
See 547.9 and 547.10 for special grounding and bonding 
requirements for agricultural buildings. 

(A) Rod, Pipe, and Plate Electrodes. Where practicable, 
rod, pipe, and plate electrodes shall be embedded below 
permanent moisture level. Rod, pipe, and plate electrodes 
shall be fi*ee from nonconductive coatings such as paint or 
enamel. 

(B) Electrode Spacing. Where more than one of the 
electrodes of the type specified in 250.52(A)(5) or (A)(7) 
are used, each electrode of one grounding system 
(including that used for air terminals) shall not be less than 
1.83 m (6 ft) from any other electrode of another grounding 
system. Two or more grounding electrodes that are bonded 
together shall be considered a single grounding electrode 
system. 



2010 California Electrical Code 



70-105 



250.54 



ARTICLE 250 - GROUNDING AND BONDING 



(C) Bonding Jumper. The bonding jumper(s) used to 
connect the grounding electrodes together to form the 
grounding electrode system shall be installed in accordance 
with 250.64(A), (B), and (E), shall be sized in accordance 
with 250.66, and shall be connected in the manner 
specified in 250.70. 

(D) Metal Underground Water Pipe. Where used as a 
grounding electrode, metal underground water pipe shall 
meet the requirements of 250.53(D)(1) and (D)(2). 

(1) Continuity. Continuity of the grounding path or the 
bonding connection to interior piping shall not rely on 
water meters or filtering devices and similar equipment. 

(2) Supplemental Electrode Required. A metal 
underground water pipe shall be supplemented by an 
additional electrode of a type specified in 250.52(A)(2) 
through (A)(8). Where the supplemental electrode is a rod, 
pipe, or plate type, it shall comply with 250.56. The 
supplemental electrode shall be permitted to be bonded to 
the grounding electrode conductor, the grounded service- 
entrance conductor, the nonflexible grounded service 
raceway, or any grounded service enclosure. 

Exception: The supplemental electrode shall be permitted 
to be bonded to the interior metal water piping at any 
convenient point as covered in 250.52(A)(1), Exception. 

(E) Supplemental Electrode Bonding Connection Size. 

Where the supplemental electrode is a rod, pipe, or plate 
electrode, that portion of the bonding jumper that is the 
sole connection to the supplemental grounding electrode 
shall not be required to be larger than 6 AWG copper wire 
or 4 AWG aluminum wire. 

(F) Ground Ring. The ground ring shall be buried at a depth 
below the earth's surface of not less than 750 mm (30 in.). 

(G) Rod and Pipe Electrodes. The electrode shall be 
installed such that at least 2.44 m (8 ft) of length is in 
contact with the soil. It shall be driven to a depth of not less 
than 2.44 m (8 ft) except that, where rock bottom is 
encountered, the electrode shall be driven at an oblique 
angle not to exceed 45 degrees from the vertical or, where 
rock bottom is encountered at an angle up to 45 degrees, 
the electrode shall be permitted to be buried in a trench that 
is at least 750 mm (30 in.) deep. The upper end of the 
electrode shall be flush with or below ground level unless 
the aboveground end and the grounding electrode 
conductor attachment are protected against physical 
damage as specified in 250.10. 

(H) Plate Electrode. Plate electrodes shall be installed not 
less than 750 mm (30 in.) below the surface of the earth. 



250.54 Auxiliary Grounding Electrodes. One or more 
grounding electrodes shall be permitted to be connected to 
the equipment grounding conductors specified in 250.118 
and shall not be required to comply with the electrode 
bonding requirements of 250.50 or 250.53(C) or the 
resistance requirements of 250.56, but the earth shall not be 
used as an effective ground-fault current path as specified 
in 250.4(A)(5) and 250.4(B)(4). 

250.56 Resistance of Rod, Pipe, and Plate Electrodes. A 

single electrode consisting of a rod, pipe, or plate that does not 
have a resistance to ground of 25 ohms or less shall be 
augmented by one additional electrode of any of the types 
specified by 250.52(A)(4) through (A)(8). Where multiple rod, 
pipe, or plate electrodes are installed to meet the requirements 
of this section, they shall not be less than 1.8 m (6 ft) apart. 

FPN: The paralleling efficiency of rods longer than 2.5 m (8 
ft) is improved by spacing greater than 1.8 m (6 ft). 

250.58 Common Grounding Electrode. Where an ac 
system is connected to a grounding electrode in or at a 
building or structure, the same electrode shall be used to 
ground conductor enclosures and equipment in or on that 
building or structure. Where separate services, feeders, or 
branch circuits supply a building and are required to be 
connected to a grounding electrode(s), the same grounding 
electrode(s) shall be used. 

Two or more grounding electrodes that are bonded 
together shall be considered as a single grounding electrode 
system in this sense. 

250.60 Use of Air Terminals. Air terminal conductors and 
driven pipes, rods, or plate electrodes used for grounding air 
terminals shall not be used in lieu of the grounding electrodes 
required by 250.50 for grounding wiring systems and 
equipment. This provision shall not prohibit the required 
bonding together of grounding electrodes of different systems. 

FPN No. 1: See 250.106 for spacing from air terminals. See 
800.100(D), 810.21(J), and 820.100(D) for bonding of 
electrodes. 

FPN No. 2: Bonding together of all separate grounding 
electrodes will limit potential differences between them and 
between their associated wiring systems. 

250.62 Grounding Electrode Conductor Material. The 

grounding electrode conductor shall be of copper, 
aluminum, or copper-clad aluminum. The material selected 
shall be resistant to any corrosive condition existing at the 
installation or shall be suitably protected against corrosion. 
The conductor shall be solid or stranded, insulated, 
covered, or bare. 



70-106 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.64 



250.64 Grounding Electrode Conductor Installation. 

Grounding electrode conductors at: the service/ at eacH 
6uM4mg orstructiire Where supplied b^^ a feedef{s) .or 
breach cifcuit(s)j; or at a separatel^^^^^ shall be 

installed as specified in 250.64(A) through (F). 

(A) Aluminum or Copper-Clad Aluminum Conductors. 

Bare aluminum or copper-clad aluminum grounding 
conductors shall not be used where in direct contact with 
masonry or the earth or where subject to corrosive 
conditions. Where used outside, aluminum or copper-clad 
aluminum grounding conductors shall not be terminated 
within 450 mm (18 in.) of the earth. 

(B) Securing and Protection Against Physical Damage. 

Where exposed, a grounding electrode conductor or its 
enclosure shall be securely fastened to the surface on which 
it is carried. A 4 AWG or larger copper or aluminum 
grounding electrode conductor shall be protected where 
exposed to physical damage. A 6 AWG grounding 
electrode conductor that is free from exposure to physical 
damage shall be permitted to be run along the surface of 
the building construction without metal covering or 
protection where it is securely fastened to the construction; 
otherwise, it shall be in rigid metal conduit, intermediate 
metal conduit, rigid nonmetallic conduit, electrical metallic 
tubing, or cable armor. Grounding electrode conductors 
smaller than 6 AWG shall be in rigid metal conduit, 
intermediate metal conduit, rigid nonmetallic conduit, 
electrical metallic tubing, or cable armor. 

(C) Continuous. Grounding electrode conductor(s) shall 
be installed in one continuous length without a splice or 
joint except as permitted in (1) and (2): 

(1) Sphcing shall be permitted only by irreversible 
compression-type connectors listed as grounding and 
bonding equipment or by the exothermic welding process. 

(2) Sections of busbars shall be permitted to be connected 
together to form a grounding electrode conductor. 



(D) Serfice with Multiple DIscotitiecting Means 
Enclosures* Where a service consists of more than a single 
enclosure as permitted in 230Jl(A)j grounding eljectrode 
connections shall be made in accordance with (P){1), 
(D)(2), or fD)(3). 

(f) :^Groundm^ 'Whcxe fte 

somc^mimimlUQ by_^_230;4D^_Exc^^^^ No.' 

2; a ; cpmnion grounding electrode conductor and grounding 
electrode ponductor taps sliall be installed The common 
grounding electrode conductor shall be sized in accordance 
with 250,^6, based on the sum of the circular mil area of 
the largest ungrounded service-entrance (^on4uctor(s). 
Where the service-entrance conduc^^^^ 
a^ $e|-vice ?drop,,or^iyioe ;|ato jhej;pjHnmon ' ;^^^ 
electrode bonductpt shali be sized in accordance with Table 



25 0,66 J Mote 1. A tap conductor shall extend to the inside 
bf each service disconnecting means enclosure. The 
grounding electrode conductor taps shall be sized in 
accordance with 250^66 for; the largest cQhductor serving 
the individual enclosure., the tap qondnctqrs; shall be 
cpimecfed to the^ coinmon : grounding electro&,cond^ 
by ^exothermic welding or with cphnecjors' (listed as 
grounding and bonding equipment in such a manner that 
pie common grounding ele^^rode conductor remains 
without a splice or joint. 

(2) ; Indrndual Grounding Electrode Conductors* A 

grounding electrode ^conduct^^ be connected between 

i?§ ,,8rp^W^<l condtjclot ;in sen^i<x equipmeh^^ 

disconnecting means eng|dsure and the grounding electi'ode 
systein. Each grounding electrode conductor shall be sized 
in accordance with 250.66 based on the service-entrance 
conductor(s) supplying the individual service disconnecting 
tneans. 

(3) Common Locaf Ion, A grounding electrode cohdu^ 
shall be connected tp, the gi'ounded service cohductor(s) in 
;awireway or other accessible, enclosure on the supply sidej 
of the service disconnecting means. The comiection shall 
be made with exothermic welding or a connector listed as 
grounding and bonding equipment. The grounding 
electrode conductor shall be sized in accordance with 
250.66 based on the service-entrance conductor's) at the 
common location wter| the connection iS; made J 

(E) Enclosures for Grounding Electrode Conductors. 

Ferrous metal enclosures for grounding electrode conductors 
shall be electrically continuous from the point of attachment to 
cabinets or equipment to the grounding electrode and shall be 
securely fastened to the ground clamp or fitting. Nonferrous 
metal enclosures shall not be required to be electrically 
continuous. Ferrous metal enclosures that are not physically 
continuous from cabinet or equipment to the grounding 
electrode shall be made electrically continuous by bonding 
each end of the raceway or enclosure to the grounding 
electrode conductor. Bonding shall apply at each end and to all 
intervening ferrous raceways, boxes, and enclosures between 
the cabinets or equipment and the grounding electrode. The 
bonding jumper for a grounding electrode conductor raceway 
or cable armor shall be the same size as, or larger than, the 
enclosed grounding electrode conductor. Where a raceway is 
used as protection for a grounding electrode conductor, the 
installation shall comply with the requirements of the 
appropriate raceway article. 

(F) Installation to Electrode(s). Grounding electrode 
conductor(s) and ; bonding jumpers . interconnecting 
igrounding electrode^ shall be installed in accordance wiii 

(1), (2), or (3). The grounding electrode conductor shall be 
sized for the largest grounding electrode conductor 
required among all the electrodes connected to it. 



2010 California Electrical Code 



70-107 



250.66 



ARTICLE 250 - GROUNDING AND BONDING 



( 1 ) the grouniding ekptrode conductor shajl be; permitted 

io! be run to any convenient grounding electrode 
available in the grounding electrode system where the 
other electrode(s), iif ariy^ are cqimecti^^ iby bonding 
lumpers per! 250:^(^(2)5 

(2) prouoding Jlectrade to' 
jbe nin to one or more grounding electrode(s) 
individually. 

(3) Bonding jumpef(s) from grouadiiag eiectrpde(s) shall 
J)e permitted to be connected p an aluminuini or copper 
busbar not less than 6 mni >^ iO nnti i(3^ m^^^^ 2jjti.); 
the busbar shall, he: sec;i:i^ly;&s^cin^ be 
installed in an accessibk locatida Giabtiections shall; 
be made, by a iistedf ci^hnbctor 6r: bj^jf & 

.welding process,- the; grounding el&trpde: conductor 
shall be permitted to be rim to the busbar, Wherei 
aluminum bu$bar$ are used, the mstallation ^ha!l 
jcoinply witii 250.64(A). 

250.66 Size of Alternating-Current Grounding 
Electrode Conductor. The size of the grounding electrode 
conductor ai the service, at; 6aph;buiiding wherej 

kippiied by a feed^r(s)J:<ir to 

separately derived System of a grounded or ungrounded ac 
system shall not be less than given in Table 250.66, except 
as permitted in 250.66(A) through (C). 

FPN: See 250.24(C) for size of ac system conductor 
brought to service equipment. 

(A) Connections to Rod, Pipe, or Plate Electrodes. 

Where the grounding electrode conductor is connected to 
rod, pipe, or plate electrodes as permitted in 250.52(A)(5) 
or (A)(7), that portion of the conductor that is the sole 
connection to the grounding electrode shall not be required 
to be larger than 6 AWG copper wire or 4 AWG aluminum 
wire. 

(B) Connections to Concrete-Encased Electrodes. Where 
the grounding electrode conductor is connected to a 
concrete-encased electrode as permitted in 250.52(A)(3), 
that portion of the conductor that is the sole connection to 
the grounding electrode shall not be required to be larger 
than 4 AWG copper wire. 

(C) Connections to Ground Rings. Where the grounding 
electrode conductor is connected to a ground ring as 
permitted in 250.52(A)(4), that portion of the conductor 
that is the sole connection to the grounding electrode shall 
not be required to be larger than the conductor used for the 
ground ring. 

250.68 Grounding Electrode Conductor and Bonding 
Jumper Connection to Grounding Electrodes, the 

connection of a groundiiig electrode conductor- at thd 
service, at each building; or sthicture ^vhere:^^ by a 
ieederfs) or Ijr^ich circuil^s); or ial, a : Separately d^iyed 
System and associated bonding jumper(s)jshaj be:n^^ as! 

l^ofiedjZSOj^^ ^ ""^"'^ ' ' """" '" 



Table 250.66 Grounding Electrode Conductor for 
Alternating-Current Systems 



Size of Largest Ungrounded 

Service-Entrance Conductor or 

Equivalent Area for Parallel 

Conductorsa (AWG/kcmil) 

Aluminum or 

Copper-Clad 

Aluminum 



Size of Grounding 

Electrode Conductor 

(AWG/kcmil) 

Aluminum 
or Copper- 
Clad 



Copper 




Copper 


Aluminum** 


2 or smaller 


1/0 or smaller 


8 


6 


1 or 1/0 


2/0 or 3/0 


6 


4 


2/0 or 3/0 


4/0 or 250 


4 


2 


Over 3/0 through 
350 


Over 250 
through 500 


2 


1/0 


Over 350 
through 600 


Over 500 
through 900 


1/0 


3/0 


Over 600 
through 1100 


Over 900 
through 1750 


2/0 


4/0 


Over 1100 


Over 1750 


3/0 


250 



Notes: 

1 . Where multiple sets of service-entrance conductors are used as 
permitted in 230.40, Exception No. 2, the equivalent size of the 
largest service-entrance conductor shall be determined by the 
largest sum of the areas of the corresponding conductors of each 
set. 

2. Where there are no service-entrance conductors, the grounding 
electrode conductor size shall be determined by the equivalent 
size of the largest service-entrance conductor required for the load 
to be served. 

aThis table also applies to the derived conductors of separately 
derived ac systems. 

bSee installation restrictions in 250.64(A). 



(A) Accessibility. ^;^ me^^amcal ._ -^M^mk^^i}^^ \to 
leiminate d grounding electrode conductor or bonding 
jumper to a grounding electrode shall be accessible. 

Exception No. 1: An encased or buried connection to a 
concrete-encased, driven, or buried grounding electrode 
shall not be required to be accessible. 

Exception No. 2: "^Expthermic^or if^reyersi£lejobm^^ 
'connections used qt\ terntinations, together with the 
mechanical means uleS to attach such terminations to 
fjreproofed structural metal whether or not the mechanical 
means is reversible, shhllnot be required to be accessible. 

(B) Effective Grounding Path. The connection of a 
grounding electrode conductor or bonding jumper to a 
grounding electrode shall be made in a manner that will 
ensure an effective grounding path. Where necessary to 



70-108 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.92 



ensure the grounding path for a metal piping system used 
as a grounding electrode, bonding shall be provided 
around insulated joints and around any equipment likely 
to be disconnected for repairs or replacement. Bonding 
jumpers- shall be of sufficient length to permit removal 
of such equipment while retaining the integrity of the 

250.70 Methods of Grounding and Bonding Conductor 
Connection to Electrodes. The grounding or bonding 
conductor shall be connected to the grounding electrode by 
exothermic welding, listed lugs, listed pressure connectors, 
listed clamps, or other listed means. Connections 
depending on solder shall not be used. Ground clamps shall 
be Hsted for the materials of the grounding electrode and 
the grounding electrode conductor and, where used on pipe, 
rod, or other buried electrodes, shall also be Hsted for direct 
soil burial or concrete encasement. Not more than one 
conductor shall be connected to the grounding electrode by 
a single clamp or fitting unless the clamp or fitting is Hsted 
for multiple conductors. One of the following methods 
shall be used: 

(1) A pipe fitting, pipe plug, or other approved device 
screwed into a pipe or pipe fitting 

(2) A listed bolted clamp of cast bronze or brass, or plain 
or malleable iron 

(3) For indoor telecommunications purposes only, a listed 
sheet metal strap-type ground clamp having a rigid 
metal base that seats on the electrode and having a 
strap of such material and dimensions that it is not 
likely to stretch during or after installation 

(4) An equally substantial approved means 



IV. Enclosure, Raceway, and Service Cable 
Conii;|eetioiis 

250.80 Service Raceways and Enclosures. Metal 
enclosures and raceways for service conductors and 
equipment shall be ^connected; to the grouaded systetri 



ppriductbr! 
groiftKiin^ 



if the electrical system is grdunded or to the 
elec trcjde conductor for electrical systems Jlia^ 



Exception: A metal elbow that is installed in an 
underground installation of rigid nonmetallic conduit and 
is isolated from possible contact by a minimum cover of 
450 mm (18 Ifl-Jjojony part of the elbow shall not be 
required to be, connected to the grounded system conductor 
pr gyggni&g electrode conductor,^ 

250.84 Underground Service Cable or Raceway. 

(A) Underground Service Cable. The sheath or armor of a 
continuous underground metal-sheathed or armored service 
cable system that is connected to the grounded system 
ccmdudbr^iOT side shall not be required to be 



iconneptea taAe grounded sy stern conductor at the building 
or structure. The sheath or armor shall be permitted to be 
insulated from the interior metal raceway or piping. 

(B) Underground Service Raceway Containing Cable. 

An underground metal service raceway that contains a 
metal-sheathed or armored cable |cgii|||;j| to the grounded 
system iDonductot shall not be required to be connectedftp 
the grounded system conductor at the building or structure. 
The sheath or armor shall be permitted to be insulated from 
the interior metal raceway or piping. 

250.86 Other Conductor Enclosures and Raceways. 

Except as permitted by 250.112(1), metal enclosures and 
raceways for other than service conductors shall be 
conaected to the eguipm^ grounding conductor. 

Exception No. I: Metal enclosures and raceways for 
conductors added to existing installations of open wire, 
knob-and-tube wiring, and nonmetallic-sheathed cable 
shall not be required to be connected to the equipment 
grounding coHductor where these enclosures or wiring 
methods comply with (1) through (4) as follows: 

(1) Do not provide an equipment ground 

(2) Are in runs of less than 7.5 m (25 ft) 

(3) Are free from probable contact with ground, 
grounded metal, metal lath, or other conductive material 

(4) Are guarded against contact by persons 

Exception No. 2: Short sections of metal enclosures or 
raceways used to provide support or protection of cable 
assemblies from physical damage shall not be required to 
be connected to the equipment grounding conductor: 

Exception No. 3: A metal elbow shall not be required to be 
connected to the equipment grounding conductor where it 
is installed in a nonmetallic raceway and is isolated from 
possible contact by a minimum cover of 450 mm (18 in.) to 
any part of the elbow or is encased in not less than 50 mm 
(2 in.) of concrete. 



V. Bonding 

250.90 General. Bonding shall be provided where 
necessary to ensure electrical continuity and the capacity to 
conduct safely any fault current Hkely to be imposed. 

250.92 Services. 

(A) Bonding of Services. The non-current-carrying metal 
parts of equipment indicated in 250.92(A)|B^^^S|iii 
shall be bonded together. 

(1) The service raceways, cable trays, cablebus framework, 
auxiliary gutters, or service cable armor or sheath except 
as permitted in 250.84 

(2) All service enclosures containing service conductors, 
including meter fittings, boxes, or the like, interposed 
in the service raceway or armor 



2010 California Electrical Code 



70---109 



250.94 



ARTICLE 250 - GROUNDING AND BONDING 



(B) Method of Bonding at the Service. Electrical 
continuity at service equipment, service raceways, and 
service conductor enclosures shall be ensured by one of the 
following methods: 

(1) Bonding equipment to the grounded service conductor 
in a manner provided in 250.8 

(2) Connections utilizing threaded couplings or threaded 
bosses on enclosures where made up wrenchtight 

(3) Threadless couplings and connectors where made up 
tight for metal raceways and metal-clad cables 

(4) Other hsted devices, such as bonding-type locknuts, 
bushings, or bushings with bonding jumpers 

Bonding jumpers meeting the other requirements of this 
article shall be used around concentric or eccentric 
knockouts that are punched or otherwise formed so as to 
impair the electrical connection to ground. Standard 
locknuts or bushings shall not be the sole means for the 
bonding required by this section. 



250.94 Bonding for Other Systems. An intarsystem 
bonding termidation for coimecting; intersystem bonding 
and grounding conductors; requited for; other systems shall 
be provided externaLt6;ebclQSures;at the service eguipineint 
and atthe discomiecting hieans^for any additional buildings, 
or stmctures; ; Jhf :mM^^ bonding termination shall be 

accessible iotconmctipn. and inspection, The intersystem 
bonding teriBiniatiohshiail have the capacity for connection 
of not less than three ititersystem bonding conductors. The 
intersystem bonding tehriination device shall not interfere 
with opening a service or metering equipment enclosure. 
The intersystem bonding terrnination shall be one of the 
following: 

( 1 ) A set of terminals Securely mounted to the meter 
enotosnre and electrically connected to the meter 
eiicldsure. the terminals shall be listed as groundixig 
and bonding equipment. 

(2) A bonding ; bar iiea^th^ service equipment enclosure,; 
meter enclosure, or raceway for service conductors.; 
:The bonding; bar shah be connected with a minimum 6 
AWG copper cdndUctdr to an equipment grounding 
cpnductor(s) in the service equipment enclosure^ rnetei; 
encloswe, or exposed nqnfle^^^^ 

(3) Aborting bar near ;& 

J>onding bar sh^U be^Gpmi^ to tlie grounding electrode 
ponductor wth a ;i|^ 

Exception: iwexisUhg biiilcimgs Or structures where any of 
the intersystem : bondirig and grounding conductors 
requkeffy -mM'SOamfy^ 810:2 1(F), 820J00(BX 
830 J 00(B) exist, installation of th& intersystem bonding 
termination 'is}not reguired^ An accessible means external 
to enclosures for connecting intersystem bonding and 
grounding electrode conductors shall be perrnitted at the 



service equipment and at the disconnecting means for any 
additional buildings or structures by at least one of the 
following means: 

(1) Exposed nonflexible metallic raceways 

(2) An exposed grounding electrode conductor 

(3) Approved means for the external connection of a 
copper or other corrosion-resistant bonding or grounding 
conductor to the grounded raceway or equipment 

FPN No. 1: A 6 AWG copper conductor with one end 
bonded to the grounded nonflexible metalhc raceway or 
equipment and with 150 mm (6 in.) or more of the other end 
made accessible on the outside wall is an example of the 
approved means covered in 250.94, Exceptiotiitem (3). 

FPN No. 2: See 800.100, 810.21, and 820.100 for bonding 
and grounding requirements for communications circuits, 
radio and television equipment, and CATV circuits. 

250.96 Bonding Other Enclosures. 

(A) General. Metal raceways, cable trays, cable armor, 
cable sheath, enclosures, frames, fittings, and other metal 
non-current-carrying parts that are to serve as grounding 
conductors, with or without the use of supplementary 
equipment grounding conductors, shall be bonded where 
necessary to ensure electrical continuity and the capacity to 
conduct safely any fault current likely to be imposed on 
them. Any nonconductive paint, enamel, or similar coating 
shall be removed at threads, contact points, and contact 
surfaces or be connected by means of fittings designed so 
as to make such removal unnecessary. 

(B) Isolated Grounding Circuits. Where installed for the 
reduction of electrical noise (electromagnetic interference) 
on the grounding circuit, an equipment enclosure supplied 
by a branch circuit shall be permitted to be isolated from a 
raceway containing circuits supplying only that equipment 
by one or more listed nonmetallic raceway fittings located 
at the point of attachment of the raceway to the equipment 
enclosure. The metal raceway shall comply with provisions 
of this article and shall be supplemented by an internal 
insulated equipment grounding conductor installed in 
accordance with 250.146(D) to ground the equipment 
enclosure. 

FPN: Use of an isolated equipment grounding conductor 
does not relieve the requirement for grounding the raceway 
system. 

250.97 Bonding for Over 250 Volts. For circuits of over 
250 vohs to ground, the electrical continuity of metal 
raceways and cables with metal sheaths that contain any 
conductor other than service conductors shall be ensured by 
one or more of the methods specified for services in 
250.92(B), except for (B)(1). 

Exception: Where oversized, concentric, or eccentric 
knockouts are not encountered, or where a box or 
enclosure with concentric or eccentric knockouts is listed 
to provide a reliable pondmg connection, the following 
methods shall be permitted: 



70-110 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.104 



(1) Threadless couplings and connectors for cables 
with metal sheaths 

(2) Two locknuts, on rigid metal conduit or 
intermediate metal conduit, one inside and one outside of 
boxes and cabinets 

(3) Fittings with shoulders that seat firmly against the 
box or cabinet, such as electrical metallic tubing 
connectors, flexible metal conduit connectors, and cable 
connectors, with one locknut on the inside of boxes and 
cabinets 

(4) Listed fittings 

250.98 Bonding Loosely Jointed Metal Raceways. 

Expansion fittings and telescoping sections of metal 
raceways shall be made electrically continuous by 
equipment bonding jumpers or other means. 

250.100 Bonding in Hazardous (Classified) Locations. 

Regardless of the voltage of the electrical system, the 
electrical continuity of non-current-carrying metal parts of 
equipment, raceways, and other enclosures in any 
hazardous (classified) location as defined in ^^^^ shall be 
ensured by any of the boriding methods specified in 
250.92(B)(2) through (B)(4). One or more of these bonding 
methods shall be used whether or not equipment grounding 
conductors §5ffla wfre|yp§ are installed. 

250.102 Equipment Bonding Jumpers. 

(A) Material. Equipment bonding jumpers shall be of 
copper or other corrosion-resistant material. A bonding 
jumper shall be a wire, bus, screw, or similar suitable 
conductor. 

(B) Attachment. Equipment bonding jumpers shall be 
attached in the manner specified by the applicable 
provisions of 250.8 for circuits and equipment and by 
250.70 for grounding electrodes. 

(C) Size — Equipment Bonding Jumper on Supply Side 
of Service. The bonding jumper shall not be smaller than 
the sizes shown in Table 250.66 for grounding electrode 
conductors. Where the service-entrance phase conductors 
are larger than 1 100 kcmil copper or 1750 kcmil aluminum, 
the bonding jumper shall have an area not less than 12!/2 
percent of the area of the largest phase conductor except 
that, where the phase conductors and the bonding jumper 
are of different materials (copper or aluminum), the 
minimum size of the bonding jumper shall be based on the 
assumed use of phase conductors of the same material as 
the bonding jumper and with an ampacity equivalent to that 
of the installed phase conductors. Where the service- 
entrance conductors are paralleled in two or more raceways 
or cables, the equipment bonding jumper, where routed 



with the raceways or cables, shall be run in parallel. The 
size of the bonding jumper for each raceway or cable shall 
be based on the size of the service-entrance conductors in 
each raceway or cable. 

(D) Size — Equipment Bonding Jumper on Load Side 
of Service. The equipment bonding jumper on the load side 
of the service overcurrent devices shall be sized, as a 
minimum, in accordance with the sizes listed in Table 
250.122, but shall not be required to be larger than the 
largest ungrounded circuit conductors supplying the 
equipment and shall not be smaller than 14 AWG. 

A single common continuous equipment bonding 
jumper shall be permitted to connect two or more raceways 
or cables where the bonding jumper is sized in accordance 
with Table 250.122 for the largest overcurrent device 
supplying circuits therein. 

(E) Installation. The equipment bonding jumper shall 
be permitted to be installed inside or outside of a 
raceway or enclosure. Where installed on the outside, 
the length of the equipment bonding jumper shall not 
exceed 1.8 m (6 ft) and shall be routed with the raceway 
or enclosure. Where installed inside a raceway, the 
equipment bonding jumper shall comply with the 
requirements of 250.119 and 250.148. 

Exception: An equipment bonding jumper longer than 1.8 
m (6 ft) shall be permitted at outside pole locations for the 
purpose of bonding or grounding isolated sections of metal 
raceways or elbows installed in exposed risers of metal 
conduit or other metal raceway, 

250.104 Bonding of Piping Systems and Exposed 
Structural Steel. 

(A) Metal Water Piping. The metal water piping system 
shall be bonded as required in (A)(1), (A)(2), or (A)(3) of 
this section. The bonding jumper(s) shall be installed in 
accordance with 250.64(A), (B), and (E). The points of 
attachment of the bonding jumper(s) shall be accessible. 

(1) General. Metal water piping system(s) installed in or 
attached to a building or structure shall be bonded to the 
service equipment enclosure, the grounded conductor at the 
service, the grounding electrode conductor where of 
sufficient size, or to the one or more grounding electrodes 
used. The bonding jumper(s) shall be sized in accordance 
with Table 250.66 except as permitted in 250.104(A)(2) 
and (A)(3). 

(2) Buildings of Multiple Occupancy. In buildings of 
multiple occupancy where the metal water piping system(s) 
installed in or attached to a building or structure for the 
individual occupancies is metallically isolated from all 



2010 California Electrical Code 



70-111 



250.104 



ARTICLE 250 - GROUNDING AND BONDING 



Other occupancies by use of nonmetallic water piping, the 
metal water piping system(s) for each occupancy shall be 
permitted to be bonded to the equipment grounding 
terminal of the panelboard or switchboard enclosure (other 
than service equipment) supplying that occupancy. The 
bonding jumper shall be sized in accordance with Table 
250.122, based on the rating of the overcurretit protective 
;device for thC; circuit supplying the occupaiicy. 

(3) Multiple Buildings or Structures Supplied by a 
Feeder(s) or Branch Circuit(s). The metal water piping 
system(s) installed in or attached to a building or structure 
shall be bonded to the building or structure disconnecting 
means enclosure where located at the building or structure, 
to the equipment grounding conductor run with the supply 
conductors, or to the one or more grounding electrodes 
used. The bonding jumper(s) shall be sized in accordance 
with 250.66, based on the size of the feeder or branch 
circuit conductors that supply the building. The bonding 
jumper shall not be required to be larger than the largest 
ungrounded feeder or branch circuit conductor supplying 
the building. 

(B) Other Metal Piping. Where installed in or attached to 
a building or structure, a metal piping system(s), including 
gas piping, that is likely to become energized shall be 
bonded to the service equipment enclosure, the grounded 
conductor at the service, the grounding electrode conductor 
where of sufficient size, or the one or more grounding 
electrodes used. The bonding jumper(s) shall be sized in 
accordance with 250.122, using the rating of the circuit that 
is likely to energize the piping system(s). The equipment 
grounding conductor for the circuit that is likely to energize 
the piping shall be permitted to serve as the bonding 
means. The points of attachment of the bonding jumper(s) 
shall be accessible. 

FPN: Bonding all piping and metal air ducts within the 
premises will provide additional safety. 

(C) Structural Metal. Exposed structural metal that is 
interconnected to form a metal building frame and is not 
intentionally grounded and is likely to become energized 
shall be bonded to the service equipment enclosure, the 
grounded conductor at the service, the grounding electrode 
conductor where of sufficient size, or the one or more 
grounding electrodes used. The bonding jumper(s) shall be 
sized in accordance with Table 250.66 and installed in 
accordance with 250.64(A), (B), and (E). The points of 
attachment of the bonding jumper(s) shall be accessible. 

(D) Separately Derived Systems. Metal water piping 
systems and structural metal that is interconnected to form 
a building frame shall be bonded to separately derived 
systems in accordance with (D)(1) through (D)(3). 



(1) Metal Water Piping System(s). The grounded 
conductor of each separately derived system shall be 
bonded to the nearest available point of the metal water 
piping system(s) in the area served by each separately 
derived system. This connection shall be made at the same 
point on the separately derived system where the grounding 
electrode conductor is connected. Each bonding jumper 
shall be sized in accordance with Table 250.66 based on 
the largest ungrounded conductor of the separately derived 
system. 

Exception No. 1: A separate bonding jumper to the metal 
water piping system shall not be required where the metal 
water piping system is used as the grounding electrode for 
the separately derived 'system and the water pipm^^^ 
is in the area served^ 

. Exception No. 2: A separate water piping bonding jumper 
shall not be required where the metal frame of a building 
or structure is used as the grounding electrode for a 
separately derived system and is bonded to the metal water 
piping in the area served by the separately derived system. 

(2) Structural Metal. Where exposed structural metal that 
is interconnected to form the building frame exists in the 
area served by the separately derived system, it shall be 
bonded to the grounded conductor of each separately derived 
system. This connection shall be made at the same point on 
the separately derived system where the grounding electrode 
conductor is connected. Each bonding jumper shall be sized 
in accordance with Table 250.66 based on the largest 
ungrounded conductor of the separately derived system. 

Exception No. 1: A separate bonding jumper to the 
building structural metal shall not be required where the 
metal frame of a building or structure is used as the 
grounding electrode for the separately derived system. 

Exception No. 2: A separate bonding jumper to the 
building structural metal shall not be required where the 
water piping of a building or structure is used as the 
grounding electrode for a separately derived system and is 
bonded to the building structural metal in the area served 
by the separately derived system. 

(3) Common Grounding Electrode Conductor. Where a 
common grounding electrode conductor is installed for 
multiple separately derived systems as permitted by 
250.30(A)(4), and exposed structural metal that is 
interconnected to form the building frame or interior metal 
piping exists in the area served by the separately derived 
system, the metal piping and the structural metal member 
shall be bonded to the common grounding electrode 
conductor. 

Exception: A separate bonding jumper from each derived 
system to metal water piping and to structural metal 
members shall not be required where the metal water 
piping and the structural metal members in the area served 
by the separately derived system are bonded to the common 
grounding electrode conductor. 



# 



70-112 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.112 



250.106 Lightning Protection Systems. The lightning 
protection system ground terminals shall be bonded to the 
building or structure grounding electrode system. 

FPN No. 1: See 250.60 for use of air terminals. For further 
information, see NFPA 780-2008, Standard for the 
Installation of Lightning Protection Systems, which contains 
detailed information on grounding, bonding, and sideflash 
distance from lightning protection systems. 

FPN No. 2: Metal raceways, enclosures, frames, and other 
non-current-carrying metal parts of electrical equipment 
installed on a building equipped with a lightning protection 
system may require bonding or spacing from the lightning 
protection conductors in accordance with NFPA 780-2008, 
Standard for the Installation of Lightning Protection 
Systems. 



VI. Equipment Grounding and Equipment Grounding 
Conductors 

250.110 Equipment Fastened in Place or Connected by 
Permanent Wiring Methods (Fixed). 

Exposed non-current-carrying metal parts of fixed 
equipment likely to become energized shall be Ooiinacted to 
ithe equipment grounding conductor under any of the 
following conditions: 

(1) Where within 2.5 m (8 ft) vertically or 1.5 m (5 ft) 
horizontally of ground or grounded metal objects and 
subject to contact by persons 

(2) Where located in a wet or damp location and not 
isolated 

(3) Where in electrical contact with metal 

(4) Where in a hazardous (classified) location as covered 
by Articles 500 through 517 

(5) Where supplied by a metal-clad, metal-sheathed, 
metal-raceway, or other wiring method that provides 
an equipment ground, except as permitted by 250.86, 
Exception No. 2, for short sections of metal enclosures 

(6) Where equipment operates with any terminal at over 
150 volts to ground 

Exception No. I: Metal frames of electrically heated 
appliances, exempted by special permission, in which case 
the frames shall be permanently and effectively insulated 
from ground. 

Exception No. 2: Distribution apparatus, such as 
transformer and capacitor cases, mounted on wooden 
poles, at a height exceeding 2.5 m (8 ft) above ground or 
grade level. 

Exception No. 3: Listed equipment protected by a system 
of double insulation, or its equivalent, shall not be required 

to be [.corin^edj^ equipment^^grMndmg, C0§di^t0n 
Where such a system is employed, the equipment shall be 
distinctively marked. 



250.112 Fastened in Place or Connected by Permanent 
Wiring Methods (Fixed) — Specific. Except as permitted 

in 250. 1 12(I)jf exposed, non-current-carrying metal parts of 
the kinds of equipment described in 250.112(A) through 
(K), and non-current-carrying metal parts of equipment 
and enclosures described in 250.1I2(L) and (M), |>haU be 
corinected to: the equipmert^^ coiiduttpr regardless 

of voltage. 

(A) Switchboard Frames and Structures. Switchboard 
frames and structures supporting switching equipment, 
except frames of 2-wire dc switchboards where effectively 
insulated from ground. 

(B) Pipe Organs. Generator and motor frames in an 
electrically operated pipe organ, unless effectively 
insulated from ground and the motor driving it. 

(C) Motor Frames. Motor frames, as provided by 430.242. 

(D) Enclosures for Motor Controllers. Enclosures for 
motor controllers unless attached to ungrounded portable 
equipment. 

(E) Elevators and Cranes. Electrical equipment for 
elevators and cranes. 

(F) Garages, Theaters, and Motion Picture Studios. 

Electrical equipment in commercial garages, theaters, and 
motion picture studios, except pendant lampholders 
supplied by circuits not over 150 volts to ground. 

(G) Electric Signs. Electric signs, outline lighting, and 
associated equipment as provided in 600.7. 

(H) Motion Picture Projection Equipment. Motion 
picture projection equipment. 

(I) Remote-Control, Signaling, and Fire Alarm Circuits. 

EquipmeS:suppiied by Class: 1 circuits shall te grounded 
imi^ss operating at fe^^ Equipment supplied 

by Class 1 power-limited circuits, by Class 2 and Class 3 
remote-control and signaling circuits, and by fire alarm 
circuits shall be grounded where system grounding is 
required by Part II or Part VIII of this article. 

(J) Luminaires. Luminaires as provided in Part V of 
Article 410, 

(K) Skid-Mounted Equipment. Permanently mounted 
electrical equipment and skids shall be P^^^^^^^^^jM'M^ 
equipment grounding conductqi! sized as required by 

250.122. 

(L) Motor-Operated Water Pumps. Motor-operated 
water pumps, including the submersible type. 

(M) Metal Well Casings. Where a submersible pump is used 
in a metal well casing, the well casing shall be connected to 
the pump circuit equipment grounding conductor. 



2010 California Electrical Code 



70-113 



250.114 



ARTICLE 250 - GROUNDING AND BONDING 



250.114 Equipment Connected by Cord and Plug. 

Under any of the conditions described in 250.114(1) 
through (4), exposed non-current-carrying metal parts of 
cord-and-plug-connected equipment likely to become 
energized shall be ^^onnected to the equipment groimding 
iDondactor. 

Exception: Listed tools, listed appliances, and listed 
equipment covered in 250.114(2) through (4) shall not be 
required to he connected to an equipment grounding 
conductor where protected by a system of double insulation 
or its equivalent. Double insulated equipment shall be 
distinctively marked, 

(1) In hazardous (classified) locations (see Articles 500 
through 517) 

(2) Where operated at over 150 volts to ground 
Exception No. 1: Motors, where guarded, shall npl be 
required to be connected to an equipment g^oujfding 
conductor. 

Exception No. 2: Metal frames of electrically heated 
appliances, exempted by special permission, shall not be 
required to be connected to an equipment grounding 
conductor; in which case the frames shall be permanently 
and effectively insulated from ground. 
I (3) In residential occupancies: 

a. Refrigerators, freezers, and air conditioners 

b. Clothes-washing, clothes-drying, dish-washing 
machines; kitchen waste disposers; information 
technology equipment; sump pumps and electrical 
aquarium equipment 

c. Hand-held motor-operated tools, stationary and 
fixed motor-operated tools, and light industrial 
motor-operated tools 

d. Motor-operated appliances of the following types: 
hedge clippers, lawn mowers, snow blowers, and 
wet scrubbers 

e. Portable handlamps 

(4) In other than residential occupancies: 

a. Refrigerators, freezers, and air conditioners 

b. Clothes-washing, clothes-drying, dish- washing 
machines; information technology equipment; 
sump pumps and electrical aquarium equipment 

c. Hand-held motor-operated tools, stationary and 
fixed motor-operated tools, and light industrial 
motor-operated tools 

d. Motor-operated appliances of the following types: 
hedge clippers, lawn mowers, snow blowers, and 
wet scrubbers 

e. Portable handlamps 

f. Cord-and-plug-connected appliances used in damp 

or wet locations or by persons standing on the 
ground or on metal floors or working inside of 
metal tanks or boilers 

g. Tools likely to be used in wet or conductive 
locations 



Exception: Tools and portable handlamps likely to be used 
in wet or conductive locations shall not be required to be 
connected '■jq :M e^ <^P^4MPi where 

supplied through an isolating transformer with an 
ungrounded secondary of not over 50 volts. 

250.116 Nonelectrical Equipment. The metal parts of the 
following nonelectrical equipment described in this section 
shall be connected to the equij)m^iit grpuhding conductqg 

(1) Frames and tracks of electrically operated cranes and 
hoists 

(2) Frames of nonelectrically driven elevator cars to which 
electrical conductors are attached 

(3) Hand-operated metal shifting ropes or cables of electric 
elevators 

FPN: Where extensive metal in or on buildings may become 
energized and is subject to personal contact, adequate 
bonding and grounding will provide additional safety. 

250.118 Types of Equipment Grounding Conductors. 

The equipment grounding conductor run with or enclosing 
the circuit conductors shall be one or more or a 
combination of the following: 

FBN:''For :;effeetiye':|rouiid-fa^^ path,; see; 250.2 

DefinitJQni 

(1) A copper, aluminum, or copper-clad aluminum 
conductor. This conductor shall be solid or stranded; 
insulated, covered, or bare; and in the form of a wire or 
a busbar of any shape. 

(2) Rigid metal conduit. 

(3) Intermediate metal conduit. 

(4) Electrical metallic tubing. 

(5) Listed flexible metal conduit meeting all the following 
conditions: 

a. The conduit is terminated m listed fittings. 

b. The circuit conductors contained in the conduit are 

protected by overcurrent devices rated at 20 
amperes or less. 

c. The combined length of flexible metal conduit and 

flexible metallic tubing and liquidtight flexible 
metal conduit in the same ground return path does 
not exceed 1.8 m (6 ft). 

d. Where used to connect equipment where flexibility 

is necessary after installation, an equipment 
grounding conductor shall be installed. 

(6) Listed liquidtight flexible metal conduit meeting all the 
following conditions: 

a. The conduit is terminated in listed fittings. 

b. For metric designators 12 through 16 (trade sizes 

3/8 through V2), the circuit conductors contained in 
the conduit are protected by overcurrent devices 
rated at 20 amperes or less. 



• 



70-114 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250,120 



c. For metric designators 21 through 35 (trade sizes Va 

through 1%), the circuit conductors contained in 
the conduit are protected by overcurrent devices 
rated not more than 60 amperes and there is no 
flexible metal conduit, flexible metallic tubing, or 
liquidtight flexible metal conduit in trade sizes 
metric designators 12 through 16 (trade sizes 3/8 
through V2) in the grounding path. 

d. The combined length of flexible metal conduit and 

flexible metallic tubing and liquidtight flexible 
metal conduit in the same ground return path does 
not exceed 1 .8 m (6 ft). 

e. Where used to connect equipment where flexibility 

is necessary after installation, an equipment 
grounding conductor shall be installed. 

(7) Flexible metallic tubing where the tubing is terminated 
in Usted fitiiBg§ and meeting the following conditions: 

a. The circuit conductors contained in the tubing are 

protected by overcurrent devices rated at 20 
amperes or less. 

b. The combined length of flexible metal conduit and 

flexible metallic tubing and liquidtight flexible 
metal conduit in the same ground return path does 
not exceed 1.8 m (6 ft). 

(8) Armor of Type AC cable as provided in 320. 108. 

(9) The copper sheath of mineral-insulated, metal-sheathed 
cable. 

(10) Type MC cable where listed and identified for 
grounding in accordance with the following: 

a. The combined metallic sheath and grounding 

conductor of interlocked metal tape-type MC cable 

b. The metallic sheath or the combined metallic sheath 

and grounding conductors of the smooth or 
corrugated tube-type MC cable 

(11) Cable trays as permitted in 392.3 and 392.7. 

(12) Cablebus framework as permitted in 370.3. 

(13) Other listed electrically continuous metal raceways 
and listed auxiliary gutters. 

(14) Surface metal raceways listed for grounding. 

250.119 Identification of Equipment Grounding 
Conductors. Unless required elsewhere in this Code, 
equipment grounding conductors shall be permitted to be 
bare, covered, or insulated. Individually covered or 
insulated equipment grounding conductors shall have a 
continuous outer finish that is either green or green with 
one or more yellow stripes except as permitted in this 
section. Conductors with insulation or individual covering 
that is green, green with one or more yellow stripes, or 
otherwise identified as permitted by this section shall not 
be used for ungrounded or grounded circuit conductors. 



Exception: Ppwer-Umited, Class :2 or Class 3 circuit 
cables containing only circuits operating less than 50 
yolts shall be pernntted to use. a cpnditctor mth green 
insulation for other than equipment grotindihg purposes: 

(A) Conductors Larger Than 6 AWG. Equipment 
grounding conductors larger than 6 AWG shall comply 
with 250.1 19(A)(1) and (A)(2). 

(1) An insulated or covered conductor larger than 6 AWG 
shall be permitted, at the time of installation, to be 
permanently identified as an equipment grounding 
conductor at each end and at every point where the 
conductor is accessible. 

Exception: Conductors larger than 6 A WG shall not be 
required to be marked in conduit bodies that contain no 
splices or unused hubs. 

(2) Identification shall encircle the conductor and shall be 
accomplished by one of the following: 

a. Stripping the insulation or covering from the entire 
exposed length 

b. Coloring the insulation or covering green at the 
tej;rnin^tidn 

c. Marking the insulation or covering with green tape 
or green adhesive labels jat the termmation 

(B) Multiconductor Cable. Where the condifions of 
maintenance and supervision ensure that only qualified 
persons service the installation, one or more insulated 
conductors in a multiconductor cable, at the time of 
installation, shall be permitted to be permanently identified 
as equipment grounding conductors at each end and at 
every point where the conductors are accessible by one of 
the following means: 

(1) Stripping the insulation from the entire exposed length 

(2) Coloring the exposed insulation green 

(3) Marking the exposed insulation with green tape or 
green adhesive labels 

(C) Flexible Cord. An uninsulated equipment grounding 
conductor shall be permitted, but, if individually covered, 
the covering shall have a continuous outer finish that is 
either green or green with one or more yellow stripes. 

250.120 Equipment Grounding Conductor Installation. 

An equipment grounding conductor shall be installed in 
accordance with 250.120(A), (B), and (C). 

(A) Raceway, Cable Trays, Cable Armor, Cablebus, or 
Cable Sheaths. Where it consists of a raceway, cable txay, 
cable armor, cablebus framework, or cable sheath or where 
it is a wire within a raceway or cable, it shall be installed in 
accordance with the applicable provisions in this Code 
using fittings for joints and terminations approved for use 
with the type raceway or cable used. All connections, 
joints, and fittings shall be made tight using suitable tools. 



2010 California Electrical Code 



70-115 



250.122 



ARTICLE 250 - GROUNDING AND BONDING 



FPN: See the UL gyidemfotmation on FHIT systems for 
equipment groimdiag coBdtictors installed in a raceway that 
aire patt of an el ectdcal circuit. protective systeni or a fire:i 
irated cable listed to rnaintaih^(;:ircuit integrity. 

(B) Aluminum and Copper-Clad Aluminum 
Conductors. Equipment grounding conductors of bare or 
insulated aluminum or copper-clad aluminum shall be 
permitted. Bare conductors shall not come in direct contact 
with masonry or the earth or where subject to corrosive 
conditions. Aluminum or copper-clad aluminum 
conductors shall not be terminated within 450 mm (18 in.) 
of the earth. 

(C) Equipment Grounding Conductors Smaller Than 6 

AWG. Equipment grounding conductors smaller than 6 
AWG shall be protected from physical damage by a 
raceway or cable armor except where run in hollow spaces 
of walls or partitions, where not subject to physical 
damage, or where protected from physical damage. 

250.122 Size of Equipment Grounding Conductors. 

(A) General. Copper, aluminum, or copper-clad aluminum 
equipment grounding conductors of the wire type shall not 
be smaller than shown in Table 250.122, but in no case 
shall they be required to be larger than the circuit 
conductors supplying the equipment. Where a cable tray, a 
raceway, or a cable armor or sheath is used as the 
equipment grounding conductor, as provided in 250.118 
and 250.134(A), it shall comply with 250.4(A)(5) or (B)(4). 

(B) Increased in Size. Where ungrounded conductors are 
increased in size, equipment grounding conductors, where 
installed, shall be increased in size proportionately 
according to the circular mil area of the ungrounded 
conductors. 

(C) Multiple Circuits. Where a single equipment 
grounding conductor is run with multiple circuits in the 
same raceway, cable, or pable tray,; it shall be sized for the 
largest overcurrent device protecting conductors in the 
raceway, cable, or cable tray. Equipment: groundiag 
conductors installed in cable trays shall meet the miBimuni 
requirements of 392.3(B)(1Xp)v 

(D) Motor Circuits. Equipment grouading conducibfs for 
motor Circuits shall be with (D)(1) or 



|(3X /General. The equiprnent grpunding conductor size; 
Ishail not be smaller than detennined by 250.122(A) based 
ipn the rating of the branch-circuit short-circuit and ground- 
iault protective device. 



(2) I«stantaneous-Trip Circuit Breaker and Motor 
Shorjt-Circuit Protector. Where the overcurrent device is 
ah; instantanec^s4rip ;: circuit b^ or a motor ■■ short- 
jcircuit protector, theleguipnientvg^^ conductqr shall 

be :si2;ed hot smalter than that g^^^ by 250422(A;) iising 
JtLeniaximumpermit^^^^ dual element time-delay 



fuse selected ■ forhvmc^-ck(^s^ 

fault protectioiii : ; in : accordanqe;J^;wrffi C:^ 430i52(C)(l)^ 

Exception iSfovi.' 

(E) Flexible Cord and Fixture Wire. The equipment 
grounding conductor in a flexible cord with the largest 
circuit conductor 10 AWG or smaller, and the equipment 
grounding conductor used with fixture wires of any size in 
accordance with 240.5, shall not be smaller than 18 AWG 
copper and shall not be smaller than the circuit conductors. 
The equipment grounding conductor in a flexible cord with 
a circuit conductor larger than 10 AWG shall be sized in 
accordance with Table 250. 122. 

(F) Conductors in Parallel. Where conductors are run in 
parallel in multiple raceways or cables as permitted in 
310.4, the equipment grounding conductors, where used, 
shall be run in parallel in each raceway or cable. 



Each parallel equipment grounding conductor shall be 
sized on the basis of the ampere rating of the overcurrent 
device protecting the circuit conductors in the raceway or 
cable in accordance with Table 250.122, 



(G) Feeder Taps. Equipment grounding conductors run 
with feeder taps shall not be smaller than shown in Table 
250.122 based on the rating of the overcurrent device ahead 
of the feeder but shall not be required to be larger than the 
tap conductors. 

250.124 Equipment Grounding Conductor Continuity. 

(A) Separable Connections. Separable connections such 
as those provided in drawout equipment or attachment 
plugs and mating connectors and receptacles shall provide 
for first-make, last-break of the equipment grounding 
conductor. First-make, last-break shall not be required 
where interlocked equipment, plugs, receptacles, and 
connectors preclude energization without grounding 
continuity. 

(B) Switches. No automatic cutout or switch shall be 
placed in the equipment grounding conductor of a premises 
wiring system unless the opening of the cutout or switch 
disconnects all sources of energy. 

250.126 Identification of Wiring Device Terminals. The 

terminal for the connection of the equipment grounding 
conductor shall be identified by one of the following: 

(1) A green, not readily removable terminal screw with a 
hexagonal head. 

(2) A green, hexagonal, not readily removable terminal nut. 

(3) A green pressure wire cormector. If the terminal for the 
grounding conductor is not visible, the conductor 



70-116 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.134 



Table 250.122 Minimum Size Equipment Grounding 
Conductors for Grounding Raceway and Equipment 





Size (AWG 


or kcmil) 


Rating or Setting of 

Automatic Overcurrent 

Device in Circuit Aliead of 

Equipment, Conduit, etc., 

Not Exceeding (Amperes) 


Copper 


Aluminum or 
Copper-Clad 
Aluminum* 


15 


14 


12 


20 


12 


10 


30 


10 


8 


40 


10 


8 


60 


10 


8 


100 


8 


6 


200 


6 


4 


300 


4 


2 


400 


3 


1 


500 


2 


1/0 


600 


1 


2/0 


800 


1/0 


3/0 


1000 


2/0 


4/0 


1200 


3/0 


250 


1600 


4/0 


350 


2000 


250 


400 


2500 


350 


600 


3000 


400 


600 


4000 


500 


800 


5000 


700 


1200 


6000 


800 


1200 



Note: Where necessary to comply with 250.4(A)(5) or (B)(4), the 

equipment grounding conductor shall be sized larger than given in 

this table. 

*See installation restrictions in 250.120. 

entrance hole shall be marked with the word green or 
ground, the letters G or GR, a grounding symbol, or 
otherwise identified by a distinctive green color. If the 
terminal for the equipment grounding conductor is 
readily removable, the area adjacent to the terminal 
shall be similarly marked. 
FPN: See FPN Figure 250.126. 




FPN Figure 250.126 One Example of a Symbol Used to 
Identify the Grounding Termination Point for an 
Equipment Grounding Conductor. 

VII. Methods of Equipment Grounding 

250.130 Equipment Grounding Conductor Connections. 

Equipment grounding conductor connections at the source 
of separately derived systems shall be made in accordance 



with 250.30(A)(1). Equipment grounding conductor 
connections at service equipment shall be made as 
indicated in 250.130(A) or (B). For replacement of non- 
grounding- type receptacles with grounding-type 
receptacles and for branch-circuit extensions only in 
existing installations that do not have an equipment 
grounding conductor in the branch circuit, connections 
shall be permitted as indicated in 250.130(C). 

(A) For Grounded Systems. The connection shall be 
made by bonding the equipment grounding conductor to 
the grounded service conductor and the grounding 
electrode conductor. 

(B) For Ungrounded Systems. The connection shall be 
made by bonding the equipment grounding conductor to 
the grounding electrode conductor. 

(C) Nongrounding Receptacle Replacement or Branch 
Circuit Extensions. The equipment grounding conductor of 
a grounding-type receptacle or a branch-circuit extension 
shall be permitted to be connected to any of the following: 

(1) Any accessible point on the grounding electrode 
system as described in 250.50 

(2) Any accessible point on the grounding electrode 
conductor 

(3) The equipment grounding terminal bar within the 
enclosure where the branch circuit for the receptacle or 
branch circuit originates 

(4) For grounded systems, the grounded service conductor 
within the service equipment enclosure 

(5) For ungrounded systems, the grounding terminal bar 
within the service equipment enclosure 

FPN: See 406.3(D) for the use of a ground-fault circuit- 
interrupting type of receptacle. 

250.132 Short Sections of Raceway. Isolated sections of 
metal raceway or cable armor, where required to be 
grounded, shall be ponhmpd to to eqiiipinpnt grounding 

coaducto| in accordance with 250.134. 

250.134 Equipment Fastened in Place or Connected by 
Permanent Wiring Methods (Fixed) — Grounding. 

Unless grounded by connection to the grounded circuit 
conductor as permitted by 250.32, 250.140, and 250.142, 
non-current-carrying metal parts of equipment, raceways, 
and other enclosures, if grounded, shall be bonnected tq^ari 
equipment grou nding conductor by one of the methods 
specified in 250.134(A) or (B). 

(A) Equipment Grounding Conductor Types. By 

^qnnecii|ig;.to: any of the equipment grounding conductors 
permitted! by 250.1 18. 



2010 California Electrical Code 



70-117 



250.136 



ARTICLE 250 - GROUNDING AND BONDING 



(B) With Circuit Conductors. By coimectitig to an 

equipment grounding conductor contained within the same 
raceway, cable, or otherwise run with the circuit conductors. 

Exception No. 1: As provided in 2 50 J 30(C), the 
equipment grounding conductor shall be permitted to be 
run separately from the circuit conductors. 

Exception No. 2: For dc circuits, the equipment grounding 
conductor shall be permitted to be run separately from the 
circuit conductors. 

FPN No. 1: See 250.102 and 250.168 for equipment 
bonding jumper requirements. 

FPN No. 2: See 400.7 for use of cords for fixed equipment. 

250.136 Equipment Considered Grounded. Under the 
conditions specified in 250.136(A) and (B), the nprmallj^ 
non-current-carrying metal parts of the equipment shall be 
considered grounded. 

(A) Equipment Secured to Grounded Metal Supports. 

Electrical equipment secured to and in electrical contact 
with a metal rack or structure provided for its support and 
connected to an equipment grounding condxiotor by one of 
the means indicated in 250.134. The structural metal frame 
of a building shall not be used as the required equipment 
grounding conductor for ac equipment. 

(B) Metal Car Frames, Metal car frames supported by 
metal hoisting cables attached to or running over metal 
sheaves or drums of elevator machines that are connected 
to an eijuipmetit grounding conduc^^ by one of the 
methods indicated in 250.134. 

250.138 Cord-and-Plug-Connected Equipment. Non- 
current-carrying metal parts of cord-and-plug-connected 
equipment, if grounded, shall be cbmiected to an equipment 
grounding conductor by one of the methods in 250.138(A) 
or(B). 

(A) By Means of an Equipment Grounding Conductor. 

By means of an equipment grounding conductor run with 
the power supply conductors in a cable assembly or 
flexible cord properly terminated in a grounding-type 
attachment plug with one fixed grounding contact. 

Exception: The grounding contacting pole of grounding- 
type plug-in ground-fault circuit interrupters shall be 
permitted to be of the movable, self-restoring type on 
circuits operating at not over 150 volts between any two 
conductors or over 150 volts between any conductor and 
ground. 

(B) By Means of a Separate Flexible Wire or Strap, By 

means of a separate flexible wire or strap, insulated or bare, 
connected to an equipment groxinding condijctor^- and 

protected as well as practicable against physical damage, 
where part of equipment. 



250.140 Frames of Ranges and Clothes Dryers. Frames 
of electric ranges, wall-mounted ovens, counter-mounted 
cooking units, clothes dryers, and outlet or junction boxes 
that are part of the circuit for these appliances shall be 
jc6mec|e&to;rh in the 

manner specifiedTy 25a 

Exception: For existing branch-circuit installations only 
where an equipment grounding conductor is not present in 
the outlet or junction box, the frames of electric ranges, 
wall-mounted ovens, counter-mounted cooking units, 
clothes dryers, and outlet or junction boxes that are part of 
the circuit for these appliances shall be permitted to be 
connected ta the grounded circuit conductor if all the 
following conditions are met. 

(1) The supply circuit is 120/240-volt, single-phase, 3- 
wire; or 208Y/120-volt derived from a 3-phase, 4-wire, wye- 
connected system. 

(2) The grounded conductor is not smaller than 10 A WG 
copper or 8 A WG aluminum. 

(3) The grounded conductor is insulated, or the grounded 
conductor is uninsulated and part of a Type SE service-entrance 
cable and the branch circuit originates at the service equipment. 

(4) Grounding contacts of receptacles fiAmished as part of 
the equipment are bonded to the equipment. 

250.142 Use of Grounded Circuit Conductor for 
Grounding Equipment. 

(A) Supply-Side Equipment. A grounded circuit 
conductor shall be permitted to ground non-current- 
carrying metal parts of equipment, raceways, and other 
enclosures at any of the following locations: 

(1) On the supply side or within the enclosure of the ac 
service -disconnecting means 

(2) On the supply side or within the enclosure of the main 
disconnecting means for separate buildings as 
provided in 250.32(B) 

(3) On the supply side or within the enclosure of the main 
disconnecting means or overcurrent devices of a 
separately derived system where permitted by 
250.30(A)(1) 

(B) Load-Side Equipment. Except as permitted in 
250.30(A)(1) and 250.32(B), a grounded circuit conductor 
shall not be used for grounding non-current-carrying metal 
parts of equipment on the load side of the service 
disconnecting means or on the load side of a separately 
derived system disconnecting means or the overcurrent 
devices for a separately derived system not having a main 
disconnecting means. 

Exception No. 1: The frames of ranges, wall-mounted 
ovens, counter-mounted cooking units, and clothes dryers 
under the conditions permitted for existing installations by 



70-118 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.148 



250. 140 shall be permitted to be fonnected to the grounded 
circuit conductor. 

Exception No. 2: It shall be permissible to ground meter 
enclosures by connection to the grounded circuit conductor 
on the load side of the service disconnect where all of the 
following conditions apply: 

(1) No service ground-fault protection is installed. 

(2) All meter enclosures are located immediately 
adjacent to the service disconnecting means. 

(3) The size of the grounded circuit conductor is not 
smaller than the size specified in Table 250.122 for 
equipment grounding conductors. 

Exception No. 3: Direct-current systems shall be permitted 
to be grounded on the load side of the disconnecting means 
or overcurrent device in accordance with 250.164. 

Exception No. 4: Electrode-type boilers operating at over 
600 volts shall be grounded as required in 490.72(E)(1) 
and 490.74. 

250.144 Multiple Circuit Connections. Where equipment 
is grounded and is supplied by separate connection to more 
than one circuit or grounded premises wiring system, ail 
equipment LS?^M4*TO: conductor , termination shall be 
provided for each such connection as specified in 250.134 
and 250.138. 

250.146 Connecting Receptacle Grounding Terminal to 

Box. An equipment bonding jumper shall be used to 
connect the grounding terminal of a grounding-type 
receptacle to a grounded box unless grounded as in 
250.146(A) through (D). The equipment bonding jumpet] 
shall be sized, in acdordance witli Table 250, 122 based on 
tiie rating of the overcurrent device protecting the circuri 
ponductoifs. 

(A) Surface-Mounted Box. Where the box is mounted on 
the surface, direct metal-to-metal contact between the 
device yoke and the box or a contact yoke or device that 
complies with 250.146(B) shall be permitted to ground the 
receptacle to the box. At least one of the insulating washers 
shall be removed from receptacles that do not have a 
contact yoke or device that complies with 250, 146(B) to 
ensure direct metal-to-metal contact. This provision shall 
not apply to cover-mounted receptacles unless the box and 
cover combination are listed as providing satisfactory 
ground continuity between the box and the receptacle, i^ 
listed: exposed ^ork cover shall be' peim the' 
grounding and bonding m^ (1) the device „i$ 
attached to the ; coyer with at least two fasteiibrs that ar^^ 
jperm^netit ; (stxch ^s ; a rivet): or have :a thread Jockmg ot; 
sctew lodkittg ; meaES and (2) when the coyer: tndunting 
ibpi^s are located pri a flat toa-tms^^ 

(B) Contact Devices or Yokes. Contact devices or yokes 
designed and listed as self-grounding shall be permitted in 
conjunction with the supporting screws to establish the 



grounding circuit between the device yoke and flush-type 

boxes. 

(C) Floor Boxes. Floor boxes designed for and listed as 
providing satisfactory ground continuity between the box 
and the device shall be permitted. 

(D) Isolated Receptacles. Where instaiied for the 

reduction of electrical noise (electromagnetic interference) 
on the grounding circuit, a receptacle in which the 
grounding terminal is purposely insulated from the 
receptacle mounting means shall be permitted. The 
receptacle grounding terminal shall be [connected to an 
insulated equipment grounding conductor run with the 
circuit conductors. This l^mpinent grounding conductor 
shall be permitted to pass through one or more panelboards 
without I connection to the panelboard grounding terminal 
|)a| as permitted in 408.40, Exception, so as to terminate 
within the same building or structure directly at an 
equipment grounding conductor terminal of the applicable 
derived system or service. [Where installed in accordance 
with t% provisions Qf this, section, this equipment 
grounding „ c^onducto^^ to pass 

teou^bpxeA 3Yit?^^y^/Ar„<>^^h^t^ishclosur^^ without being 
connecied to such enclosures. 

FPN: Use of an isolated equipment grounding conductor 
does not relieve the requirement for grounding the raceway 
system and outlet box. 

250.148 Continuity and Attachment of Equipment 
Grounding Conductors to Boxes. Where circuit 
conductors are spliced within a box, or terminated on 
equipment within or supported by a box, any equipment 
grounding conductor(s) associated with those circuit 
conductors shall be connected within the box or to the box 
with devices suitable for the use in accordance with 
250. 148(A) through (E). 

Exception: The equipment grounding conductor permitted 
in 250.146(D) shall not be required to be eomected to the 
other equipment grounding conductors or to the box. 

(A) Connections. Connections and spHces shall be made in 
accordance with 1 10.14(B) except that insulation shall not 
be required. 

(B) Grounding Continuity. The arrangement of grounding 
connections shall be such that the disconnection or the 
removal of a receptacle, luminaire, or other device fed from 
the box does not interfere with or interrupt the grounding 
continuity. 

(C) Metal Boxes. A connection shall be made between the 
one or more equipment grounding conductors and a metal 
box by means of a grounding screw that shall be used for 
no other purpose, equipment listed for grpu^ or a 
listed grounding device. 



2010 California Electrical Code 



70-119 



250.160 



ARTICLE 250 - GROUNDING AND BONDING 



(D) Non metallic Boxes. One or more equipment grounding 
conductors brought into a nonmetallic outlet box shall be 
arranged such that a connection can be made to any fitting 
or device in that box requiring grounding. 

(E) Solder. Connections depending solely on solder shall 
not be used. 



VIII. Direct-Current Systems 

250.160 General. Direct-current systems shall comply 
with Part VIII and other sections of Article 250 not 
specifically intended for ac systems. 

250.162 Direct-Current Circuits and Systems to Be 
Grounded.. Direct-current circuits and systems shall be 
grounded as provided for in 250.162(A) and (B). 

(A) Two-Wire, Direct-Current Systems. A 2-wire, dc 
system supplying premises wiring and operating at greater 
than 50 volts but not greater than 300 volts shall be grounded. 

Exception No. 1: A system equipped with a ground 
detector and supplying only industrial equipment in limited 
areas shall not be required to be grounded. 

Exception No. 2: A rectifier-derived dc system supplied 
from an ac system complying with 250.20 shall not be 
required to be grounded. 

Exception No. 3: Direct-current fire alarm circuits having 
a maximum current of 0.030 ampere as specified in Article 
760, Part III, shall not be required to be grounded. 

(B) Three-Wire, Direct-Current Systems. The neutral 
conductor of all 3-wire, dc systems supplying premises 
wiring shall be grounded. 

250.164 Point of Connection for Direct-Current 
Systems. 

(A) Off-Premises Source. Direct-current systems to be 
grounded and supplied from an off-premises source shall 
have the grounding connection made at one or more supply 
stations. A grounding connection shall not be made at 
individual services or at any point on the premises wiring. 

(B) On-Premises Source. Where the dc system source is 
located on the premises, a grounding connection shall be 
made at one of the following: 

(1) The source 

(2) The first system disconnection means or overcurrent device 

(3) By other means that accomplish equivalent systern 
protection and that utilize equipment listed and 
identified for the use 



250.166 Size of the Direct-Current Grounding Electrode 
Conductor. The size of the grounding electrode conductor 
for a dc system shall be as specified in 250.166(A) and;(iB),' 

bxcept a^^'getmi^^ through (E). 

(A) Not Smaller Than the Neutral Conductor. Where the 
dc system consists of a 3 -wire balancer set or a balancer 
winding with overcurrent protection as provided in 
445.12(D), the grounding electrode conductor shall not be 
smaller than the neutral conductor and not smaller than 8 
AWG copper or 6 AWG aluminum. 

(B) Not Smaller Than the Largest Conductor. Where the 
dc system is other than as in 250.166(A), the grounding 
electrode conductor shall not be smaller than the largest 
conductor suppHed by the system, and not smaller than 8 
AWG copper or 6 AWG aluminum. 

(C) Connected to Rod, Pipe, or Plate Electrodes. Where 
cormected to rod, pipe, or plate electrodes as in 
250.52(A)(5) or (A)(7), that porfion of the grounding 
electrode conductor that is the sole connection to the 
grounding electrode shall not be required to be larger than 
6 AWG copper wire or 4 AWG aluminum wire. 

(D) Connected to a Concrete-Encased Electrode. Where 
connected to a concrete-encased electrode as in 
250.52(A)(3), that portion of the grounding electrode 
conductor that is the sole connection to the grounding 
electrode shall not be required to be larger than 4 AWG 
copper wire. 

(E) Connected to a Ground Ring. Where connected to a 
ground ring as in 250.52(A)(4), that portion of the 
grounding electrode conductor that is the sole connecfion to 
the grounding electrode shall not be required to be larger 
than the conductor used for the ground ring. 

250.168 Direct-Current ^ystey Bonding Jumper. For 
idirect*-cuitent systems that are to be grounded, anunspliced, 
|»ondingjmpper_sh^^^ 

boutce 'Of ;ttie3t?L?X?tg!7^/,di^M9^^ ^^. 

jsysterri; is grounded.; The size of the bonding jumper shall 
not be smaller than the system grounding electrode 
conductor specified in 250.166 and slmil com^^ thd 

p^pvi^ion^ of 250.28{A^^ {G)\ 

250.169 Ungrounded Direct-Current Separately 
Derived Systems. Except as otherwise permitted in 250.34 
for portable and vehicle-mounted generators, an 
ungrounded dc separately derived system supplied from a 
stand-alone power source (such as an engine-generator set) 
shall have a grounding electrode conductor connected to an 
electrode that complies with Part III of this article to 
provide for grounding of metal enclosures, raceways, 
cables, and exposed non-current-carrying metal parts of 



70-120 



2010 California Electrical Code 



ARTICLE 250 - GROUNDING AND BONDING 



250.184 



equipment. The grounding electrode conductor connection 
shall be to the metal enclosure at any point on the 
separately derived system from the source to the first 
system disconnecting means or overcurrent device, or it 
shall be made at the source of a separately derived system 
that has no disconnecting means or overcurrent devices. 

The size of the grounding electrode conductor shall be 
in accordance with 250.166. 



IX. Instruments, Meters, and Relays 

250.170 Instrument Transformer Circuits. Secondary 
circuits of current and potential instrument transformers shall 
be grounded where the primary windings are connected to 
circuits of 300 vohs or more to ground and, where on 
switchboards, shall be grounded irrespective of voltage. 

Exception No. 1: Circuits where the primary windings are 
connected to circuits of less than 1000 volts with no live 
parts or wiring exposed or accessible to other than 
qualified persons. 

Exception No. 2: Cuwent transformer secondaries 

fe(ftdrtd ib' begrounded: 

250.172 Instrument Transformer Cases. Cases or 

frames of instrument transformers shall be Connected to the 
equipmeBt gr^^ conductor where accessible to other 

than qualified persons. 

Exception: Cases or frames of current transformers, the 
primaries of which are not over 150 volts to ground and 
that are used exclusively to supply current to meters. 

250.174 Cases of Instruments, Meters, and Relays 
Operating at Less Than 1000 Volts. Instruments, meters, 
and relays operating with windings or working parts at less 
than 1000 volts shall be lqonnec|e§;^^^ 
§§5]^Sg[S)n4ucto as specified in 250.174(A), (B), or (C). 

(A) Not on Switchboards. Instruments, meters, and relays 
not located on switchboards, operating with windings or 
working parts at 300 volts or more to ground, and 
accessible to other than qualified persons, shall have the 
cases and other exposed metal parts connected to the 
equipment grounding conductor. 

(B) On Dead-Front Switchboards. Instruments, meters, 
and relays (whether operated from current and potential 
transformers or connected directly in the circuit) on 
switchboards having no live parts on the front of the panels 
shall have the cases coBnected tO:iiejequi£mett^^ 
Iponductoi 



(C) On Live-Front Switchboards. Instruments, meters, 
and relays (whether operated from current and potential 
transformers or connected directly in the circuit) on 
switchboards having exposed live parts on the front of 
panels shall not have their cases connected to thq 
equipmeaf grounding cpjaduc^^ Mats of insulating rubber 
or other suitable floor insulation shall be provided for the 
operator where the voltage to ground exceeds 150. 

250.176 Cases of Instruments, Meters, and Relays — 
Operating Voltage 1 kV and Over. Where instruments, 
meters, and relays have current-carrying parts of 1 kV and 
over to ground, they shall be isolated by elevation or 
protected by suitable barriers, grounded metal, or insulating 
covers or guards. Their cases shall not be connected to thd 
bquipment grounding conductor. 

Exception: Cases of electrostatic ground detectors where 
the internal ground segments of the instrument are 
connected to the instrument case and grounded and the 
ground detector is isolated by elevation. 

250.178 Instrument Grounding Conductor. The 

bqtiipment grounding conductor for secondary circuits of 
instrument transformers and for instrument cases shall not 
be smaller than 12 AWG copper or 10 AWG aluminum. 
Cases of instrument transformers, instruments, meters, and 
relays that are mounted directly on grounded metal surfaces 
of enclosures or grounded metal switchboard panels shall 
be considered to be grounded, and no additional jequipinent 
grounding conductor shall be required. 



X. Grounding of Systems and Circuits of 1 kV and 
Over (High Voltage) 

250.180 General. Where high-voltage systems are 
grounded, they shall comply with all applicable provisions 
of the preceding sections of this article and with 250.182 
through 250.190, which supplement and modify the 
preceding sections. 

250.182 Derived Neutral Systems. A system neutral 
^1^1 derived from a grounding transfr)rmer shall be 
permitted to be used for grounding high- voltage systems. 

250.184 Solidly Grounded Neutral Systems. Solidly 
grounded neutral systems shall be permitted to be either 
single point grounded or multigrounded neutral. 

(A) Neutral Conductor. 

(1) Insulation Level. The minimum insulation level for neutral 
conductors of soUdly grounded systems shall be 600 volts. 

Exception No. 1: Bare copper conductors shall be permitted 
to be used for the neutral conductor of the following: 

(1) 'Spyice-mtrance conductors 



(2) 'Sejyicejgterals^ 

(3) Direct-buried pon^^^ offeeders\ 



2010 California Electrical Code 



70-121 



250.186 



ARTICLE 250 - GROUNDING AND BONDING 



Exception No. 2: Bare conductors shall be permitted for the 
neutral conductor of overhead portions installed outdoors. 
Exception No. 3: The grounded neutral conductor' shall be 
permitted to be a bare conductor if isolated from phase 
conductors and protected from physical damage. 

FPN: See 225.4 for conductor covering where within 3.0 m 
(10 ft) of any building or other structure. 

(2) Ampacity. The neutral conductor shall be of sufficient 
ampacity for the load imposed on the conductor but not less 
than 33 V3 percent of the ampacity of the phase conductors. 
Exception: In industrial and commercial premises under 
engineering supervision, it shall be permissible to size the 
ampacity of the neutral conductor to not less than 20 
percent of the ampacity of the phase conductor. 

(B) Single-Point Grounded Neutral System. Where a 
single-point grounded neutral system is used, the following 
shall apply: 

(1) A single-point grounded neutral system shall be 
permitted to be supplied from (a) or (b): 

a. A separately derived system 

b. A multigrounded neutral system with an equipment 
grounding conductor cormected to the 
multigrounded neutral ;cohductor at the source of 
the single-point grounded heutxal system 

(2) A grounding electrode shall be provided for the 
system. 

(3) A grounding electrode conductor shall connect the 
grounding electrode to the system neutral jconductor, 

(4) A bonding jumper shall connect the equipment 
grounding conductor to the grounding electrode 
conductor. 

(5) An equipment grounding conductor shall be provided 
to each building, structure, and equipment enclosure. 

(6) A neutral conductor shall only be required where 
phase-to-neutral loads are supplied. 

(7) The neutral conductor,; where provided, shall be 
insulated and isolated from earth except at one 
location. 

(8) An equipment grounding conductor shall be run 
with the phase conductors and shall comply with 
(a), (b), and (c): 

a. Shall not carry continuous load 

b. May be bare or insulated 

c. Shall have sufficient ampacity for fault current duty 

(C) Multigrounded Neutral Systems. Where a 
multigrounded neutral system is used, the following shall 
apply; 

(1) The neutral conductor of a sohdly grounded neutral 
system shall be permitted to be grounded at more than 
one point. Grounding shall be permitted at one or more 
of the following locations: 

a. Transformers supplying conductors to a building or 
other structure 



b. Underground circuits where the neutral gondUcte^ is 
exposed 

c. Overhead circuits installed outdoors 

(2) The multigrounded neutral conductor shall be grounded 

at each transformer and at other additional locations by 
connection to a grounding electrode. 

(3) At least one grounding electrode shall be installed and 
connected to the multigrounded neutral conductor 
every 400 m (1300 ft). 

(4) The maximum distance between any two adjacent 
electrodes shall not be more than 400 m (1300 ft). 

(5) In a multigrounded shielded cable system, the shielding 
shall be grounded at each cable joint that is exposed to 
personnel contact. 



250*186 Impedance Grounded Neutral Systems. 

Impedance grounded neutral systems in which a grounding 
impedance, usually a resistor, Hmits the ground- fault 
current shall be permitted where all of the following 
conditions are met: 

(1) The conditions of maintenance and supervision ensure 
that only qualified persons service the installation. 

(2) Ground detectors are installed on the system. 

(3) Line-to -neutral loads are not served. 

Impedance grounded neutral systems shall comply 
with the provisions of 250.186(A) through (D). 

(A) Location. The grounding impedance shall be inserted 
in the grounding conductor between the grounding 
electrode of the supply system and the neutral point of the 
supply transformer or generator. 

(B) Identified and Insulated. The neutral conductor of an 
impedance grounded neutral system shall be identified, as 
well as fully insulated with the same insulation as the phase 
conductors. 

(C) System Neutral jConductorl Connection. The system 
neutral conductor shall not be connected to ground, except 
through the neutral grounding impedance. 

(D) Equipment Grounding Conductors. Equipment 
grounding conductors shall be permitted to be bare and 
shall be electrically connected to the ground bus and 
grounding electrode conductor. 

250.188 Grounding of Systems Supplying Portable or 
Mobile Equipment. Systems supplying portable or 
mobile high-voltage equipment, other than substations 
installed on a temporary basis, shall comply with 
250.188(A) through (F). 

(A) Portable or Mobile Equipment. Portable or mobile 
high- voltage equipment shall be supplied from a system 
having its neutral Jc6ridp.Qtor; grounded through an 
impedance. Where a delta-connected high-voltage system 



70-122 



2010 California Electrical Code 



ARTICLE 280 - SURGE ARRESTERS, OVER 1 kV 



280.5 



is used to supply portable or mobile equipment, a system 
neutral jjoSOffld; associated neutral cS^Ectpi^ shall be 
derived. 

(B) Exposed Non-Current-Carrying Metal Parts. 

Exposed non-current-carrying metal parts of portable or 
mobile equipment shall be connected by an equipment 
grounding conductor to the point at which the system 
neutral impedance is grounded. 

(C) Ground-Fault Current. The voltage developed 
between the portable or mobile equipment frame and 
ground by the flow of maximum ground- fault current shall 
not exceed 100 volts. 

(D) Ground-Fault Detection and Relaying. Ground-fault 
detection and relaying shall be provided to automatically 
de-energize any high-voltage system component that has 
developed a ground fault. The continuity of the equipment 
grounding conductor shall be continuously monitored so as 
to de-energize automatically the high-voltage circuit to the 
portable or mobile equipment upon loss of continuity of the 
equipment grounding conductor. 

(E) Isolation. The grounding electrode to which the 
portable or mobile equipment system neutral impedance is 
connected shall be isolated from and separated in the 
ground by at least 6.0 m (20 ft) fi-om any other system or 
equipment grounding electrode, and there shall be no direct 
connection between the grounding electrodes, such as 
buried pipe and fence, and so forth. 

(F) Trailing Cable and Couplers. High-voltage trailing 
cable and couplers for interconnection of portable or 
mobile equipment shall meet the requirements of Part III of 
Article 400 for cables and 490.55 for couplers. 

250.190 Grounding of Equipment. All non-current- 
carrying metal parts of fixed, portable, and mobile 
equipment and associated fences, housings, enclosures, and 
supporting structures shall be grounded. 

Exception: Where isolated from ground and located so as 
to prevent any person who can make contact with ground 
from contacting such metal parts when the equipment is 
energized. 









Equ?j:>menl grounding conductors not an integral part 
of a cable assembly shall not be smaller than 6 AWG 
copper or 4 AWG aluminum. 

FPN: See 250.110, Exception No. 2, for pole-mounted 
distribution apparatus. 



I. General 

280.1 Scope. This article covers general requirements, 
installation requirements, and connection requirements for surge 
arresters installed on premises wiring systems over 1 kV. 



psMlftii:!Fhere:^ 



280.3 Number Required. Where used at a point on a 
circuit, a surge arrester shall be connected to each 
ungrounded conductor. A single installation of such surge 
arresters shall be permitted to protect a number of 
interconnected circuits, provided that no circuit is exposed 
to surges while disconnected from the surge arresters. 

280.4 Surge Arrester Selection. ^\ip ^w%^ w^BpiB ^^ 

gompiy^wthjm and (B). 

j[A) Ratog* Th^^ rato be eqiial to 

^r greater tliati the maxkmm oggmto^ votoge 

Available at the point of appUoaijQn] 

^Mi&jCm^^^ 0|)etatitig voltage shaflbe the phase^o^gtoiaiid 

j^J^ ;^Imp€dan^^PX ;Uii'grduaded ;''|ystei5- ;Thejoaa|pmuiiT( 
pptttinu^p^s operating voltage shall; be Jie |jfliase*t<>"phase 

vqikge;oftlie^systejS 

(B) Silicon Carbide Types. The rating of a silicon carbide- 
type surge arrester shall be not less than 125 percent of the 
taiag specified iti 286.4(A).! 

FPN No. 1 : For further information on surge arresters, see 
ANSI/IEEE C62. 11-2005, Standard for Metal-Oxide Surge 
Arresters for Alternating-Current Power Circuits ^I--fcVJ^_ 
and ANSI/IEEE C62.22-1997, Guide for the Application of 
Metal-Oxide Surge Arresters for Alternating-Current 
Systems. 

FPN No. 2: The selection of a properly rated metal oxide 
arrester is based on considerations of maximum continuous 
operating voltage and the magnitude and duration of 
overvoltages at the arrester location as affected by phase-to- 
ground faults, system grounding techniques, switchin 
surges, and other causes. See the manufacturer's appHcation 
rules for selection of the specific arrester to be used at a 
particular location. 



2010 California Electrical Code 



70-123 



280.11 



ARTICLE 285 - SURGE-PROTECTIVE DEVICES (SPDs), 1 kV OR LESS 



280.5 jUbstiiig^^A^ ^ncstm shall be a listed device^ 
II. Installation 

280.11 Location. Surge arresters shall be permitted to be 
located indoors or outdoors. Surge arresters shall be made 
inaccessible to unqualified persons, unless listed for 
installation in accessible locations. 

280.12 Routing of Surge Arrester (Sroiiiiidiiig 
Conductors.; The conductor used to connect the surge 
arrester to line, bus, or equipment and to a gr6Mdiilg 
conductor cqnipteption point as provided in 280,21: shall not 
be any longer than necessary and shall avoid unnecessary 
bends. 



III. Connecting Surge Arresters 

280.21 'Qonmctipni The arrester grounding conductor 
shall be connected to one of the following: 

(1) Grounded service conductor 

(2) Grounding electrode conductor 

(3) Grounding electrode for the service 

(4) Equipment grounding terminal in the service equipment 

# 

280.23 Siirge-Arrester Conductors. The conductor 
between the surge arrester and the line and the surge 
arrester and the grounding connection shall not be smaller 
than 6 AWG copper or aluminum. 

280.24 Intercoiiiiectipiis. The grounding conductor of a 
surge arrester protecting a transformer that supplies a 
secondary distribution system shall be interconnected as 
specified in 280.24(A), (B), or (C). 

(A) Metallic Interconnections. A metallic interconnection 
shall be made to the secondary grounded circuit conductor 
or the secondary circuit grounding conductor provided that, 
in addition to the direct grounding connection at the surge 
arrester, the following occurs: 

(1) Additional Gronndlng Connectioii. The grounded 
conductor of the secondary has elsewhere a grounding 
connection to a continuous metal underground water piping 
system. In urban water-pipe areas where there are at least 
four water-pipe connections on the neutral conductor; and 
not fewer jthan four such connections in each mile of 
neutral ^cohductor^ the metallic interconnection shall be 
permitted to be made to the secondary neutral conductor 
with omission of the direct grounding connection at the 
surge arrester. 

(2) MnltigrpuMe^^^^ The 

grounded conductor of the secondary system is a part of a 
multigrouiided neutral system or static wire of which the 
primary neutral conductor or static wire has at least four 
grounding connections in each mile of line in addition to a 
grounding connection at each service. 



(B) Through Spark Gap or Device. Where the surge 
arrester grounding conductor is not connected as in 
280.24(A) or where the secondary is not grounded as in 
280.24(A) but is otherwise grounded as in 250.52, an 
interconnection shall be made through a spark gap or listed 
device as required by (B)(1) or (B)(2): 

(1) jUnground^d orlDnigrpuiided JPr^^^ System. For 

ungrounded or unigrounded primary systems, the spark gap 
or listed device shall have a 60-Hz breakdown voltage of at 
least twice the primary circuit voltage but not necessarily 
more than 10 kV, and there shall be at least one other 
ground on the grounded conductor of the secondary that is 
not less than 6.0 m (20 ft) distant from the surge-arrester 
grounding electrode. 

(2) Miultigrounded l Neutral Mmar^ System. For 

multigrounded neutral primary systems, the spark gap or 
listed device shall have a 60-Hz breakdown of not more than 
3 kV, and there shall be at least one other ground on the 
grounded conductor of the secondary that is not less than 6.0 
m (20 ft) distant from the surge-arrester grounding electrode. 

(C) By Special Permission. An interconnection of the 
surge-arrester ground and the secondary neutral Conductor, 
other than as provided in 280.24(A) or (B), shall be 
permitted to be made only by special permission. 



280.25 Grounding Conductor Connections 
'Enclosures. Except as indicated in this article, surge-arrester 
grounding conductor connections shall be made as specified in 
Article 250, Parts HI and X. Grounding conductors installed in 
metal enclosures shall corriply with 250.64(E).: 



ARtlCLE285 

^urge-Protective Devices (SPPs)^ 1 kV or Less 

I. General 

285.1 Scope. This article covers general requirements, 
installation requirements, and connection requirements for 
SFDs [surge arresters and transient voltage surge 
suppressors (TTVSSs)] permanently installed on premises 
wiring systems 1 kV or less. 

fGPNlSlp, 1: Surge arresters less ihani_^k\^re also koo as 
type 1 SFBs: 

JFPN No* 2: Transient yoltage ; surge suppressors (TVSSs) 

ate also known as Type 2 and TypeXSPDs;.; 



285.3 Uses Not Permitted. |An Sffi^j^urg^ 
pPVSS); device shall not be installed in the following: 



70-124 



2010 California Electrical Code 



ARTICLE 285 - SURGE-PROTECTIVE DEVICES (SPDs), 1 kV OR LESS 



285.2a 



( 1 ) Circuits exceeding [l kV 

(2) On ungrounded systems, impedance grounded systems, 
or comer grounded delta systems unless listed 
specifically for use on these systems. 

(3) Where the rating of the SFD (surge an-ester or l^SSJ is less 

than the maximum continuous phase-to-ground power 
frequency voltage available at the point of application 

FPN: For further information on S?M (SEISSIS see NEMA 
LS 1-1992, Standard for Low Voltage Surge Suppression 
Devices. The selection of a properly rated SFl!)'(TySS) is 
based on criteria such as maximum continuous operating 
voltage, the magnitude and duration of overvoltages at the 
suppressor location as affected by phase-to-ground faults, 
system grounding techniques, and switching surges. 

285.4 Number Required. Where used at a point on a 
circuit, the SroP;:|sUfgb^;Ja&es^ shall be 
connected to each ungrounded conductor. 

285.5 Listing. An SPD (surg^ OT^ester or tySS)' shall be a 
listed device. 

285.6 Sliort-Circuit Current Rating. The SPD (surge 

lirester 6f TySSJ shall be marked with a short-circuit 
current rating and shall not be installed at a point on the 
system where the available fault current is in excess of that 
rating. This marking requirement shall not apply to 
receptacles, 

II. Installation 

285.11 Location. jsro§j|$jy;g4'.w^s1^^: o?:!^^ shall 
be permitted to be located indoors or outdoors and shall be 
made inaccessible to unqualified persons, unless listed for 
installation in accessible locations. 

285.12 Routing of Connections. The conductors used to 

connect the MD| (surge anrestet or T^^ to the line or bus 
and to ground shall not be any longer than necessary and 
shall avoid unnecessary bends. 

IIL Connecting SPDs. 

285.21 Connection. Where an iSPEi (smge ;atteste?^ ot 
ifySS) device is installed, it shall comply with 285.23, 
through 285,28. 

285 J3 Type 1 SPDs (Surge Arresters)* 

Type 1 SPDs shall be installed in accordance witH 

a85:23(A)W® 

(A) Jiistallatiott*_; T^e J 1: ^SpDs (sui'ge arresters)' | shajT be' 

In^fedias follows^ 



(1) jType 1 SPi>s (surge an^esters) shall be perniitted to bq 
connected to the supply side of the service disconnept 
^s perrnittad in 230.82(4) pi; 

(2) Type ,1 SPDs (^ge arresters) shall be perniitted to be 
botoec^ in 285;24; 

(B) At vthe; Service, When irist^lWd : at : seraces^ tlie 
grpuhding pohductor x)f a Type 1: S]pi)i$&ll:be connected: ^to 
oneof;fcjK|lqy^ 

(1) Giw£dfedser^ 

(2) Orduniiing electrode condwtdr 

(3) Grounding electrode for the service 

(4) Equipment grounding terminal in the service equipment 

285^4:T^g;2:SI^^:C^ 

fType 2! SPD^ (TV SSs) skail :l^e installed in. accordance Wiffi 

i(A)| Service-Supplied Building or Structure. pType i 

;SPD$ (TVSSs) shall be connected anywhere on the load 
side of a service disconnect overcurrent device required in 
230.91, unless installed in accordance with 230.82(8). 

(B) Feeder-Supplied Building or Structure.^!rype 2 SPD^ 

(TVSSs)! shall be connected s^l :0i^;;bmi4^ sfructui^ 
anywhere] on the load side of the first overcurrent device at 
the building or structure. 



(C) Separately Derived System. The SPD (TVSS) shall 
be connected on the load side of the first overcurrent device 
in a separately derived system. 

285.25 Type 3 SPDs. Type 3 SPDs (TVSSs) shall be 
permitted to be installed anywhe^re on the load side of 
branch^circuit dvetcuirent protection up to the equipment 
served,^ provided the connection is a minimum 10 m (30 ftj 
bf conductor : distance firqm the sei^^^ sepfarately 

idetiy ed system disconnect; 

285.2<^ Conductor Size. Line and grounding conductors shall 
not be smaller than 14 AWG copper or 12 AWG aluminum. 



285.27^ Connection Between Conductors. An SPD (surge; 
aTOSter or TVSS) shall be permitted to be connected 
between any two conductors — ungrounded conductor(s), 
grounded conductor, grounding conductor. The grounded 
conductor and the grounding conductor shall be 
interconnected only by the normal operation of the SPD 
(surge arrester or TVSS) during a surge. 

285.28 Grounding Conductor ConnectiQiis and 
Enclosures* Except as indicated in this article, SPD 
grounding cotitiections shall be made as specified in Axticle 
250, Part ni Grounding conductors imstalled in metal 
ienclosures shall comply with 250,64(E)- 



2010 California Electrical Code 



70-125 



CHAPTER 3 CALIFORNIA MATRIX ADOPTION TABLE 




The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures subject to HCD 1 and/or HCD 2. 
70-125.1 2010 California Electrical Code 



CHAPTER 3 CALIFORNIA MATRIX ADOPTION TABLE 



CHAPTER 3 -WIRING METHODS AND MATERIALS 



Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


DPH 


1 


2 


AC 


SS 


ss/cc 


1 


2 


3 


4 


Adopt Entire Chapter 


X 


X 








X 


X 


X 


X 


X 


X 




Adopt Entire Chapter as amended 
(amended sections listed below) 






X 


X 


















Adopt only those articles / sections that 
are listed below 


























Article / Section 


334/334.10 






X 


X 


















334.12 






X 


X 


















394/394.12 






X 
















































The ♦ designation indicates that the State Fire Marshal's adoption of this chapter or individual sections is appHcable to structures subject to HOD 1 and/or HOD 2. 
2010 Cahfomia Electrical Code 70-125.2 



CHAPTER 3 



ARTICLE 300 - WIRING METHODS 



Chapter 3 Wiring Methods and Materials 



ARTICLE 300 

Wiring Methods 



I. General Requirements 
300.1 Scope. 

(A) All Wiring Installations. This article covers wiring 
methods for all wiring installations unless modified by 
other articles. 

(B) Integral Parts of Equipment. The provisions of this 
article are not intended to apply to the conductors that form 
an integral part of equipment, such as motors, controllers, 
motor control centers, or factory assembled control 
equipment or listed utilization equipment. 

(C) Metric Designators and Trade Sizes. Metric 

designators and trade sizes for conduit, tubing, and 
associated fittings and accessories shall be as designated in 
Table 300.1(C). 

I Table 300.1(C) Metric Designators and Trade Sizes 



Metric 
Designator 



Trade 
Size 



12 
16 
21 
27 
35 
41 
53 
63 
78 
91 
103 
129 
155 



1 

VA 

V/2 

2 

2^2 

3 

3/2 

4 
5 
6 



Note: The metric designators and trade sizes are for identification 
purposes only and are not actual dimensions. 



300.2 Limitations. 

(A) Voltage. Wiring methods specified in Chapter 3 shall 
be used for 600 volts, nominal, or less where not 
specifically limited in some section of Chapter 3. They 
shall be permitted for over 600 volts, nominal, where 
specifically permitted elsewhere in this Code. 



(B) Temperature. Temperature hmitation of conductors 
shall be in accordance with 310.10. 

300.3 Conductors. 

(A) Single Conductors, Single conductors specified in 
Table 310.13(A) shall only be installed where part of a 
recognized wiring method of Chapter 3. 

Exception: Individual conductors shall be permitted where 
installed as separate overhead conductors in accordance 
with 225. 6. 

(B) Conductors of the Same Circuit. All conductors of 
the same circuit and, where used, the grounded conductor 
and all equipment grounding conductors and bonding 
conductors shall be contained within the same raceway, 
auxiliary gutter, cable tray, cablebus assembly, trench, 
cable, or cord, unless otherwise permitted in accordance 
with 300.3(B)(1) through (B)(4). 

(1) Paralleled Installations. Conductors shall be permitted to 
be run in parallel in accordance with the provisions of 310.4. 
The requirement to run all circuit conductors within the same 
raceway, auxiliary gutter, cable tray, trench, cable, or cord shall 
apply separately to each portion of the paralleled installation, 
and the equipment grounding conductors shall comply with the 
provisions of 250.122. Parallel runs in cable tray shall comply 
with the provisions of 392.8(D). 

Exception: Conductors installed in nonmetallic raceways 
run underground shall be permitted to be arranged as 
isolated phase installations. The raceways shall be 
installed in close proximity, and the conductors shall 
comply with the provisions of 300.20(B). 

(2) Grounding and Bonding Conductors. Equipment 
grounding conductors shall be permitted to be installed 
outside a raceway or cable assembly where in accordance 
with the provisions of 250.130(C) for certain existing 
installations or in accordance with 250.134(B), Exception 
No. 2, for dc circuits. Equipment bonding conductors shall 
be permitted to be installed on the outside of raceways in 
accordance with 250.102(E). 

(3) Nonferrous Wiring Methods. Conductors in wiring 
methods with a nonmetallic or other nonmagnetic sheath, 
where run in different raceways, auxihary gutters, cable 
trays, trenches, cables, or cords, shall comply with the 
provisions of 300.20(B). Conductors in single-conductor 
Type MI cable with a nonmagnetic sheath shall comply 
with the provisions of 332.31. Conductors of single- 
conductor Type MC cable with a nonmagnetic sheath shall 
comply with the provisions of 330.31, 330,116, and 
300.20(B). 



70-126 



2010 California Electrical Code 



ARTICLE 300 - WIRING METHODS 



300.4 



(4) Enclosures. Where an auxiliary gutter runs between a 
column-width panelboard and a pull box, and the pull box 
includes neutral terminations, the neutral conductors of 
circuits suppHed from the panelboard shall be permitted to 
originate in the pull box. 
(C) Conductors of Different Systems. 

(1) 600 Volts, Nominal, or Less. Conductors of kc^andjdg 
circuits, rated 600 volts, nominal, or less, shall be permitted 
to occupy the same equipment wiring enclosure, cable, or 
raceway. All conductors shall have an insulation rating 
equal to at least the maximum circuit voltage applied to any 
conductor within the enclosure, cable, or raceway. 
Exception: For solar photovoltaic systems in accordance 
with 690,4 (B). 

FPN: See 725.|36iA) for Class 2 and Class 3 circuit 
conductors. 

(2) Over 600 Volts, Nominal. Conductors of circuits rated 
over 600 volts, nominal, shall not occupy the same 
equipment wiring enclosure, cable, or raceway with 
conductors of circuits rated 600 volts, nominal, or less 
unless otherwise permitted in (C)(2)(a) through (C)(2)(e). 

(a) Secondary wiring to electric-discharge lamps of 
1000 volts or less, if insulated for the secondary voltage 
involved, shall be permitted to occupy the same luminaire, 
sign, or outline lighting enclosure as the branch-circuit 
conductors. 

(b) Primary leads of electric-discharge lamp ballasts 
insulated for the primary voltage of the ballast, where 
contained within the individual wiring enclosure, shall be 
permitted to occupy the same luminaire, sign, or outhne 
lighting enclosure as the branch-circuit conductors. 

(c) Excitation, control, relay, and ammeter conductors 
used in connection with any individual motor or starter 
shall be permitted to occupy the same enclosure as the 
motor-circuit conductors. 

(d) In motors, switchgear and control assemblies, and 
similar equipment, conductors of different voltage ratings 
shall be permitted. 

(e) In manholes, if the conductors of each system are 
permanently and effectively separated from the conductors 
of the other systems and securely fastened to racks, 
insulators, or other approved supports, conductors of 
different voltage ratings shall be permitted. 

Conductors having nonshielded insulation and 
operating at different voltage levels shall not occupy the 
same enclosure, cable, or raceway. 

300.4 Protection Against Physical Damage. Where 
subject to physical damage, conductors shall be protected. 
(A) Cables and Raceways Through Wood Members. 
(1) Bored Holes. In both exposed and concealed locations, 
where a cable- or raceway-type wiring method is installed 
through bored holes in joists, rafters, or wood ^members, 
holes shall be bored so that the edge of the hole is not less 
than 32 mm (VA in.) from the nearest edge of the wood 



member. Where this distance cannot be maintained, the 
cable or raceway shall be protected from penetration by 
screws or nails by a steel plate(si) or bushing(s)|, at least 1.6 
mm (1/16 in.) thick, and of appropriate length and width 
installed to cover the area of the wiring. 
Exception No. 1: Steel plates shall not be required to 
protect rigid metal conduit, intermediate metal conduit, 
rigid nonmetaUic conduit, or electrical metallic tubing. 
Exception No. 2: A listed and marked steel plate less than 
1.6 mm (1/16 in.) thick that provides equal or better 
protection against nail or screw penetration shall be 
permitted. 

(2) Notches in Wood. Where there is no objection because 
of weakening the building structure, in both exposed and 
concealed locations, cables or raceways shall be permitted 
to be laid in notches in wood studs, joists, rafters, or other 
wood members where the cable or raceway at those points 
is protected against nails or screws by a steel plate at least 
1.6 mm (1/16 in.) thick, and of appropriate length and 
width, installed to cover the area of the wiring. The steel 
plate shall be installed before the building finish is apphed. 
Exception No. 1: Steel plates shall not be required to 
protect rigid metal conduit, intermediate metal conduit, 
rigid nonmetaUic conduit, or electrical metallic tubing. 
Exception No. 2: A listed and marked steel plate less than 
1.6 mm (1/16 in.) thick that provides equal or better 
protection against nail or screw penetration shall be 
permitted. 

(B) Nonmetallic-Sheathed Cables and Electrical 
NonmetaUic Tubing Through Metal Framing Members. 

(1) Nonmetallic-Sheathed Cable. In both exposed and 
concealed locations where nonmetaUic- sheathed cables 
pass through either factory- or field-punched, cut, or drilled 
slots or holes in metal members, the cable shall be 
protected by listed bushings or listed grommets covering all 
metal edges that are securely fastened in the opening prior 
to installation of the cable. 

(2) Nonmetallic-Sheathed Cable and Electrical 
NonmetaUic Tubing. Where nails or screws are likely to 
penetrate nonmetallic-sheathed cable or electrical 
nonmetaUic tubing, a steel sleeve, steel plate, or steel clip 
not less than 1.6 mm (1/16 in.) in thickness shaU be used to 
protect the cable or tubing. 

Exception: A listed and marked steel plate less than 1.6 
mm (1/16 in.) thick that provides equal or better protection 
against nail or screw penetration shall be permitted. 

(C) Cables Through Spaces Behind Panels Designed to 
Allow Access. Cables or raceway-type wiring methods, 
installed behind panels designed to allow access, shall be 
supported according to their appUcable articles. 

(D) Cables and Raceways Parallel to Framing Members 
and Furring Strips. In both exposed and concealed 
locations, where a cable- or raceway-type wiring method is 



2010 California Electrical Code 



70-127 



300.5 



ARTICLE 300 - WIRING METHODS 



installed parallel to framing members, such as joists, 
rafters, or studs, or is installed parallel to furring strips, the 
cable or raceway shall be installed and supported so that 
the nearest outside surface of the cable or raceway is not 
less than 32 mm (VA in.) from the nearest edge of the 
framing member or frirring strips where nails or screws are 
likely to penetrate. Where this distance cannot be 
maintained, the cable or raceway shall be protected from 
penetration by nails or screws by a steel plate, sleeve, or 
equivalent at least 1.6 mm (1/16 in.) thick. 

Exception No. 1 : Steel plates, sleeves, or the equivalent 
shall not be required to protect rigid metal conduit, 
intermediate metal conduit, rigid nonmetallic conduit, or 
electrical metallic tubing. 

Exception No. 2: For concealed work in finished 
buildings, or finished panels for prefabricated buildings 
where such supporting is impracticable, it shall be 
permissible to fish the cables between access points. 

Exception No. 3: A listed and marked steel plate less than 
1.6 mm (1/16 in.) thick that provides equal or better 
protection against nail or screw penetration shall be 
permitted, 

(E) Cables and Raceways Installed IJttder Roof Deckiiig, A 

cable- or raceway-type vidring tnethod^ irfetalled in exposi^ C^ 
concealed locations Mder metalrcormgated sheet roof decking, 
shatt be installed and sii$)porteci so :t surface of 

the cable or raceway is not less than 38 mm (IH in*) frqm the 
nearest surface of theroofdeclangi 

FPN: R(X)f deckkig inat^l is often repaired or lepkced afier the 
initial raceway or cabling and roofing installation and may be 

peaetcated by the^scre^ws ;or o&f .inStolcatd^^ designed, to 
provide 'Md down" stiiarigtK o^^^ membrane or 

roof iMuiating material i 

Exception: Rigid ^^(^l£onduUM[mte}n^ J^^M: £^^dmt 

shall no{be required p£om^ 

(F) Cables and Raceways Installed in ShaUow Grooves. 

Cable- or raceway-type wiring methods installed in a groove, to 
be covered by wallboard, siding, paneling, carpeting, or similar 
finish, shall be protected by 1.6 mm (1/16 in.) thick steel plate, 
sleeve, or equivalent or by not less than 32-mm (lV4-in.) free 
space for the frill length of the groove in which the cable or 
raceway is installed. 

Exception No. 1: Steel plates, sleeves, or the equivalent shall 
not be required to protect rigid metal conduit, intermediate 
metal conduit, rigid nonmetallic conduit, or electrical metallic 
tubing. 

Exception No. 2: A listed and marked steel plate less than 1,6 
mm (1/16 in.) thick that provides equal or better protection 
against nail or screw penetration shall be permitted. 



(G) Insulated Fittings. Where raceways "pontaki 4 AWG or 
larger insulated circuit conductors and these conductors enter a 
cabinet, box, enclosure, or raceway, the conductors shall be 
protected by a substantial fitting providing a smoothly rounded 
insulating surface, unless the conductors are separated from the 
fitting or raceway by substantial insulating material that is 
securely fastened in place. 

Exception: Where threaded hubs or bosses that are an integral 
part of a cabinet, box, enclosure, or raceway provide a 
smoothly rounded or flared entry for conductors. 

Conduit bushings constructed wholly of insulating material 
shall not be used to secure a fitting or raceway. The insulating 
fitting or insulating material shall have a temperature rating not 
less than the insulation temperature rating of the installed 
conductors. 

300.5 Underground Installations. 

(A) Minimum Cover Requirements. Direct-buried cable or 
conduit or other raceways shall be mstalled to meet the 
minimum cover requirements of Table 300.5. (B) JW^t 
Locatiqiis; TTie interior jpf enclosures or r^ewys msta(la| 
underground shall be cqrfsidered to be a :wet location; MsiJated 
^conductors and cables installed tti these enclosures or raceways 
in underground installations shaU be fist^ for j^e m 
locafions and siall comjly with 3 1 d8(G).^toy e^^ 
isplices in an xmderground instaUatioji shallbe apprpve^^ 
locations' 

(C) Underground Cables Under Buildings. Underground 
cable installed under a building shall be in a raceway. 

(D) Protection from Damage. Direct-buried conductors and 
cables shall be protected from damage in accordance with 
300.5(D)(1) through (D)(4). 

(1) Emerging from Grade. Direct-buried conductors and 
cables emerging fi-om grade and g)^;^Sin;c^^ 

Table 300.5 shall be protected by enclosures or raceways 
extending from the minimum cover distance below grade 
required by 300.5(A) to a point at least 2.5 m (8 ft) above 
finished grade. In no case shall the protection be required to 
exceed 450 mm (18 in.) below finished grade. 

(2) Conductors Entering BuUdings. Conductors entering a 
building shall be protected to the point of entrance. 

(3) Service Conductors. Underground service conductors 
that are not encased in concrete and that are buried 450 mm 
(18 in.) or more below grade shall have their location 
identified by a warning ribbon that is placed in the trench at 
least 300 mm (12 in.) above the underground installafion. 



• 



70-128 



2010 California Electrical Code 



ARTICLE 300 - WIRING METHODS 



300.5 



Table 300.5 Minimum Cover Requirements, to 600 Volts, Nominal, Burial in Millimeters (Inches) 





Type of Wiring Method 


or Circuit 








Column 1 Direct 

Burial Cables or 

Conductors 


Column 2 Rigid 
Metal Conduit 
or Intermediate 
Metal Conduit 


Column 3 

Nonmetallic 

Raceways 

Listed for 

Direct Burial 

Without 

Concrete 

Encasement or 

Other 

Approved 

Raceways 


Column 4 

Residential 
Branch Circuits 
Rated 120 Volts 

or Less with 

GFCI Protection 

and Maximum 

Overcurrent 

Protection of 20 

Amperes 


Column 5 

Circuits for 

Control of 

Irrigation and 

Landscape 

Lighting Limited 

to Not More Than 

30 Volts and 

Installed with 

Type UF or in 

Other Identified 

Cable or Raceway 


Location of Wiring Method or 
Circuit 


mm in. 


mm in. 


mm in. 


mm in. 


mm in. 


All locations not specified below 


600 24 


150 6 


450 18 


300 12 


150 6 


In trench below 50-mm (2 -in.) thick 
concrete or equivalent 


450 18 


150 6 


300 12 


150 6 


150 6 


Under a building 



(in raceway only) 









(in raceway only) 



(in raceway only) 


Under minimum of 102 -mm (4-in.) 
thick concrete exterior slab with 
no vehicular traffic and the slab 
extending not less than 152 mm 
(6 in.) beyond the underground 
installation 


450 18 


100 4 


100 4 


150 6 
(direct burial) 
100 4 
(in raceway) 


150 6 
(direct burial) 
100 4 
(in raceway) 


Under streets, highways, roads, 
alleys, driveways, and parking 
lots 


600 24 


600 24 


600 24 


600 24 


. 600 24 


One- and two-family dwelling 
driveways and outdoor parking 
areas, and used only for dwelling- 
related purposes 


450 18 


450 18 


450 18 


300 12 


450 18 


In or under airport runways, 
including adjacent areas where 
trespassing prohibited 


450 18 


450 18 


450 18 


450 18 


450 18 



Notes: 

1. Cover is defined as the shortest distance in millimeters (inches) measured between a point on the top surface of any direct-buried 
conductor, cable, conduit, or other raceway and the top surface of finished grade, concrete, or similar cover. 

2. Raceways approved for burial only where concrete encased shall require concrete envelope not less than 50 mm (2 in.) thick. 

3. Lesser depths shall be permitted where cables and conductors rise for terminations or splices or where access is otherwise required. 

4. Where one of the wiring method types listed in Columns 1-3 is used for one of the circuit types in Columns 4 and 5, the shallowest 
depth of burial shall be permitted. 

5. Where solid rock prevents compliance with the cover depths specified in this table, the wiring shall be installed in metal or nonmetallic 
raceway permitted for direct burial. The raceways shall be covered by a minimum of 50 mm (2 in.) of concrete extending down to rock. 



2010 Califomia Electrical Code 



70-129 



300.6 



ARTICLE 300 - WIRING METHODS 



(4) Enclosure or Raceway Damage. Where the enclosure or 
raceway is subject to physical damage, the conductors shall be 
installed in rigid metal conduit, intermediate metal conduit, 
Schedule 80 f^& conduit, or equivalent. 

(E) Splices and Taps. Direct-buried conductors or cables shall 
be permitted to be spHced or tapped without the use of spHce 
boxes. The splices or taps shall be made in accordance with 
110.14(B). 

(F) Backfill. Backfill that contains large rocks, paving 
materials, cinders, large or sharply angular substances, or 
corrosive material shall not be placed in an excavation where 
materials may damage raceways, cables, or other substructures 
or prevent adequate compaction of fill or contribute to corrosion 
of raceways, cables, or other substructures. 

Where necessary to prevent physical damage to the 
raceway or cable, protection shall be provided in the form of 
granular or selected material, suitable running boards, suitable 
sleeves, or other approved means. 

(G) Raceway Seals. Conduits or raceways through which 
moisture may contact Uve parts shall be sealed or plugged at 
either or both ends. 

FPN: Presence of hazardous gases or vapors may also necessitate 
sealing of underground conduits or raceways entering buildings. 

(H) Bushing. A bushing, or terminal fitting, with an integral 
bushed opening shall be used at the end of a conduit or other 
raceway that terminates underground where the conductors or 
cables emerge as a direct burial wiring method. A seal 
incorporating the physical protection characteristics of a bushing 
shall be permitted to be used in lieu of a bushing. 

(T) Conductors of the Same Circuit. All conductors of the 
same circuit and, where used, the grounded conductor and all 
equipment grounding conductors shall be installed in the same 
raceway or cable or shall be installed in close proximity in the 
same trench. 

Exception No. 1: Conductors in parallel in raceways or cables 
shall be permitted, but each raceway or cable shall contain all 
conductors of the same circuit including egu^fnent grounding 
conductors. 

Exception No. 2: Isolated phase, polarity, grounded conductor, 
and equipment grounding and bonding conductor installations 
shall be permitted in nonmetallic raceways or cables with a 
nonmetallic covering or nonmagnetic sheath in close proximity 
where conductors are paralleled as permitted in 310.4, and 
where the conditions of 300.20(B) are met. 

(J) Eartb Movement. Where direct-buried conductors, 
raceways, or cables are subject to movement by settlement or 
firost, direct-buried conductors, raceways, or cables shall be 



arranged so as to prevent damage to the enclosed conductors or 
to equipment connected to the raceways. 

FPN: This section recognizes "S" loops in underground direct 
burial to raceway transitions, expansion fittings in raceway risers 
to fixed equipment, and, generally, the provision of flexible 
connections to equipment subject to settlement or frost heaves. 

(K) Directional Boring. Cables or raceways installed using 
directional boring equipment shall be approved for the purpose. 

300.6 Protection Against Corrosion and Deterioration. 

Raceways, cable trays, cablebus, auxiliary gutters, cable armor, 
boxes, cable sheathing, cabinets, elbows, couplings, fittings, 
supports, and support hardware shall be of materials suitable for 
the environment in which they are to be installed. 

(A) Ferrous Metal Equipment. Ferrous metal raceways, cable 
trays, cablebus, auxiliary gutters, cable armor, boxes, cable 
sheathing, cabinets, metal elbows, couplings, nipples, fittings, 
supports, and support hardware shall be suitably protected 
against corrosion inside and outside (except threads at joints) by 
a coating of approved corrosion-resistant material. Where 
corrosion protection is necessary and the conduit is threaded in 
the field, the threads shall be coated with an approved 
electrically conductive, corrosion-resistant compound. 

Exception: Stainless steel shall not be required to have 
protective coatings. 

(1) Protected from Corrosion Solely by Enamel. Where 
protected from corrosion solely by enamel, ferrous metal 
raceways, cable trays, cablebus, auxihary gutters, cable armor, 
boxes, cable sheathing, cabinets, metal elbows, couphngs, 
nipples, fittings, supports, and support hardware shall not be 
used outdoors or in wet locations as described in 300.6(D). 

(2) Organic Coatings on Boxes or Cabinets. Where boxes or 

cabinets have an approved system of organic coatings and are 
marked "Raintight," "Rainproof," or "Outdoor Type," they shall 
be permitted outdoors. 

(3) In Concrete or in Direct Contact with the Earth. Ferrous 
metal raceways, cable armor, boxes, cable sheathing, cabinets, 
elbows, couphngs, nipples, fittings, supports, and support 
hardware shall be permitted to be installed in concrete or in 
direct contact with the earth, or in areas subject to severe 
corrosive influences where made of material approved for the 
condition, or where provided with corrosion protection 
approved for the condition. 

(B) Aluminum Metal Equipment Aluminum raceways, cable 
trays, cablebus, auxiliary gutters, cable armor, boxes, cable 
sheathing, cabinets, elbows, couplings, nipples, fittings, 
supports, and support hardware embedded or encased in 
concrete or in direct contact with the earth shall be provided 
with supplementary corrosion protection. 



70-130 



2010 California Electrical Code 



ARTICLE 300 - WIRING METHODS 



300.11 



(C) Nonmetallic Equipment. Nonmetallic raceways, cable 
trays, cablebus, auxiliary gutters, boxes, cables with a 
nonmetallic outer jacket and internal metal armor or jacket, 
cable sheathing, cabinets, elbows, couplings, nipples, fittings, 
supports, and support hardware shall be made of material 
approved for the condition and shall comply with (C)(1) and 
(C)(2) as appUcable to the specific installation. 

(1) Exposed to Sunlight. Where exposed to sunhght, the 
materials shall be listed as sunlight resistant or shall be 
identified as sunlight resistant. 

(2) Chemical Exposure. Where subject to exposure to 
chemical solvents, vapors, splashing, or immersion, materials or 
coatings shall either be inherently resistant to chemicals based 
on their hsting or be identified for the specific chemical reagent. 

(D) Indoor Wet Locations. In portions of dairy processing 
facilities, laundries, canneries, and other indoor wet locations, 
and in locations where walls are frequently washed or where 
there are surfaces of absorbent materials, such as damp paper or 
wood, the entire wiring system, where installed exposed, 
including all boxes, fittings, raceways, and cable used therewith, 
shall be mounted so that there is at least a 6-mm (V4-in.) airspace 
between it and the wall or supporting surface. 

Exception: Nonmetallic raceways, boxes, and fittings shall be 
permitted to be installed without the airspace on a concrete, 
masonry, tile, or similar surface. 

FPN: In general, areas where acids and alkali chemicals are 
handled and stored may present such corrosive conditions, 
particularly when wet or damp. Severe corrosive conditions may 
also be present in portions of meatpacking plants, tanneries, glue 
houses, and some stables; in installations immediately adjacent to 
a seashore and swimming pool areas; in areas where chemical 
deicers are used; and in storage cellars or rooms for hides, 
casings, fertilizer, salt, and bulk chemicals. 

300.7 Raceways Exposed to Different Temperatures. 

(A) Sealing. Where portions of a cable raceway or sleeve are 
known to be subjected to different temperatures and where 
condensation is known to be a problem, as in cold storage areas 
of buildings or where passing from the interior to the exterior of 
a building, the raceway or sleeve shall be filled with an 
approved material to prevent the circulation of warm air to a 
colder section of the raceway or sleeve. An explosionproof seal 
shall not be required for this purpose. 

(B) Expansion Fittings. Raceways shall be provided with 
expansion fittings where necessary to compensate for thermal 
expansion and contraction. 

FPN: Table 352.44 and ;Tab§fm44 provide the expansion 
information for polyvinyl chloride (PVC) M fer rem&C^ 

|iegn|setog;raJBjond^^^ A nominal 



number for steel conduit can be determined by multiplying the 
expansion length in ||a|ie;^3||^ by 0.20. The coefficient of 
expansion for steel electrical metallic tubing, intermediate metal 
conduit, and rigid conduit is (M70; x"loj (0.0000117 mm per 
mm of conduit for each °C in temperature change) [S-teO >5 lOj 
(0.0000065 in. per inch of conduit for each °F in temperature 
change)]. 

)&3S&: lM;,?P?flB#^^^ ,oE ekpapsioii jfor ahin&um 

lefepfticff.Me^c Jibing;, aid ^mimmti^ .filial 

boiKii4t &r each m t^mpemtui^ clisp^ P'^O''^' W. 

fempemture changeji 

300.8 Installation of Conductors with Other Systems. 

Raceways or cable trays containing electrical conductors shall 
not contain any pipe, tube, or equal for steam, water, air, gas, 
drainage, or any service other than electrical. 

(JOO.? Jfoiceways to Wet Xocaiioiis Above Grade. Wher3 

Igceway^arej^Blled^^ the iiferiol 

lof these, raceways shSJ be considered to be a^we^k^^aSoi^ 
lasplated conductors and cables iiiistalM in p^y^^^S^J^'^i 
lobatipnsjafcpvegi^ sM comply with 310,8(C), 

300.10 Electrical Continuity of Metal Raceways and 
Enclosures. Metal raceways, cable armor, and other metal 
enclosures for conductors shall be metallically joined together 
into a continuous electrical conductor and shall be connected to 
all boxes, fittings, and cabinets so as to provide eflective 
electrical continuity. Unless specifically permitted elsewhere in 
this Code, raceways and cable assembhes shall be mechanically 
secured to boxes, fittings, cabinets, and other enclosures. 

Exception No. J: Short sections of raceways used to provide 
support or protection of cable assemblies from physical damage 
shall not be required to be made electrically continuous. 

Exception No. 2: Equipment enclosures to be isolated, as 
permitted by 250.96(B), shall not be required to be metallically 
joined to the metal raceway. 

300.11 Securing and Supporting. 

(A) Secured in Place. Raceways, cable assembhes, boxes, 
cabinets, and fittings shall be securely fastened in place. Support 
wires that do not provide secure support shall not be permitted 
as the sole support. Support wires and associated fittings that 
provide secure support and that are installed in addition to the 
ceiling grid support wires shall be permitted as the sole support. 
Where independent support wires are used, they shall be 
secured at both ends. Cables and raceways shall not be 
supported by ceiling grids. 



2010 California Electrical Code 



70-131 



300.12 



ARTICLE 300 - WIRING METHODS 



(1) Fire-Rated Assemblies. Wiring located within the cavity of 
a fire-rated floor-ceiUng or roof-ceiling assembly shall not be 
secured to, or supported by, the ceiling assembly, including the 
ceiling support wires. An independent means of secure support 
shall be provided and shall be permitted to be attached to the 
assembly. Where independent support wires are used, they shall 
be distinguishable by color, tagging, or other effective means 
firom those that are part of the fire-rated design. 

Exception: The ceiling support system shall he permitted to 
support wiring and equipment that have been tested as part of 
the fire-rated assembly. 

FPN: One method of determining fire rating is testing in 
accordance with NFPA 251-2006, Standard Methods of Tests of 
Fire Resistance of Building Construction and Materials. 

(2) Non-Fire-Rated Assemblies. Wiring located within the 
cavity of a non-fire-rated floor-ceiling or roof-ceiling assembly 
shall not be secured to, or supported by, the ceiling assembly, 
including the ceiling support wires. An independent means of 
secure support shall be provided and ^feall be permitted to be 
attadied to Jie assemb>iy 

Exception: The ceiling support system shall be permitted to 
support branch-circuit wiring and associated equipment where 
installed in accordance with the ceiling system manufacturer's 
instructions. 

(B) Raceways Used as Means of Support. Raceways shall be 
used only as a means of support for other raceways, cables, or 
nonelectrical equipment under any of the following conditions: 

(1) Where the raceway or means of support is identified for the 
piupose 

(2) Where the raceway contains power supply conductors for 
electrically controlled equipment and is used to support 
Class 2 circuit conductors or cables that are solely for the 
purpose of connection to the equipment control circuits 

(3) Where the raceway is used to support boxes or conduit 
bodies in accordance with 314.23 or to support luminaires 
in accordance with 410.36(E) 

(C) Cables Not Used as Means of Support Cable wiring 
methods shall not be used as a means of support for other 
cables, raceways, or nonelectrical equipment. 

300.12 Mechanical Continuity — Raceways and Cables. 

Metal or nonmetallic raceways, cable armors, and cable sheaths 
shall be continuous between cabinets, boxes, fittings, or other 
enclosures or outlets. 

Exception No. 1: Short sections of raceways used to provide 
support or protection of cable assemblies from physical damage 
shall not be required to be mechanically continuous. 



Exception No. 2: yiacmays and cables imtalkd into the bottoni 
pf open bottom equipmen^^^ fnopr control 

centersj^'andrfioa shall not be 

reqUjredjoiem equipment^ 

300.13 Mechanical and Electrical Continuity — 
Conductors. 

(A) General, Conductors in raceways shall be continuous 
between outiets, boxes, devices, and so forth. There shall be no 
spHce or tap within a raceway unless permitted by 300.15; 
368.56(A); 376.56; 378.56; 384.56; 386.56; 388.56; or 390.6. 

(B) Device Removal, In multiwire branch circuits, the 
contmuity of a grounded conductor shall not depend on device 
connections such as lampholders, receptacles, and so forth, 
where the removal of such devices would interrupt the 
continuity. 

300.14 Length of Free Conductors at Outlets, Junctions, 
and Switch Points. At least 150 mm (6 in.) of fi'ee conductor, 
measured fi*om the point in the box where it emerges from its 
raceway or cable sheath^ shall be left at each outiet, junction, 
and switch point for splices or the connection of luminaires or 
devices. Where the opening to an outiet, junction, or switch 
point is less than 200 mm (8 in.) in any dimension, each 
conductor shall be long enough to extend at least 75 mm (3 in.) 
outside the opening. 

Exception: Conductors that are not spliced or terminated at the 
outlet, junction, or switch point shall not be required to comply 
with 300.14. 

300.15 Boxes, Conduit Bodies, or Fittings — Where 
Required. A box shall be installed at each outlet and switch 
point for concealed knob-and-tube wiring. 

Fittings and connectors shall be used only with the specific 
wiring methods for which they are designed and listed. 

Where the wiring method is conduit, tubing, Type AC 
cable, Type MC cable. Type MI cable, nonmetallic-sheathed 
cable, or other cables, a box or conduit body shall be installed at 
each conductor splice point, outlet point, switch point, junction 
point, termination point, or pull point, unless otherwise 
permitted in 300. 1 5(A) through (M). 

(A) Wiring Methods with Interior Access. A box or conduit 
body shall not be required for each spUce, junction, switch, pull, 
termination, or outlet points in wiring methods with removable 
covers, such as wireways, multioutlet assemblies, auxiliary 
gutters, and surface raceways. The covers shall be accessible 
after installation. 

(B) Equipment. An integral junction box or wiring 
compartment as part of approved equipment shall be permitted 
inheuofabox. 



# 



70-132 



2010 California Electrical Code 



ARTICLE 300 - WIRING METHODS 



300.18 



(C) Protection. A box or conduit body shall not be required 
where cables enter or exit from conduit or tubing that is used to 
provide cable support or protection against physical damage. A 
fitting shall be provided on the end(s) of the conduit or tubing to 
protect the cable from abrasion. 

(D) Type MI Cable. A box or conduit body shall not be 
required where accessible fittings are used for straight-through 
splices in mineral-insulated metal-sheathed cable. 

(E) Integral Enclosure. A wiring device with integral 
enclosure identified for the use, having brackets that securely 
fasten the device to walls or ceilings of conventional on-site 
firame construction, for use with nonmetallic-sheathed cable, 
shall be permitted in heu of a box or conduit body. 

FPN: See 334.30(C); 545.10; 550.15(1); 551.47(E), Exception 
No. 1; and 552.48(E), Exception No. 1. 

(F) Fitting. A fitting identified for the use shall be permitted in 
Ueu of a box or conduit body where conductors are not sphced 
or terminated within the fitting. The fitting shall be accessible 
after installation. 

(G) Direct-Buried Conductors, As permitted in 300.5(E), a 
box or conduit body shall not be required for splices and taps in 
direct-buried conductors and cables. 

(H) Insulated Devices. As permitted in 334.40(B), a box or 
conduit body shall not be required for insulated devices supplied 
by nonmetallic-sheathed cable. 

(I) Enclosures. A box or conduit body shall not be required 
where a splice, switch, terminal, or pull point is in a cabinet or 
cutout box, in an enclosure for a switch or overcurrent device as 
permitted in 312.8, in a motor controller as permitted in 
430.10(A), or in a motor control center. 

(J) Luminaires. A box or conduit body shall not be required 
where a luminaire is used as a raceway as permitted in 410.64 
and 410.65. 

(K) Embedded. A box or conduit body shall not be required for 
splices where conductors are embedded as permitted in 424.40, 
424.41(D), 426.22(B), 426.24(A), and 427.19(A). 

(L) Manholes and Handhole Enclosures. A box or conduit 
body shall not be required for conductors in manholes or 
handhole enclosures, except where connecting to electrical 
equipment. The installation shall comply with the provisions of 
Part V of Article 110 for manholes, and 314.30 for handhole 
enclosures. 

(M) Closed Loop. A box shall not be required with a closed- 
loop power distribution system where a device identified and 
listed as suitable for installation without a box is used. 



300.16 Raceway or Cable to Open or Concealed Wiring. 

(A) Box, jC?oAdpft:Bp#i'.^^^^^^^ A box, condifit bod)?, or 

terminal fitting having a separately bushed hole for each 
conductor shall be used wherever a change is made from 
conduit, electrical metallic tubing, electrical nonmetallic tubing, 
nonmetallic-sheathed cable. Type AC cable, Type MC cable, or 
mineral-insulated, metal-sheathed cable and surface raceway 
wiring to open wiring or to concealed knob-and-tube wiring. A 
fitting used for this purpose shall contain no taps or splices and 
shall not be used at luminaire outiets. ^j^coadiit bojiy jased for 
i€^ :shaU cotklam ao taps or splices, unless itpoirtplS 



(B) Bushing. A bushing shall be permitted in Heu of a b(3x or 

terminal where the conductors emerge from a raceway and enter 
or terminate at equipment, such as open switchboards, 
unenclosed control equipment, or similar equipment. The 
bushing shall be of the insulating type for otiier than lead- 
sheathed conductors. 

300.17 Number and Size of Conductors in Raceway. The 

number and size of conductors in any raceway shall not be more 
than will permit dissipation of tiie heat and ready installation or 
withdrawal of the conductors without damage to the conductors 
or to their insulation. 

FPN: See the following sections of this Code: intermediate metal 
conduit, 342.22; rigid metal conduit, 344.22; flexible metal 
conduit, 348.22; liquidtight flexible metal conduit, 350.22; ^yC 
conduit, 352.22; MJM-'<SS^~'JB^; \]l^iJM^:^MsM; 
liquidtight nonmetallic flexible conduit, 356.22; electrical 
metallic tubing, 358.22; flexible metallic tubing, 360.22; 
electrical nonmetallic tubing, 362.22; cellular concrete floor 
raceways, 372.11; cellular metal floor raceways, 374.5; metal 
wireways, 376.22; nonmetallic wireways, 378.22; surface metal 
raceways, 386.22; surface nonmetallic raceways, 388.22; 
underfloor raceways, 390.5; fixture wire, 402.7; theaters, 520.6; 
signs, 600.31(C); elevators, 620.33; audio signal processing, 
amplification, and reproduction equipment, 640.23(A) and 
640.24; Class 1, Class 2, and Class 3 circuits. Article 725; fire 
alarm circuits, Article 760; and optical fiber cables and raceways, 
Article 770. 

300. IS Raceway Installations. 

(A) Complete Runs. Raceways, otiier tiian busways or exposed 
raceways having hinged or removable covers, shall be installed 
complete between outlet, junction, or splicing points prior to the 
installation of conductors. Where required to facilitate the 
installation of utilization equipment, the raceway shall be 
permitted to be initially installed v^thout a terminating 
connection at tiie equipment. Prev^ed raceway assembhes shall 
be permitted only where specifically permitted in this Code for 
the applicable wiring method. 



2010 California Electrical Code 



70-133 



300.19 



ARTICLE 300 - WIRING METHODS 



Exception: Short sections of raceways used to contain 
conductors or cable assemblies for protection from physical 
damage shall not be required to be installed complete 
between outlet, junction, or splicing points. 

(B) Welding. Metal raceways shall not be supported, 
terminated, or connected by welding to the raceway unless 
specifically designed to be or otherwise specifically permitted to 
be in this Code. 

300.19 Supporting Conductors in Vertical Raceways. 

(A) Spacing Intervals — Maximum. Conductors in vertical 
raceways shall be supported if the vertical rise exceeds the 
values in Table 300.19(A). One cable support shall be provided 
at the top of the vertical raceway or as close to the top as 
practical. Intermediate supports shall be provided as necessary 
to limit supported conductor lengths to not greater than those 
values specified in Table 300.19(A). 

Exception: Steel wire armor cable shall be supported at the top 
of the riser with a cable support that clamps the steel wire 
armor. A safety device shall be permitted at the lower end of the 
riser to hold the cable in the event there is slippage of the cable 
in the wire-armored cable support. Additional wedge-type 
supports shall be permitted to relieve the strain on the 
equipment terminals caused by expansion of the cable under 
load. 

5(JS) Fire-Rated Cables and Coiiductprs. Support methods 
Wd spacing intervals for fire-rated cables and conductors 
Ishall comply with any restrictions provided in the listing of 
the electrical circuit protective system used and in no case 
|hatl exceed lif! vaiues^in T^ 

(C) Support Methods. One of the following methods of 
support shall be used: 

Table 300.19(A) Spacings for Conductor Supports 



(1) By clamping devices constructed of or employing 
insulating wedges inserted in the ends of the raceways. 
Where clamping of insulation does not adequately 
support the cable, the conductor also shall be clamped. 

(2) By inserting boxes at the required intervals in which 
insulating supports are installed and secured in a 
satisfactory manner to withstand the weight of the 
conductors attached thereto, the boxes being provided 
with covers. 

(3) Injunction boxes, by deflecting the cables not less than 
90 degrees and carrying them horizontally to a 
distance not less than twice the diameter of the cable, 
the cables being carried on two or more insulating 
supports and additionally secured thereto by tie wires 
if desired. Where this method is used, cables shall be 
supported at intervals not greater than 20 percent of 
those mentioned in the preceding tabulation. 

(4) By a method of equal effectiveness. 

300.20 Induced Currents in ferrous Metal Enclosures 
or F^rrbu^ Metal Raceways. 

(A) Conductors Grouped Together. Where conductors 
carrying alternating current are installed in ferrous metal 
enclosures or ^ferrous metal raceways, they shall be arranged 
so as to avoid heating the surrounding ferrous metal by 
induction. To accomphsh this, all phase conductors and, 
where used, the grounded conductor and all equipment 
grounding conductors shall be grouped together. 

Exception No. 1: Equipment grounding conductors for 
certain existing installations shall be permitted to be 
installed separate from their associated circuit conductors 
where run in accordance with the provisions of 250.130(C). 













Conductors 








Aluminum 


or Copper-Clad 








Support of Conductors in 




Aluminum 




Copper 




Size of Wire 


m 






ft 


m 


ft 




Vertical Raceways 














18 AWG through 8 AWG 


Not greater than 


30 






100 


30 


100 


6AWGthroughl/0AWG 


Not greater than 


60 






200 


30 


100 


2/0 AWG through 4/0 AWG 


Not greater than 


55 






180 


25 


80 


Over 4/0 AWG through 350 kcmil 


Not greater than 


41 






135 


18 


60 


Over 350 kcmil through 500 kcmil 


Not greater than 


36 






120 


15 


50 


Over 500 kcmil through 750 kcmil 


Not greater than 


28 






95 


12 


40 


Over 750 kcmil 


Not greater than 


26 






85 


11 


35 



70-134 



2010 California Electrical Code 



ARTICLE 300 - WIRING METHODS 



300.22 



Exception No. 2: A single conductor shall be permitted to 
he installed in a ferromagnetic enclosure and used for skin- 
effect heating in accordance with the provisions of 426.42 
and 427.47. 

(B) Individual Conductors. Where a single conductor 
carrying alternating current passes through metal with 
magnetic properties, the inductive effect shall be 
minimized by (1) cutting slots in the metal between the 
individual holes through which the individual conductors 
pass or (2) passing all the conductors in the circuit through 
an insulating wall sufficiently large for all of the 
conductors of the circuit. 

Exception: In the case of circuits supplying vacuum or electric- 
discharge lighting systems or signs or X-ray apparatus, the 
currents carried by the conductors are so small that the 
inductive heating effect can be ignored where these conductors 
are placed in metal enclosures or pass through metal 

FPN: Because aluminum is not a magnetic metal, there will 
be no heating due to hysteresis; however, induced currents 
will be present. They will not be of sufficient magnitude to 
require grouping of conductors or special treatment in 
passing conductors through aluminum wall sections. 

300.21 Spread of Fire or Products of Combustion. 

Electrical installations in hollow spaces, vertical shafts, and 
ventilation or air-handling ducts shall be made so that the 
possible spread of fire or products of combustion will not 
be substantially increased. Openings around electrical 
penetrations through fire-resistant-rated walls, partitions, 
floors, or ceilings shall be firestopped using approved 
methods to maintain the fire resistance rating. 

FPN: Directories of electrical construction materials 
published by qualified testing laboratories contain many 
listing installation restrictions necessary to maintain the fire- 
resistive rating of assemblies where penetrations or openings 
are made. Building codes also contain restrictions on 
membrane penetrations on opposite sides of a fire-resistance- 
rated wall assembly. An example is the 600-mm (24-in.) 
minimum horizontal separation that usually applies between 
boxes installed on opposite sides of the wall. Assistance in 
complying with 300.21 can be found in building codes, fire 
resistance directories, and product listings. 

300.22 Wiring in Ducts, Plenums, and Other Air- 
Handling Spaces. The provisions of this section apply to 
the installation and uses of electrical wiring and equipment 
in ducts, plenums, and other air-handling spaces. 

FPN: See Article 424, Part VI, for duct heaters. 

(A) Ducts for Dust, Loose Stock, or Vapor Removal. No 

wiring systems of any t3^e shall be installed in ducts used 
to transport dust, loose stock, or flammable vapors. No 
wiring system of any type shall be installed in any duct, or 
shaft containing only such ducts, used for vapor removal or 
for ventilation of commercial-type cooking equipment. 

(B) Ducts or Plenums Used for Environmental Air. Only 
wiring methods consisting of Type MI cable, Type MC 



cable employing a smooth or corrugated impervious metal 
sheath without an overall nonmetallic covering, electrical 
metallic tubing, flexible metaUic tubing, intermediate metal 
conduit, or rigid metal conduit without an overall 
nonmetallic covering shall be installed in ducts or plenums 
specifically fabricated to transport environmental air. 
Flexible metal conduit shall be permitted, in lengths not to 
exceed 1.2 m (4 ft), to connect physically adjustable 
equipment and devices permitted to be in these ducts and 
plenum chambers. The connectors used with flexible metal 
conduit shall effectively close any openings in the 
connection. Equipment and devices shall be permitted 
within such ducts or plenum chambers only if necessary for 
their direct action upon, or sensing of, the contained air. 
Where equipment or devices are installed and illumination 
is necessary to facilitate maintenance and repair, enclosed 
gasketed-type luminaires shall be permitted. 

(C) Other Space Used for Environmental Air. This 
section applies to space used for environmental air- 
handling purposes other than ducts and plenums as 
specified in 300.22(A) and (B). It does not include 
habitable rooms or areas of buildings, the prime purpose of 
which is not air handling. 

FPN: The space over a hung ceiling used for environmental 
air-handling purposes is an example of the type of other 
space to which this section applies. 

Exception: This section shall not apply to the joist or stud 
spaces of dwelling units where the wiring passes through such 
spaces perpendicular to the long dimension of such spaces. 

(1) Wiring Methods. The wiring methods for such other 
space shall be Hmited to totally enclosed, nonventilated, 
insulated busway having no provisions for plug-in 
connections. Type MI cable. Type MC cable without an 
overall nonmetallic covering. Type AC cable, or other 
factory-assembled muhiconductor control or power cable 
that is specifically listed for the use, or listed prefabricated 
cable assemblies of metallic manufactured wiring systems 
without nonmetallic sheath. Other types of cables, 
conductors, jaiid. raceways shall be permitted. to be installed 
in electrical metallic tubing, flexible metallic tubing, 
intermediate metal conduit, rigid metal conduit without an 
overall nonmetallic covering, flexible metal conduit, or, 
where accessible, surface metal raceway or metal wireway 
with metal covers or solid bottom metal cable tray with 
soHd metal covers. 

(2) Equipment. Electrical equipment with a metal 
enclosure, or with a nonmetallic enclosure listed for the use 
and having adequate fire-resistant and low-smoke- 
producing characteristics, and associated wiring material 
suitable for the ambient temperature shall be permitted to 
be installed in such other space unless prohibited elsewhere 
in this Code. 

Exception: Integral fan systems shall be permitted where 
specifically identified for such use. 



2010 California Electrical Code 



70-135 



300.23 



ARTICLE 300 - WIRING METHODS 



(D) Information Technology Equipment. Electrical 
wiring in air-handling areas beneath raised floors for 
information technology equipment shall be permitted in 
accordance with Article 645. 

300.23 Panels Designed to Allow Access. Cables, 
raceways, and equipment installed behind panels designed 
to allow access, including suspended ceiling panels, shall 
be arranged and secured so as to allow the removal of 
panels and access to the equipment. 

IL Requirements for over 600 Volts, Nominal 

300.31 -Covers Required. Suitable covers shall be 
installed on all boxes, fittings, and similar enclosures to 
prevent accidental contact with energized parts or physical 
damage to parts or insulation. 

300.32 Conductors of Different Systems. See 

300.3(C)(2). 

300.34 Conductor Bending Radius. The conductor shall 
not be bent to a radius less than 8 times the overall 
diameter for nonshielded conductors or 12 times the overall 
diameter for shielded or lead-covered conductors during or 
after installation. For multiconductor or multiplexed single- 
conductor cables having individually shielded conductors, 
the minimum bending radius is 12 times the diameter of the 
individually shielded conductors or 7 times the overall 
diameter, whichever is greater. 

300.35 Protection Against Induction Heating. Metallic 
raceways and associated conductors shall be arranged so as 
to avoid heating of the raceway in accordance with the 
applicable provisions of 300.20. 

300.37 Aboveground Wiring Methods. Aboveground 
conductors shall be installed in rigid metal conduit, in 
intermediate metal conduit, in electrical metallic tubing, in 
rigid nonmetallic conduit, in cable trays, as busways, as 
cablebus, in other identified raceways, or as exposed runs 
of metal-clad cable suitable for the use and purpose. In 
locations accessible to qualified persons only, exposed runs 
of Type MV cables, bare conductors, and bare busbars 
shall also be permitted. Busbars shall be permitted to be 
either copper or aluminum. 

300.39 Braid-Covered Insulated Conductors — 
Exposed Installation. Exposed runs of braid-covered 
insulated conductors shall have a flame-retardant braid. If 
the conductors used do not have this protection, a flame- 
retardant saturant shall be applied to the braid covering 
after installation. This treated braid covering shall be 
stripped back a safe distance at conductor terminals, 
according to the operating voltage. Where practicable, this 
distance shall not be less than 25 mm (1 in.) for each 
kilovoh of the conductor-to-ground voltage of the circuit. 



300.40 Insulation Shielding. MetaUic and 

semiconducting insulation shielding components of 
shielded cables shall be removed for a distance dependent 
on the circuit voltage and insulation. Stress reduction 
means shall be provided at all terminations of factory- 
applied shielding. 

Metallic shielding components such as tapes, wires, or 
braid^ or (^mbinad (his_ thereof, ^all^Jb^ to a 

grounding, cd]Suctor, grounding busbar,:or a grounding 
ielectrode. 

300.42 Moisture or Mechanical Protection for Metal- 
Sheathed Cables. Where cable conductors emerge from a 
metal sheath and where protection against moisture or 
physical damage is necessary, the insulation of the 
conductors shall be protected by a cable sheath terminating 
device. 

300.50 Underground Installations. 

(A) General. Underground conductors shall be identified 
for the voltage and conditions under which they are 
installed. Direct burial cables shall comply with the 
provisions of 310.7. Underground cables shall be installed 
in accordance with 300.50(A)(1) or (A)(2), and the 
installation shall meet the depth requirements of Table 
300.50. 

(1) Shielded Cables and Nonshielded Cables in Metal- 
Sheathed Cable Assemblies. Underground cables, 
including nonshielded, Type MC and moisture-impervious 
metal sheath cables, shall have those sheaths grounded 
through an effective grounding path meeting the 
requirements of 250.4(A)(5) or (B)(4). They shall be direct 
buried or installed in raceways identified for the use. 

(2) Other Nonshielded Cables. Other nonshielded cables 
not covered in 300.50(A)(1) shall be installed in rigid metal 
conduit, intermediate metal conduit, or rigid nonmetallic 
conduit encased in not less than 75 mm (3 in.) of concrete. 

(B) Protection from Damage. Conductors emerging from 
the ground shall be enclosed in listed raceways. Raceways 
installed on poles shall be of rigid metal conduit, 
intermediate metal conduit. Schedule 80 jP VC conduit, or 
equivalent, extending from the minimum cover depth 
specified in Table 300.50 to a point 2.5 m (8 ft) above 
finished grade. Conductors entering a building shall be 
protected by an approved enclosure or raceway from the 
minimum cover depth to the point of entrance. Where 
direct-buried conductors, raceways, or cables are subject to 
movement by settlement or frost, they shall be installed to 
prevent damage to the enclosed conductors or to the 
equipment connected to the raceways. Metallic enclosures 
shall be grounded. 



# 



70-136 



2010 California Electrical Code 



ARTICLE 300 - WIRING METHODS 



300.50 



Table 300.50 Minimum Co vera Requirements 





General Conditions (not otherwise specified) 


Special Conditions (use if applicable) 




(1) 

Direct-Buried 

Cables 


(2) 

Rigid 

Non metallic 

Conduit^ 


(3) 

Rigid Metal 

Conduit and 

Intermediate 

Metal Conduit 


(4) 

Raceways under 

buildings or 

exterior concrete 

slabs, 100 mm 

(4 in.) minimum 
thickness^ 


(5) 

Cables in airport 

runways or 

adjacent areas 

where trespass is 

prohibited 


(6) 

Areas subject 
to vehicular 

traffic, such as 

thoroughfares 

and 

commercial 

parking areas 


Circuit Voltage 


mm 


in. 


mm 


in. 


mm 


in. 


mm 


in. 


mm 


in. 


mm 


in. 


Over 600 V 

through 22 kV 


750 


30 


450 


18 


150 


6 


100 


4 


450 


18 


600 


24 


Over 22 kV 

through 40 kV 


900 


36 


600 


24 


150 


6 


100 


4 


450 


18 


600 


24 


Over 40 kV 


1000 


42 ^ 


750 


30 


150 


6 


100 


4 


450 


18 


600 


24 



General Notes: 

1 . Lesser depths shall be permitted where cables and conductors rise for terminations or splices or where access is otherwise required. 

2. Where solid rock prevents compliance with the cover depths specified in this table, the wiring shall be installed in a metal or nonmetallic 
raceway permitted for direct burial. The raceways shall be covered by a minimum of 50 mm (2 in.) of concrete extending down to rock. 

jfeVmrnijium^co^ ISd 

mm (6 ia|fbteacji^5^ (2 m*} of conwt^iot equiyai^t placed entirely within the ^ei]K^k oyer the underground installatioB. 

Specific Footnotes: 

a Cover is defined as the shortest distance in millimeters (inches) measured between a point on the top surface of any direct-buried 
conductor, cable, conduit, or other raceway and the top surface of finished grade, concrete, or similar cover. 

b Listed by a qualified testing agency as suitable for direct burial without encasement. All other nonmetallic systems shall require 50 mm 
(2 in.) of concrete or equivalent above conduit in addition to the table depth. 

c The slab shall extend a minimum of 150 mm (6 in.) beyond the underground installation, and a warning ribbon or other effective means 
suitable for the conditions shall be placed above the underground installation. 

P JJt^^md d3Jeot"bu0ed^mblg...lfaat..afe gpt '^i£^|g4 <^^^tpci^^y^^gj^cm^m4 ,^.M4# l§9JMBlW,MdM. MPJfe,b^fe>w;,^^e shalj 
E£ye thei| lOcai&dn ideMfied b^a warning ribboB Jhatjs placed iti the, ti^ndi ht least 3M??ilCl^JiAi&^.S^.i^M?li 



(C) Splices. Direct burial cables shall be permitted to be 
spliced or tapped v^ithout the use of splice boxes, provided 
they are installed using materials suitable for the 
application. The taps and splices shall be watertight and 
protected from mechanical damage. Where cables are 
shielded, the shielding shall be continuous across the splice 
or tap. 

Exception: At splices of an engineered cabling system, 
metallic shields of direct-buried single-conductor cables 
with maintained spacing between phases shall be permitted 
to be interrupted and overlapped. Where shields are 
interrupted and overlapped, each shield section shall be 
grounded at one point. 



(D) Backfill. Backfill containing large rocks, paving 
materials, cinders, large or sharply angular substances, or 
corrosive materials shall not be placed in an excavation 
where materials can damage or contribute to the corrosion 
of raceways, cables, or other substructures or where it may 
prevent adequate compaction of fill. 

Protection in the form of granular or selected material 
or suitable sleeves shall be provided to prevent physical 
damage to the raceway or cable. 

(E) Raceway Seal. Where a raceway enters from an 
underground system, the end within the building shall be 
sealed with an identified compound so as to prevent the 
entrance of moisture or gases, or it shall be so arranged to 
prevent moisture from contacting live parts. 



2010 California Electrical Code 



70-137 



310.1 



ARTICLE 3 1 - CONDUCTORS FOR GENERAL WIRING 



ARTieLE310 

Conductors fdr General Wiring 

310.1 Scope. This article covers general requirements for 
conductors and their type designations, insulations, 
markings, mechanical strengths, ampacity ratings, and uses. 
These requirements do not apply to conductors that form an 
integral part of equipment, such as motors, motor 
controllers, and similar equipment, or to conductors 
specifically provided for elsewhere in this Code. 

FPN: For flexible cords and cables, see Article 400. For 
fixture wires, see Article 402. 

310.2 Conductors. 

(A) Insulated. Conductors shall be insulated. 

Exception: Where covered or bare conductors are 
specifically permitted elsewhere in this Code, 

FPN: See 250.184 for insulation of neutral conductors of a 
solidly grounded high-voltage system. 

(B) Conductor Material. Conductors in this article shall 
be of aluminum, copper-clad aluminum, or copper unless 
otherwise specified. 

310.3 Stranded Conductors. Where installed in 
raceways, conductors of size 8 AWG and larger shall be 
stranded. 

Exception: As permitted or required elsewhere in this Code. 

310.4 Conductors in Parallel. 

(A) Generail. Aluminum, copper-clad aluminum, or copper 
conductors of size 1/0 AWG and larger, comprising each 
phase, polarity, neutral, or grounded circuit conductor shall 
be permitted to be connected in parallel (electrically joined 
at both ends). 

Exception No. 1: Conductors in sizes smaller than 1/0 
A WG shall be permitted to be run in parallel to supply 
control power to indicating instruments, contactors, relay^s, 
solenoids, and similar control devices, or for frequencies of 
360 Hz and higher, provided all of the following apply: 

(a) They are contained within the same raceway or 
cable. 

(b) The ampacity of each individual conductor is 
sufficient to carry the entire load current shared by the 
parallel conductors. 

(c) The overcurrent protection is such that the 
ampacity of each individual conductor will not be exceeded 
if one or more of the parallel conductors become 
inadvertently disconnected. 



Exception No. 2: Under engineering supervision, 
grounded neutral conductors in sizes 2 AWG and larger 
shall be permitted to be run in parallel for existing 
installations. 

FPN te JBkception;;JS Exception No. 2 can be used to 
alleviate overheating of neutral conductors in existing 
installations due to high content of triplen harmonic currents. 



(B) Conductor Characterislics. The paralleled conductors 
in each phase, polarity, neutral, grounded circuit conductor, 
or equipment gro^inding^cOIld^ictor shall comply with all of 
the following: 

(1) Be the same length 

(2) Have the same conductor material 

(3) Be the same size in circular mil area 

(4) Have the same insulation type 

(5) Be terminated in the same manner 

(C) Separata Cables oi^ Raceways. Where run in separate 
cables^or raceways, the |ables or raceways with conductors 
shall have the same htAber of coEductots an^^ 

the]; same, elecfical^ Conductors of one 

phase, jpolarity, neutral, grourided circuit conductor, or 
aqtiipment groundiag^^^c^^ shall not be required to 

have the same physical characteristics as those of another 
phase, polarity, neutral, grounded circuit conductor, or 
equipment grounding co'pd^^ to achieve balance. 



@); Anyyaeji^ Conductors installed in parallel 

shall comply with the provisions of 3 10.15(B)(2)(a). 

(Ej JEqiiipment Grouiipiiig Conductors, Where parallel 
equipment grounding cbEductors are usdd, they shall be 
sized in accordance with 250 J 22. Sectioned equipment 
groua4ing conductors smaller than 1/0 AWG shall be 
permitted in multic0n4uctor cables in accordance; with 
3 10. 1 3 i provided the combined circular mil area in each 
g^fe cbmplies ^ 

310.5 Minimum Size of Conductors. The minimum size 
of conductors shall be as shown in Table 310.5, except as 
permitted elsewhere in this Code. 



Table 310.5 Minimum Size of Conductors 




Conductor Voltage 
Rating (Volts) 


Minimum Conductor Size (AWG) 


Copper 


Aluminum or 

Copper-Clad 

Aluminum 


0-2000 

2001-8000 

8001-15,000 

15,001-28,000 

28,001-35,000 


14 
8 
2 
1 
1/0 


12 
8 
2 
1 
1/0 



• 



• 



70-138 



2010 California Electrical Code 



ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING 



310.11 



310.6 Shielding. Solid dielectric insulated conductors 
operated above 2000 volts in permanent installations shall 
have ozone-resistant insulation and shall be shielded. All 
metallic^ insulation shields^shall J)e_jb<)niiiected ib^^ 
grounding^elcGtrbde eonHuctor, j^oundi^^^ Or g 
grounding elecfa^ode, Shielding shall be for the purpose of 
confining the voltage stresses to the insulation. 

Exception No. 1 : Nonshielded insulated conductors listed 
by a qualified testing laboratory shall be permitted for use 
up to 2400 volts under the following conditions: 

(a) Conductors shall have insulation resistant to 
electric discharge and surface tracking, or the insulated 
conductor(s) shall be covered with a material resistant to 
ozone, electric discharge, and surface tracking. 

(b) Where used in wet locations, the insulated 
conductor(s) shall have an overall nonmetallic jacket or a 
continuous metallic sheath. 

(c) Insulation and jocket thicknesses shall be in 
accordance with 9jMe-Jj[bCl3fB}^ 

EXceptionWo<2jj Where permitted in 310. 7, ^§xceptiqn Na^i 

310.7 Direct-Burial Conductors. Conductors used for direct- 
burial applications shall be of a type identified for such use. 

Cables rated above 2000 volts shall be shielded. 

Exception No. 1: Nonshielded multiconductor cables rated 
2001-2400 volts shall be permitted if the cable has an 
overall metallic sheath or armor. 

The metaUic shield, sheath, or armor shall be 

jpomiectei#-'-a:^utii<^^ 

Exception No. 2:^ 4irfi^<i;i^^Mi^ 

'pfmU$:-i^PS^e 'mted-tip-- to SOWvdlis -imi^ 'ar^-pm^iifpd^lyy^ 

FPN No. 1: See 300.5 for installation requirements for 
conductors rated 600 volts or less. 

FPN No. 2: See 300.50 for installation requirements for 
conductors rated over 600 volts. 

310.8 Locations. 

(A) Dry Locations. Insulated conductors and cables used in 
dry locations shall be any of the types identified in this Code. 

(B) Dry and Damp Locations. Insulated conductors and 
cables used in dry and damp locations shall be Types PEP, 
FEPB, MTW, PFA, RHH, RHW, RHW-2, SA, THHN, 
THW, THW-2, THHW, THWN, THWN-2, TW, XHH, 
XHHW, XHHW-2, Z, or ZW. 

(C) Wet Locations. Insulated conductors and cables used 
in wet locations shall comply with one of the following: 

(1) Be moisture-impervious metal-sheathed 



(2) Be types MTW, RHW, RHW-2, TW, THW, THW-2, 
THHW, THWN, THWN-2, XHHW, XHHW-2, ZW 

(3) Be of a type listed for use in wet locations 

(D) Locations Exposed to Direct Sunlight. Insulated 
conductors or cables used where exposed to direct rays of 
the sun shall comply with (0)(1) or 03X2): 

(1) Conductors and cables shall be listed, or listed and 
marked, as being sunlight resistant 

(2) Conduptors and cables shaUbg covered with insulating 
material, such as tape or sleeving, that is listed, or 
listed and marked, as being sunlight resistant 

310.9 Corrosive Conditions. Conductors exposed to oils, 
greases, vapors, gases, fumes, liquids, or other substances 
having a deleterious effect on the conductor or insulation 
shall be of a type suitable for the application. 

310.10 Temperature Limitation of Conductors. No 

conductor shall be used in such a manner that its operating 
temperature exceeds that designated for the type of insulated 
conductor involved. In no case shall conductors be associated 
together in such a way, with respect to type of circuit, the 
wiring method employed, or the nxunber of conductors, that 
the limiting temperature of any conductor is exceeded. 

FPN: The temperature rating of a conductor [see Table 
3IM1S and labie^lllglllg)! is the maximum 
temperature, at any location along its length, that the 
conductor can withstand over a prolonged time period 
without serious degradation. The allowable ampacity tables, 
the ampacity tables of Article 310 and the ampacity tables 
of Annex B, the correction factors at the bottom of these 
tables, and the notes to the tables provide guidance for 
coordinating conductor sizes, types, allowable ampacities, 
ampacities, ambient temperatures, and number of associated 
conductors. 

The principal determinants of operating 
temperature are as follows: 

(1) Ambient temperature — ambient temperature may vary 
along the conductor length as well as from time to 
time. 

(2) Heat generated internally in the conductor as the result 
of load current flow, including fundamental and 
harmonic currents. 

(3) The rate at which generated heat dissipates into the 
ambient medium. Thermal insulation that covers or 
surrounds conductors affects the rate of heat 
dissipation, 

(4) Adjacent load-carrying conductors — adjacent 
conductors have the dual effect of raising the ambient 
temperature, and impeding heat dissipation. 

m 

310.11 Marking. 

(A) Required Information. All conductors and cables 
shall be marked to indicate the following information, 
using the applicable method described in 310.11(B): 



2010 California Electrical Code 



70-139 



310.12 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



(1) The maximum rated voltage. 

(2) The proper type letter or letters for the type of wire or 
cable as specified elsewhere in this Code. 

(3) The manufacturer's ' name, trademark, or other 
distinctive marking by which the organization 
responsible for the product can be readily identified. 

(4) The AWG size or circular mil area. 

FPN: See Conductor Properties, Table 8 of Chapter 9, for 
conductor area expressed in SI units for conductor sizes 
specified in AWG or circular mil area. 

(5) Cable assemblies where the neutral conductor is smaller 
than the ungrounded conductors shall be so marked. 

(B) Method of Marking. 

(1) Surface Marking. The following conductors and 
cables shall be durably marked on the surface. The AWG 
size or circular mil area shall be repeated at intervals not 
exceeding 610 mm (24 in.). All other markings shall be 
repeated at intervals not exceeding 1.0 m (40 in.). 

(1) Single-conductor and multiconductor rubber- and 
thermoplastic-insulated wire and cable 

(2) NonmetaUic-sheathed cable 

(3) Service-entrance cable 

(4) Underground feeder and branch-circuit cable 

(5) Tray cable 

(6) Irrigation cable 

(7) Power-limited tray cable 

(8) Instrumentation tray cable 

(2) Marker Tape. Metal-covered multiconductor cables 
shall employ a marker tape located within the cable and 
running for its complete length. 

Exception No. I: Mineral-insulated, metal-sheathed cable. 

Exception No. 2: Type AC cable. 

Exception No. 3: The information required in 310.11(A) 
shall be permitted to be durably marked on the outer 
nonmetallic covering of Type MC, Type ITC, or Type PLTC 
cables at intervals not exceeding 1.0 m (40 in.). 

Exception No. 4: The information required in 310.11(A) 
shall be permitted to be durably marked on a nonmetallic 
covering under the metallic sheath of Type ITC or Type 
PLTC cable at intervals not exceeding 1.0 m (40 in.). 

FPN: Included in the group of metal-covered cables are 
Type AC cable (Article 320), Type MC cable (Article 330), 
and lead-sheathed cable. 

(3) Tag Marking. The following conductors and cables 
shall be marked by means of a printed tag attached to the 
coil, reel, or carton: 

(1) Mineral-insulated, metal-sheathed cable 



(2) Switchboard wires 

(3) Metal-covered, single-conductor cables 

(4) Type AC cable 

(4) Optional Marking of Wire Size. The information 
required in 310.11(A)(4) shall be permitted to be marked 
on the surface of the individual insulated conductors for the 
following multiconductor cables: 

(1) Type MC cable 

(2) Tray cable 

(3) Irrigation cable 

(4) Power-limited tray cable 

(5) Power-limited fire alarm cable 

(6) Instrumentation tray cable 

(C) Suffixes to Designate Number of Conductors. A type 
letter or letters used alone shall indicate a single insulated 
conductor. The letter suffixes shall be indicated as follows: 

(1) D — For two insulated conductors laid parallel within 
an outer nonmetallic covering 

(2) M — For an assembly of two or more insulated conductors 
twisted spirally within an outer nonmetallic covering 

(D) Optional Markings. All conductors and cables 
contained in Chapter 3 shall be permitted to be surface 
marked to indicate special characteristics of the cable 
materials. These markings include, but are not limited to, 
markings for limited smoke, sunlight resistant, and so forth. 

310.12 Conductor Identification. 

(A) Grounded Conductors. Insulated or covered 
grounded conductors shall be identified in accordance with 
200.6. 

(B) Equipment Grounding Conductors. Equipment 
grounding conductors shall be in accordance with 250.119. 

(C) Ungrounded Conductors. Conductors that are 
intended for use as ungrounded conductors, whether used 
as a single conductor or in multiconductor cables, shall be 
finished to be clearly distinguishable from grounded and 
grounding conductors. Distinguishing markings shall not 
conflict in any manner with the surface markings required 
by 310.11(B)(1). Branch-circuit ungrounded conductors 
shall be identified in accordance with 210.5(C). Feeders 
shall be idendfied in accordance with 215.12. 

Exception: Conductor identification shall be permitted in 
accordance with 200. 7. 

310.13 Conductor Constructions and Applications. 

Insulated conductors shall comply with the applicable 
provisions of Table 310.13^tjwughtabie3;^^ 



• 



70-140 



2010 California Electrical Code 



ARTICLE 310 — CONDUCTORS FOR GENERAL WIRING 



310.13 



These conductors shall be permitted for use in any of 
the wiring methods recognized in Chapter 3 and as speci- 
fied in their respective tables or as permitted elsewhere in 
this Code. 

FPN: Thermoplastic insulation may stiffen at temperatures 
lower than -10°C (+14°F). Thermoplastic insulation may 
also be deformed at normal temperatures where subjected 



to pressure, such as at points of support. Thermoplastic 
insulation, where used on dc circuits in wet locations, may 
result in electroendosmosis between conductor and 
insulation. 

Equipment grounding conductors shall be permitted to 
be sectioned within a listed mnlticpnductor cable, provided 
the -combined circular ml^^^ complies with 250422. 



Table 310.13(A) Conductor Applications and Insulations Rated 600 Volts 













Tiiickness of Insulation 








Maximum Operating 














Trade Name 


Type Letter 


Temperature 


Application Provisions 


Insulation 


AWG or kcmil 


mm 


mils 


Outer Covering^ 


Fluorinated 


FEPor 


90°C 


Dry and damp locations 


Fluorinated ethylene 


14-10 


0.51 


20 


None 


ethylene 


FEPB 


194°F 




propylene 


8-2 


0.76 


30 




propylene 














200°C 
392°F 


Dry locations — special 
applications^ 


Fluorinated ethylene 
propylene 


14-8 


0.36 


14 


Glass braid 






















6-2 


0.36 


14 


Glass or other suitable 
braid material 


Mineral insulation 


MI 


90X 


Dry and wet locations 


Magnesium oxide 


18-16^ 


0.58 


23 


Copper or alloy steel 


(metal sheathed) 




194°F 






16-10 


0.91 


36 








250X 


For special applications'^ 




9-4 


1.27 


50 








482°F 






3-500 


1.40 


55 




Moisture-, heat-, 


MTW 


60°C 


Machine tool wiring in 


Flame-retardant 




(A) 


(A) 


(A) None 


and oil-resistant 




140°F 


wet locations 


moisture-, heat-, and 
oil-resistant 








(B) Nylon jacket or 


thermoplastic 






equivalent 






90X 


Machine tool wiring in 


thermoplastic 


22-12 


0.76 


30 








194°F 


dry locations. 
FPN: See NFPA 79. 




10 

8 

6 

4-2 

1-^/0 

213-500 

501-1000 


0.76 
1.14 
1.52 
1.52 
2.03 
241 
2.79 


30 
45 
60 
60 
80 
95 
110 




Paper 




85°C 
185T 


For underground service 
conductors, or by special 
permission 


Paper 








Lead sheath 


Perfluoro-alkoxy 


PFA 


90°C 
194°F 


Dry and damp locations 


Perfluoro-alkoxy 


14-10 
8-2 


0.51 
0,76 


20 
30 


None 






200°C 


Dry locations — special 




1^/0 


1.14 


45 








392°F 


applications^ 












Perfluoro-alkoxy 


PFAH 


250''C 


Dry locations only. Only 


Perfluoro-alkoxy 


14-10 


0.51 


20 


None 






482°F 


for leads within apparatus 
or within raceways 
connected to apparatus 
(nickel or nickel-coated 
copper only) 




8-2 
I^/O 


0.76 
1.14 


30 

45 




Thermoset 


RHH 


90"C 


Dry and damp locations 




14-10 


1.14 


45 


Moisture-resistant, 


• 




194°F 






8-2 

1-1/0 

213-500 

501-1000 

1001-2000 


1.52 
2.03 
241 
2.79 
3.18 


60 
80 
95 
110 
125 


flame-retardant, 
nonmetallic covering' 


Moisture- 


RHW^ 


75°C 


Dry and wet locations 


Flame-retardant, 


14-10 


1.14 


45 


Moisture-resistant, 


resistant 




167°F 




moisture- 


8-2 


1.52 


60 


flame-retardant, 


thermoset 








resistant thermoset 


I^/O 


2 03 


80 


nonmetallic coveringi 




RHW-2 


90^*0 






213-500 


2.41 


95 






}94,T 






501-1000 


2.79 


110 












1001-2000 


3.18 


125 




Silicone 


SA 


90°C 


Dry and damp locations 


Silicone rubber 


14-10 


1.14 


45 


Glass or other suitable 






194°F 






8-2 
1-4/0 


1.52 
2.03 


60 
80 


braid material 






200T 


For special application^ 




213-500 


241 


95 








392°F 






501-1000 
1001-2000 


2.79 
3.18 


110 

125 





(Continues) 



2010 California Electrical Code 



70-141 



310.13 



ARTICLE 310 — CONDUCTORS FOR GENERAL WIRING 



Table 310.13(A) Continued 













Thickness of Insulation 








Maximum Operating 














Trade Name 


T^pe Letter 


Temperature 


Application Provisions 


Insulation 


AWG or kcmil 


mm 


mils 


Outer Covering* 


Thermoset 


SIS 


90°C 


Switchboard wiring only 


Flame-retardant 


14-10 


0.76 


30 


None 






194°F 




thermoset 


8-2 
1^/0 


1.14 
2.41 


45 

11 




Thennoplastic and 


TBS 


90°C 


Switchboard wiring only 


Thermoplastic 


14-10 


0.76 


30 


Flame-retardant, 


fibrous outer 




194°F 






8 


1.14 


45 


nonmetallic covering 


braid 










6-2 
1-4/0 


1.52 
2.03 


60 
80 




Extended polytetra- 


TFE 


250^0 


Dry locations only. Only 


Extruded polytetra- 


14-10 


0.51 


20 


None 


fluoro- 




482T 


for leads within 


fluoroethylene 


8-2 


0.76 


30 




ethylene 






apparatus or within 
raceways connected to 
apparatus, or as open 
wiring (nickel or 
nickel-coated copper 
only) 




1-4/0 


1.14 


45 




Heat-resistant 


THHN 


90''C 


Dry and damp locations 


Flame-retardant, 


14-12 


0.38 


15 


Nylon jacket or 


thermoplastic 




194T ■ 




heat-resistant 
thermoplastic 


10 

8-6 

4-2 

1^/0 

250-500 

501-1000 


0.51 
0.76 
1.02 
1.27 
1.52 
1.78 


20 
30 
40 
50 
60 
70 


equivalent 


Moisture- and 


THHW 


75°C 


Wet location 


Flame-retardant, 


14-10 


0.76 


30 


None 


heat-resistant 




167°F 




moisture- and 


' 8 


1.14 


45 




thermoplastic 








heat-resistant 


6-2 


1.52 


60 








90°C 
194°F 


Dry location 


thermoplastic 


1-4/0 

213-500 

501-1000 

:1001>20p0 


2.03 
2.41 
2.79 
:3J8 


80 

95 

110 

:12A 




Moisture- and 


THW 


75°C 


Dry and wet locations 


Flame-retardant, 


14-10 


0.76 


30 


None 


heat-resistant 




167°F 




moisture- and 


8 


1.14 


45 




thermoplastic 




90°C 


Special applications 


heat-resistant 


6-2 


1.52 


60 








194°F 


within electric discharge 
lighting equipment. 
Limited to 1000 
open-circuit volts or 
less, (size 14-8 only as 
permitted in 410.68) 


thermoplastic 


1^/0 
213-500 
501-1000 
1001--200q 


2.03 
2.41 
2.79 
3.18 


80 
95 
110 

|125^ 






frHW-2 


r90«C 


pry' and wet Ipications 








.194^F 














Moisture- and 


THWN 


75''C 


Dry and wet locations 


Flame-retardant, 


14-12 


0.38 


15 


Nylon jacket or 


heat-resistant 




167°F 




moisture- and 


10 


0.51 


20 


equivalent 


thermoplastic 








heat-resistant 
thermoplastic 


8-6 
4-2 


0.76 
1.02 


30 
40 














THWN-2 


|90^C 






1^/0 
250-500 
501-1000 


1.27 
1.52 
1.78 


50 
60 
70 




Moisture- 


TW 


60°C 


Dry and wet locations 


Flame-retardant, 


14-10 


0.76 


30 


None 


resistant 




140°F 




moisture- 


8 


1.14 


45 . 




thermoplastic 








resistant 
thermoplastic 


6-2 

1-4/0 
213-500 
501-1000 
1001-2000 


1.52 
2.03 
2.41 
2.79 
3.18 


60 
80 
95 
110 
125 




Underground feeder 


UF 


60°C 


See Article 340. 


Moisture- 


14-10 


1.52 


601 


Integral with insulation 


and branch-circuit 




140°F 




resistant 


8-2 


2.03 


8ol 




cable — single 










1^/0 


2.41 


^^i 




conductor (for 


















Type UF cable 




75°C 




Moisture- and 










employing more 




167°F| 




heat-resistant 










than one 


















conductor, see 


















Article 340.) 




















70-142 



2010 Califomia Electrical Code 



ARTICLE 310 — CONDUCTORS FOR GENERAL WIRING 



310.13 



Table 310.13|(A) ConHnued 













Thickness of Insulation 








Maximum Operating 














TVade Name 


Type Letter 


Temperature 


Application Provisions 


Insulation 


AWG or kcmil 


mm 


mils 


Outer Covering^ 


Underground 


USE 


75°C 


See Article 338. 


Heat- and 


14-10 


1.14 


45 


Moisture-resistant 


service- 




167'^F 




moisture-resistant 


8-2 


1.52 


60 


nonmetallic covering 


entrance cable — 










1^/0 


2.03 


80 


(See 338.2.) 


single conductor 










213-500 


2.41 


95i| 




(for Type USE 










501-1000 


2.79 


no' 




cable employing 










1001-2000 


3.18 


125 




more than one 


















conductor, see 


















Article 338.) 




















}^Wl 


rs?s 


Dry;anJ' wibt" locations 








J94*f* 














Thermoset 


XHH 


90X 


Dry and damp locations 


Flame-retardant 


14-10 


0.76 


30 


None 






194^F 




thermoset 


8-2 

1-4/0 

213-500 

501-1000 

1001-2000 


1.14 
1.40 
1.65 
2.03 
2.41 


45 
55 
65 
80 
95 




Moisture- 


XHHW^ 


90°C 


Dry and damp locations 


Flame-retardant, 


14-10 


0.76 


30 


None 


resistant 




194°F 




moisture- 


8-2 


1.14 


45 




thermoset 




75^C 
167°F 


Wet locations 


resistant thermoset 


1^/0 
213-500 
501-1000 
1001-2000 


1.40 
1.65 
2.03 
2.41 


55 
65 
80 
95 




Moisture- 


XHHW-2 


90"C 


Dry and wet locations 


Flame-retardant, 


14-10 


0.76 


30 


None 


resistant 




194°F 




moisture- 


8-2 


1.14 


45 




thermoset 








resistant thermoset 


1-4/0 
213-500 
501-1000 
1001-2000 


1.40 
1.65 
2.03 
2.41 


55 
65 
80 
95 




Modified ethylene 


Z 


90X 


Dry and damp locations 


Modified ethylene 


14-12 


0.38 


15 


None 


tetrafluoro- 




194°F 




tetrafluoro- 


10 


0.51 


20 




ethylene 




150°C 


Dry locations — special 


ethylene 


8-4 


0.64 


25 








302°F 


applications^ 




3-1 
1/0-4/0 


0.89 
1,14 


35 
45 




Modified ethylene 


zw 


1S°C 


Wet locations 


Modified ethylene 


14-10 


0.76 


30 


None 


tetrafluoro- 




\6TV 




tetrafluoro- 


8-2 


1.14 


45 




ethylene 




90°C 
194T 
150°C 
302°F 


Dry and damp locations 

Dry locations — special 
applications^ 


ethylene 












zw-a 


90"q 


Dryland "Wet locations 








■my 















' Some insulations do not require an outer covering. 

■^ Where design conditions require maximum conductor operating temperatures above 90°C (194°F). 

^ For signaling circuits permitting 300-volt insulation. 

• 

^ Some rubber insulations do not require an outer covering. 
^ Includes integral jacket. 
^ For ampacity limitation, see 340.80. 

^ Insulation thickness shall be permitted to be 2.03 mm (80 mils) for listed Type USE conductors that have 
been subjected to special investigations. The nonmetallic covering over individual rubber-covered conduc- 
tors of aluminum-sheathed cable and of lead-sheathed or multiconductor cable shall not be required to be 
flame retardant. For Type MC cable, see 330.104. For nonmetallic- sheathed cable, see Article 334, Part III. 
For Type UF cable, see Article 340, Part III. 



Si 



2010 CaHfomia Electrical Code 



70-143 



310.13 



ARTICLE 3 1 - CONDUCTORS FOR GENERAL WIRING 



Table 310.13(B) Thickness of Insulation for Nonshielded 
Types RHH and BJBLW Solid DMectiicItisulated Conductors 
Rated 2000 Volts 





Column A^ 


Column B^ 


Conductor Size 










(AWG or kcmil) 


mm 


mils 


mm 


mils 


14-10 


2.03 


80 


1.52 


60 


8 


2.03 


80 


1.78 


70 


6-2 


2.41 


95 


1.78 


70 


1-2/0 


2.79 


110 


2.29 


90 , 


3/0-4/0 


2.79 


110 


2.29 


90 


213-500 


3.18 


125 


2.67 


105 


501-1000 


3.56 


140 


3.05 


120 


1001-2000 


3.56 


140 


3.56 


140 



tolumn A insulations are limited to natural, SBR, and butyl rubbers. 

^Column B insulations are materials such as cross-linked 
polyethylene, ethylene propylene rubber, and composites thereof. 

Table 310.13(C| Conductor Application and Insulation Rated 2001 yolts and Higheij 



Trade 
Name 


Type Letter 


Maximum 

Operating 

Temperature 


Application 
Provision 


Insulation 


Outer Covering 


Medium voltage 
solid dielectric 


MV-90 
MV-105* 


90°C 
105°C 


Dry or wet locations 

• 


Thermo- 
plastic or thermo- 
setting 


Jacket, sheath, or 
armor 



* Where design conditions require maximum conductor temperatures above 90°C. 

Table 310.13(D) Thickness of tnsulatibii^ and Jacket for Nonshielded Solid Dielectric Insiiil^ted; Cond^ Rated; 2400 Voll^ 







Dry Locations, Single Conductor 








Wet or Dry Locations 






Without Jacket 
Insulation 




With Jacket 




Single Conductor 


Multicondu( 
Insulation 






Insulation 


Jacket 


Insulation 


Jacket 


:tor 


Conductor Size 






















(AWG or 
kcmil) 


mm 


mils 


mm 


mils 


mm 


mils 


mm 


mils 


mm 


mils 


mm 


mils 


8 


2.79 


110 


2.29 


90 


0.76 


30 


3.18 


125 


2.03 


80 


2.29 


90 


6 


2.79 


110 


2.29 


90 


0.76 


30 


3.18 


125 


2.03 


80 


2.29 


90 


4-2 


2.79 


110 


2.29 


90 


1.14 


45 


3.18 


125 


2.03 


80 


2.29 


90 


1-2/0 


2.79 


110 


2.29 


90 


1.14 


45 


3.18 


125 


2.03 


80 


2.29 


90 


3/0-4/0 


2.79 


no 


2.29 


90 


1.65 


65 


3.18 


125 


2.41 


95 


2.29 


90 


213-500 


3.05 


120 


2.29 


90 


1.65 


65 


3.56 


140 


2.79 


110 


2.29 


90 


501-750 


3.30 


130 


2.29 


90 


1.65 


65 


3.94 


155 


3.18 


125 


2.29 


90 


751-1000 


3.30 


130 


2.29 


90 


1.65 


65 


3.94 


155 


3.18 


125 


2.29 


90 


mirnm 


Mi 


IS 


2,92 


m 


i0: 


M~ 


4:32 


S70 


3.56 


m^ 


%^ 


U'^. 


iisi-fism 


%56 


m 


2,92 


ni 


2.03 


^<> 


4.32 


P9, 


3.56 


140 


2S2 


US 


iSOMOpCi 


346 


l40 


2,92 


lis, 


^M 


^ 


432 


;17? 


3.94 


m 


3^56 


140 



*Under a common overall covering such as a jacket, sheath, or armor. 



70-144 



2010 California Electrical Code 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



310.15 



Table 310.13(E) Thickness of Insulation for Shielded Solid Dielectric Insulated Conductors Rated 2001 to 35,000 Volts 


2001-5000 


















Volts 


5001-8000 Volts 




8001-15,000 Volts 


15,001-25,000 Volts 


il 




100 


133 


173 


100 133 


173 


100 133 


173 


ftrctnt 


Percent 
Insulation 


Percent 
Insulation 


Percent 
Insulation 


Percent Percent 
Insulation Insulation 


Percent 
Insulation 


Percent Percent 
Insulation Insulation 


Percent 

Insulation 


I-ev€l 


I 


Level 1 


Level 2 


Level3 


Levell Level2 


Level3 


Levell Level2 


Level3 


Conductor 




















Size 




















(AWG 




















or kcmil) mm 


mils 


mm mils 


mm mils 


mm mils 


mm mils mm 


mils 


mm mils 


mm mils mm mils 


mm mils 


8 2.29 


90 


— — 


— — 


— — 


_ _ . _ 


— 


— — 


_ _ _ _ 


_ __ 


6^ 2.29 


90 


2.92 115 


3.56 140 


4.45 175 


— — — 


— 


— — 


— — — — 


— — 


2 2 29 


90 


2 92 115 


3 56 140 


4 45 175 


4.45 175 5.59 
4.45 175 5.59 


220 
220 


6 60 76ft 






1 2.29 


90 


2.92 115 


3.56 140 


4.45 175 


6.60 260 


6.60 260 8.13 320 


10.67 420 


1/0-2000 2.29 


90 


2.92 115 


3.56 140 


4.45 175 


4.45 175 5.59 


220 


6.60 260 


6.60 260 8.13 320 


10.67 420 








25,001- 


28,000 volts 








28,001-35,000 volts 






100 




133 


173 




100 


133 


173 






Percent 


Percent 


Percent 




Percent 


Percent 


Percent 






Insulation 


Insulation 


Insulation 




Insulation 


Insulation 


Insulation 






Levell 


Level 2 


Level3 




Levell 


Level2 


LeveB 


Conductor 


mm mils 


mm 


mils 


mm mils 




mm mils 


mm mils 


mm mils 


Size 




















(AWG 




















or kcmil) 




















1 




7.11 280 


8.76 


345 


11. .30 445 




— — 


— — 


— — 


1/0-2000 




7.11 280 


8.76 


345 


11.30 445 




8.76 345 


10.67 420 


14.73 580 



100 Percent Insulation Level. Cables in this category shall be permitted to be applied where the system is provided with relay protection such that ground 
faults will be cleared as rapidly as possible but, in any case, within 1 minute. While these cables are applicable to the great majority of cable installations that 
are on grounded systems, they shall be permitted to be used also on other systems for which the application of cables is acceptable, provided the above 
clearing requirements are met in completely de-energizing the faulted section. 

^ 133 Percent Insulation Level. This insulation level corresponds to that formerly designated for ungrounded systems. Cables in this category shall be 
permitted to be applied in situations where the clearing time requirements of the 100 percent level category cannot be met and yet there is adequate 
assurance that the faulted section will be de-energized in a time not exceeding 1 hour. Also, they shall be permitted to be used in 100 percent insulation level 
applications where additional insulation is desirable. 
^ 173 Percent Insulation Level. Cables in this category shall be permitted to be apphed under all of the following conditions: 

(1) In industrial establishments where the conditions of maintenance and supervision ensure that only qualified persons service the installation 

(2) Where the fault clearing time requirements of the 133 percent level category cannot be met 

(3) Where an orderly shutdown is essential to protect equipment and personnel 

(4) There is adequate assurance that the faulted section will be de-energized in an orderly shutdown 

Also, cables with this insulation thickness shall be permitted to be used in 100 or 133 percent insulation level applications where additional insulation 
strength is desirable. 



310.14 Aluminum Conductor Material. Solid aluminum 
conductors 8, 10, and 12 AWG shall be made of an AA- 
8000 series electrical grade aluminum alloy conductor 
material. Stranded aluminum conductors 8 AWG through 
1000 kcmil marked as Type RHH, RHW, XHHW, THW, 
THHW, THWN, THHN, service-entrance Type SE Style U 
and SE Style R shall be made of an AA-8000 series 
electrical grade aluminum alloy conductor material. 

310.15 Ampacities for Conductors Rated 0-2000 Volts. 
(A) General. 

(1) Tables or Engineering Supervision. Ampacities for 
conductors shall be permitted to be determined by tables as 
provided in 310.15(B) or under engineering supervision, as 
provided in 310.15(C). 



FPN No. 1 : Ampacities provided by this section do not take 
voltage drop into consideration. See 210.19(A), FPN No. 4, 
for branch circuits and 215.2(A), FPN No. 2, for feeders. 
FPN No. 2: For the allowable ampacities of Type MTW 
wire, see Table 13.5.1 in NFPA 79-2007, Electrical 
Standard for Industrial Machinery. 
(2) Selection of Ampacity. Where more than one 
calculated or tabulated ampacity could apply for a given 
circuit length, the lowest value shall be used. 
Exception: Where two different ampacities apply to 
adjacent portions of a circuit, the higher ampacity shall be 
permitted to be used beyond the point of transition, a 
distance equal to 3.0 m (10 ft) or 10 percent of the circuit 
length figured at the higher ampacity, whichever is less. 
FPN: See 110.14(C) for conductor temperature limitations 
due to termination provisions. 



2010 Califomia Electrical Code 



70-145 



310.15 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



(B) Tables. Ampacities for conductors rated to 2000 
volts shall be as specified in the Allowable Ampacity Table 
310.16 through Table 310.19, and Ampacity Table 310.20 
and Table 3 10.21 as modified by (B)(1) through (B)(6). 
FPN: Table 310.16 through Table 310.19 are application tables 
for use in determining conductor sizes on loads calculated in 
accordance with Article 220. Allowable ampacities result from 
consideration of one or more of the following: 

(1) Temperature compatibility with connected equipment, 
especially the connection points. 

(2) Coordination with circuit and system overcurrent 
protection. 

(3) Compliance with the requirements of product listings 
or certifications. See 110.3(B). 

(4) Preservation of the safety benefits of established 
industry practices and standardized procedures. 

(1) General. For explanation of type letters used in tables 
and for recognized sizes of conductors for the various 
conductor insulations, see Cfable' 3ip.l3(Al and Table 
310.13^^ For installation requirements, see 310.1 through 
310.10 and the various articles of this Code. For flexible 
cords, see Table 400.4, Table 400.5(A), and Table 
400.5(B). 

(2) Adjustment Factors. 

(a) More Than Three Current-Carrying Conductors in 
a Raceway or Cable. Where the number of current-carrying 
conductors in a raceway or cable exceeds three, or where 
single conductors or multiconductor cables are iiisilBiled 

than 600 mm (24 in.) and are not installed in raceways, the 
allowable ampacity of each conductor shall be reduced as 
shown in Table 310.15(B)(2)(a). Each current-carrying 
conductor of a paralleled set of conductors shall be counted 
as a current-carrying conductor. 

Table 310.15(B)(2)(a) Adjustment Factors for More Than 
Three Current-Carrying Conductors in a Raceway or Cable 



Number of 

Current-Carrying 

Conductors 



Percent of Values in Tables 
310.16 through 310.19 as 

Adjusted for Ambient 
Temperature if Necessary 



4-6 

7-9 

10-20 

21-30 

31^0 

41 and above 



80 
70 
50 
45 
40 
35 



FPN No. 2: See 366.23(A) for adjustment factors for 
conductors in sheet metal auxiliary gutters and ^^^^H 
for ^i^fr^i^ factors for conductors in metal wire ways. 

Exception No. 1: Where conductors of different systems, as 
provided in 300.3, are installed in a common raceway or 
cable, the derating factors shown in Table 3 10 A 5(B)(2)(a) 
shall apply only to the number of power and lighting 
conductors (Articles 210, 215, 220, and 230). 

Exception No. 2: For conductors installed in cable trays, 
the provisions of 392.11 shall apply. 

Exception No. 3: Derating factors shall not apply to 
conductors in nipples having a length not exceeding 600 
mm (24 in.). 

Exception No. 4: Derating factors shall not apply to 
underground conductors entering or leaving an outdoor 
trench if those conductors have physical protection in the 
form of rigid metal conduit, intermediate metal conduit, or 
rigid nonmetallic conduit having a length not exceeding 
3.05 m (10 ft) and if the number of conductors does not 
exceedfour. 

Exception No. 5: Adjustment factors shall not apply to 
Type AC cable or to Type MC cable without an overall 
outer jacket under the following conditions: 

(1) Each cable has not more than three current- 
carrying conductors. 

(2) The conductors are 12 AWG copper. 

(3) Not more than 20 current-carrying conductors are 
bundled, stacked, or supported on "bridle rings. " 

A 60 percent adjustment factor shall be applied where the 
current-carrying conductors in these cables that are 
stacked or bundled longer than 600 mm (24 in.) without 
maintaining spacing exceeds 20. 

(b) More Than One Conduit, Tube, or Raceway. 
Spacing between conduits, tubing, or raceways shall be 
maintained. 

^ (c) 'Camhits Mx^osedJpSunl^^ 
^|i|ct^suailigM_ o^ afeoye rooftops, the adjuSietits showri 

|5t^r||ure',for;;^^ 



FPN No. 1: See Annex B, Table B.310.11, for adjustment 
factors for more than three current-carrying conductors in a 
raceway or cable with load diversity. 



'lo^tioxis.^^^ 

Fundumentaisl 



; the; ASHRAE r Haadbook 



70-146 



2010 California Electrical Code 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



310.15 



Table 310.15(B)(2)(c) Ambient Temperature Adjustment for 
Conduits Exposed to Sunligiit On or Above Rooftops 



Distance Above Roof to 
Bottom of Conduit 



Temperature Adder 



0-13 mm (1/2 in.) 33 

Above 1 3 mm QA in.) - 90 22 

mm (3/2 in.) 

Above 90 mm (3^2 in.) - 17 

300 mm (12 in.) 

Above 300 mm (12 in.) - 14 

900 mm (36 in.) 



60 
40 

30 

25 



ioMt^^^MA^^^M ^^^^9}?^^^l.^Mi:M^J^^^ The 

feeder conductors to a dv^elling unit shall not be required to 
have an allov^able ampacity rating greater than their 
service-entrance conductors. The grounded conductor shall 
be permitted to be smaller than the ungrounded conductors, 
provided the requirements of 215.2, 220.61, and 230.42 
are met. 



Table 310.15(B)(6) Conductor Types and Sizes for 120/240- 
Volt, 3-Wire, Single-Phase Dv^^elling Services and Feeders. 
Conductor Types RHH, RHW, RHW-2, THHN, THHW, 
THW, THW-2, THWN, THWN-2, XHHW, XHHW-2, SE, 
USE, USE-2 



JRf N t^ t^ble 3i:0,i5(BX^Xft):;;T^^^ tetnp^atvire adde^^^ 

pPable '|lO, !'5(B)(2)(c) ,arr|kse§lon 

(3) Bare or Covered Conductors. Where bare or covered 
conductors are InstaUedj with insulated conductors, the; 
jtetnperaty^e rating of the bare or covered conductor shall 
be equal |o the lowest temperature ratiag of the ini^ulated 
conductors for tte purpose of determining ampacity J 

(4) Neutral Conductor. 

(a) A neutral conductor that carries only the 
unbalanced current fi-om other conductors of the same 
circuit shall not be required to be counted when applying 

the provisions of 3 1 0. 1 5(B)(2)(a). 

(b) In a 3 -wire circuit consisting of two phase 
conductor^ and the neutral jetodtictOT] of a 4- wire, 3 -phase, 
wye-connected system, a common conductor carries 
approximately the same current as the line-to-neutral load 
currents of the other conductors and shall be counted when 
applying the provisions of 310.15(B)(2)(a). 

(c) On a 4-wire, 3 -phase v^e circuit where the major 
portion of the load consists of nonlinear loads, harmonic 
currents are present in the neutral conductor; the neutral 
l^nductpj shall therefore be considered a current-carrying 
conductor. 

(5) Grounding or Bonding Conductor. A grounding or 
bonding conductor shall not be counted when applying the 
provisions of 310.15(B)(2)(a). 

(6) 120/240-Volt, 3-Wire, Single-Phase Dwelling 
Services and Feeders. For individual dwelling units of 
one-family, two-family, and multifamily dwellings, 
conductors, as listed in Table 310.15(B)(6), shall be 
permitted as 120/240- volt, 3 -wire, single-phase service- 
entrance conductors, service-lateral conductors, and feeder 
conductors that serve as the main power feeder to each 
dweUing unit and are installed in raceway or cable with or 
without an equipment grounding conductor. For application 
of this section, the main power feeder shall be the feeder 
between the main disconnect and the panelboard 0iati 
^ygppliies,^ither f y branch circm^ or by feederj^ qrjBpfc,^^^^ 



Conductor (AWG or kcmil) 



Service or Feeder 
Rating (Amperes) 



Copper 



Aluminum or 

Copper-Clad 

Aluminum 



100 
110 
125 
150 
175 
200 
225 
250 
300 
350 
400 



4 

3 

2 

1 

1/0 
2/0 
3/0 
4/0 
250 
350 
400 



2 

1 

1/0 
2/0 
3/0 
4/0 
250 
300 
350 
500 
600 



(C) Engineering Supervision. Under engineering 
supervision, conductor ampacities shall be permitted to be 
calculated by means of the following general formula: 



/ = 



TC-{TA^ATD) 
RDC{14^¥C)RCA 



where: 

rC= conductor temperature in degrees Celsius (°C) 
TA= ambient temperature in degrees Celsius C^C) 

^TD= dielectric loss temperature rise 

RDC= dc resistance of conductor at temperature TC 

YC= component ac resistance resulting from skin 
effect and proximity effect 

RCA= effective thermal resistance between 
conductor and surrounding ambient 

FPN: See Annex B for examples of formula applications. 



2010 California Electrical Code 



70-147 



310.15 



ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING 



Table 310.16 Allowable Ampacities of Insulated Conductors Rated Through 2000 Volts, 60°C Through 90°C (140°F Through 
194°F), Not More Than Three Current-Carrying Conductors in Raceway, Cable, or Earth (Directly Buried), Based on Ambient 
Temperature of 30°C (86°F) 





Temperature Rating of Conductor [See Table 310J3(A),1 






60°C (140°F) 


75°C (167°F) 


90°C (194°F) 


60°C (140°F) 


75°C (167°F) 


90°C (194°F) 










Types TBS, SA, 
















SIS, FEP, FEPB, 






Types TBS, SA, 








Types RHW, 


MI, RHH, RHW-2, 




Types RHW, 


SIS, THHN, 








THHW, 


THHN, THHW, 




THHW, 


THHW, THW-2, 








THW, 


THW-2, THWN-2, 




THW, 


THWN-2, RHH, 








THWN, 


USE-2, XHH, 




THWN, 


RHW-2, USE-2, 




Size 




XHHW, 


XHHW, XHHW-2, 


Types TW, 


XHHW, 


XHH, XHHW, 




AWGor 


Types TW, UF 


USE, ZW 


ZW-2 


UF 


USE 


XHHW-2, ZW-2 


Size AWG or 


kcmil 


COPPER 


ALUMINUM OR COPPER-CLAD ALUMINUM 


kcmil 


18 
16 
14* 


— 


— 


14 
18 

25 


— 


— 


— 


~ 


20 


• 20 














12* 


25 


25 


30 


20 


20 


25 


12* 


10* 


30 


35 


40 


25 


30 


35 


10* 


8 


40 


50 


55 


30 


40 


45 


8 


6 


55 


65 


75 


40 


50 


60 


6 


4 


70 


85 


95 


55 


65 


75 


4 


3 


85 


100 


110 


65 


75 


85 


3 


2 


95 


115 


130 


- 75 


90 


100 


2 


1 


110 


130 


150 


85 


100 


115 


1 


1/0 


125 


150 


170 


100 


120 


135 


1/0 


2/0 


145 


175 


195 


115 


135 


150 


2/0 


3/0 


165 


200 


225 


130 


155 


175 


3/0 


4/0 


195 


230 


260 


150 


180 


205 


4/0 


250 


215 


255 


290 


170 


205 


230 


250 


300 


240 


285 


320 


190 


230 


255 


300 


350 


260 


310 


350 


210 


250 


280 


350 


400 


280 


335 


380 


225 


270 


305 


400 


500 


320 


380 


430 


260 


310 


350 


500 


600 


355 


420 


475 


285 


340 


385 


600 


700 


385 


460 


520 


310 


375 


420 


700 


750 


400 


475 


535 


320 


385 


435 


750 


800 


410 


490 


555 


330 


395 


450 


800 


900 


435 


520 


585 


355 


425 


480 


900 


1000 


455 


545 


615 


375 


445 


500 


1000 


1250 


495 


590 


665 


405 


485 


545 


1250 


1500 


520 


625 


705 


435 


520 


585 


1500 


1750 


545 


650 


735 


455 


545 


615 


1750 


2000 


560 


665 


750 


470 


560 


630 


2000 



CORRECTION FACTORS 



Ambient 
Temp. (°C) 


For ambient temperatures other than 30°C (86°F), multiply the allowable ampacities shown above by the 

appropriate factor shown below. 


Ambient 
Temp. (°F) 


21-25 


1.08 


1.05 


1.04 


1.08 


1.05 


1.04 


70-77 


26-30 


1.00 


1.00 


1.00 


1.00 


1.00 


1.00 


78-86 


31-35 


0.91 


0.94 


0.96 


0.91 


0.94 


0.96 


87-95 


36-40 


0.82 


0.88 


0.91 


0.82 


0.88 


0.91 


96-104 


41^5 


0.71 


0.82 


0.87 


0.71 


0.82 


0.87 


105-113 


46-50 


0.58 


0.75 


0.82 


0.58 


0.75 


0.82 


11^122 


51-55 


0.41 


0.67 


0.76 


0.41 


0.67 


0.76 


123-131 


56-60 


— 


0.58 


0.71 


— 


0.58 


0.71 


132-140 


61-70 


— 


0.33 


0.58 


— 


0.33 


0.58 


141-158 


71-80 


— 


— 


0.41 


— 


— 


0.41 


159-176 



^ See 240.4(D). 



70-148 



2010 California Electrical Code 



ARTICLE 31 - CONDUCTORS FOR GENERAL WIRING 



310.15 



Table 310.17 Allowable Ampacities of Single-Insulated Conductors Rated Through 2000 Volts in 


Free Air, Based on 


Ambient Air 


Temperature of 30°C (86°F) 














Temperature Rating of Conductor |si^!iiiiP9il(|il 






60°C (140°F) 


75^C (167^F) 


90°C (194°F) 


60°C (140°F) 


75°C 
(167°F) 


90^C (194°F) 










Types TBS, SA, SIS, 






Types TBS, SA, 










FEP, FEPB, MI, 




Types 


SIS, THHN, 








Types RHW, 


RHH, RHW-2, 




RHW, 


THHW, THW-2, 








THHW, 


THHN, THHW, 




THHW, 


THWN-2, RHH, 








THW, 


THW-2, THWN-2, 




THW, 


RHW-2, USE-2, 




Size 




THWN, 


USE-2, XHH, XHHW, 




thWn, 


XHH, XHHW, 




AWGor 


Types TW, UF 


XHHW, ZW 


XHHW-2, ZW-2 


Types TW, UF 


XHHW 


XHHW-2, ZW-2 


Size AWG 


kcmil 


COPPER 


ALUMINUM OR COPPER-CLAD ALUMINUM 


or kcmil 


18 


— 


— 


18 


— 


— 


— 


— 


16 


— 


— 


24 


— 


— 


— 


— 


14* 


25 


30 


35 


— 


— 


— 


— 


12* 


30 


35 


40 


25 


30 


35 


12* 


10* 


40 


50 


55 


35 


40 


40 


10* 


8 


60 


70 


80 


45 


55 


60 


8 


6 


80 


95 


' 105 


60 


75 


80 


6 


4 


105 


125 


140 


80 


100 


110 


4 


3 


120 


145 


165 


95 


115 


130 


3 


2 


140 


170 


190 


110 


135 


150 


2 


1 


165 


195 


220 


130 


155 


175 


1 


1/0 


195 


230 


260 


150 


180 


205 


1/0 


2/0 


225 


265 


300 


175 


210 


235 


2/0 


3/0 


260 


310 


350 


200 


240 


275 


3/0 


4/0 


300 


360 


405 


235 


280 


315 


4/0 


250 


340 


405 


455 


265 


315 


355 


250 


300 


375 


445 


505 


290 


350 


395 


300 


350 


420 


505 


570 


330 


395 


445 


350 


400 


455 


545 


615 


355 


425 


480 


400 


500 


515 


620 


700 


405 


485 


545 


500 


600 


575 


690 


780 


455 


540 


615 


600 


700 


630 


755 


855 


500 


595 


675 


700 


750 


655 


785 


885 


515 


620 


700 


750 


800 


680 


815 


920 


535 


645 


725 


800 


900 


730 


870 


985 


580 


700 


785 


900 


1000 


780 


935 


1055 


625 


750 


845 


1000 


1250 


890 


1065 


1200 


710 


855 


960 


1250 


1500 


980 


1175 


1325 


795 


950 


1075 


1500 


1750 


1070 


1280 


1445 


875 


1050 


1185 


1750 


2000 


1155 


1385 


1560 


960 


1150 


1335 


2000 









CORRECTION FACTORS 








Ambient 
Temp. (°C) 


For ambient temperatures other than 30°C (86°F), multiply the allowable ampacities shown above by the appropriate 

factor shown below. 


Ambient 
Temp. (°F) 


21-25 


1.08 


1.05 


1.04 


1.08 


1.05 


1.04 


70-77 


26-30 


1.00 


1.00 


1.00 


1.00 


1.00 


1.00 


78-86 


31-35 


0.91 


0.94 


0.96 


0.91 


0.94 


0.96 


87-95 


36^0 


0.82 


0.88 


0.91 


0.82 


0.88 


0.91 


96-104 


41-45 


0.71 


0.82 


0.87 


0.71 


0.82 


0.87 


105-113 


46-50 


0.58 


0.75 


0.82 


0.58 


0.75 


0.82 


114-122 


51-55 


0.41 


0.67 


0.76 


0.41 


0.67 


0.76 


123-131 


56-60 


— 


0.58 


0.71 


— 


0.58 


0.71 


132-140 


61-70 


— 


0.33 


0.58 


— 


0.33 


0.58 


141-158 


71-80 


— 


— 


0.41 


~~ 


— 


0.41 


159-176 



■ See 240.4(D). 



2010 California Electrical Code 



70-149 



310.15 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



Table 310.18 Allowable Ampacities of Insulated Conductors Rated Through 2000 Volts, 150°C Through 250°C (302°r Through 
482°F). Not More Than Three Current-Carrying Conductors in Raceway or Cable, Based on Ambient Air Temperature of 40°C 
(104°F) 





Temperature Rating of Conductor i$^§:Tm£ilSfX$M)S 






150°C (302°F) 


200°C (392°F) 


250°C (482°F) 


150°C (302°F) 








Types FEP, 










TypeZ 


FEPB, PFA, SA 


Types PFAH, TFE 


TypeZ 








NICKEL OR 


ALUMINUM OR 








NICKEL-COATED 


COPPER-CLAD 








COPPER 


ALUMINUM 




SizeAWGorkcmil 


COPPER 






Size AWG or kcmil 


14 


34 


36 


39 


— 


14 


12 


43 


45 


54 


30 


12 


10 


55 


60 


73 


44 


10 


8 


76 


83 


93 


57 


8 


6 


96 


110 


117 


75 


6 


4 


120 


125 


148 


94 


4 


3 


143 


152 


166 


109 


3 


2 


160 


171 


191 


124 


2 


1 


186 


197 


215 


145 


1 


1/0 


215 


229 


244 


169 


1/0 


2/0 


251 


260 


273 


198 


2/0 


3/0 


288 


297 


308 


227 


3/0 


4/0 


332 


346 


361 


260 


4/0 



CORRECTION FACTORS 



Ambient Temp. 

(°C) 


For ambient temperatures other than 40°C (104°F), multiply the allowable ampacities 
shown above by the appropriate factor shown below. 


Ambient Temp. (°F) 


41-50 


0.95 


0.97 


0.98 


0.95 


105-122 


51-60 


0.90 


0.94 


0.95 


0.90 


123-140 


61-70 


0.85 


0.90 


0.93 


0.85 


141-158 


71-80 


0.80 


0.87 


0.90 


0.80 


159-176 


81-90 


0.74 


0.83 


0.87- 


0.74 


177-194 


91-100 


0.67 


0.79 


0.85 


0.67 


195-212 


101-120 


0.52 


0.71 


0.79 


0.52 


213-248 


121-140 


0.30 


0.61 


0.72 


0.30 


249-284 


141-160 


~ 


0.50 


0.65 


— 


285-320 


161-180 


— 


0.35 


0.58 


— 


321-356 


181-200 


— 


— 


0.49 


— 


357-392 


201-225 


— 


— 


0.35 


— 


393^37 



70-150 



2010 California Electrical Code 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



310.15 



Table 310.19 Allowable Ampacities of Single-Insulated Conductors, Rated Through 2000 Volts, 150^C Through 250X (302°F 
Through 482°F), in Free Air, Based on Ambient Air Temperature of 40°C (104^F) 















Temperature Rating of Conductor 'iSti^^blkSMM&A 






150°C 

(302<^F) 


200°C (392°F) 


250°C(482°F) 


150°C (302°F) 






TypeZ 


Types FEP, 
FEPB, PFA, SA 


Types PFAH,lFli: 


TypeZ 




SizeAWGorkcmil 


COPPER 


NICKEL, OR NICKEL- 
COATED COPPER 


ALUMINUM OR COPPER- 
CLAD ALUMINUM 


SizeAWGorkcmil 


14 


46 


54 


59 


— 


14 


12 


60 


68 


78 


47 


12 


10 


80 


90 


107 


63 


10 


8 


106 


124 


142 


83 


8 


6 


155 


165 


205 


112 


6 


4 


190 


220 


278 


148 


4 


3 


214 


252 


327 


170 


3 


2 


255 


293 


381 


198 


2 


1 


293 


344 


440 


228 


1 


1/0 


339 


399 


532 


263 


1/0 


2/0 


390 


467 


591 


305 


2/0 


3/0 


451 


546 


708 


351 


3/0 


4/0 


529 


629* 


830 


411 


4/0 



CORRECTION FACTORS 



Ambient Temp. (°Q 


For ambient temperatures other than 40°C (104°F), multiply the allowable ampacities shown 
above by the appropriate factor shown below. 


Ambient Temp. (°F) 


41-50 


0.95 


0,97 


0.98 


0.95 


105-122 


51-60 


0.90 


0.94 


0.95 


0.90 


123-140 


61-70 


0.85 


0.90 


0.93 


0.85 


141-158 


71-80 


0.80 


0.87 


0.90 


0.80 


159-176 


81-90 


0.74 


0.83 


0.87 


0.74 


177-194 


91-100 


0.67 


0.79 


0.85 


0.67 


195-212 


101-120 


0.52 


0.71 


0.79 


0.52 


213-248 


121-140 


0.30 


0.61 


0.72 


0.30 


249-284 


141-160 


— 


0.50 


0.65 


— 


285-320 


161-180 


— 


0.35 


0.58 


— 


321-356 


181-200 


— 


— 


0.49 


— 


357-392 


201-225 


— . 


— 


0.35 


— 


393^37 



2010 California Electrical Code 



70-151 



310.15 



ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING 



Table 310.20 Ampacities of Not More Than Three Single Insulated Conductors, Rated Through 2000 Volts, Supported on a 
Messenger, Based on Ambient Air Temperature of 40°C (104°F) 





Temperature Rating of Conductor [See fable 3X0 JJC^^^ 






75°C (167°F) 


90°C(194^F) 


75°C (167°F) 


90°C (194°F) 






Types RHW, 

THHW,THW, 

THWN,XHHW, 

ZW 


Types MI, THHN, 
THHW,THW-2, 
THWN-2,RHH, 
RHW-2,USE-2, 
XHHW,XHHW- 
2,ZW-2 


Types RHW, THW, 

IHWN,TIIHW, 

XHHW 


Types THHN, THHW, 
RHH,XHHW,RHW-2, 

XHHW-2,THW-2, 
THWN-2,USE-2,ZW-2 




SizeAWGorkcmil 


COPPER 


ALUMINUM OR COPPER-CLAD ALUMINUM 


SizeAWGorkcmil 


8 


57 


66 


44 


51 


8 


6 


76 


89 


59 


69 


6 


4 


101 


117 


78 


91 


4 


3 


118 


138 


92 


107 


3 


2 


135 


158 


106 


123 


2 


1 


158 


185 


123 


144 


1 


1/0 


183 


214 


/143 


167 


1/0 


2/0 


212 


247 


165 


193 


2/0 


3/0 


245 


287 


192 


224 


3/0 


4/0 


287 


335 


224 


262 


4/0 


250 


320 


374 


251 


292 


250 


300 


359 


419 


282 


328 


300 


350 


397 


464 


312 


364 


350 


400 


430 


503 


339 


395 


400 


500 


496 


580 


392 


458 


500 


600 


553 


647 


440 


514 


600 


700 


610 


714 


488 


570 


700 


750 


638 


747 


512 


598 


750 


800 


660 


773 


532 


622 


800 


900 


704 


826 


572 


669 


900 


1000 


748 


879 


612 


716 


1000 



CORRECTION FACTORS 



Ambient Temp. (°C) 


For ambient temperatures other than 40°C (104°F), multiply the allowable ampacities shown 
above by the appropriate factor shown below. 


Ambient Temp. (°F) 


21-25 


1.20 


1.14 


1.20 


1.14 


70-77 


26-30 


1.13 


1.10 


1.13 


1.10 


79-86 


31-35 


1.07 


1.05 


1.07 


1.05 


88-95 


36-40 


1.00 


1.00 


1.00 


1.00 


97-104 


41^5 


0.93 


0.95 


0.93 


0.95 


106-113 


46-50 


0.85 


0.89 


0.85 


0.89 


115-122 


51-55 


0.76 


0.84 


0.76 


0.84 


124-131 


' 56-60 


0.65 


0.77 


0.65 


0.77 


133-140 


61-70 


0.38 


0.63 


0.38 


0.63 


142-158 


71-80 


— 


0.45 


— - 


0.45 


160-176 



70-152 



2010 California Electrical Code 



ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING 



310.15 



Table 310.21 Ampacities of Bare or Covered Conductors in 
Conductor Temperature, 610 mm/sec (2 ft/sec) Wind Velocity 



Free Air, Based on 40^C (104°F) Ambient, 80°C (176°F) Total 





Copper 


Conductors 






AAC Aluminum Conductors. 






Bare 




Covered 




Bare 


Covered 


AWGor 




AWG 




AWGor 




AWGor 




kcmil 


Amperes 


or kcmil 


Amperes 


kcmil 


Amperes 


kcmil 


Amperes 


8 


98 


8 


103 


8 


76 


8 


80 


6 


124 


6 


130 


6 


96 


6 


101 


4 


155 


4 


163 


4 


121 


4 


127 


2 


209 


2 


219 


2 


163 


2 


171 


1/0 


282 


1/0 


297 


1/0 


220 


1/0 


231 


2/0 


329 


2/0 


344 


2/0 


255 


2/0 


268 


3/0 


382 


3/0 


401 


3/0 


297 


3/0 


312 


4/0 


444 


4/0 


466 


4/0 


346 


4/0 


364 


250 


494 


250 


519 


266.8 


403 


266.8 


423 


300 


556 


300 


584 


336.4 


468 


336.4 


492 


500 


773 


500 


812 


397.5 


522 


397.5 


548 


750 


1000 


750 


1050 


477.0 


588 


477.0 


617 


1000 


1193 


1000 


1253 


556.5 


650 


556.5 


682 


— 


— 


— 


— 


636.0 


709 


636.0 


744 


— 


— 


— 


— 


795.0 


819 


795.0 


860 


— 


— 


— 


— 


954.0 


920 


— 


— 


— 


— 


— 


— 


1033.5 


968 


1033.5 


1017 


— 


— 


— 


— 


1272 


1103 


1272 


1201 


— 


— 


— 


— 


1590 


1267 


1590 


1381 


— 


— 


— 


— 


2000 


1454 


2000 


1527 



2010 California Electrical Code 



70-153 



310.60 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



310.60 Conductors Rated 2001 to 35,000 Volts. 

(A) DeHnitions. 

Electrical Ducts. As used in Article 310, electrical ducts 
shall include any of the electrical conduits recognized in 
Chapter 3 as suitable for use underground; other raceways 
round in cross section, listed for underground use, and 
embedded in earth or concrete. 

Thermal Resistivity. As used in this Code, the heat transfer 
capability through a substance by conduction. It is the 
reciprocal of thermal conductivity and is designated Rho 
and expressed in the units °C-cm/watt. 

(B) Ampacities of Conductors Rated 2001 to 35,000 
Volts. Ampacities for soHd dielectric-insulated conductors 
shall be permitted to be determined by tables or under 
engineering supervision, as provided in 310.60(C) and (D). 

(1) Selection of Ampacity. Where more than one 
calculated or tabulated ampacity could apply for a given 
circuit length, the lowest value shall be used. 

Exception: Where two different ampacities apply to 
adjacent portions of a circuit, the higher ampacity shall be 
permitted to be used beyond the point of transition, a 
distance equal to 3,0 m (10 ft) or 10 percent of the circuit 
length figured at the higher ampacity, whichever is less. 

FPN: See 110.40 for conductor temperature Hmitations due 
to termination provisions. 

(C) Tables. Ampacities for conductors rated 2001 to 
35,000 volts shall be as specified in the Ampacity Table 
310.67 through Table 310.86. Ampacities at ambient 
temperatures other than those shown in the tables shall be 
determined by the formula in 3 10.60(C)(4). 

FPN No. 1: For ampacities calculated in accordance with 
310.60(B), reference IEEE 835-1994 (IPCEA Pub. No. P- 
46-426), Standard Power Cable Ampacity Tables, and the 
references therein for availability of all factors and 
constants. 

FPN No. 2: Ampacities provided by this section do not take 
voltage drop into consideration. See 210.19(A), FPN No. 4, 
for branch circuits and 215.2(A), FPN No. 2, for feeders. 

(1) Grounded Shields. Ampacities shown in Table 
310.69, Table 310.70, Table 310.81, and Table 310.82 are 



for cable with shields grounded at one point only. Where 
shields are grounded at more than one point, ampacities 
shall be adjusted to take into consideration the heating due 
to shield currents. 

(2) Burial Depth of Underground Circuits. Where the 
burial depth of direct burial or electrical duct bank circuits 
is modified from the values shown in a figure or table, 
ampacities shall be permitted to be modified as indicated in 

(C)(2)(a) and (C)(2)(b). 

(a) Where burial depths are increased in part(s) of an 
electrical duct run, no decrease in ampacity of the 
conductors is needed, provided the total length of parts of 
the duct run increased in depth is less than 25 percent of the 
total run length. 

(b) Where burial depths are deeper than shown in a 
specific underground ampacity table or figure, an ampacity 
derating factor of 6 percent per 300-mm (1-ft) increase in 
depth for all values of rho shall be permitted. 

No rating change is needed where the burial depth is 
decreased. 

(3) Electrical Ducts in Figure 310.60. At locations where 
electrical ducts enter equipment enclosures from under 
ground, spacing between such ducts, as shown in Figure 
310.60, shall be permitted to be reduced without requiring 
the ampacity of conductors therein to be reduced. 

(4) Ambients Not in Tables. Ampacities at ambient 
temperatures other than those shown in the tables shall be 
determined by means of the following formula: 



h = iu 



j TC-TA^-ATD 
TC-TA-ATD 



where: 



/ 1= ampacity from tables at ambient TAi 

1 2= ampacity at desired ambient TA2 

TC= conductor temperature in degrees Celsius (°C) 

TAi^ surrounding ambient from tables in degrees 
Celsius (°C) 

TA2= desired ambient in degrees Celsius (°C) 
^TD= dielectric loss temperature rise 



70-154 



2010 California Electrical Code 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



310.60 






Detail 1 

290 mm X 290 mm 
{115 in, X 11 .5 In.) 
Electrical duct bank 
One electrical duct 




190 mm {7.5 ia) 



Detail 2 

475 mm X 475 mm 
(19 in. X 19 in.) 
Eitctrical duct bank 
Thme electrical ducts 
or 



m^ 



190 mm 190 mm 
(7,5 in,) (7.5 in J 

675 mm x 290 mm 
(27 in. X 115 in.) 
Etectrical duct bank 
Three etectrical ducts 



Detail 5 
Buried 3 
oonductor 
cable 



600 mm 



(24 in.) 



Detail 6 

Buried 3 

conductor 

cables 



1 



12^ 


T®® 


05i^ 


' V ^ , 


^^2L 


-®,® 


g c 


^ V 




-® ® : 




O 




, 




3. 'J 


< ■ ■>^ 





190 mm (7.5 in.) 

Details 

475 mm X 675 mm 
(19 in. X 27 in.) 
Electrical duel bank 
Six etectrical ducts 
or 




190 mm 

(7.Bin.) 



190 mm 

(7.5 \n.) 



675 mm X 475 mm 
(27 in. X 19 in.) 
Eiectrical duct bank 
Six electrical ducts 



190 mm 
{IB in.) 



: 



190 mm 
(7.5 m.) 



Detail 7 

Buried triplax^ 
cables (1 circuit) 



190 mm 190 mm 

(7.5 in.) (7,5 in,) 



r 



600 mm 



(24 In.) 



1 



< H* H*" 

# • * 



600 mm 



Details 

Buried triplaxed 
cables (2 circuils) 



190 mm 190 mm 
(7,5 in,) (7,5 in.) 



(24 in.) 



Detail 9 

BuiwI slngle-conductor 
cables (1 circuit) 



Defaiil 10 

Byri^ singla*conductor 
cables (2 circyis) 



Note: Minimum burial depths to top electrical ducts or cables shall be 
in accordance with 300.50. Maximum depth to the top of electrical 
duct banks shall be 750 mm (30 in.) and maximum depth to the top 
of direct buried cables shall be 900 mm (36 in.). 



Legend 

f^ BackWI (earth or concrete) 

O Electrical duct 



• Cable or cabtes 



Figure 310.60 Cable Installation Dimensions for Use with Table 310.77 Through Table 310.86. 



2010 California Electrical Code 



70-155 



310.60 



ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING 



(D) Engineering Supervision. Under engineering 
supervision, conductor ampacities shall be permitted to be 
calculated by means of the following general formula: 



Table 310.68 Ampacities of Insulated Single Aluminum 
Conductor Cables Triplexed in Air Based on Conductor 
Temperatures of 90°C (194°F) and 105^C (221°F) and 
Ambient Air Temperature of 40°C(104°F) 





j TC-{TA^ATD) 






Tempei 


-ature Rating of Conductor [S< 


ee Table ^^lil?;©;.] 








2001- 


5000 Volts 




5001-35,000 Volts 




f 








Conducto] 


Ampacity 






Ampacity 


where: 


r 90°C 


105°C 






90°C 


105°C 


TC= 


conductor temperature in ° 


C 




Size 


(194°F) (221°F) 


(194°F) 1 


(22rF) 












(AWG or 


Type 


lype 






lype 


Type 


TA= 


ambient temperature in °C 






kcmil) 


MV-90 MV-105 


MV.90 MV-105 


AjY 


8 


50 


57 












)= dielectric loss temperature rise 




6 


70 


77 






75 


84 


RDC 


'= dc resistance of conductor at temperature TC 


4 


90 


100 






100 


110 


YC= component ac resistance 

effect anH nrnYimitv effect 


resulting 


from skin 


2 
1 


125 
145 


135 
160 






130 
150 


150 

175 




^ 


■^ 






1/0 


170 


185 






175 


200 


RCA 


= effective 


J thermal 


resistance 


between 


2/0 


195 


215 






200 


230 


conductor and surrounding ambient 




3/0 


225 


250 






230 


265 


FPN: Se 


Q Annex B for examples of formula applications. 


4/0 


265 


290 






270 


305 




■ 250 


295 


325 






300 


335 












350 


365 


405 






370 


415 


Table 310.67 Ampacities of Insulated Single Copper 


500 


460 


510 






460 


515 


Conductor 


Cables Triplexed in Air 


Based on 


Conductor 






Temperatures of 90°C 


(194°F) and 


lOS^^C (22PF) and 


750 


600 


665 






590 


660 


Ambient Air Temperature of 40°C (104^F) 




1000 


715 


800 






700 


780 




Temperature 


Rating of Conductor [See Table 310J3:((3,] 


Table 310.69 Ampacities 


of Insulated 


Single 


Copper 




2001-5000 Volts 


5001-35,000 Volts 


Conductor Isolated 


in Air Based on i 


Conductor Temperatures 




Ampacity 


Ampacity 


of 90°C 
Temperati 


(194°F) and 105°C (221°F) and Ambic 
Lireof40°C(104°F) 


snt Air 


Conductor 


90°C 


105°C 


90°C 


105^C 




Size 


(194°F) 


(221°F) 


(194°F) 


(221°F) 




Temperature Rating of Conductor [S( 


ee Table glfllCJ,) 


(AWG 


Type 


Type 


Type 


Type 




2001-5000 Volts 
Ampacity' 


5001-15,000 
Volts Ampacity 


15,001-35,000 
Volts Ampacity 


or kcmil) 


MV-90 


MV-105 


MV-90 


MV-105 


Conductor 


90°C 
(194°F) 


105°C 
(221°F) 


90°C 
(194°F) 


105°C 

(221°F) 


90°C 
(194°F) 


105°C 

(221°F) 












Size 


8 


65 


74 


' — 


— 


(AWG 


Type 


Tjpe 


Type 


Type 


Type 


Type 


6 


90 
120 


99 
130 


100 
130 


110 
140 


or kcmil) 


MV-90 


MV-105 


MV-90 


MV-105 


MV-90 


MV-105 


4 


8 


83 


93 


~ 


— 


— 


— 












6 


110 


120 


110 


125 


— 


— 


2 


160 


175 


170 


195 


4 


145 


160 


150 


165 


— 


— 


1 


185 


205 


195 


225 


2 
1 


190 

225 


215 

250 


195 

225 


215 
250 


225 


— 


1/0 


215 


240 


225 


255 


250 












1/0 


260 


290 


260 


290 


260 


290 


2/0 


250 


275 


260 


295 


























2/0 


300 


330 


300 


335 


300 


330 


3/0 


290 


320 


300 


340 


3/0 


345 


385 


345 


385 


345 


380 


4/0 


335 


375 


345 


390 


4/0 
250 


400 

445 


445 
495 


400 
445 


445 
495 


395 
440 


445 


250 


375 


415 


380 


430 


490 












350 


550 


615 


550 


610 


545 


605 


350 


465 


515 


470 


525 


























500 


695 


lis 


685 


765 


680 


755 


500 


580 


645 


580 


650 


750 


900 


1000 


885 


990 


870 


970 


750 


750 


835 


730 


820 


1000 


1075 


1200 


1060 


1185 


1040 


1160 


1000 


880 


980 


850 


950 


1250 
1500 


1230 
1365 


1370 
1525 


1210 
1345 


1350 
1500 


1185 
1315 


1320 
1465 






















1750 


1495 


1665 


1470 


1640 


1430 


1595 












2000 


1605 


1790 


1575 


1755 


1535 


1710 



70-156 



2010 California Electrical Code 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



310.60 



Table 310.70 Ampacities of Insulated Single Aluminum 
Conductor Isolated in Air Based on Conductor Temperatures 
of 90°C (194^F) and 105°C (221°F) and Ambient Air 
Temperature of 40°C (104°F) 

Temperature Rating of Conductor [See Table 3i0.B (G),l 



Conductor 

Size 

(AWG 

or kcmil) 



2001-5000 Volts 
Ampacity 

90°C 105X 
(194°F) (22PF) 

Type Type 

MV-90 MV-105 



5001-15,000 
Volts Ampacity 

90°C 105°C 
(194°F) (221T) 

Type Type 
MV-90 MV-105 



15,001-35,000 
Volts Ampacity 

90°C 105°C 
(194<='F) (221°F) 

Type Type 
MV-90 MV-105 



64 

85 
115 
150 
175 



71 
95 
125 
165 
195 



87 
115 
150 
175 



97 
130 
170 
195 



175 



195 



1/0 

2/0 
3/0 
4/0 



200 225 

230 260 

270 300 

310 350 



200 
235 
270 
310 



225 
260 
300 
350 



200 
230 
270 
310 



225 
260 
300 
345 



250 
350 
500 
750 



345 385 

430 480 

545 605 

710 790 



345 
430 
535 
700 



385 
480 
600 
780 



345 
430 
530 
685 



380 
475 
590 
765 



1000 
1250 
1500 
1750 
2000 



855 950 

980 1095 

1105 1230 

1215 1355 

1320 1475 



840 
970 
1085 
1195 
1295 



940 
1080 
1215 
1335 
1445 



825 
950 
1060 
1165 
1265 



920 
1055 
1180 
1300 
1410 



Table 310.71 Ampacities of an Insulated Three-Conductor 
Copper Cable Isolated in Air Based on Conductor 
Temperatures of 90°C (194°F) and 105°C (22PF) and 
Ambient Air Temperature of 40^C (104^F) 



Temperature Rating 
310^ 



of Conductor [See Table 



Conductor 

Size 

(AWG 

or kcmil) 



2001-5000 Volts 
Ampacity 

90°C 105°C 

(194°F) (221°F) 

Type Type 

MV-90 MV-105 



5001-35,000 Volts 
Ampacity 



90^C 
(194°F) 

Type 
MV-90 



105°C 
(221°F) 

Type 
MV-105 



59 
79 
105 
140 
160 



66 

88 
115 
154 
180 



93 
120 
165 
185 



105 
135 
185 
210 



1/0 
2/0 
3/0 
4/0 



185 
215 
250 
285 



205 
240 
280 
320 



215 
245 
285 
325 



240 
275 
315 
360 



250 
350 
500 
750 
1000 



320 
395 
485 
615 
705 



355 
440 
545 
685 
790 



360 
435 
535 
670 
770 



400 
490 
600 

745 
860 



Table 310.72 Ampacities of an Insulated Three-Conductor 
Aluminum Cable Isolated in Air Based on Conductor 
Temperatures of 90^C (194°F) and 105°C (221°F) and 
Ambient Air Temperature of 40°C (104°F) 

Temperature Rating of Conductor [See Table $WM (Qt,] 



2001-5000 Volts 
Ampacity 



5001-35,000 Volts 
Ampacity 



Conductor 

Size 

(AWG 

or kcmil) 



90^C 
(194°F) 

Type 
MV-90 



105°C 

(221°F) 

Type 
MV-105 



90°C 
(194^F) 

Type 
MV-90 



105°C 

(22PF) 

Type 

MV-105 



46 
61 

81 

110 

125 



51 
68 
90 
120 
140 



72 
95 
125 
145 



80 
105 
145 
165 



1/0 


145 


160 


170 


185 


2/0 


170 


185 


190 


215 


3/0 


195 


215 


220 


245 


4/0 


225 


250 


255 


285 



250 
350 
500 
750 
1000 



250 
310 
385 
495 
585 



280 
345 
430 
550 
650 



280 
345 
425 
540 
635 



315 
385 
475 
600 
705 



Table 310.73 Ampacities of an Insulated Triplexed or Three 
Single-Conductor Copper Cables in Isolated Conduit in Air 
Based on Conductor Temperatures of 90°C (194°F) and 
105°C (221'^F) and Ambient Air Temperature of 40°C (104°F) 

Temperature Rating of Conductor [See Table 3l0;i3 <Q,] 



2001-5000 Volts 
Ampacity 



5001-35,000 Volts 
Ampacity 



Conductor 

Size 

(AWG 

or kcmil) 



90°C 
(194°F) 

Type 
MV-90 



105X 

(22FF) 

Type 
MV-105 



90°C 
(194°F) 

Type 
MV-90 



105°C 
(221°F) 

Type 
MV-105 



55 
75 
97 
130 
155 



61 

84 

110 

145 

175 



83 
110 
150 
170 



93 
120 
165 
190 



1/0 

2/0 
3/0 
4/0 



180 
205 
240 
280 



200 
225 
270 
305 



195 

225 
260 
295 



215 
255 
290 
330 



250 
350 
500 
750 
1000 



315 
385 
475 
600 
690 



355 
430 
530 
665 
770 



330 
395 
480 
585 
675 



365 
440 
535 
655 
755 



2010 California Electrical Code 



70-157 



310.60 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



Table 310.74 Ampacities of an Insulated Triplex ed or Three 
Single-Conductor Aluminum Cables in Isolated Conduit in 
Air Based on Conductor Temperatures of 90°C (194°F) and 
lOS^C (22PF) and Ambient Air Temperature of 40°C (104°F) 



Table 310.76 Ampacities of an Insulated Three-Conductor 
Aluminum Cable in Isolated Conduit in Air Based on 
Conductor Temperatures of 90°C (194°F) and 105°C (221°F) 
and Ambient Air Temperature of 40°C (104°F) 





Temperature Rating of Conductor [See Table 1^10,13 (Cj,l 




Temperaturt 


; Rating of Conductor [See Tabl 






leaiO,B(C|,l 




2001-5000 Volts 
Ampacity 


5001-35,000 Volts 
Ampacity 


Conductor 

Size 

(AWG 


2001-5000 Volts 
Ampacity 


5001-35,000 Volts 
Ampacity 




90°C 
(194°F) 

Type 
MV-90 


105°C 
(221°F) 

Type 
MV-105 


90°C 
(194°F) 

Type 
MV-90 


105°C 
(221'^F) 

Type 
MV-105 


Conductor 

Size 

(AWG 

or kcmil) 


90°C 
(194°F) 

Type 


105°C 
(221°F) 

Type 


90°C 
(194°F) 

Type 


105°C 

(22FF) 

Type 


8 


43 
58 


48 
65 


65 


72 


or kcmil) 


MV-90 


MV-105 


MV-90 


MV-105 


6 


8 


41 


46 


— 


— 


4 

2 
1 


76 
100 
120 


85 
115 
135 


84 
115 
130 


94 
130 
150 


6 

4 
2 


53 
71 
96 


59 
79 
105 


64 
84 
115 


71 

94 


1/0 


140 


155 


150 


170 


125 


2/0 


160 

190 


175 
210 


175 
200 


200 

225 


1 


110 


125 


130 


145 


3/0 


1/0 


130 


145 


150 


170 


4/0 


215 


240 


230 


260 


2/0 
3/0 


150 

170 


165 ■ 
190 


170 
195 


190 


250 


250 


280 


255 


290 


220 


350 
500 
750 


305 
380 
490 


340 
425 
545 


310 

385 
485 


350 

430 
540 


4/0 


200 


225 


225 


255 


250 


220 


245 


250 


280 


1000 


580 


645 


565 


640 


350 
500 


275 
340 


305 
380 


305 
380 


340 


Table 310.75 Ampacities of an Insulated Three-Conductor 


425 


Copper Cable in Isolated Conduit 
Temperatures of 90°C (194*^F) 
Ambient Air Temperature of 40°C 


in Air Based on 
and 105°C (2 

(i04°r) 

jnductor [SeeTabh 


Conductor 
21°F) and 


750 
1000 


430 
505 


480 
560 


470 
550 


520 
615 




Temperature Rating of C< 


;mi3(qi,] 














2001-5000 Volts 


5001-35,000 Volts 














Ampacity 


Ampacity 












Conductor 


90°C 


105°C 


90°C 


105°C 




Size 


(194<^F) 


(221°F) 


(194°F) 


(22PF) 












(AWG 


Type 


Type 


Type 


Type 












or kcmil) 


MV-90 


MV-105 


MV-90 


MV-105 












8 


52 


58 


— 


— 












6 


69 


77 


83 


92 












4 


91 


100 


105 


120 












2 


125 


135 


145 


165 












1 


140 


155 


165 


185 












1/0 


165 


185 


195 


215 




2/0 


190 


210 


220 


245 












3/0 


220 


245 


250 


280 












4/0 


255 


285 


290 


320 












250 


280 


315 


315 


350 




350 


350 


390 


385 


430 












500 


425 


475 


470 


525 












750 


525 


585 


570 


635 












1000 


590 


660 


650 


725 













70-158 



2010 California Electrical Code 



ARTICLE 310 - CONDUCTORS FOR GENERAL WIRING 



310.60 



Table 310.77 Ampacities of Three Single-Insulated Copper 
Conductors in Underground Electrical Ducts (Three 
Conductors per Electrical Duct) Based on Ambient Earth 
Temperature of 20^C (68°F), Electrical Duct Arrangement 
per Figure 310.60, 100 Percent Load Factor, Thermal 
Resistance (RHO) of 90, Conductor Temperatures of 90°C 
(194°F) and 105°C (22PF) 



Table 310.78 Ampacities of Three Single-Insulated 
Aluminum Conductors in Underground Electrical Ducts 
(Three Conductors per Electrical Duct) Based on Ambient 
Earth Temperature of 20°C (68°F), Electrical Duct 
Arrangement per Figure 310.60, 100 Percent Load Factor, 
Thermal Resistance (RHO) of 90, Conductor Temperatures of 
90^C (194^F) and lOS^C (221°F) 





Temperature Rating of Conductor 


[See Table 3id.i3l:€),l 




Temperatui 


re Rating of Conductor [See Table 3l€i3 (Q,] 




2001-5000 Volts 


5001-35,000 Volts 




2001-! 


5000 Volts 


5001-35,000 Volts 




Ampacity 


Ampacity 


Conductor 


Ampacity 


Ampacity 


Conductor 


90°C 


105°C 


90'^C 


105°C 


90°C 


105°C 


90°C 


105°C 


Size 


(194°F) 


(221°F) 


(194°F) 


(221°F) 


Size 


(194°F) 


(221°F) 


(194°F) 


(221°F) 


(AWG 


Type 


Type 


Type 


Type 


(AWG 


Type 


Type 


Type 


Type 


or kcmil) 


MV-90 


MV-105 


MV-90 


MV-105 


or kcmil) 


MV-90 


MV-105 


MV-90 


MV-105 


One Circuit 


(See Figure 


310.60, Detail 1.) 






OneCu-cuit( 


;See Figure 310.60, Detail 1.) 






8 


64 


69 


— 


— 


8 


50 


54 


— 


— 


6 


85 


92 


90 


97 


6 


66 


71 


70 


75 


4 


110 


120 


115 


125 


4 


86 


93 


91 


98 


2 


145 


155 


155 


165 


2 


115 


125 


120 


130 


1 


170 


180 


175 


185 


1 


130 


140 


135 


145 



1/0 


195 


210 


200 


215 


2/0 


220 


235 


230 


245 


3/0 


250 


270 


260 


275 


4/0 


290 


310 


295 


315 



1/0 


150 


160 


155 


165 


2/0 


170 


185 


175 


190 


3/0 


195 


210 


200 


215 


4/0 


225 


245 


230 


245 



250 
350 
500 
750 
1000 



320 
385 
470 
585 
670 



345 
415 
505 
630 
720 



Three Circuits (See Figure 310.60, Detail 2.) 



56 
73 
95 
125 
140 



60 
79 
100 
130 
150 



325 


345 


390 


415 


465 


500 


565 


610 


640 


690 




— 


— 


77 


83 


99 


105 


130 


135 


145 


155 



250 
350 
500 
750 
1000 



250 
305 
370 
470 
545 



270 
325 
400 
505 
590 



Three Cu-cuits (See Figure 310.60, DetaH 2.) 



44 
57 
74 
96 
110 



47 
61 
80 
105 
120 



1/0 


160 


175 


165 


175 


2/0 


185 


195 


185 


200 


3/0 


210 


225 


210 


225 


4/0 


235 


255 


240 


255 



250 
350 
500 
750 
1000 



260 

315 
375 
460 
525 



280 
335 
405 
495 
565 



Six Circuits (See Figure 310.60, Detail 3.) 



48 
62 
80 
105 
115 



52 
67 
86 
110 
125 



260 


280 


310 


330 


370 


395 


440 


475 


495 


535 




64 


68 


82 


88 


105 


115 


120 


125 



250 
350 
500 
750 
1000 



205 
245 
295 
370 
425 



220 
265 
320 
395 
460 



Six Circuits (See Figure 310.60, Detail 3.) 



38 
48 
62 
80 
91 



41 
52 
67 
86 
98 



1/0 


135 


145 


135 


145 


2/0 


150 


160 


150 


165 


3/0 


170 


185 


170 


185 


4/0 


195 


210 


190 


205 



250 


270 


305 


330 


370 


400 


455 


490 


525 


565 




— 


— 


60 


65 


77 


83 


100 


105 


110 


120 



1/0 


125 


135 


125 


140 


2/0 


145 


155 


145 


155 


3/0 


160 


175 


165 


175 


4/0 


185 


200 


185 


200 



200 


220 


245 


260 


290 


315 


355 


385 


405 


440 


50 


54 


64 


69 


80 


88 


90 


99 



1/0 


105 


110 


105 


110 


2/0 


115 


125 


115 


125 


3/0 


135 


145 


130 


145 


4/0 


150 


165 


150 


160 



250 


210 


225 


210 


225 


250 


165 


180 


165 


175 


350 


250 


270 


245 


265 


350 


195 


210 


195 


210 


500 


300 


325 


290 


310 


500 


240 


255 


230 


250 


750 


365 


395 


350 


375 


750 


290 


315 


280 


305 


1000 


410 


445 


390 


415 


1000 


335 


360 


320 


345 



2010 California Electrical Code 



70-159 



310.60 



ARTICLE 3 1 - CONDUCTORS FOR GENERAL WIRING 



Table 310.79 Ampacities of Three Insulated Copper 
Conductors Cabled Within an Overall Covering (Three- 
Conductor Cable) in Underground Electrical Ducts (One 
Cable per Electrical Duct) Based on Ambient Earth 
Temperature of 20°C (68°F), Electrical Duct Arrangement 
per Figure 310.60, 100 Percent Load Factor, Thermal 
Resistance (RHO) of 90, Conductor Temperatures of 90°C 
(194°F) and lOS'^C (221°C) 

Temperature Rating of Conductor [See Table 310.13 (€),J 



Conductor 

Size 

(AWG 

or kcmil) 



2001-5000 Volts 
Ampacity 



90°C 

(194°F) 

Type MV- 

90 



105°C 

(221°F) 

Type MV- 

105 



5001-35,000 Volts 
Ampacity 



90°C 
(194°F) 

Type 
MV-90 



One Circuit (See Figure 310.60, Detail 1.) 



59 
78 
100 
135 
155 



64 
84 
110 
145 
165 



115 
150 
170 



250 
350 
500 
750 
1000 



290 
355 
430 
530 
600 



315 
380 
460 
570 
645 



310 
375 
450 
545 
615 



53 
69 
89 
115 
135 



57 
74 
96 
125 
145 



75 
97 
125 
140 



250 
350 
500 
750 
1000 



245 
295 
355 
430 
485 



265 
315 

380 
465 
520 



255 
305 
360 
430 
485 



Six Circuits (See Figure 310.60, Detail 3.) 



46 
60 
77 
98 
110 



50 
65 
83 
105 
120 



63 
81 
105 
115 



105°C 
(221°F) 

Type 
MV-105 



95 
125 
160 
185 



1/0 


175 


190 


195 


210 


2/0 


200 


220 


220 


235 


3/0 


230 


250 


250 


270 


4/0 


265 


285 


285 


305 



335 
400 
485 
585 
660 



Three Circuits (See Figure 310.60, Detail 2.) 



81 
105 
135 
155 



1/0 


150 


165 


160 


175 


2/0 


170 


185 


185 


195 


3/0 


195 


210 


205 


220 


4/0 


225 


240 


230 


250 



270 
325 
385 
465 
515 



68 
87 
110 
125 



1/0 


125 


135 


130 


145 


2/0 


145 


155 


150 


160 


3/0 


165 


175 


170 


180 


4/0 . 


185 


200 


190 


200 



Table 310.80 Ampacities of Three Insulated Aluminum 
Conductors Cabled Within an Overall Covering (Three- 
Conductor Cable) in Underground Electrical Ducts (One 
Cable per Electrical Duct) Based on Ambient Earth 
Temperature of 20°C (68°r), Electrical Duct Arrangement 
per Figure 310.60, 100 Percent Load Factor, Thermal 
Resistance (RHO) of 90, Conductor Temperatures of 90°C 
(194°F) and 105°C (221°C) 

Temperature Rating of Conductor [See Table 31043 (Q,] 



2001-5000 Volts 

Ampacity 

Conductor 90°C 105°C 
Size (194°F) (221°F) 
(AWG Type MV- Type MV- 
or kcmil) 90 105 



5001-35,000 Volts 
Ampacity 



90°C 
(194°F) 

Type 
MV-90 



One Circuit (See Figure 310.60, Detail 1.) 



46 
61 
80 
105 
120 



50 
66 
86 
110 
130 



69 
89 
115 
135 



250 
350 
500 
750 
1000 



230 
280 
340 
425 
495 



245 
310 
365 
460 
535 



245 
295 
355 
440 
510 



41 
54 
70 
90 
105 



44 
58 
75 
97 
110 



59 
75 
100 
110 



250 
350 
500 
750 
1000 



190 
230 
280 
345 
400 



205 
250 
300 
375 
430 



200 
240 
285 
350 
400 



Six Circuits (See Figure 310.60, Detail 3.) 



36 
46 
60 

77 
87 



39 
50 
65 
83 
94 



49 
63 
80 
90 



105°C 

(221°F) 

Type 
MV-105 



74 
96 
125 
145 



1/0 


140 


150 


150 


165 


2/0 


160 


170 


170 


185 


3/0 


180 


195 


195 


210 


4/0 


205 


220 


220 


240 



265 
315 
385 
475 
545 



Three Circuits (See Figure 310.60, Detail 2.) 



64 
81 
105 
120 



1/0 


120 


125 


125 


135 


2/0 


135 


145 


140 


155 


3/0 


155 


165 


160 


175 


4/0 


175 


185 


180 


195 



215 
255 
305 
375 
430 



53 

86 
98 



1/0 


99 


105 


105 


110 


2/0 


110 


120 


115 


125 


3/0 


130 


140. 


130 


140 


4/0 


145 


155 


150 


160 



250 


200 


220 


205 


220 


250 


160 


170 


160 


170 


350 


240 


270 


245 


275 


350 


190 


205 


190 


205 


500 


290 


310 


290 


305 


500 


230 


245 


230 


245 


750 


350 


375 


340 


365 


750 


280 


305 


275 


295 


1000 


390 


420 


380 


405 


1000 


320 


345 


315 


335 



70-160 



2010 California Electrical Code 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



310.60 



Table 310.81 Ampacities of Single Insulated Copper 
Conductors Directly Buried in Earth Based on Ambient Earth 
Temperature of 20°C (68°F), Arrangement per Figure 310.60, 
100 Percent Load Factor, Thermal Resistance (RHO) of 90, 
Conductor Temperatures of 90°C (194°F) and 105°C (221°C) 



Table 310.82 Ampacities of Single Insulated Aluminum 
Conductors Directly Buried in Earth Based on Ambient Earth 
Temperature of 20^C (68°F), Arrangement per Figure 310.60, 
100 Percent Load Factor, Thermal Resistance (RHO) of 90, 
Conductor Temperatures of 90°C (194°F) and 105°C (221°F) 





Temperature 


! Rating of Conductor [See Table 31045 (€),] 




Temperature Rating of Conductor [See Table 


3WJ!3i(E),] 




2001-5000 Volts 


5001-35,000 Volts 




2001-5000 Volts 


5001-35,000 Volts 




Ampacity 


Ampacity 


Conductor 


Ampacity 


Ampacity 


Conductor 


90°C 


105°C 


90^C 


105°C 


90°C 


105°C 


90°C 


105°C 


Size 


(194°F) 


(221°F) 


(194'^F) 


(221°F) 


Size 


(194°F) 


(221°F) 


(194°F) 


(221°F) 


(AWG 


Type 


Type 


Type 


Type 


(AWG 


Type 


Type 


Type 


Type 


or kcmil) 


MV-90 


MV-105 


MV-90 


MV-105 


or kcmil) 


MV-90 


MV-105 


MV-90 


MV-105 


One Circuit, Three Conductors (See Figure 310.60, 


Detail 9.) 


One Circuit, Three Conductors (See Figure 


310.60, DetaU 9.) 


8 


110 


115 


— 


— 


8 


85 


90 


— 


— 


6 


140 


150 


130 


140 


6 


110 


115 


100 


110 


4 


180 


195 


170 


180 


4 


140 


150 


130 


140 


2 


230 


250 


210 


225 


2 


180 


195 


165 


175 


1 


260 


280 


240 


260 


1 


205 


220 


185 


200 


1/0 


295 


320 


275 


295 


1/0 


230 


250 


215 


230 


2/0 


335 


365 


310 


335 


2/0 


265 


285 


245 


260 


3/0 


385 


415 


355 


380 


3/0 


300 


320 


275 


295 


4/0 


435 


465 


405 


435 


4/0 


340 


365 


315 


340 


250 


470 


510 


440 


475 


250 


370 


395 


345 


370 


350 


570 


615 


535 


575- 


350 


445 


480 


415 


450 


500 


690 


745 


650 


700 


500 


540 


580 


510 


545 


750 


845 


910 


805 


865 


750 


665 


720 


635 


680 


1000 


980 


1055 


930 


1005 


1000 


780 


840 


740 


795 


Two Circui 


its. Six Conductors (See 

100 110 


Figure 310.60, Detail 10.) 


Two Circuits, Six Conductors (See Figure 310.60, Detail 10.) 


8 


8 . 


80 


85 


— 


— 


6 


130 


140 


120 


130 


6 


100 


110 


95 


100 


4 


165 


180 


160 


170 


4 


130 


140 


125 


130 


2 


215 


230 


195 


210 


2 


165 


180 


155 


165 


1 


240 


260 


225 


240 


1 


190 


200 


175 


190 


1/0 


275 


295 


255 


275 


1/0 


215 


230 


200 


215 


2/0 


310 


335 


290 


315 


2/0 


245 


260 


225 


245 


3/0 


355 


380 


330 


355 


3/0 


275 


295 


255 


275 


4/0 


400 


430 


375 


405 


4/0 


310 


335 


290 


315 


250 


435 


470 


410 


440 


250 


340 


365 


320 


345 


350 


520 


560 


495 


530 


350 


410 


440 


385 


415 


500 


630 


680 


600 


645 


500 


495 


530 


470 


505 


750 


775 


835 


740 


795 


750 


610 


655 


580 


625 


1000 


890 


960 


855 


920 


1000 


710 


765 


680 


730 



2010 California Electrical Code 



70-161 



310.60 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



Table 310.83 Ampacities of Three Insulated Copper 
Conductors Cabled Within an Overall Covering (Three- 
Conductor Cable), Directly Buried in Earth Based on 
Ambient Earth Temperature of 20°C (68°F), Arrangement 
per Figure 310.60, 100 Percent Load Factor, Thermal 
Resistance (RHO) of 90, Conductor Temperatures of 90*'C 
(194°F) and 105°C (22PF) 



Table 310.84 Ampacities of Three Insulated Aluminum 
Conductors Cabled Within an Overall Covering (Three- 
Conductor Cable), Directly Buried in Earth Based on 
Ambient Earth Temperature of 20°C (68°F), Arrangement 
per Figure 310.60, 100 Percent Load Factor, Thermal 
Resistance (RHO) of 90, Conductor Temperatures of 90°C 
(194°F) and 105^C (22PF) 





Temperature 


! Rating of Conductor [See Table miS(C),j 




Temperature Rating of Conductor [See Tabl 






le3JM?jgSl 




2001-5000 Volts 
Ampacity 


5001-35,000 Volts 
Ampacity 


Conductor 
Size 


2001-5000 Volts 
Ampacity 


5001-35,000 Volts 
Ampacity 


Conductor 
Size 


90^C 
(194°F) 


105°C 
(221°F) 


90°C 
(194°F) 


105^C 
(221°F) 


90°C 
(194°F) 


105°C 
(221°F) 


90°C 
(194°F) 


105°C 

(22rF) 


(AWG 
or kcmil) 


Type 
MV-90 


Type 
MV-105 


Type 
MV-90 


Type 
MV-105 


(AWG 

or kcmil) 


Type 
MV-90 


Type 
MV-105 


Type 
MV-90 


Type 
MV-105 


One Circuit 


(See Figure 310.60, Detail 5.) 






One Circuit (See Figure 310.60, DetaU 5.) 






8 


85 


89 


— 


— 


8 


65 


70 


— 


— 


6 


105 


115 


115 


120 


6 


80 


88 


90 


95 


4 


135 


150 


145 


155 


4 


105 


115 


115 


125 


2 


180 


190 


185 


200 


2 


140 


150 


145 


155 


1 


200 


215 


210 


225 


1 


155 


170 


165 


175 


1/0 


230 


245 


240 


255 


1/0 


180 


190 


185 


200 


2/0 


260 


280 


270 


290 


2/0 


205 


220 


210 


225 


3/0 


295 


320 


305 


330 


3/0 


230 


250 


240 


260 


4/0 


335 


360 


350 


375 


4/0 


260 


280 


270 


295 


250 


365 


395 


380 


410 


250 


285 


310 


300 


320 


350 


440 


475 


460 


495 


350 


345 


375 


360 


390 


500 


530 


570 


550 


590 


500 


420 


450 


435 


470 


750 


650 


700 


665 


720 


750 


520 


560 


540 


580 


1000 


730 


785 


750 


810 


1000 


600 


650 


620 


665 


Two Circuits (See Figure 310.60, DetaO 6.) 






Two Qrcuits (See Figure 310.60, DetaU 6.) 






8 


80 


84 


— 


— 


8 


60 


66 


— 


— 


6 


100 


105 


105 


115 


6 


75 


83 


80 


95 


4 


130 


140 


135 


145 


4 


100 


110 


105 


115 


2 


165 


180 


170 


185 


2 


130 


140 


135 


145 


1 


185 


200 


195 


210 


1 


145 


155 


150 


165 


1/0 


215 


230 


220 


235 


1/0 


165 


180 


170 


185 


2/0 


240 


260 


250 


270 


2/0 


190 


205 


195 


210 


3/0 


275 


295 


280 


305 


3/0 


215 


230 


220 


240 


4/0 ■ 


310 


335 


320 


345 


4/0 


245 


260 


250 


270 


250 


340 


365 


350 


375 


250 


265 


285 


275 


295 


350 


410 


440 


420 


450 


350 


320 


345 


330 


355 


500 


490 


525 


500 


535 


500 


385 


415 


395 


425 


750 


595 


640 


605 


650 


750 


480 


515 


485 


525 


1000 


665 


715 


675 


730 


1000 


550 


590 


560 


600 



70-162 



2010 California Electrical Code 



ARTICLE 3 10 - CONDUCTORS FOR GENERAL WIRING 



310.60 



Table 310.85 Ampacities of Three Triplexed Single Insulated 
Copper Conductors Directly Buried in Earth Based on 
Ambient Earth Temperature of 20°C (68^F), Arrangement 
per Figure 310.60, 100 Percent Load Factor, Thermal 
Resistance (RHO) of 90, Conductor Temperatures 90°C 
(194^r) and 105°C (221°F) 



Table 310.86 Ampacities of Three Triplexed Single Insulated 
Aluminum Conductors Directly Buried in Earth Based on 
Ambient Earth Temperature of 20°C (68°F), Arrangement 
per Figure 310.60, 100 Percent Load Factor, Thermal 
Resistance (RHO) of 90, Conductor Temperatures 90°C 
(194°F) and 105°C (221°F) 





Temperature Rating of Conductor [See Table 310.13 j[C),] 




Temperature 


Rating of Conductor [See Table aiftBffiM 




2001-5000 Volts 
Ampacity 


5001-35,000 Volts 
Ampacity 


Conductor 
Size 


2001-5000 Volts 
Ampacity 


5001-35,000 Volts 
Ampacity 


Conductor 
Size 


90°C (194°F) 


105°C 

(221°F) 


90°C 
(194°F) 


105°C 

(221°F) 


90°C 
(194°F) 


105°C 

(22PF) 


90°C 
(194°F) 


105^C 
(221°F) 


(AWG 
or kcmil) 


Type 
MV-90 


Type 
MV-105 


Type 
MV-90 


Type 
MV-105 


(AWG 
or kcmil) 


Type 
MV-90 


Type 
MV-105 


Type 
MV-90 


Type 
MV-105 


One Circuit 


, Three Conductors (See Figure 

90 95 


j310.60,DetaO7.) 


One Circuit, Three Conductors (See Figure 310.60, DetaU 7.) 


8 


8 


70 


75 


— 


— 


6 


120 


130 


115 


120 


6 


90 


100 


90 


95 


4 


150 


165 


150 


160 


4 


120 


130 


115 


125 


2 


195 


205 


190 


205 


2 


155 


165 


145 


155 


1 


225 


240 


215 


230 


1 


175 


190 


165 


175 


1/0 


255 


270 


245 


260 


1/0 


200 


210 


190 


205 


2/0 


. 290 


310 


275 


295 


2/0 


225 


240 


215 


230 


3/0 


330 


360 


315 


340 


3/0 


255 


275 


245 


265 


4/0 


375 


405 


360 


385 


4/0 


290 


310 


280 


305 


250 


410 


445 


390 


410 


250 


320 


350 


305 


325 


350 


490 


580 


470 


505 


350 


385 


420 


370 


400 


500 


590 


635 


565 


605 


500 


465 


500 


445 


480 


750 


725 


780 


685 


740 


750 


580 


625 


550 


590 


1000 


825 


885 


770 


830 


1000 


670 


725 


635 


680 


Two Circuits, Six Conductors (See Figure 310.60, DetaU 8.) 


Two Circuits, Sbc Conductors (See Figure 


i 310.60, Detail 8.) 


8 


85 


90 


— 


— 


8 


65 


70 


— 


— 


6 


110 


115 


105 


115 


6 


85 


95 


85 


90 


4 


140 


150 


140 


150 


4 


110 


120 


105 


115 


2 


180 


195 


175 


190 


2 


140 


150 


135 


145 


1 


205 


220 


200 


215 


1 


160 


170 


155 


170 


1/0 


235 


250 


225 


240 


1/0 


180 


195 


175 


190 


2/0 


265 


285 


255 


275 


2/0 


205 


220 


200 


215 


3/0 


300 


320 


290 


315 


3/0 


235 


250 


225 


245 


4/0 


340 


365 


325 


350 


4/0 


265 


285 


255 


275 


250 


370 


395 


355 


380 


250 


290 


310 


280 


300 


350 


445 


480 


425 


455 


350 


350 


375 


335 


360 


500 


535 


575 


510 


545 


500 


420 


455 


405 


435 


750 


650 


700 


615 


660 


750 


520 


560 


485 


. 525 


1000 


740 


795 


690 


745 


1000 


600 


645 


565 


605 



2010 California Electrical Code 



70-163 



312.1 



ARTICLE 3 12 - CABINETS, CUTOUT BOXES, AND METER SOCKET ENCLOSURES 



ARtICLE3l2 

Cabinets, Cutout Boxes, and Meter Socket 
;'':' 'Enclosures^'O V:,\ ' 



312.1 Scope. This article covers the installation and 
construction specifications of cabinets, cutout boxes, and 
meter socket enclosures. 



I. Installation 



312.2 DaiByp^:.a|Ld,"W0^ . In damp or wet 

locations, surface-type enclosures within the scope of this 
article shall be placed or equipped so as to prevent moisture 
or water from entering and accumulating within the cabinet 
or cutout box, and shall be mounted so there is at least 6- 
mm (y4-in.) airspace between the enclosure and the wall or 
other supporting surface. Enclosures installed in wet 
locations shall be weatherproof For enclosures in wet 
locations, raceways or cables entering above the level of 
uninsulated live parts shall use fittings listed for wet 
locations. 

Exception: Nonmetallic enclosures shall be permitted to be 
installed without the airspace on a concrete, masonry, tile, 
or similar surface. 

FPN: For protection against corrosion, see 300.6. 



312.3 Position in Wall. In walls of concrete, tile, or other 
noncombustible material, cabinets shall be installed so that 
the front edge of the cabinet is not set back of the finished 
surface more than 6 mm (% in.). In walls constructed of 
wood or other combustible material, cabinets shall be flush 
with the finished surface or project therefrom. 



312^_ Repairing ^fesfflisS^ 

SoBCombii^tfblgj surfaces that are broken or incomplete 
shall be repaired so there will be no gaps or open spaces 
greater than 3 mm (1/8 in.) at the edge of the cabinet or 
cutout box employing a flush-type cover. 

312.5 Cabinets, Cutout Boxes, and Meter Socket 
Enclosures. Conductors entering enclosures within the 
scope of this article shall be protected from abrasion and 
shall comply with 312.5(A) through (C). 

(A) Openings to Be Closed. Openings through which 
conductors enter shall be adequately closed. 

(B) Metal Cabinets, Cutout Boxes, and Meter Socket 
Enclosures. Where metal enclosures within the scope of this 
article are installed with messenger-supported wiring, open 
wiring on insulators, or concealed knob-and-tube wiring, 
conductors shall enter through insulating bushings or, in dry 
locations, through flexible tubing extending from the last 
insulating support and firmly secured to the enclosure. 



(C) Cables. Where cable is used, each cable shall be 
secured to the cabinet, cutout box, or meter socket 
enclosure. 

Exception: Cables with entirely nonmetallic sheaths shall 
be permitted to enter the top of a surface-mounted 
enclosure through one or more nonflexible raceways not 
less than 450 mm (18 in.) and not more than 3.0 m (10 ft) 
in length, provided all of the following conditions are met: 

(a) Each cable is fastened within 300 mm (12 in.), 
measured along the sheath, of the outer end of the raceway. 

(b) The raceway extends directly above the enclosure 
and does not penetrate a structural ceiling. 

(c) A fitting is provided on each end of the raceway to 
protect the cable (s) from abrasion and the fittings remain 
accessible after installation. 

(d) The raceway is sealed or plugged at the outer end 
using approved means so as to prevent access to the 
enclosure through the raceway. 

(e) The cable sheath is continuous through the 
raceway and extends into the enclosure beyond the fitting 
not less than 6 mm (Vi in.). 

(f) The raceway is fastened at its outer end and at 
other points in accordance with the applicable article. 

(g) Where installed as conduit or tubing, the allowable 
cable fill does not exceed that permitted for complete 
conduit or tubing systems by Table 1 of Chapter 9 of this 
Code and all applicable notes thereto. 

FPN: See Table 1 in Chapter 9, including Note 9, for 
allowable cable fill in circular raceways. See 
310.15(B)(2)(a) for required ampacity reductions for 
multiple cables installed in a common raceway. 

312.6 Deflection of Conductors. Conductors at terminals 
or conductors entering or leaving cabinets or cutout boxes 
and the like shall comply with 312.6(A) through (C). 

Exception: Wire-bending space in enclosures for motor 
controllers with provisions for one or two wires per 
terminal shall comply with 430. 1 0(B), 

(A) Width of Wiring Gutters. Conductors shall not be 
deflected within a cabinet or cutout box unless a gutter 
having a width in accordance with Table 312.6(A) is 
provided. Conductors in parallel in accordance with 310.4 
shall be judged on the basis of the number of conductors in 
parallel. 

(B) Wire-Bending Space at Terminals. Wire-bending 
space at each terminal shall be provided in accordance with 
312.6(B)(1) or (B)(2). 

(1) Conductors Not Entering or Leaving Opposite 
Wall. Table 312.6(A) shall apply where the conductor does 
not enter or leave the enclosure through the wall opposite 
its terminal. 



70-164 



2010 California Electrical Code 



ARTICLE 3 12 - CABINETS, CUTOUT BOXES, AND METER SOCKET ENCLOSURES 



312.10 



Table 312.6(A) Minimum Wire-Bending Space at Terminals and Minimum Width of Wiring Gutters 















Wires per Terminal 










Wire Size 




1 




2 




3 




4 




£ 


i 


(AWG or kcmil) 


mm 




in. 


mm 


in. 


mm 


in. 


mm 


in. 


mm 


in. 


14-10 


Not; 


specified 


— 


— 


— 


— 


— 


— 


— 


— 


8-6 


38,1 




V/i 


— 


— 


~~ 


— 


— 


— 


— 


— 


4-3 


50.8 




2 


— 


— 


— 


— 


— 


— 


— 


— 


2 


63.5 




2/2 


— 


— 


— 


— 


— 


— 


— 


— 


1 


76.2 




3 


— 


— 


— 


— 


— 


— 


— 


— 


1/0-2/0 


88.9 




3^/2 


127 


5 


178 


7 


— 


— 


— 


— 


3/0-4/0 


102 




4 


152 


6 


203 


8 


— 


— 


— 


— 


250 


114 




4/2 


152 


6 


203 


8 


254 


10 


— 


— 


300-350 


127 




5 


203 


8 


254 


10 


305 


12 


— 


— 


400-500 


152 




6 


203 


8 


254 


10 


305 


12 


356 


14 


600-700 


203 




8 


254 


10 


305 


12 


356 


14 


406 


16 


750-900 


203 




8 


305 


12 


356 


14 


406 


16 


457 


18 


1000-1250 


254 




10 


— 


— 


— 


— 


— 


— 


— 


— 


1500-2000 


305 




12 


— 


— 


— 


— 


— 


— 


— 


— 



Note: Bending space at terminals shall be measured in a straight line fi*om the end of the lug or wire connector (in the direction that the 
wire leaves the terminal) to the wall, barrier, or obstruction. 



(2) Conductors Entering or Leaving Opposite Wall. 

Table 312.6(B) shall apply where the conductor does enter 
or leave the enclosure through the wall opposite its 
terminal. 

Exception No, 1: Where the distance between the wall and 
its terminal is in accordance with Table 312.6(A), a 
conductor shall be permitted to enter or leave an enclosure 
through the wall opposite its terminal, provided the 
conductor enters or leaves the enclosure where the gutter 
joins an adjacent gutter that has a width that conforms to 
Table 312. 6(B) for the conductor. 

Exception No. 2: A conductor not larger than 350 kcmil 
shall be permitted to enter or leave an enclosure 
containing only a meter socket (s) through the wall opposite 
its terminal provided the distance between the terminal 
and the opposite wall is not less than that specified in 
Table 312.6(A) and the terminal is a lay-in type, where the 
terminal is either of the following: 

(a) Directed toward the opening in the enclosure and 
within a 45 degree angle of directly facing the enclosure 
wall 

(b) Directly facing the enclosure wall and offset not 
greater than 50 percent of the bending space specified in 
Table 312.6(A) 

FPN: Offset is the distance measured along the enclosure 
wall from the axis of the centerline of the terminal to a line 
passing through the center of the opening in the enclosure. 

(C) Conductors 4 AWG or Larger. Installation shall 
comply with 300.4(G). 



312.7 Space in Enclosures. Cabinets and cutout boxes 
shall have sufficient space to accommodate all conductors 
installed in them without crowding. 

312.8 Enclosures for Switches or Overcurrent Devices. 

Enclosures for switches or overcurrent devices shall not be 
used as junction boxes, auxiliary gutters, or raceways for 
conductors feeding through or tapping off to other switches 
or overcurrent devices, unless adequate space for this 
purpose is provided. The conductors shall not fill the 
wiring space at any cross section to more than 40 percent 
of the cross-sectional area of the space, and the conductors, 
splices, and taps shall not fill the wiring space at any cross 
section to more than 75 percent of the cross-sectional area 
of that space. 

312.9 Side or Back Wiring Spaces or Gutters. Cabinets 
and cutout boxes shall be provided with back-wiring 
spaces, gutters, or wiring compartments as required by 
312.11(C) and (D). 

II. Construction Specifications 

312.10 Material. Cabinets, cutout boxes, and meter socket 
enclosures shall comply with 312.10(A) through (C). 

(A) Metal Cabinets and Cutout Boxes. Metal enclosures 
within the scope of this article shall be protected both 
inside and outside against corrosion. 

FPN: For information on protection against corrosion, see 
300.6. 

(B) Strength. The design and construction of enclosures 
within the scope of this article shall be such as to secure 
ample strength and rigidity. If constructed of sheet steel, 
the metal thickness shall not be less than 1.35 mm (0.053 
in.) uncoated. 



2010 California Electrical Code 



70-165 



312.10 



ARTICLE 312 - CABINETS, CUTOUT BOXES, AND METER SOKET ENCLOSURES 



Table 312.6(B) Minimum Wire-Bending Space at Terminals 














Wires per Terminal 


Wire Size (AWG or kcmil) 


1 


2 


3 


4 or 


More 




Compact 
Stranded AA- 


















8000 Aluminum 
















All Other 
Conductors 


Alloy 
Conductors 
(See Note 3.) 


mm in. 


mm 


in. 


mm 


in. 


mm 


in. 


14-10 


12-8 


Not specified 


— 


— 


— 




— 


— 


8 


6 


38.1 V/2 


— 


— 


— 




— 


— 


6 


4 


50.8 2 


— 


— 


— 




— 


— 


4 


2 


76.2 3 


— 


— 


— 




— 


— 


3 


1 


76.2 3 


— 


— 


— 




— 


— 


2 


1/0 


88.9 3/2 


— 


— 


— 




— 


— 


1 


2/0 


114 4^2 


— 


— 


— 




— 


___ 


1/0 


3/0 


. 140 5/2 


140 


5/2 


178 


7 


— 


— 


2/0 


4/0 


152 6 


152 


6 


190 


7^2 


— 


— 


3/0 


250 


165^ 6^2^ 


165^ 


6/2^ 


203 


8 


— 


— 


4/0 


300 


jygb 7b 


190^ 


7/2^ 


216^ 


8'/2^ 


— 


— 


250 


350 


216^ 8/2^ 


229^ 


8^/2^ 


254^ 


9b 


254 


10 


300 


400 


254^ 10^ 


254^ 


10^ 


279^ 


lib 


305 


12 


350 


500 


. 305^ . 12^ 


305^ 


12^ 


330^ 


13^ 


356^ 


14d 


400 


600 


330^ 13^ 


330^ 


13^ 


356^ 


14e 


381^ 


15^ 


500 


700-750 


356^ 14^ 


356^ 


14e 


381^ 


15^ 


406^ 


16^ 


600 


800-900 


381^ 15^ 


406^ 


16^ 


457^ 


18^ 


483^ 


19^ 


700 


1000 


406^ 16^ 


457^ 


18^ 


508^ 


20^ 


559^ 


22e 


750 


~ 


432^ 17^ 


483^ 


19e 


559^ 


22e 


610^ 


24e 


800 


— 


457 18 


508 


20 


559 


22 


610 


24 


900 


— 


483 19 


559 


22 


610 


24 


610 


24 


1000 


— 


508 . 20 


— 


— 


— 




— 




1250 


— 


559 22 


— 


— 


— 




— 




1500 


— 


610 24 


— 


— 


— 




— 




1750 


— 


610 24 


— 


— 


— 




— 




2000* 


— 


610 24 


— 


— 


— 




— 





1. Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector in a direction perpendicular to 
the enclosure wall. 

2. For removable and lay-in wire terminals intended for only one wire, bending space shall be permitted to be reduced by the following 
number of millimeters (inches): 

^ 12.7 mm (Yi in.) ^ 50.8 mm (2 in.) 

b 25.4 mm (1 in.) ^ 76.2 mm (3 in.) 

^38.1mm(U/2in.) 

3. This column shall be permitted to determine the required wire-bending space for compact stranded aluminum conductors in sizes up to 
1000 kcmil and manufactured using AA-8000 series electrical grade aluminum alloy conductor material in accordance with 310.14. 



70-166 



2010 Cahfomia Electrical Code 



ARTICLE 314 - OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLES 



314.3 



(C) Nonmetallic Cabinets. Nonmetallic cabinets shall be 
listed, or they shall be submitted for approval prior to 
installation. 

312.11 Spacing. The spacing within cabinets and cutout 
boxes shall comply with 312.1 1(A) through (D). 

(A) General. Spacing within cabinets and cutout boxes 
shall be sufficient to provide ample room for the 
distribution of wires and cables placed in them and for a 
separation between metal parts of devices and apparatus 
mounted within them in accordance with (A)(1), (A)(2), 
and (A)(3). 

(1) Base. Other than at points of support, there shall be an 
airspace of at least 1.59 mm (0.0625 in.) between the base 
of the device and the wall of any metal cabinet or cutout 
box in which the device is mounted. 

(2) Doors. There shall be an airspace of at least 25.4 mm 
(1.00 in.) between any live metal part, including live metal 
parts of enclosed fuses, and the door. 

Exception: Where the door is lined with an approved 
insulating material or is of a thickness of metal not less 
than 2.36 mm (0.093 in.) uncoated, the airspace shall not 
be less than 12. 7 mm (0.500 in.). 

(3) Live Parts. There shall be an airspace of at least 12.7 
mm (0.500 in.) between the walls, back, gutter partition, if 
of metal, or door of any cabinet or cutout box and the 
nearest exposed current-carrying part of devices mounted 
within the cabinet where the voltage does not exceed 250. 
This spacing shall be increased to at least 25.4 mm (1.00 
in.) for voltages of 251 to 600, nominal. 

Exception: Where the conditions in 312.11(A)(2), Exception, 
are met, the airspace for nominal voltages from 251 to 600 
shall be permitted to be not less than 12. 7 mm (0.500 in.). 

(B) Switch Clearance. Cabinets and cutout boxes shall be 
deep enough to allow the closing of the doors when 30- 
ampere branch-circuit panelboard switches are in any 
position, when combination cutout switches are in any 
position, or when other single-throw switches are opened 
as far as their construction permits. 

(C) Wiring Space. Cabinets and cutout boxes that contain 
devices or apparatus connected within the cabinet or box to 
more than eight conductors, including those of branch 
circuits, meter loops, feeder circuits, power circuits, and 
similar circuits, but not including the supply circuit or a 
continuation thereof, shall have back-wiring spaces or one 
or more side-wiring spaces, side gutters, or wiring 
compartments. 

(D) Wiring Space — Enclosure. Side-wiring spaces, side 
gutters, or side-wiring compartments of cabinets and cutout 



boxes shall be made tight enclosures by means of covers, 
barriers, or partitions extending from the bases of the 
devices contained in the cabinet, to the door, frame, or 
sides of the cabinet. 

Exception: Side-wiring spaces, side gutters, and side- 
wiring compartments of cabinets shall not be required to 
be made tight enclosures where those side spaces contain 
only conductors that enter the cabinet directly opposite to 
the devices where they terminate. 

Partially enclosed back-wiring spaces shall be 
provided with covers to complete the enclosure. Wiring 
spaces that are required by 312.11(C) and are exposed 
when doors are open shall be provided with covers to 
complete the enclosure. Where adequate space is provided 
for feed-through conductors and for splices as required in 
312.8, additional barriers shall not be required. 



Outlet J Device, Pull^ and Junction Boxes; 
Conduit Bodies; Fittings J and Handtiole 
^' ■ Enclosures . ' = ■ /' ''.^-\. . . 



I. Scope and General 

314.1 Scope. This article covers the installation and use of 
all boxes and conduit bodies used as outlet, device, 
junction, or pull boxes, depending on their use, and 
handhole enclosures. Cast, sheet metal, nonmetallic, and 
other boxes such as FS, FD, and larger boxes are not 
classified as conduit bodies. This article also includes 
installation requirements for fittings used to join raceways 
and to connect raceways and cables to boxes and conduit 
bodies. 

314.2 Round Boxes. Round boxes shall not be used where 
conduits or connectors requiring the use of locknuts or 
bushings are to be connected to the side of the box. 

314.3 Nonmetallic Boxes. Nonmetallic boxes shall be 
permitted only with open wiring on insulators, concealed 
knob-and-tube wiring, cabled wiring methods with entirely 
nonmetallic sheaths, flexible cords, and nonmetallic 
raceways. 

Exception No. 1: Where internal bonding means are 
provided between all entries, nonmetallic boxes shall be 
permitted to be used with metal raceways or metal- 
armored cables. 

Exception No. 2: Where integral bonding means with a 
provision for attaching an equipment bonding jumper 



2010 California Electrical Code 



70-167 



314.4 



ARTICLE 314 - OUTLET, DEVICE, PULL, AND JUNCTION BOXES; FITTINGS; AND HANDHOLES 



inside the box are provided between all threaded entries in 

nonmetallic boxes listed for the purpose, nonmetallic boxes 

shall be permitted to be used with metal raceways or 

metal-armored cables. 

314 A Metal Boxes. Metal bo^^^^ 

FoMed in accordka^ witli Pafe^^ of 

i^&ii^ffli^ ^ """^ "" " "' 

314.5 Short-Radius Conduit Bodies. Conduit bodies 
such as capped elbows and service -entrance elbows that 
enclose conductors 6 AWG or smaller, and are only 
intended to enable the installation of the raceway and the 
contained conductors, shall not contain splices, taps, or 
devices and shall be of sufficient size to provide free space 
for all conductors enclosed in the conduit body. 

II. Installation 

314.15 Damp or Wet Locations. In damp or wet 
locations, boxes, conduit bodies, and fittings shall be 
placed or equipped so as to prevent moisture from entering 
or accumulating within the box, conduit body, or fitting. 
Boxes, conduit bodies, and fittings installed in wet 
locations shall be listed for use in wet locations. 

FPN No. 1 : For boxes in floors, see 3 14.27(C). 
FPN No. 2: For protection against corrosion, see 300.6. 
# 

314.16 Number of Conductors in Outlet, Device, and 
Junction Boxes, and Conduit Bodies. Boxes and conduit 
bodies shall be of sufficient size to provide free space for 
all enclosed conductors. In no case shall the volume of the 
box, as calculated in 314.16(A), be less than the fill 
calculation as calculated in 314.16(B). The minimum 
volume for conduit bodies shall be as calculated in 
314.16(C). 

The provisions of this section shall not apply to terminal 
housings supplied with motors &tgfetfgmti|l. 

FPN: For volume requirements of motor jfrigenerit^ 

terminal housings, see 430.12. 

Boxes and conduit bodies enclosing conductors 4 AWG or 
larger shall also comply with the provisions of 314.28. 
(A) Box Volume Calculations. The volume of a wiring 
enclosure (box) shall be the total volume of the assembled 
sections and, where used, the space provided by plaster 
rings, domed covers, extension rings, and so forth, that are 
marked with their volume or are made from boxes the 
dimensions of which are listed in Table 314.16(A). 
(1) Standard Boxes. The volumes of standard boxes that 
are not marked with their volume shall be as given in Table 
314.16(A). 



(2) Other Boxes. Boxes 1650 cm3 (100 in.3) or less, other 
than those described in Table 314.16(A), and nomnetallic 
boxes shall be durably and legibly marked by the 
manufacturer with their volume. Boxes described in Table 
314.16(A) that have a volume larger than is designated in 
the table shall be permitted to have their volume marked as 
required by this section. 

(B) Box Fill Calculations. The volumes in paragraphs 
314.16(B)(1) through (B)(5), as applicable, shall be added 
together. No allowance shall be required for small fittings 
such as locknuts and bushings. 

(1) Conductor Fill. Each conductor that originates outside 
the box and terminates or is spliced within the box shall be 
counted once, and each conductor that passes through the 
box without splice or termination shall be counted once. 
!l§?bJpJ9PJM.?S?L<i^u^b conductor not less than twice 
the minimum length required for free conductors in 300.14 
shall be counted twice. The conductor fill shall be 
calculated using Table 314.16(B). A conductor, no part of 
which leaves the box, shall not be counted. 

Exception: An equipment grounding conductor or 
conductors or not over four fixture wires smaller than 14 
AWG, or both, shall be permitted to be omitted from the 
calculations where they enter a box from a domed 
luminaire or similar canopy and terminate within that box. 

(2) Clamp Fill. Where one or more internal cable clamps, 
whether factory or field supplied, are present in the box, a 
single volume allowance in accordance with Table 
314.16(B) shall be made based on the largest conductor 
present in the box. No allowance shall be required for a 
cable connector with its clamping mechanism outside the 
box. 

(3) Support Fittings Fill. Where one or more luminaire 
studs or hickeys are present in the box, a single volume 
allowance in accordance with Table 314.16(B) shall be 
made for each type of fitting based on the largest conductor 
present in the box. 

(4) Device or Equipment Fill. For each yoke or strap 
containing one or more devices or equipment, a double 
volume allowance in accordance with Table 314.16(B) 
shall be made for each yoke or strap based on the largest 
conductor connected to a device(s) or equipment supported 
by that yoke or strap. ^Jdgvice^^u^ 

III' Tay^ ^^^WM.^^^- 'h^f^PHMZ^!^!.!^^ . ^^^9:pi 
gmviHed for^each/gang lequjr^/or mi^^ 

(5) Equipment Grounding Conductor Fill. Where one 
or more equipment grounding conductors or equipment 
bonding jumpers enter a box, a single volume allowance 
in accordance with Table 314.16(B) shall be made based 
on the largest equipment grounding conductor or equip - 



70-168 



2010 California Electrical Code 



ARTICLE 314 - OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLES 314.17 



Table 314.16(A) 


Metal Boxes 






















Box Trade Size 


Minimum Volume 


Maximum Number of Conductors* 
i(krratt^d 'by ^A^wS^isiz^ 


mm 


in. 




3 
cm 


3 
in. 


18 


16 


14 


12 


10 


8 


6 


100 X 32 


(4x11/4) 


round/octagonal 


205 


12.5 


8 


7 


6 


5 


5 


5 


2 


100 X 38 


(4x 11/2) 


round/octagonal 


254 


15.5 


10 


8 


7 


6 


6 


5 


3 


100 X 54 


(4 X 2%) 


round/octagonal 


353 


21.5 


14 


12 


10 


9 


8 


7 


4 


100 X 32 


(4x 1%) 


square 


295 


18.0 


12 


10 


9 


8 


7 


6 


3 


100 X 38 


(4x 1V4) 


square 


344 


21.0 


14 


12 


10 


9 


8 


7 


4 


100 X 54 


(4 X 2%) 


square 


497 


30.3 


20 


17 


15 


13 


12 


10 


6 


120 X 32 


(4"A6xP/4) 


square 


418 


25.5 


17 


14 


12 


11 


10 


8 


5 


120x38 


(4^Vi6xiy2) 


square 


484 


29.5 


19 


16 


14 


13 


11 


9 


5 


120 X 54 


(4' V|6 X 2%) 


square 


689 


42.0 


28 


24 


21 


18 


16 


14 


8 


75 X 50 x 38 


(3x2x11/2) 


device 


123 


7.5 


5 


4 


3 


3 


3 


2 


1 


75 X 50 X 50 


(3x2x2) 


device 


164 


10.0 


6 


5 


5 


4 


4 


3 


2 


75 X 50 X 57 


(3 X 2 X 2/4) 


device 


172 


10.5 


7 


6 


5 


4 


4 


3 


2 


75X50X.65 


(3 X 2 X 2/2) 


device 


205 


12.5 


8 


7 


6 


5 


5 


4 


2 


75 X 50 X 70 


(3 X 2 X 2y4) 


device 


230 


14.0 


9 


8 


7 


6 


5 


4 


2 


75 X 50 X 90 


(3 X 2 X 3/2) 


device 


295 


18.0 


12 


10 


9 


8 


7 


6 


3 


100 X 54 X 38 


(4x2^8x1/2) 


device 


169 


10.3 


6 


5 


5 


4 


4 


3 


2 


100 X 54 X 48 


(4 X 2y8x V/s) 


device 


213 


13.0 


8 


7 


6 


5 


5 


4 


2 


100 X 54 X 54 


(4 X 2/8 X 2/8) 


device 


238 


14.5 


9 


8 


7 


6 


5 


4 


2 


95 X 50 X 65 


(3/4 X 2 X 2/2) 


masonry box/gang 


230 


14.0 


9 


8 


7 


6 


5 


4 


2 


95 X 50 X 90 


(374 X 2 X 3/2) 


masonry box/gang 


344 


21.0 


14 


12 


10 


9 


8 


7 


4 


min. 44.5 depth 


FS — single cover/gang (VA) 


221 


13.5 


9 


7 


6 


6 


5 


4 


2 


min. 60.3 depth 


FD — single cover/gang (IVs) 


295 


18.0 


12 


10 


9 


8 


7 


6 


3 


min. 44.5 depth 


FS — multiple cover/gang (1/4) 


295 


18.0 


12 


10 


9 


8 


7 


6 


3 


min. 60.3 depth 


FD — multiple cover/gang (278) 


395 


24.0 


16 


13 


12 


10 


9 


8 


4 



* Where no voume allowances are required by 314.16(B)(2) through (B)(5). 



Table 314.16(B) Volume Allowance Required per Conductor 



Free Space Within Box for Each 
Conductor 


Size of Conductor 
(AWG) 


cm^ 




in.3 


18 


24.6 




1.50 


16 


28.7 




1.75 


14 


32.8 




2.00 


12 


36.9 




2.25 


10 


41.0 




2.50 


8 


49.2 




3.00 


6 


81.9 




5.00 



merit bonding jumper present in the box. Where an 
additional set of equipment grounding conductors, as 
permitted by 250.146(D), is present in the box, an additional 
volume allowance shall be made based on the largest 
equipment grounding conductor in the additional set. 



(C) Conduit Bodies. 

(1) General. Conduit bodies enclosing 6 AWG conductors 
or smaller, other than short-radius conduit bodies as 
described in 314.5, shall have a cross-sectional area not 
less than twice the cross-sectio^nal area of the largest 
conduit or tubing to which fey can bd attached. The 
maximum number of conductors permitted shall be the 
maximum number permitted by Table 1 of Chapter 9 for 
the conduit or tubing to which it is attached. 

(2) With Splices, Taps, or Devices. Only those conduit 
bodies that are durably and legibly marked by the 
manufacturer with their volume shall be permitted to 
contain splices, taps, or devices. The maximum number of 
conductors shall be calculated in accordance with 
314.16(B). Conduit bodies shall be supported in a rigid and 
secure manner. 

314,17 Conductors Entering Boxes, Conduit Bodies, or 
Fittings. Conductors entering boxes, conduit bodies, or 



2010 California Electrical Code 



70-169 



314.19 



ARTICLE 314 - OUTLET, DEVICE, PULL, AND JUNCTION BOXES; FITTINGS; AND HANDHOLES 



fittings shall be protected from abrasion and shall comply 
with 314.17(A) through (D). 

(A) Openings to Be Closed. Openings through which 
conductors enter shall be adequately closed. 

(B) Metal Boxes and Conduit Bodies. Where metal boxes 
or conduit bodies are installed with messenger-supported 
wiring, open wiring on insulators, or concealed knob-and- 
tube wiring, conductors shall enter through insulating 
bushings or, in dry locations, through flexible tubing 
extending fi-om the last insulating support to not less than 6 
mm (% in.) inside the box and beyond any cable clamps. 
Except as provided in 300.15(C), the wiring shall be firmly 
secured to the box or conduit body. Where raceway or 
cable is installed with metal boxes or conduit bodies, the 
raceway or cable shall be secured to such boxes and 
conduit bodies. 

(C) Nonmetallic Boxes and Conduit Bodies. Nonmetallic 
boxes and conduit bodies shall be suitable for the lowest 
temperature-rated conductor entering the box. Where 
nonmetallic boxes and conduit bodies are used with 
messenger-supported wiring, open wiring on insulators, or 
concealed knob-and-tube wiring, the conductors shall enter the 
box through individual holes. Where flexible tubing is used to 
enclose the conductors, the tubing shall extend from the last 
insulating support to not less than 6 mm (Va in.) inside the box 
and beyond any cable clamp. Where nonmetallic-sheathed 
cable or multiconductor Type UF cable is used, the sheath 
shall extend not less than 6 mm (% in.) inside the box and 
beyond any cable clamp. In all instances, all permitted wu-ing 
methods shall be secured to the boxes. 

Exception: Where nonmetallic-sheathed cable or 

multiconductor Type UF cable is used with single gang 
boxes not larger than a nominal size 57 mm ^100 mm (2V4 
in. X 4 in.) mounted in walls or ceilings, and where the cable 
is fastened within 200 mm (8 in.) of the box measured along 
the sheath and where the sheath extends through a cable 
knockout not less than 6 mm (V4 in.), securing the cable to 
the box shall not be required. Multiple cable entries shall be 
permitted in a single cable knockout opening. 

(D) Conductors 4 AWG or Larger. Installation shall 
comply with 300.4(G). 

FPN: See 110.12(A) for requirements on closing unused 
cable and raceway knockout openings. 

314.19 Boxes Enclosing Flush Devices. Boxes used to 
enclose flush devices shall be of such design that the 
devices will be completely enclosed on back and sides and 
substantial support for the devices will be provided. Screws 
for supporting the box shall not be used in attachment of 
the device contained therein. 

314.20 In Wall or Ceiling. In walls or ceilings with a surface 
of concrete, tile, gypsum, plaster, or other noncombustible 
material, boxes employing a flush-type cover or faceplate shall 
be installed so that the front edge of the box, plaster ring, 



extension ring, or listed extender will not be set back of the 
finished surface more than 6 mm QA in.). 

In walls and ceilings constructed of wood or other 
combustible surface material, boxes, plaster rings, 
extension rings, or listed extenders shall be flush with the 
finished surface or project therefrom. 

314.21 Repairing Plaster and Drywall or Plasterboard. 

Plaster, drywall, or plasterboard surfaces that are broken or 
incomplete around boxes employing a flush-type cover or 
faceplate shall be repaired so there will be no gaps or open 
spaces greater than 3 mm (1/8 in.) at the edge of the box. 

314.22 Surface Extensions. Surface extensions shall be 
made by mounting and mechanically securing an extension 
ring over the box. Equipment grounding shall be in 
accordance with t*art VI of Article 250. 

Exception: A surface extension shall be permitted to be 
made from the cover of a box where the cover is designed 
so it is unlikely to fall off or be removed if its securing 
means becomes loose. The wiring method shall be flexible 
for a length sufficient to permit removal of the cover and 
provide access to the box interior, and arranged so that 
any grounding continuity is independent of the connection 
between the box and cover. 

314.23 Supports. Enclosures within the scope of this 
article shall be supported in accordance with one or more 
of the provisions in 314.23(A) through (H). 

(A) Surface Mounting. An enclosure mounted on a 
building or other surface shall be rigidly and securely 
fastened in place. If the surface does not provide rigid and 
secure support, additional support in accordance with other 
provisions of this section shall be provided. 

(B) Structural Mounting. An enclosure supported from a 
structural member of a building or from grade shall be 
rigidly supported either directly or by using a metal, 
polymeric, or wood brace. 

(1) Nails and Screws. Nails and screws, where used as a 
fastening means, shall be attached by using brackets on the 
outside of the enclosure, or they shall pass through the 
interior within 6 mm (% in.) of the back or ends of the 
enclosure. Screws shall not be permitted to pass through 
the box unless exposed threads in the box are protected 
using approved means to avoid abrasion of conductor 
insulation. 

(2) Braces. Metal braces shall be protected against 
corrosion and formed from metal that is not less than 0.51 
mm (0.020 in.) thick uncoated. Wood braces shall have a 
cross section not less than nominal 25 mm x 50 mm (1 in. 
X 2 in.). Wood braces in wet locations shall be treated for 



70-170 



2010 California Electrical Code 



ARTICLE 3 14 - OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLES 



314.23 



the conditions. Polymeric braces shall be identified as 
being suitable for the use. 

(C) Mounting in Finisiied Surfaces. An enclosure 
mounted in a finished surface shall be rigidly secured 
thereto by clamps, anchors, or fittings identified for the 
application. 

(D) Suspended Ceilings. An enclosure mounted to 
structural or supporting elements of a suspended ceiling 
shall be not more than 1650 cm3 (100 in. 3) in size and 
shall be securely fastened in place in accordance with 
either (D)(1) or (D)(2). 

(1) Framing Members. An enclosure shall be fastened to 
the framing members by mechanical means such as bolts, 
screws, or rivets, or by the use of clips or other securing 
means identified for use with the type of ceiling framing 
member(s) and enclosure(s) employed. The framing 
members shall be adequately supported and securely 
fastened to each other and to the building structure. 

(2) Support Wires. The installation shall comply with the 
provisions of 300.11(A), The enclosure shall be secured, using 
methods identified for the purpose, to ceiling support wire(s), 
including any additional support wire(s) installed for that 
purpose. Support wire(s) used for enclosure support shall be 
fastened at each end so as to be taut within the ceiling cavity. 

(E) Raceway Supported Enclosure, Without Devices, 
Luminaires, or Lampholders. An enclosure that does not 
contain a device(s) other than splicing devices or support a 
luminaire(s), lampholder, or other equipment and is 
supported by entering raceways shall not exceed 1650 cm3 
(100 in. 3) in size. It shall have threaded entries or have 
hubs identified for the purpose. It shall be supported by two 
or more conduits threaded wrenchtight into the enclosure or 
hubs. Each conduit shall be secured within 900 mm (3 ft) 
of the enclosure, or within 450 mm (18 in.) of the enclosure 
if all conduit entries are on the same side. 

Exception: Rigid metal, intermediate metal, or rigid 
nonmetallic conduit or electrical metallic tubing shall he 
permitted to support a conduit body of any size, including a 
conduit body constructed with only one conduit entry, 
provided the trade size of the conduit body is not larger 
than the largest trade size of the conduit or electrical 
metallic tubing. 

(F) Raceway-Supported Enclosures, with Devices, 
Luminaires, or Lampholders. An enclosure that contains 
a device(s), other than splicing devices, or supports a 
luminaire(s), lampholder, or other equipment and is 
supported by entering raceways shall not exceed 1650 cm3 
(100 in.3) in size. It shall have threaded entries or have 
hubs identified for the purpose. It shall be supported by two 



or more conduits threaded wrenchtight into the enclosure or 
hubs. Each conduit shall be secured within 450 mm (18 in.) 
of the enclosure. 

Exception No. 1: Rigid metal or intermediate metal 
conduit shall be permitted to support a conduit body of any 
size, including a conduit body constructed with only one 
conduit entry, provided the trade size of the conduit body is 
not larger than the largest trade size of the conduit. 

Exception No. 2: An unbroken length(s) of rigid or 
intermediate metal conduit shall be permitted to support a 
box used for luminaire or lampholder support, or to 
support a wiring enclosure that is an integral part of a 
luminaire and used in lieu of a box in accordance with 
300.15(B), where all of the following conditions are met: 

(a) The conduit is securely fastened at a point so that 
the length of conduit beyond the last point of conduit 
support does not exceed 900 mm (3 ft). 

(b) The unbroken conduit length before the last point 
of conduit support is 300 mm (12 in.) or greater, and that 
portion of the conduit is securely fastened at some point 
not less than 300 mm (12 in) from its last point of support. 

(c) Where accessible to unqualified persons, the 
luminaire or lampholder, measured to its lowest point, is at 
least 2,5 m (8 ft) above grade or standing area and at least 
900 mm (3 ft) measured horizontally to the 2.5 m (8 ft) 
elevation from windows, doors, porches, fire escapes, or 
similar locations. 

(d) A luminaire supported by a single conduit does not 
exceed 300 mm (12 in.) in any direction from the point of 
conduit entry. 

(e) The weight supported by any single conduit does 
not exceed 9 kg (20 lb). 

(f) At the luminaire or lampholder end, the conduit(s) 
is threaded wrenchtight into the box, conduit body, or 
integral wiring enclosure, or into hubs identified for the 
purpose. Where a box or conduit body is used for support, 
the luminaire shall be secured directly to the box or 
conduit body, or through a threaded conduit nipple not 
over 75 mm (3 in.) long. 

(G) Enclosures in Concrete or Masonry. An enclosure 
supported by embedment shall be identified as suitably 
protected from corrosion and securely embedded in 
concrete or masonry. 

(H) Pendant Boxes. An enclosure supported by a pendant 
shall comply with 314.23(H)(1) or (H)(2). 

(1) Flexible Cord. A box shall be supported from a 
multiconductor cord or cable in an approved manner that 
protects the conductors against strain, such as a strain-relief 
connector threaded into a box with a hub. 

(2) Conduit. A box supporting lampholders or luminaires, 
or wiring enclosures within luminaires used in lieu of 



2010 California Electrical Code 



70-171 



Iii§i 



ARTICLE 314 - OUTLET, DEVICE, PULL, AND JUNCTION BOXES; FITTINGS; AND HANDHOLES 



boxes in accordance with 300.15(B), shall be supported by 
rigid or intermediate metal conduit stems. For stems longer 
than 450 mm (18 in.), the stems shall be connected to the 
wiring system with flexible fittings suitable for the 
location. At the luminaire end, the conduit(s) shall be 
threaded wrenchtight into the box or wiring enclosure, or 
into hubs identified for the purpose. 

Where supported by only a single conduit, the threaded 
joints shall be prevented from loosening by the use of set- 
screws or other effective means, or the luminaire, at any 
point, shall be at least 2.5 m (8 ft) above grade or standing 
area and at least 900 mm (3 ft) measured horizontally to the 
2.5 m (8 ft) elevation from windows, doors, porches, fire 
escapes, or similar locations. A luminaire supported by a 
single conduit shall not exceed 300 mm (12 in.) in any 
horizontal direction from the point of conduit entry. 
314.24 Minimfim Depth of Bote% for Outlets. DevicesJ 

have sufficient depth to allow ^qnij^mmt msiaUed withiil 
f hem to be mounted p^roperly and with mfficimt clearance 
jto ptevetit damagejoxotiduotoi^ withm the boK. 
JtAlT Outlet BQ^es Without Enclosed EN g^ices or ytiliza%ii! 

iqgig^ig^^t JNoJ^ ^ internal depth of less tfaari 

(B) lOiitiet and Deyii^e Box^ with Enclosed Bevices. Bqxe^ 

iiifendod to enclosejusfi devices shaff^^ m inteinal depth of 

notless AaB 218 |OT^^ in',), 

(Q^'Uttpzation\Equ^^ QMS^i^^M deyJ.?^ boxes that 

bgd^se Mliza^c§^ jxitm^ 

jdep Jhi , &at . accoxhm^jattes ihe rearwardi^^^ oi ihi 

6qmpmQiit and the sias of th& condv^is^^^at sijppiy the 
equipmen^^ Mtoal depth shall inc&dfej ^ere use4 tii^tpf 
any extension boxes, piaster rings, or raised mycm. Tlie mtemal 
dq>tii shall comply with all appHcabie provisions of (C)(l] 

SllM; ___,„.,„ ,^^I1„_ . [1 

.{13^'Large EqvipjXLmt^^^ .^jg^^e^^jitilization 

i^u^ent ftiatpt^jg^^ 

ftooji the mounting plane of teboxstetf hav^ a dgpthtfaat is koj 
less thm the depth of the eqmpment plus 6 mm QA in,) 

pX„ Conductors^ I^pger TIiot 4 AWG, "Boxes that eiKJiosei 

jajfeafipn ^ equipmeni^^sjppW fp^-A 

p)_^^ Gottductor$ J^^^ ^utii^SttQ 

egm^eS gjppUeJ^^ 'sMlSvi^ 

mtemal, deplii tet is nbt te^^ti^ 52Aiimi^)M M;)l 
(4)jCoiidiictors 12 or JO AW& Boxes tot ^clo^ ttflmtipn 
^egmpment,stfflHea,bxl2 or id A^G conducfe shall^^ve at^ 
Intemai dq^ iiat is not less tfel 30 J fa^ Where S^ 

§^rneM;^^^ pf _fli| 

Ifoi by moie than ZB mm (J Hn.), the:bjdx;shMl '^ a deptti 



hot less than^tto of th^el '^quij)ment plnS;6^tnm^(^^^ 

^(^^^ ; Cbiidwetpi? 14 AWG aiid^Sitta^ Boxes Jm^encfpse 

jeguipnGient supplied by 14 AWG or staalier conductes shall 

have ajtepth&at B;npt les| ft^23.8ton|y^^^^ 

Exception to (Q^l)thtm^ (C)(5): Utitization equiprmnl 
'that is Uit0d ip b^ imt0 boxes shalTbi^ 

permitted! 

314.25 Covers and Canopies. In completed installations, 
each box shall have a cover, faceplate, lampholder, or 
luminaire canopy, except where the installation complies 
with 410.24(B). 

(A) Nonmetallic or Metal Covers and Plates. Nonmetalhc or 
metal covers and plates shall be permitted. Where metal covers 
or plates are used, they shall comply with the grounding 
requirements of 250.1 10. 

FPN: For additional grounding requirements, see 410.42(A) 
for metal luminaire canopies, and 404.12 and 406.5(B) for 
metal faceplates. 

(B) Exposed Combustible Wall or Ceiling Finish. Where 
a luminaire canopy or pan is used, any combustible wall or 
ceiling finish exposed between the edge of the canopy or 
pan and the outlet box shall be covered with 
noncombustible material. 

(C) Flexible Cord Pendants. Covers of outlet boxes and 
conduit bodies having holes through which flexible cord 
pendants pass shall be provided with bushings designed for 
the purpose or shall have smooth, well-rounded surfaces on 
which the cords may bear. So-called hard rubber or 
composition bushings shall not be used. 

314.27 Outlet Boxes. 

(A) Boxes at Luminaire Outlets. Boxes used at luminaire 
or lampholder outlets IE .a celling shall be designed for the 
pu^ose iand^shall Jte iaquire^ toj^support a tomin|irei 
^weighing a m o]f 23 kg X5,0 ;lb)*„ B^ used ai 

|iminair£otJa^^ 

fe)t file purpoie arid shaj bemiifedb^ interior of tfie 

box to indicate, the maxtoum weigM 

is permitted tob^ suppojl^ % fe brainthe wall^ if other 

pia^'23!kg (50 j^^ At every outlet used exclusively for 

lighting, the box shall be designed or installed so that a 

luminaire may be attached. 

Exception: A wall-mounted luminaire weighing not more 
than 3 kg (6 lb) shall be permitted to be supported on other 
boxes or plaster rings that are secured to other boxes, 
provided the luminaire or its supporting yoke is secured to 
the box with no fewer than two No. 6 or larger screws. 



70-172 



2010 California Electrical Code 



ARTICLE 3 14 - OUTLET, DEVICE, PULL AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLES 



314.29 



(B) Maximum Luminaire Weight Outlet boxes or 
fittings 6,migmd for tke supporr of ; tamimires a^^ 
installed as required by 314.23 shall be permitted to 
support aj liumnair^ weighing 23 kg (50 lb) or less. A 
luminaire that weighs more than 23 kg (50 lb) shall be 
supported independently of the outlet box unless the 
outlet box is listed and Marked for the maxiiniini weight 
to be supported. 

(C) Floor Boxes. Boxes listed specifically for this 
application shall be used for receptacles located in the 
floor. 

Exception: Where the authority having jurisdiction 
judges them free from likely exposure to physical damage, 
moisture, and dirt, boxes located in elevated floors of 
show windows and similar locations shall be permitted to 
be other than those listed for floor applications. 
Receptacles and covers shall be listed as an assembly for 
this type of location. 

(D) Boxes at Ceiling-Suspended (Paddle) Fan Outlets. 

Outlet boxes or outlet box systems used as the sole 
support of a ceiling-suspended (paddle) fan shall be 
listed, shall be marked by their manufacturer as suitable 
for this purpose, and shall not support ceiling-suspended 
(paddle) fans that weigh more than 32 kg (70 lb). For 
outlet boxes or outlet box systems designed to support 
ceiling-suspended (paddle) fans that weigh more than 16 
kg (35 lb), the required marking shall include the 
maximum weight to be supported. 

p) Utiililatioii Equipment. Boxes used for th^ support 
bf titiiizatioii equipment other than; ceiling-suspendpd 
(paddle) fans shkll meet the req^femeMspf 3i4^27(^^^ 
m6:(B) mt the suppoitofalumii^ake^^ 
and weigit 

Exception: jJtiUzation equipment weighing not more than 
'$ kg (6 fb) shall be permitted to be supported on othen 

Jyoxes or Iplaster rings that are secured to other boxes,\ 
irovidedkhe equipment or its supporting yoke is secured 

314.28 Pull and Junction Boxes and Conduit Bodies. 

Boxes and conduit bodies used as pull or junction boxes 
shall comply with 314.28(A) through (D). 

Exception: Terminal housings supplied with motors shall 
comply with the provisions of 430.12. 

(A) Minimum Size. For raceways containing conductors 
of 4 AWG or larger |jiat:^e''i;egu^ and 

for cables containing conductors of 4 AWG or larger, the 
minimum dimensions of pull or junction boxes installed 
in a raceway or cable run shall comply with (A)(1) 
through (A)(3). Where an enclosure dimension is to be 
calculated based on the diameter of entering raceways, the 
diameter shall be the metric designator (trade size) 
expressed in the units of measurement employed. 



(1) Straiglit Pulls. In straight pulls, the length of the box 
shall not be less than eight times the metric designator 
(trade size) of the largest raceway. 



(2) Angle or U Pulls, )^r SpMclesJ Where splices or where 
angle or U pulls are made, the distance between each 
raceway entry inside the box and the opposite wall of the 
box shall not be less than six times the metric designator 
(trade size) of the largest raceway in a row. This distance 
shall be increased for additional entries by the amount of 
the sum of the diameters of all other raceway entries in the 
same row on the same wall of the box. Each row shall be 
calculated individually, and the single row that provides the 
maximum distance shall be used. 

Exception: Where a raceway or cable entry is in the wall 
of a box or conduit body opposite a removable cover, the 
distance from that wall to the cover shall be permitted to 
comply with the distance required for one wire per 
terminal in Table 312.6(A). 

The distance between raceway entries enclosing the 
same conductor shall not be less than six times the metric 
designator (trade size) of the larger raceway. 

When transposing cable size into raceway size in 
314.28(A)(1) and (A)(2), the minimum metric designator 
(trade size) raceway required for the number and size of 
conductors in the cable shall be used. 

(3) Smaller Dimensions. Boxes or conduit bodies of 
dimensions less than those required in 314.28(A)(1) and 
(A)(2) shall be permitted for installations of combinations 
of conductors that are less than the maximum conduit or 
tubing fill (of conduits or tubing being used) permitted by 
Table 1 of Chapter 9, provided the box or conduit body has 
been listed for, and is permanently marked with, the 
maximum number and maximum size of conductors 
permitted. 

(B) Conductors in Pull or Junction Boxes. In pull boxes 
or junction boxes having any dimension over 1.8 m (6 ft), 
all conductors shall be cabled or racked up in an approved 
manner. 

(C) Covers. All pull boxes, junction boxes, and conduit 
bodies shall be provided with covers compatible with the 
box or conduit body construction and suitable for the 
conditions of use. Where used, metal covers shall comply 
with the grounding requirements of 250.1 10. 

(D) Permanent Barriers. Where permanent barriers are 
installed in a box, each section shall be considered as a 
separate box. 

314.29 Boxes, Conduit Bodies, and Handhole 
Enclosures to Be Accessible. Boxes, conduit bodies, and 
handhole enclosures shall be installed so that the wiring 



2010 California Electrical Code 



70-173 



314.30 



ARTICLE 314 - OUTLET, DEVICE, PULL, AND JUNCTION BOXES; FITTINGS; AND HANDHOLES 



contained in them can be rendered accessible without 
removing any part of the building or, in underground 
circuits, without excavating sidewalks, paving, earth, or 
other substance that is to be used to establish the finished 
grade. 

Exception: Listed boxes and handhole enclosures shall be 
permitted where covered by gravel, light aggregate, or 
noncohesive granulated soil if their location is effectively ' 
identified and accessible for excavation. 

314.30 Handhole Enclosures. Handhole enclosures shall 
be designed and installed to withstand all loads likely to be 
imposed on them. They shall be idetitified for use jt^ 
imderground systemsi 

FPN: See ANSI/SCTE 77-2002, Specification for 
Underground Enclosure Integrity, for additional 
information on deUberate and nondeliberate traffic loading 
that can be expected to bear on underground enclosures. 

(A) Size. Handhole enclosures shall be sized in accordance 
with 314.28(A) for conductors operating at 600 volts or 
below, and in accordance with 314.71 for conductors 
operating at over 600 volts. For handhole enclosures 
without bottoms where the provisions of 314.28(A)(2), 
Excepfion, or 314.71(B)(1), Excepfion No. 1, apply, the 
measurement to the removable cover shall be taken from 
the end of the conduit or cable assembly. 

(B) Wiring Entries. Underground raceways and cable 
assemblies entering a handhole enclosure shall extend into 
the enclosure, but they shall not be required to be 
mechanically connected to the enclosure. 

(C) Enclosed Wiring. All enclosed conductors and any 
sphces or terminations, if present, shall be listed as suitable 
for wet locations. 

(D) Covers. Handhole enclosure covers shall have an 
identifying mark or logo that prominently identifies the 
fimcfion of the enclosure, such as "electric." Handhole 
enclosure covers shall require the use of tools to open, or 
they shall weigh over 45 kg (100 lb). Metal covers and 
other exposed conductive surfaces shall be bonded in 
accordance with 250.92(A) if the conductors in the 
handhole are service conductors^ or iti accordance with 
S50*96(A) if the conductors in the handtole are feeder or 
bf anctcircuit conduetdi^^ 

III. Construction Specifications 

314.40 Metal Boxes, Conduit Bodies, and Fittings. 

(A) Corrosion Resistant. Metal boxes, conduit bodies, and 
fittings shall be corrosion resistant or shall be well- 
galvanized, enameled, or otherwise properly coated inside 
and out to prevent corrosion. 



FPN: See 300.6 for limitation in the use of boxes and 
fittings protected from corrosion solely by enamel. 

(B) Thiclmess of Metal. Sheet steel boxes not over 1650 
cm3 (100 in.3) in size shall be made from steel not less 
than 1.59 mm (0.0625 in.) thick. The wall of a malleable 
iron box or conduit body and a die-cast or permanent-mold 
cast aluminum, brass, bronze, or zinc box or conduit body 
shall not be less than 2.38 mm (3/32 in.) thick. Other cast 
metal boxes or conduit bodies shall have a wall thickness 
not less than 3.17 mm (1/8 in.). 

Exception No. I: Listed boxes and conduit bodies shown to 
have equivalent strength and characteristics shall be 
permitted to be made of thinner or other metals. 

Exception No. 2: The walls of listed short radius conduit 
bodies, as covered in 314.5, shall be permitted to be made 
of thinner metal. 

(C) Metal Boxes Over 1650 cm3 (100 in.3). Metal boxes 
over 1650 cm3 (100 in.3) in size shall be constructed so as to 
be of ample strength and rigidity. If of sheet steel, the metal 
thickness shall not be less than 1.35 mm (0.053 in.) uncoated. 

(D) Grounding Provisions. A means shall be provided in 
each metal box for the connection of an equipment 
grounding conductor. The means shall be permitted to be a 
tapped hole or equivalent. 

314.41 Covers. Metal covers shall be of the same material 
as the box or conduit body with which they are used, or 
they shall be lined with firmly attached insulating material 
that is not less than 0.79 mm (1/32 in.) thick, or they shall 
be Hsted for the purpose. Metal covers shall be the same 
thickness as the boxes or conduit body for which they are 
used, or they shall be Hsted for the purpose. Covers of 
porcelain or other approved insulating materials shall be 
permitted if of such form and thickness as to afford the 
required protecfion and strength. 

314.42 Bushings. Covers of outlet boxes and conduit bodies 
having holes through which flexible cord pendants may pass 
shall be provided with approved bushings or shall have 
smooth, well-rounded surfaces on which the cord may bear. 
Where individual conductors pass through a metal cover, a 
separate hole equipped with a bushing of suitable insulating 
material shall be provided for each conductor. Such separate 
holes shall be connected by a slot as required by 300.20. 

314.43 Nonmetallic Boxes. Provisions for supports or 
other mounting means for nonmetallic boxes shall be 
outside of the box, or the box shall be constructed so as to 
prevent contact between the conductors in the box and the 
supporting screws. 

314.44 Marking. All boxes and conduit bodies, covers, 
extension rings, plaster rings, and the like shall be durably 



70-174 



2010 California Electrical Code 



ARTICLE 320 - ARMORED CABLE: TYPE AC 



320.10 



and legibly marked with the manufacturer's name or 
trademark. 



IV. Pull and Junction Boxes for Use on Systems over 
600 Volts, Nominal 

314.70 General. Where pull and junction boxes are used 
on systems over 600 volts, the installation shall comply 
with the provisions of Part IV and also with the following 
general provisions of this article: 

(1) Part I, 314.2, 314.3, and 314.4 

(2) Part II, 314.15; 314.17; 314.20; 314.23(A), (B), or (G); 
314.28(B); and 3 14.29 

(3) Part III, 314.40(A) and (C) and 314.41 

314.71 Size of Pull and Junction Boxes. Pull and 
junction boxes shall provide adequate space and 
dimensions for the installation of conductors, and they shall 
comply with the specific requirements of this section. 

Exception: Terminal housings supplied with motors shall 
comply with the provisions of 430.12. 

(A) For Straight Pulls. The length of the box shall not be 
less than 48 times the outside diameter, over sheath, of the 
largest shielded or lead-covered conductor or cable 
entering the box. The length shall not be less than 32 times 
the outside diameter of the largest nonshielded conductor 
or cable. 

(B) For Angle or U Pulls. 

(1) Distance to Opposite Wall. The distance between 
each cable or conductor entry inside the box and the 
opposite wall of the box shall not be less than 36 times the 
outside diameter, over sheath, of the largest cable or 
conductor. This distance shall be increased for additional 
entries by the amount of the sum of the outside diameters, 
over sheath, of all other cables or conductor entries through 
the same wall of the box. 

Exception No. 1: Where a conductor or cable entry is in 
the wall of a box opposite a removable cover, the distance 
from that wall to the cover shall be permitted to be not less 
than the bending radius for the conductors as provided in 
300.34. 

Exception No. 2: Where cables are nonshielded and not 
lead covered, the distance of 36 times the outside diameter 
shall be permitted to be reduced to 24 times the outside 
diameter. 

(2) Distance Between Entry and Exit. The distance 
between a cable or conductor entry and its exit from the 
box shall not be less than 36 times the outside diameter, 
over sheath, of that cable or conductor. 

Exception: Where cables are nonshielded and not lead 
covered, the distance of 36 times the outside diameter shall 
be permitted to be reduced to 24 times the outside 
diameter. 



(C) Removable Sides. One or more sides of any pull box 
shall be removable. 

314.72 Construction and Installation Requirements. 

(A) Corrosion Protection. Boxes shall be made of 
material inherently resistant to corrosion or shall be 
suitably protected, both internally and externally, by 
enameling, galvanizing, plating, or other means. 

(B) Passing Through Partitions. Suitable bushings, 
shields, or fittings having smooth, rounded edges shall be 
provided where conductors or cables pass through 
partitions and at other locations where necessary. 

(C) Complete Enclosure. Boxes shall provide a complete 
enclosure for the contained conductors or cables. 

(D) Wiring Is Accessible. Boxes shall be installed so that 
the wiring is accessible without removing any part of the 
building. Working space shall be provided in accordance 
with 110.34. 

(E) Suitable Covers. Boxes shall be closed by suitable 
covers securely fastened in place. Underground box covers 
that weigh over 45 kg (100 lb) shall be considered meeting 
this requirement. Covers for boxes shall be permanently 
marked "DANGER — HIGH VOLTAGE — KEEP OUT." 
The marking shall be on the outside of the box cover and 
shall be readily visible. Letters shall be block type and at 
least 13 mm QA in.) in height. 

(F) Suitable for Expected Handling. Boxes and their 
covers shall be capable of withstanding the handling to 
which they are likely to be subjected. 



i^-mored Cable: Type AC 



I. General 

320.1 Scope. This article covers the use, installation, and 
construction specifications for armored cable, Type AC. 

320.2 Definition. 

Armored Cable, Type AC. A fabricated assembly of 
insulated conductors in a flexible metallic enclosure. See 
320.100. 

II. Installation 

320.10 Uses Permitted. Type AC cable shall be permitted 
as follows: 

(1) Bof^AptimA^ in both exposed and 
concealed work 

(2) In cable trays 



2010 California Electrical Code 



70-175 



320.12 



ARTICLE 320 - ARMORED CABLE: TYPE AC 



(3) In dry locations 

(4) Embedded in plaster finish on brick or other masonry, 
except in damp or wet locations 

(5) To be run or fished in the air voids of masonry block or 
tile walls where such walls are not exposed or subject 
to excessive moisture or dampness 

FPN: The "Uses Permitted" is not an all-inclusive list. 

320.12 Uses Not Permitted. Type AC cable shall not be 
used as follows: 

(1) Where subject to physical damage 

(2) In damp or wet locations 

(3) In air voids of masonry block or tile walls where such walls 

are exposed or subject to excessive moisture or dampness 

(4) Where exposed to corrosive fumes or vapors 

(5) Embedded in plaster finish on brick or other masonry 
in damp or wet locations 

320.15 Exposed Work. Exposed runs of cable, except as 
provided in 300.11(A), shall closely follow the surface of 
the building finish or of running boards. Exposed runs shall 
also be permitted to be installed on the underside of joists 
where supported at each joist and located so as not to be 
subject to physical damage. 

320.17 Through or Parallel to Framing Members. Type AC 

cable shall be protected in accordance with 300.4(A), (C), and 
(D) where installed through or parallel to framing members. 

320.23 In Accessible Attics. Type AC cables in accessible 
attics or roof spaces shall be installed as specified in 
320.23(A) and (B). 

(A) Where Run Across the Top of Floor Joists. Where 
run across the top of floor joists, or within 2.1 m (7 ft) of 
floor or floor joists across the face of rafters or studding, in 
attics and roof spaces that are accessible, the cable shall be 
protected by substantial guard strips that are at least as high 
as the cable. Where this space is not accessible by 
permanent stairs or ladders, protection shall only be 
required within 1.8 m (6 ft) of the nearest edge of the 
scuttle hole or attic entrance. 

(B) Cable Installed Parallel to Framing Members. Where 

the cable is installed parallel to the sides of rafters, studs, or 
floor joists, neither guard strips nor running boards shall be 
required, and the installation shall also comply with 300.4(D). 

320.24 Bending Radius. Bends in Type AC cable shall be 
made such that the cable is not damaged. The radius of the 
curve of the inner edge of any bend shall not be less than 
five times the diameter of the Type AC cable. 



320.30 Securing and Supporting. 

(A) General. Type AC cable shall be supported and secured 
by staples, cable ties, straps, hangers, or similar fittings, 
designed and installed so as not to damage the cable. 

(B) Securing. Unless otherwise provided, Type AC cable 
shall be secured within 300 mm (12 in.) of every outlet 
box, junction box, cabinet, or fitting and at intervals not 
exceeding 1.4 m (4/2 ft) where installed on or across 
framing members. 

(C) Supporting. Unless otherwise provided, Type AC 
cable shall be supported at intervals not exceeding 1.4 m 
(41/2 ft). 

Horizontal runs of Type AC cable installed in wooden or 
metal framing members or similar supporting means shall 
be considered supported where such support does not 
exceed 1.4-m (4V2-ft) intervals. 

(D) Unsupported Cables. Type AC cable shall be 
permitted to be unsupported where the cable complies with 
any of the following: 

(1) Is fished between ' access points through concealed 
spaces in finished buildings or structures and 
supporting is impracticable 

(2) Is not more than 600 mm (2 ft) in length at terminals 
where flexibility is necessary 

(3) Is not more than 1.8 m (6 ft) in length from the last 
point of cable support to the point of connection to a 
luminaire(s) or other electrical equipment and the 
cable and point of connection are within an accessible 
ceiling. For the purposes of this section. Type AC 
cable fittings shall be permitted as a means of cable 
support. 

320.40 Boxes and Fittings. At all points where the armor 
of AC cable terminates, a fitting shall be provided to 
protect wires from abrasion, unless the design of the outlet 
boxes or fittings is such as to afford equivalent protection, 
and, in addition, an insulating bushing or its equivalent 
protection shall be provided between the conductors and 
the armor. The connector or clamp by which the Type AC 
cable is fastened to boxes or cabinets shall be of such 
design that the insulating bushing or its equivalent will be 
visible for inspection. Where change is made from Type 
AC cable to other cable or raceway wiring methods, a box, 
fitting, or conduit body shall be installed at junction points 
as required in 300. 1 5. 

320.80 Ampacity. The ampacity shall be determined by 

310.15. 



• 



70-176 



2010 California Electrical Code 



ARTICLE 322 - FLAT CABLE ASSEMBLIES: TYPE FC 



322.56 



(A) Thermal Insulation. Armored cable installed in 
thermal insulation shall have conductors rated at 90°C 
(194°F). The ampacity of cable installed in these 
applications shall be that of 60°C (140°F) conductors. The 
90°C (194°F) rating shall be permitted to be used for 
ampacity derating purposes, provided the final derated 
ampacity does not exceed that for a 60°C (140T) rated 
conductor. 

(B) Cable Tray. The ampacity of Type AC cable installed in 
cable tray shall be determined in accordance with 392. 1 1 . 

III. Construction Specifications 

320.100 Construction. Type AC cable shall have an 
armor of flexible metal tape and shall have an internal 
bonding strip of copper or aluminum in intimate contact 
with the armor for its entire length. 

320.104 Conductors. Insulated conductors shall be of a 
type hsted in Table 310.13(A) or those identified for use in 
this cable. In addition, the conductors shall have an overall 
moisture-resistant and fire-retardant fibrous covering. For 
Type ACT, a moisture-resistant fibrous covering shall be 
required only on the individual conductors. 



320.108 Equipment Grounding Cijuducton Type AC 
cable shall provide an adequate path for fault current as 

I;equife35y ■25d'4{A)(5) or lB)(4)io'^^^^ 

320.120 Marking. The cable shall be marked in 
accordance with 310.11, except that Type AC shall have 
ready identification of the manufacturer by distinctive 
external markings on the cable sheath throughout its entire 
length. 



'l;-:. ARTICLE W^ 

jiMatCable'Asseiiih 



I. General 

322.1 Scope. This article covers the use, installafion, and 
construction specifications for flat cable assemblies, Type 
FC. 

322.2 Definition. 

Flat Cable Assembly, Type FC. An assembly of parallel 
conductors formed integrally with an insulating material 
web specifically designed for field installation in surface 
metal raceway. 



II. Installation 

322.10 Uses Permitted. Flat cable assemblies shall be 
permitted only as follows: 



(1) As branch circuits to supply suitable tap devices for 
lighting, small appliances, or small power loads. The 
rating of the branch circuit shall not exceed 30 
amperes. 

(2) Where installed for exposed work. 

(3) In locations where they will not be subjected to physical 
damage. Where a flat cable assembly is installed less than 
2.5 m (8 ft) above the floor or fixed working platform, it 
shall be protected by a cover identified for the use. 

(4) In surface metal raceways identified for the use. The 
channel portion of the surface metal raceway systems 
shall be installed as complete systems before the flat 
cable assemblies are pulled into the raceways. 

322.12 Uses Not Permitted. Flat cable assemblies shall 
not be used as follows: 

(1) Where subject to corrosive vapors unless suitable for 
the application 

(2) In hoistways or on elevators or escalators 

(3) In any hazardous (classified) location 

(4) Outdoors or in wet or damp locations unless identified 
for the use 

322.30 Securing and Supporting. The flat cable 
assemblies shall be supported by means of their special 
design features, within the surface metal raceways. 

The surface metal raceways shall be supported as 
required for the specific raceway to be installed, 

322.40 Boxes and Fittings. 

(A) Dead Ends. Each flat cable assembly dead end shall be 
terminated in an end-cap device identified for the use. 

The dead-end fitting for the enclosing surface metal 
raceway shall be identified for the use. 

(B) Luminaire Hangers. Luminaire hangers installed with 
the flat cable assemblies shall be identified for the use. 

(C) Fittings. Fittings to be installed with flat cable 
assemblies shall be designed and installed to prevent 
physical damage to the cable assemblies. 

(D) Extensions. All extensions from flat cable assemblies 
shall be made by approved wiring methods, within the 
junction boxes, installed at either end of the flat cable 
assembly runs. 

322.56 Splices and Taps. 

(A) Splices. Sphces shall be made in listed junction boxes. 

(B) Taps. Taps shall be made between any phase conductor 
and the grounded conductor or any other phase conductor 
by means of devices and fittings identified for the use. Tap 
devices shall be rated at not less than 15 amperes, or more 



2010 California Electrical Code 



70-177 



322.100 



ARTICLE 324 - FLAT CONDUCTOR CABLE; TYPE FCC 



than 300 volts to ground, and shall be color-coded in 
accordance with the requirements of 322.120(C). 

III. Construction 

322.100 Construction. Flat cable assemblies shall consist 
of two, three, four, or five conductors. 

322.104 Conductors. Flat cable assemblies shall have 
conductors of 10 AWG special stranded copper wires. 

322.112 Insulation. The entire flat cable assembly shall be 
formed to provide a suitable insulation covering all the 
conductors and using one of the materials recognized in 
Table 310.13|a5 for general branch-circuit wiring. 

322.120 Marking. 

(A) Temperature Rating. In addition to the provisions of 
3 10. 1 1, Type FC cable shall have the temperature rating 
durably marked on the surface at intervals not exceeding 
600 mm (24 in.). 

(B) Identification of Grounded Conductor. The 

grounded conductor shall be identified throughout its 
length by means of a distinctive and durable white or gray 
marking. 

FPN: The color gray may have been used in the past as an 
ungrounded conductor. Care should be taken when working 
on existing systems. 

(C) Terminal Block Identification. Terminal blocks 
identified for the use shall have distinctive and durable 
markings for color or word coding. The grounded 
conductor section shall have a white marking or other 
suitable designation. The next adjacent section of the 
terminal block shall have a black marking or other suitable 
designation. The next section shall have a red marking or 
other suitable designation. The final or outer section, 
opposite the grounded conductor section of the terminal 
block, shall have a blue marking or other suitable 
designation. 



]'■■■:■:]■■[.. ARTICLE:324;:. ;/.,:^: 
Flat €o»ductar Cable: Type FCC 



I. General 

324.1 Scope. This article covers a field-installed wiring 
system for branch circuits incorporating Type FCC cable 
and associated accessories as defined by the article. The 
wiring system is designed for installation under carpet 
squares. 



324.2 Definitions. 

Bottom Shield. A protective layer that is installed between 
the floor and Type FCC flat conductor cable to protect the 
cable fi*om physical damage and may or may not be 

incorporated as an integral part of the cable. 

Cable Connector. A connector designed to join Type FCC 
cables without using a junction box. 

FCC System. A complete wiring system for branch circuits 
that is designed for installation under carpet squares. The FCC 
system includes Type FCC cable and associated shielding, 
connectors, terminators, adapters, boxes, and receptacles. 

Insulating End. An insulator designed to electrically 
insulate the end of a Type FCC cable. 

Metal Shield Connections. Means of connection designed 
to electrically and mechanically connect a metal shield to 
another metal shield, to a receptacle housing or self- 
contained device, or to a transition assembly. 

Top Shield. A grounded metal shield covering under- 
carpet components of the FCC system for the purposes of 
providing protection against physical damage. 

Transition Assembly. An assembly to facilitate 
connection of the FCC system to other wiring systems, 
incorporating (1) a means of electrical interconnection and 
(2) a suitable box or covering for providing electrical safety 
and protection against physical damage. 

Type FCC Cable. Three or more flat copper conductors 
placed edge-to-edge and separated and enclosed within an 
insulating assembly. 

324.6 Listing Requirements. Type FCC cable and 
associated fittings shall be listed. 

II. Installation 
324.10 Uses Permitted. 

(A) Branch Circuits. Use of FCC systems shall be 
permitted both for general-purpose and apphance branch 
circuits and for individual branch circuits. 

(B) Branch-Circuit Ratings. 

(1) Voltage. Voltage between ungrounded conductors 
shall not exceed 300 volts. Voltage between ungrounded 
conductors and the grounded conductor shall not exceed 
150 volts. 

(2) Current. General-purpose and appliance branch 
circuits shall have ratings not exceeding 20 amperes. 
Individual branch circuits shall have ratings not exceeding 
30 amperes. 



# 



70-178 



2010 California Electrical Code 



ARTICLE 324 - FLAT CONDUCTOR CABLE: TYPE FCC 



324.56 



(C) Floors. Use of FCC systems shall be permitted on 
hard, sound, smooth, continuous floor surfaces made of 
concrete, ceramic, or composition flooring, wood, and 
similar materials, 

(D) Walls. Use of FCC systems shall be permitted on wall 
surfaces in surface metal raceways. 

(E) Damp Locations. Use of FCC systems in damp 
locations shall be permitted. 

(F) Heated Floors. Materials used for floors heated in 
excess of 30°C (86°F) shall be identified as suitable for use 
at these temperatures. 

(G) System Height. Any portion of an FCC system with a 
height above floor level exceeding 2.3 mm (0.090 in.) shall 
be tapered or feathered at the edges to floor level. 



324.12 Uses Not Permitted. FCC systems shall not be 
used in the following locations: 

(1) Outdoors or in wet locations 

(2) Where subject to corrosive vapors 

(3) In any hazardous (classified) location 

(4) In residential, school, and hospital buildings 

324.18 Crossings. Crossings of more than two Type FCC 
cable runs shall not be permitted at any one point. 
Crossings of a Type FCC cable over or under a flat 
communications or signal cable shall be permitted. In each 
case, a grounded layer of metal shielding shall separate the 
two cables, and crossings of more than two flat cables shall 
not be permitted at any one point. 

324.30 Securing and Supporting. All FCC system 
components shall be firmly anchored to the floor or wall 
using an adhesive or mechanical anchoring system 
identified for this use. Floors shall be prepared to ensure 
adherence of the FCC system to the floor until the carpet 
squares are placed. 

324.40 Boxes and Fittings. 

(A) Cable Connections and Insulating Ends. All Type 
FCC cable connections shall use connectors identified for 
their use, installed such that electrical continuity, 
insulation, and sealing against dampness and liquid spillage 
are provided. All bare cable ends shall be insulated and 
sealed against dampness and liquid spillage using listed 
insulating ends. 

(B) Polarization of Connections. All receptacles and 
connections shall be constructed and installed so as to 
maintain proper polarization of the system. 



(C) Shields. 

(1) Top Shield. A metal top shield shall be installed over 
all floor-mounted Type FCC cable, connectors, and 
insulating ends. The top shield shall completely cover all 
cable runs, comers, connectors, and ends. 

(2) Bottom Shield. A bottom shield shall be installed 
beneath all Type FCC cable, connectors, and insulating 
ends. 

(D) Connection to Other Systems. Power feed, grounding 
connection, and shield system connection between the FCC 
system and other wiring systems shall be accomplished in a 
transition assembly identified for this use. 

(E) Metal-Shield Connectors. Metal shields shall be 
connected to each other and to boxes, receptacle housings, 
self-contained devices, and transition assemblies using 
metal-shield connectors. 

324.41 Floor Coverings. Floor-mounted Type FCC cable, 
cable connectors, and insulating ends shall be covered with 
carpet squares not larger than 914 mm (36 in.) square. 
Carpet squares that are adhered to the floor shall be 
attached with release-type adhesives. 

324.42 Devices. 

(A) Receptacles. All receptacles, receptacle housings, and 
self-contained devices used with the FCC system shall be 
identified for this use and shall be connected to the Type 
FCC cable and metal shields. Connection from any 
grounding conductor of the Type FCC cable shall be made 
to the shield system at each receptacle. 

(B) Receptacles and Housings. Receptacle housings and 
self-contained devices designed either for floor mounting 
or for in- wall or on- wall mounting shall be permitted for 
use with the FCC system. Receptacle housings and self- 
contained devices shall incorporate means for facilitating 
entry and termination of Type FCC cable and for 
electrically connecting the housing or device with the metal 
shield. Receptacles and self-contained devices shall comply 
with 406.3. Power and communications outlets installed 
together in common housing shall be permitted in 
accordance with 800.133(A)(1)(c), Exception No. 2. 

324.56 Splices and Taps. 

(A) FCC Systems Alterations. Alterations to FCC 
systems shall be permitted. New cable connectors shall be 
used at new connection points to make alterations. It shall 
be permitted to leave unused cable runs and associated 
cable connectors in place and energized. All cable ends 
shall be covered with insulating ends. 



2010 California Electrical Code 



70-179 



324.60 



ARTICLE 326 - INTEGRATED GAS SPACER CABLE: TYPE IGS 



(B) Transition Assemblies. All transition assemblies shall 
be identified for their use. Each assembly shall incorporate 
means for facilitating entry of the Type FCC cable into the 
assembly, for connecting the Type FCC cable to grounded 
conductors, and for electrically connecting the assembly to 
the metal cable shields and to equipment grounding 
conductors. 

324.60 Grounding. All metal shields, boxes, receptacle 
housings, and self-contained devices shall be electrically 
continuous to the equipment grounding conductor of the 
supplying branch circuit. All such electrical connections shall 
be made with connectors identified for this use. The electrical 
resistivity of such shield system shall not be more than that of 
one conductor of the Type FCC cable used in the installation. 

III. Construction 

324.100 Construction. 

(A) Type FCC Cable. Type FCC cable shall be listed for 
use with the FCC system and shall consist of three, four, or 
five flat copper conductors, one of which shall be an 
equipment grounding conductor. 

(B) Shields. 

(1) Materials and Dimensions. All top and bottom 
shields shall be of designs and materials identified for their 
use. Top shields shall be metal. Both metallic and 
nonmetallic materials shall be permitted for bottom shields. 

(2) Resistivity. Metal shields shall have cross-sectional 
areas that provide for electrical resistivity of not more than 
that of one conductor of the Type FCC cable used in the 
installation. 

324.101 Corrosion Resistance. Metal components of the 
system shall be either corrosion resistant, coated with 
corrosion-resistant materials, or insulated from contact with 
corrosive substances. 

324.112 Insulation. The insulating material of the cable 
shall be moisture resistant and flame retardant. All 
insulating materials in the FCC systems shall be identified 
for their use. 

324.120 Markings. 

(A) Cable Marking. Type FCC cable shall be clearly and 
durably marked on both sides at intervals of not more than 
610 mm (24 in.) with the information required by 
310.1 1(A) and with the following additional information: 

( 1 ) Material of conductors 

(2) Maximum temperature rating 

(3) Ampacity 

(B) Conductor Identification. Conductors shall be clearly 
and durably identified on both sides throughout their length 
as specified in 310.12. 



^i;V:r;:;^RTIGLE 326,; \.:^/:"r\^ ' 
Integrated Gas Spacer Cable: T^e IGS 

I. General 

326.1 Scope. This article covers the use, installation, and 
construction specifications for integrated gas spacer cable, 
Type IGS. 

326.2 Definition. 

Integrated Gas Spacer Cable, Type IGS. A factory 
assembly of one or more conductors, each individually 
insulated and enclosed in a loose fit, nonmetallic flexible 
conduit as an integrated gas spacer cable rated through 
600 volts. 

II. Installation 

326.10 Uses Permitted. Type IGS cable shall be permitted 
for use under ground, including direct burial in the earth, as 
the following: 

(1) Service-entrance conductors 

(2) Feeder or branch-circuit conductors 

326.12 Uses Not Permitted. Type IGS cable shall not be 
used as interior wiring or be exposed in contact with 
buildings. 

326.24 Bending Radius. Where the coilable nonmetallic 
conduit and cable is bent for installation purposes or is 
flexed or bent during shipment or installation, the radii of 
bends measured to the inside of the bend shall not be less 
than specified in Table 326.24. 

Table 326.24 Minimum Radii of Bends 



Conduit Size 




Minimum Radii 


Metric Designator 


Trade Size 


mm in. 


53 


2 


600 24 


78 


3 


900 35 


103 


4 


1150 45 



326.26 Bends. A run of Type IGS cable between pull 
boxes or terminations shall not contain more than the 
equivalent of four quarter bends (360 degrees total), 
including those bends located immediately at the pull box 
or terminations. 

326.40 Fittings. Terminations and sphces for Type IGS 
cable shall be identified as a type that is suitable for 
maintaining the gas pressure within the conduit. A valve 
and cap shall be provided for each length of the cable and 
conduit to check the gas pressure or to inject gas into the 
conduit. 



70-180 



2010 California Electrical Code 



ARTICLE 328 - MEDIUM VOLTAGE CABLE: TYPE MV 



328.80 



326.80 Ampacity. The ampacity of Type IGS cable shall 
not exceed the values shown in Table 326.80. 



Table 326.80 


Ampacity of Type IGS Cable 




Size (kcmil) 


Amperes 


Size (kcmil) 


Amperes 


250 


119 


2500 


376 


500 


168 


3000 


412 


750 


206 


3250 


429 


1000 


238 


3500 


445 


1250 


266 


3750 


461 


1500 


292 


4000 


476 


1750 


315 


4250 


491 


2000 


336 


4500 


505 


2250 


357 


4750 


519 



in. Construction Specifications 

326.104 Conductors. The conductors shall be solid 

aluminum rods, laid parallel, consisting of one to nineteen 

12.7 mm (Y2 in.) diameter rods. The minimum conductor 

size shall be 250 kcmil, and the maximum size shall be 

4750 kcmil. 

326.112 Insulation. The insulation shall be dry kraft paper 

tapes and a pressurized sulfur hexafluoride gas (SFe), both 

approved for electrical use. The nominal gas pressure shall 

be 138 kPa gauge (20 pounds per square inch gauge). The 

thickness of the paper spacer shall be as specified in Table 

326.112. 

Table 326.112 Paper Spacer Thickness 



Thickness 


Size (kcmil) 


mm 




in. 


250-1000 

1250-4750 


1.02 
1.52 




0.040 
0.060 



326.116 Conduit. The conduit shall be a medium density 
polyethylene identified as suitable for use with natural gas 
rated pipe in metric designator 53, 78, or 103 (trade size 2, 
3, or 4). The percent fill dimensions for the conduit are 
shown in Table 326.1 16. 

The size of the conduit permitted for each conductor size 
shall be calculated for a percent fill not to exceed those 
found in Table 1, Chapter 9. 
Table 326.116 Conduit Dimensions 



Conduit Size 



Actual Outside 
Diameter 



Actual Inside 
Diameter 



Metric 


Trade 










Designator 


Size 


mm 


in. 


mm 


in. 


53 


2 


60 


2.375 


49.46 


1.947 


78 


3 


89 


3.500 


73.30 


2.886 


103 


4 


114 


4.500 


94.23 


3.710 



:J:';;:^j:\--MeitM^ Type:MV. ;': i'-i 

I. General 

328.1 Scope. This article covers the use, installation, 
and construction specifications for medium voltage 
cable, Type MV. 

328.2 Definition. 

Medium Voltage Cable, Type MV. A single or 
multiconductor solid dielectric insulated cable rated 2001 
volts or higher. 

II. Installation 

328.10 Uses Permitted. Type MV cable shall be permitted 
for use on power systems rated up to 35,000 volts nominal 
as follows: 

(1) In wet or dry locations 

(2) In raceways 

(3) fn\ ^aEle Srays, where „ identified for^ t^^ ras6, ih; 
fe<?Prdance^y92^ 



326.120 Marking. The cable shall be marked in 
accordance with 310.11(A), 310.11(B)(1), and 310.1 1(D). 



Exception: ^Type^ MV^bhlkai has an overatV metallic 
^sheath of jirinor, also complies; with the requirements for 
yfype MCcabhyand is identified as . '\MV or MCXsHallbk 
permHted to, be in^taHedin cable trays ih accordance j^itti 

M2,mmM '" "' '^^ ^^'"" ' ""^""^ 

(4) Direct buried in accordance with 300.50 

(5) In messenger-supported wiring ^§ccQ^<^r^'6 wiih^^fB^ 

(6) [p^?$osjeffT55rfi5^^ 

Exception: Typ!Bi^J^fV xdble that; has an overall metalEo, 
Wteath pr^armpK'alsocd^ the requirements fori 

^'ypeMC cabled dfki is t MC'- shall bi 

perinitt^d /d. 'be'' instuUed \gs^ ^^posed jwtsgfjnefql^clad 
'cable' in accprdgnce, yyjth:300J74 

FPN: The ''Uses Permitted" is not an all-inclusive list. 
328.12 Uses Not Permitted.^^^T^^ not be 

usedjWhere exposed to direct sunlight iiiiless ^ identified fo^ 
theusgi 

328.80 Ampacity. The ampacity of Type MV cable shall 
be determined in accordance with 310.60. The ampacity of 
Type MV cable installed in cable tray shall be determined 
in accordance with 392.13. 



III. Construction Specifications 

328.100 Construction. Type MV cables shall have 
copper, aluminum, or copper-clad aluminum conductors 
and shall comply with Table ;5rO:i3(C) and Table 
310.13(D) or Table 310.13(E). 

328.120 Marking. Medium voltage cable shall be marked 
as required by 310.11. 



2010 California Electrical Code 



70-181 



328.100 



ARTICLE 330 - METAL-CLAD CABLE: TYPE MC 



ARTICLE 330 

Metal-Clad Cable: f ype MC 



L General 

330.1 Scope. This article covers the use, installation, and 
construction specifications of metal-clad cable, Type MC. 

330.2 Definition. 

Metal Clad Cable, Type MC. A factory assembly of one or 
more insulated circuit conductors with or without optical 
fiber members enclosed in an armor of interlocking metal 
tape, or a smooth or corrugated metallic sheath. 



II. Installation 

330.10 Uses Permitted. 

(A) General Uses. Type MC cable shall be permitted as 
follows: 

(1) For services, feeders, and branch circuits 

(2) For power, lighting, control, and signal circuits 

(3) Indoors or outdoors 

(4) Exposed or concealed 

(5) To be direct buried where identified for such use 

(6) In cable tray where identified for such use 

(7) In any raceway 

(8) As aerial cable on a messenger 

(9) In hazardous (classified) locations as permitted 

(10) In dry locations and embedded in plaster finish on 
brick or other masonry except in damp or wet locations 

(11) In wet locations where any of the following 
conditions are met: 

a. The metallic covering is impervious to moisture. 

b. A lead sheath or moisture-impervious jacket is 

provided under the metal covering. 

c. The insulated conductors under the metallic 

covering are listed for use in wet locations and a 
corrosion-resistant jacket is provided oyer the 
metallic sheath. 

(12) Where single-conductor cables are used, all phase 
conductors and, where used, the neutral conductor 
shall be grouped together to minimize induced voltage 
on the sheath. 



(B) Specific Uses. Type MC cable shall be permitted to be 
installed in compliance with Parts II and III of Article 725 
and 770.133 as applicable and in accordance with 
330.10(B)(1) through (B)(4). 

(1) Cable Tray. Type MC cable installed in cable tray shall 
comply with 392.3, 392.4, 392.6, and 392.8 through 392.13. 

(2) Direct Buried. Direct-buried cable shall comply with 
300.5 or 300.50, as appropriate. 

(3) Installed as Service-Entrance Cable. Type MC cable 
installed as service-entrance cable shall be permitted in 
accordance with 230.43. 

(4) Installed Outside of Buildings oiv Striietjure^^ or as 
Aerial Cable. Type MC cable installed outside of 
buildings |ojr ;staciures or as aerial cable shall comply with 
225.10, 396.10, and 396.12. 

FPN: The "Uses Pennitted" is not an all-inclusive list. 

330.12 Uses Not Permitted^ Type MC cable shall not be 

used ||g||er;qiffi^ oM|^||loWing,i^^ 

(1) Where subject to physical damage 

(2) Where exposed to| any qf the destructive corrosiye 
conditions m j[a) or (h% .M§k^jJt%. J?i?!,^fU?. ,^^?§ft, or 
armoris resista.nt to 5ie COT protected by 
materialresistaht to the conditions: 



a. 



b. 



Direct buried in the earth or embedded in con^^ 
unless identified^r direct^to 

Exposed to cinder fills, strong chlorides, caustic, 
^jkalis^ or vapors of chlorine or of hydrochloric acidd 

330.17 Through or Parallel to Framing Members. Type MC 
cable shall be protected in accordance with 300.4(A), (C), and 
(D) where installed through or parallel to framing members. 

330.23 In Accessible Attics. The installation of Type MC 
cable in accessible attics or roof spaces shall also comply 
with 320.23. 

330.24 Bending Radius. Bends in Type MC cable shall be 
so made that the cable will not be damaged. The radius of 
the curve of the inner edge of any bend shall not be less 
than required in 330.24(A) through (C). 

(A) Smooth Sheath. 

(1) Ten times the extemal diameter of the metallic sheath for 
cable not more than 19 mm (% in.) in extemal diameter 

(2) Twelve times the extemal diameter of the metalHc sheath 
for cable more than 19 mm (Va in.) but not more than 38 
mm (1/4 in.) in extemal diameter 



70-182 



2010 California Electrical Code 



ARTICLE 330 ~ METAL-CLAD CABLE: TYPE MC 



330.116 



(3) Fifteen times the external diameter of the metaUic sheath 
for cable more than 38 mm (IVi in.) in external diameter 

(B) Interlocked-Type Armor or Corrugated Sheath. 

Seven times the external diameter of the metallic sheath. 

(C) Shielded Conductors. Twelve times the overall diameter 
of one of the individual conductors or seven times the overall 
diameter of the multiconductor cable, whichever is greater. 

330.30 Securing and Supporting. 

(A) General. Type MC cable shall be supported and 
secured by staples, cable ties, straps, hangers, or similar 
fittings or other approved means designed and installed so 
as not to damage the cable. 

(B) Securing. Unless otherwise provided, cables shall be 
secured at intervals not exceeding 1.8 m (6 ft). Cables 
containing four or fewer conductors sized no larger than 10 
AWG shall be secured within 300 mm (12 in.) of every 
box, cabinet, fitting, or other cable termination. 

(C) Supporting. Unless otherwise provided, cables shall 
be supported at intervals not exceeding 1.8 m (6 ft). 

Horizontal runs of Type MC cable installed . in wooden or 
metal framing members or similar supporting means shall 
be considered supported and secured where such support 
does not exceed 1.8-m (6-ft) intervals. 

(D) Unsupported Cables. Type MC cable shall be 
permitted to be unsupported where the cable: 

(1) Is fished between access points through concealed 
spaces in finished buildings or structures and 
supporting is impractical; or 

(2) Is not more than 1.8 m (6 ft) in length fi-om the last 
point of cable support to the point of connection to 
luminairej or other electrical equipment and the cable 
and point of connection are within an accessible 
ceiling. For the purpose of this section, Type MC cable 
fittings shall be permitted as a means of cable support. 

330.31 Single Conductors. Where single-conductor 
cables with a nonferrous armor or sheath are used, the 
installation shall comply with 300.20. 

330.40 Boxes and Fittings. Fittings used for connecting 
Type MC cable to boxes, cabinets, or other equipment shall 
be listed and identified for such use. 

330.80 Ampacity. The ampacity of Type MC cable shall 
be detennined in accordance with 310.15 or 310.60 for 14 
AWG and larger conductors and in accordance with Table 
402.5 for 18 AWG and 16 AWG conductors. The 
installation shall not exceed the temperature ratings of 
terminations and equipment. 



(A) Type MC Cable Installed in Cable Tray. The 

ampacities for Type MC cable installed in cable tray shall 
be determined in accordance with 392. II and 392. 13. 

(B) Single Type MC Conductors Grouped Together. 

Where single Type MC conductors are grouped together in 
a triangular or square configuration and installed on a 
messenger or exposed with a maintained free airspace of 
not less than 2.15 times one conductor diameter (2.15 x 
O.D.) of the largest conductor contained within the 
configuration and adjacent conductor configurations or 
cables, the ampacity of the conductors shall not exceed the 
allowable ampacities in the following tables: 

(1) Table 310.20 for conductors rated through 2000 volts 

(2) Table 310.67 and Table 310.68 for conductors rated over 
2000 vohs 



III. Construction Specifications 

330.104 Conductors. Conductors shall be of copper, 

aluminum, copper-clad aluminum, nipkej. -0^ nickelrC-oateS 
itoppetj, solid or stranded. The minimum conductor size 
shall be 18 AWG copper, mckgl^jr^yMckg 
and 12 AWG aluminum or copper-clad aluminum. 

330.108 Equipment Grounding Coiiductor. Where Type 
MC cable is used to provide m equipment grounding 
conductorj it shall comply with 250.1 18(10) and 250. 122. 

330.112 Insulation. Insulated conductors shall comply 
with 330.1 12(A) or (B). 

(A) 600 Volts. Insulated conductors in sizes 18 AWG and 
16 AWG shall be of a type listed in Table 402.3, with a 
maximum operating temperature not less than 90°C 
(194°F).and as permitted by 725.49. Conductors larger than 
16 AWG shall be of a type listed in Table 310.13(A) or of a 
type identified for use in Type MC cable. 

(B) Over 600 Volts. Insulated conductors shall be of a type 
Hsted in Table 310.13(C) through Table 310.13(E). 

330.116 Sheath. Metallic covering shall be one of the 
following types: smooth metallic sheath, corrugated 
metallic sheath, interlocking metal tape armor. The metallic 
sheath shall be continuous and close fitting. A nonmagnetic 
sheath or armor shall be used on single conductor Type 
MC. Supplemental protection of an outer covering of 
corrosion-resistant material shall be permitted and shall be 
required where such protection is needed. The sheath shall 
not be used as a current-carrying conductor. 

FPN: See 300.6 for protection against corrosion. 



2010 California Electrical Code 



70-183 



332.1 



ARTICLE 332 ~ MINERAL-INSULATED, METAL-SHEATHED CABLE: TYPE MI 



ARTICLE 332 

Mineral-Insulated^ Metal-Sheathed 
Gable: Type MI 



I. General 

332.1 Scope. This article covers the use, installation, and 
construction specifications for mineral-insulated, metal- 
sheathed cable. Type MI. 

332.2 Definition. 

Mineral-Insulated, Metal-Sheathed Cable, Type MI. A factory 
assembly of one or more conductors insulated with a highly 
compressed refectory mineral insulation and enclosed in a 
hquidtight and gastight continuous copper or alloy steel sheath. 



II. Installation 

332.10 Uses Permitted. Type MI cable shall be permitted 
as follows: 

(1) For services, feeders, and branch circuits 

(2) For power, Hghting, control, and signal circuits 

(3) In dry, wet, or continuously moist locations 

(4) Indoors or outdoors 

(5) Where exposed or concealed 

(6) Where embedded in plaster, concrete, fill, or other 

masonry, whether above or below grade 

(7) In any hazardous (classified) location 

(8) Where exposed to oil and gasoHne 

(9) Where exposed to corrosive conditions not 

deteriorating to its sheath 

(10) In underground runs where suitably protected against 

physical damage and corrosive conditions 

(11) In or attached to cable tray 

FPN: The "Uses Permitted" is not an all-inclusive list. 

332.12 Uses Not Permitted. Type MI cable shall not be 
used under the following conditions or in the following 
locations: 

(1) In underground runs unless protected from physical 
damage, where necessary 

(2) Where exposed to conditions that are destructive and 
corrosive to the metallic sheath, unless additional 
protection is provided 



332.17 Through or Parallel to Framing Members. Type 
MI cable shall be protected in accordance with 300.4 where 
installed through or parallel to framing members. 

332.24 Bending Radius. Bends in Type MI cable shall be so 
made that the cable will not be damaged. The radius of the inner 
edge of any bend shall not be less than required as follows: 

(1) Five times the external diameter of the metalhc sheath 
for cable not more than 19 mm (Va in.) in external 
diameter 

(2) Ten times the external diameter of the metalUc sheath 
for cable greater than 19 mm (Va in.) but not more than 
25 mm (1 in.) in external diameter 

332.30 Securing and Supporting. Type MI cable shall be 
supported and secured by staples, straps, hangers, or 
similar fittings, designed and installed so as not to damage 
the cable, at intervals not exceeding 1.8 m (6 ft). 

(A) Horizontal Runs Through Holes and Notches. In 

other than vertical runs, cables installed in accordance with 
300.4 shall be considered supported and secured where 
such support does not exceed 1.8 m (6 ft) intervals. 

(B) Unsupported Cable. Type MI cable shall be permitted 
to be unsupported where the cable is fished between access 
points through concealed spaces in finished buildings or 
structures and supporting is impracticable. 

(C) Cable Trays. All MI cable installed in cable trays shall 
comply with 392.8(B). 

332.31 Single Conductors. Where single-conductor 
cables are used, all phase conductors and, where used, the 
neutral conductor shall be grouped together to minimize 
induced voltage on the sheath. 

332.40 Boxes and Fittings. 

(A) Fittings. Fittings used for connecting Type MI cable to 
boxes, cabinets, or other equipment shall be identified for 
such use. 

(B) Terminal Seals. Where Type MI cable terminates, an 
end seal fitting shall be installed immediately after 
stripping to prevent the entrance of moisture into the 
insulation. The conductors extending beyond the sheath 
shall be individually provided with an insulating material. 

332.80 Ampacity. The ampacity of Type MI cable shall be 
determined in accordance with 310.15. The conductor 
temperature at the end seal fitting shall not exceed the 
temperature rating of the listed end seal fitting, and the 
installation shall not exceed the temperature ratings of 
terminations or equipment. 



70-184 



2010 California Electrical Code 



ARTICLE 334 - NONMETALLIC- SHEATHED CABLE: TYPES NM, NMC, AND NMS 



334.10 



(A) Type MI Cable Installed in Cable Tray. The 

ampacities for Type MI cable installed in cable tray shall 
be determined in accordance with 392. 1 1 . 

(B) Single Type MI Conductors Grouped Together. 

Where single Type MI conductors are grouped together in 
a triangular or square configuration, as required by 332.31, 
and installed on a messenger or exposed with a maintained 
free air space of not less than 2.15 times one conductor 
diameter (2.15 x O.D.) of the largest conductor contained 
within the configuration and adjacent conductor 
configurations or cables, the ampacity of the conductors 
shall not exceed the allowable ampacities of Table 310.17. 

III. Construction Specifications 

332.104 Conductors. Type MI cable conductors shall be 
of solid copper, nickel, or nickel-coated copper with a 
resistance corresponding to standard AWG and kcmil sizes. 

332.108 Equipment Grounding Conductor* Where the 
outer sheath js 5^de of copper, jt shall provide an adequate 
path Ip s^0 as a^ condmctar. Wher^| 

jiie ;0Uter |t&^ ofste^l^ a separate equipment 

grounding conductor shall be provided. 

332.112 Insulation. The conductor insulation in Type MI 
cable shall be a highly compressed refractory mineral that 
provides proper spacing for all conductors. 

332.116 Sheath. The outer sheath shall be of a continuous 
construction to provide mechanical protection and moisture 
seal. 



'ARfflGljE:334^^ 



Nonilietallic-Sheathed Cable: Types NM, 



L General 

334.1 Scope. This article covers the use, installation, and 
construction specifications of nonmetaUic-sheathed cable. 

334.2 Definitions. 

Nonmetallic -Sheathed Cable. A factory assembly of two or 
more insulated conductors enclosed within an overall 
nonmetallic jacket. 

Type NM. Insulated conductors enclosed within an overall 
nonmetallic jacket. 

Type NMC. Insulated conductors enclosed within an 

overall, corrosion resistant, nonmetallic jacket. 

Type NMS. Insulated power or control conductors with 

signaling, data, and communications conductors within an 

overall nonmetallic jacket. 

334.6 Listed. Type NM, Type NMC, and Type NMS 

cables shall be listed. 



11. Installation 

334.10 Uses Permitted. Type NM, Type NMC, and Type 
NMS cables shall be permitted to be used in the following: 

(1) One- and two-family dwellings. 

(2) Multifamily dwellings permitted to be of Types III, IV, 
and V construction except as prohibited in 334.12. 

(3) Other structures permitted to be of Types III, IV, and V 
construction except as prohibited in 334.12. Cables 
shall be concealed within walls, floors, or ceilings that 
provide a thermal barrier of material that has at least a 
15 -minute finish rating as identified in hstings of fire- 
rated assemblies. 

FPN No. 1: Types of building construction and occupancy 
classifications are defined in NFPA 220-1999, Standard on C 
Types of Building Construction, or the applicable building A 
code, or both. 

FPN No. 2: See Annex E for determination of building 
types [NFPA 220, Table 3-1]. 

(4) Cable trays in structures permitted to be Types III, IV, 
or V where the cables are identified for the use. 

FPN: See 310.10 for temperature limitation of conductors. 

Note: [HCD 1 and HCD 2] Types III, IV, and V construction as q 
referenced in Section 334.10 items (2), (3), and (4) shall be as f^ 
defined in Title 24, Part 2, California Building Code. q 

(A) Type NM. Type NM cable shall be permitted as 
follows: 

(1) For both exposed and concealed work in normally dry 
locations except as prohibited in 334.10(3) 

(2) To be installed or fished in air voids in masonry block 
or tile walls 

(B) Type NMC. Type NMC cable shall be permitted as 
follows: 

(1) For both exposed and concealed work in dry, moist, 
damp, or corrosive locations, except as prohibited by 
334.10(3) 

(2) In outside and inside walls of masonry block or tile 

(3) In a shallow chase in masonry, concrete, or adobe 
protected against nails or screws by a steel plate at 
least 1.59 mm (1/16 in.) thick and covered with 
plaster, adobe, or similar finish 

(C) Type NMS. Type NMS cable shall be permitted as 
follows: 

(1) For both exposed and concealed work in normally dry 
locations except as prohibited by 334.10(3) 

(2) To be installed or fished in air voids in masonry block 
or tile walls 

334.12 Uses Not Permitted. 

(A) Types NM, NMC, and NMS. Types NM, NMC, and 
NMS cables shall not be permitted as follows: 

(1) In any dwelling or structure not specifically permitted 
in 334,10(1), (2), and (3) 



2010 California Electrical Code 



70-185 



334.12 



ARTICLE 332 - MINERAL-INSULATED, METAL-SHEATHED CABLE: TYPE MI 



Exception: 'fyp^:^NM,^^ NMQJgnd ^ -NMS cable shall be 
perfniked in f^ when instalied 

'Within raceways permitted id %e instaJled in Type I and U 
cgnstructipn. 

C Note: [HCD 1 and HCD 2] Types I and II construction as 
A referenced in Section 334.12 item(l) Exception shall be as 
C defined in Title 24, Part 2, California Building Code. 

(2) Exposed in dropped or suspended ceilings in other than 
one- and two- family and multifamily dwellings 

(3) As service-entrance cable 

(4) In commercial garages having hazardous (classified) 
locations as defined in 51:13 

(5) In theaters and similar locations, except where 

permitted in 5 18.4(B) 

(6) In motion picture studios 

(7) In storage battery rooms 

(8) In hoistways or on elevators or escalators 

(9) Embedded in poured cement, concrete, or aggregate 

(10) In hazardous (classified) locations, except where 
permitted by the following: 

a. 501.10(B)(3) 

b. 502.10(B)(3) 

c. 504.20 

(B) Types NM and NMS. Types NM and NMS cables 
shall not be used under the following conditions or in the 
following locations: 

(1) Where exposed to corrosive fumes or vapors 

(2) Where embedded in masonry, concrete, adobe, fill, or 
plaster 

(3) In a shallow chase in masonry, concrete, or adobe and 
covered with plaster, adobe, or similar finish 

(4) In w# or darnp locations 

334.15 Exposed Work. In exposed work, except as 
provided in 300.11(A), cable shall be installed as specified 
in 334.15(A) through (C). 

(A) To Follow Surface. Cable shall closely follow the 
surface of the building finish or of running boards. 

(B) Protection from Physical Damage. Cable shall be 
protected from physical damage where necessary by rigid 
metal conduit, intermediate metal conduit, electrical 
metallic tubing, Schedule 80 PVC conduit, or other 
approved means. Where passing through a floor, the cable 
shall be enclosed in rigid metal conduit, intermediate metal 
conduit, electrical metallic tubing. Schedule 80 PVC 



conduit, or other approved means extending at least 150 
mm (6 in.) above the floor. 

Type NMC cable installed in shallow chases pr 
grooves, in masonry, concrete, or adobe, shall be protected 
m accc^dancej^vjffih and 

covered with plaster, adobe, or similar finish. 

(C) In Unfinished Basements jind Crawl Spaces. Where 
cable is run at angles with joists in unfinished basements 

^i^d crawt 'Sp^^^^^ it shall be permissible to secure cables 
not smaller than two 6 AWG or three 8 AWG conductors 
directly to the lower edges of the joists. Smaller cables 
shall be run either through bored holes in joists or on 
running boards. NM cable installed on the wall of an 
unfinished basement shall be permitted to be installed in a 
listed conduit or tubing or jshall be protected in accordance 
with 30(X4- Conduit or tubing shall be provided with a 
smtabk imuiatmg bushing or adapter at the point the cable 
enters the raceway. Jhe NM cable sheath shall extend 
through the conduit o4 tubing; and into the outlet or device 
box not less than 6 m The cable shall be secured 

;witMn3W nm ^^ where the cable enters 

the con^^ Metal conduit, tubing, and metal 

outlet boxes shall be c|>nnected to aii equipment grounding 
conductor^: ^^ 

334.17 Through or Parallel to Framing Members, ^^w 

Types NM, NMC, or NMS cable shall be protected in 
accordance with 300.4 where installed through or parallel 
to framing members. Grommets used as required in 
300.4(B)(1) shall remain in place and be listed for the 
purpose of cable protection. 

334.23 In Accessible Attics. The installation of cable in 
accessible attics or roof spaces shall also comply with 

320.23. 

334.24 Bending Radius. Bends in Types NM, NMC, and 
NMS cable shall be so made that the cable will not be 
damaged. The radius of the curve of the inner edge of any 
bend during or after installation shall not be less than five 
times the diameter of the cable. 

334.30 Securing and Supporting. Nonmetallic-sheathed 
cable shall be supported and secured by staples, cable ties, 
straps, hangers, or similar fittings designed and installed so 
as not to damage the cable, at intervals not exceeding 1 .4 m 
(4V2 ft) and within 300 mm (12 in.) of every outlet box, 
junction box, cabinet, or fitting. Flat cables shall not be 
stapled on edge. 

Sections of cable protected from physical damage by 
raceway shall not be required to be secured within the 
raceway. 



70-186 



2010 California Electrical Code 



ARTICLE 334 - NONMETALLIC-SHEATHED CABLE: TYPES NM, NMC, AND NMS 



334.116 



(A) Horizontal Runs Through Holes and Notches. In 

other than vertical runs, cables installed in accordance with 
300.4 shall be considered to be supported and secured 
where such support does not exceed 1.4-m (4V2-ft) intervals 
and the nonmetallic-sheathed cable is securely fastened in 
place by an approved means within 300 mm (12 in.) of 
each box, cabinet, conduit body, or other nonmetallic- 
sheathed cable termination. 

FPN: See 314.17(C) for support where nonmetallic boxes 
are used. 

(B) Unsupported Cables. Nonmetallic-sheathed cable 
shall be permitted to be unsupported where the cable: 

(1) Is fished between access points through concealed 
spaces in finished buildings or structures and 
supporting is impracticable. 

(2) Is not more than 1.4 m (4/4 ft) from the last point of 
cable support to the point of connection to a luminaire 
or other piece of electrical equipment and the cable 
and point of connection are within an accessible 
ceiling. 

(C) Wiring Device Without a Separate Outlet Box. A 

wiring device identified for the use, without a separate 
outlet box, and incorporating an integral cable clamp shall 
be permitted where the cable is secured in place at intervals 
not exceeding 1.4 m (4!/2 ft) and within 300 mm (12 in.) 
from the wiring device wall opening, and there shall be at 
least a 300 mm (12 in.) loop of unbroken cable or 150 mm 
(6 in.) of a cable end available on the interior side of the 
finished wall to permit replacement. 

334.40 Boxes and Fittings. 

(A) Boxes of Insulating Material. Nonmetallic outlet 
boxes shall be permitted as provided by 314.3. 

(B) Devices of Insulating Material; Switch, outlet, and tap 
devices of insulating material shall be permitted to be used 
without boxes in exposed cable wiring and for rewiring in 
existing buildings where the cable is concealed and fished. 
Openings in such devices shall form a close fit around the 
outer covering of the cable, and the device shall frilly 
enclose the part of the cable from which any part of the 
covering has been removed. Where connections to 
conductors are by binding-screw terminals, there shall be 
available as many terminals as conductors. 

(C) Devices with Integral Enclosures. Wiring devices 
with integral enclosures identified for such use shall be 
permitted as provided by 300.15(E). 

334.80 Ampacity. The ampacity of Types NM, NMC, and 
NMS cable shall be determined in accordance with 310.15. 
The ampacity shall be in accordance with the 60^C (HO'^F) 



conductor temperature rating. The 90°C (194°F) rating 
shall be permitted to be used for ampacity derating 
purposes, provided the final derated ampacity does not 
exceed that for a 60°C (140°F) rated conductor. The 
ampacity of Types NM, NMC, and NMS cable installed in 
cable tray shall be determined in accordance with 392. 1 1 . 

Where more than two NM cables containing two or 
more current-carrying conductors are iBStaited^i^TOltiQUt 

ppening in[ wood framing that is to be fire- or draft-stopped 
using thermal insulation, cautfc^ or sealing foam, the 
allowable ampacity of each conductor shall be adjusted in 
accordance with Table 310.15(B)(2)(a) knd thepTOvimom 

bf 3 j p. j;5(A)(2),^ Exc^^ 

jWJiere more thaii two NM .^?]i?I?§ -^PO^^i^^S !^ 



more ciiirent-car^ 

gdirti^Jhermd 

jbetweea cables, &e alb wable ampacity of each coaduqto^ 

shall be adjusted in accordmi^cewidi^ X?!?M ?l9f lKW^)i^):: 



III. Construction Specifications 

334.100 Construction. The outer cable sheath of 
nonmetallic-sheathed cable shall be a nonmetallic material 

334.104 Conductors. The 600-volt insulated conductors 
shall be sizes 14 AWG through 2 AWG copper conductors 
or sizes 12 AWG through 2 AWG aluminum or copper- 
clad aluminum conductors. The jcommumcations; 
conductors shall comply with Part V of Article 800. 

334.108 Equipment Grounding iConducte^^^ In addition 
to the insulated conductors, the cable shall have an 
insulated, |Dpvere3j or bare b^uipment grounding conductor, 

334.112 Insulation. The insulated power conductors shall be 
one of the types listed in Table 310.13j;A3 that are suitable for 
branch-circuit wiring or one that is identified for use in these 
cables. Conductor insulation shall be rated at 90°C (194°F). 

FPN: Types NM, NMC, and NMS cable identified by the 
markings NM-B, NMC-B, and NMS-B meet this 
requirement. 

334.116 Sheath. The outer sheath of nonmetallic-sheathed 
cable shall comply with 334.1 16(A), (B), and (C). 

(A) Type NM. The overall covering shall be flame 
retardant and moisture resistant. 

(B) Type NMC. The overall covering shall be flame 
retardant, moisture resistant, fiingus resistant, and corrosion 
resistant. 



2010 California Electrical Code 



70-187 



336.1 



ARTICLE 336 ~ POWER AND CONTROL TRAY CABLE: TYPE TC 



(C) Type NMS. The overall covering shall be flame 
retardant and moisture resistant. The sheath shall be 
applied so as to separate the power conductors from the 
communications conductors. 



ARTICLE 336 

Power aiid Control Tray Cable: Type TC 

I. General 

336.1 Scope. This article covers the use, installation, and 
construction specifications for power and control tray 
cable, Type TC. 

336.2 Definition. 

Power and Control Tray Cable, Type TC. A factory 
assembly of two or more insulated conductors, with or 
without associated bare or covered grounding conductors, 
under a nonmetallic jacket. 

II. Installation 

336.10 Uses Permitted. Type TC cable shall be permitted 

to be used as follows: 

(1) For power, lighting, control, and signal circuits. 

(2) In cable trays. 

(3) In raceways. 

(4) In outdoor locations supported by a messenger wire. 

(5) For Class 1 circuits as permitted in Parts II and III of 
Article 725. 

(6) For non-power-limited fire alarm circuits if conductors 
comply with the requirements of 760.49. 

(7) In industrial establishments where the conditions of 
maintenance and supervision ensure that only qualified 
persons service the installation, and where the cable is 
continuously supported and protected against physical 
damage using mechanical protection, such as struts, 
angles, or channels, Type TC tray cable that complies 
with the crush and impact requirements of Type MC 
cable and is identified for such use with the marking 
Type TC-ER shall be permitted between a cable tray 
and the utilization equipment or device. The cable shall 
be secured at intervals not exceeding 1.8 m (6 ft). 
Equipment grounding for the utilization equipment shall 
be provided by an equipment grounding conductor 
within the cable. In cables containing conductors sized 6 
AWG or smaller, the equipment grounding conductor 
shall be provided within the cable or, at the time of 
installation, one or more insulated conductors shall be 
permanently identified as an equipment grounding 
conductor in accordance with 250.1 19(B). 



Exception: Wltere not subject to physical 0mqge, Typ^ TC-ER 
shall be permitted to tramiiionibetween cable frays and between 
cablS trays and vtilkation equipment gt decides for a distance 
pot to exceed LS m (6 ft) without cohtinygus support. The cable 
'shall be mechanically supported Where exiting the cable tray to 
'ensure that the minimum bending radius is, not exceeded: 

(8) Where installed in wet locations, Type TC cable shall 
also be resistant to moisture and corrosive agents. 

FPN: See 310.10 for temperature limitation of conductors. 

336.12 Uses Not Permitted. Type TC tray cable shall not 
be installed or used as follows: 

(1) Installed where it will be exposed to physical damage 

(2) Installed outside a raceway or cable tray system, except 
as permitted in 336.10(7) 

(3) Used where exposed to direct rays of the sun, unless 
identified as sunlight resistant 

(4) Direct buried, unless identified for such use 

336.24 Bending Radius. Bends in Type TC cable shall be 
made so as not to damage the cable. For Type TC cable 
without metal shielding, the minimum bending radius shall 
be as follows: 

(1) Four times the overall diameter for cables 25 mm (1 
in.) or less in diameter 

(2) Five times the overall diameter for cables larger than 25 
mm (1 in.) but not more than 50 mm (2 in.) in diameter 

(3) Six times the overall diameter for cables larger than 50 
mm (2 in.) in diameter 

Type TC cables with metallic shielding shall have a 
minimum bending radius of not less than 12 times the cable 
overall diameter. 

336.80 Ampacity. The ampacity of Type TC tray cable 
shall be determined in accordance with 392. 11 for 14 AWG 
and larger conductors, in accordance with 402.5 for 18 
AWG through 16 AWG conductors where installed in 
cable tray, and in accordance with 310.15 where installed 
in a raceway or as messenger-supported wiring. 

III. Construction Specifications 

336.100 Construction. A metallic sheath or armor as 
defined in 330.116 shall not be permitted either under or 
over the nonmetallic jacket. Metallic shield(s) shall be 
permitted over groups of conductors, under the outer 
jacket, or both. 

336.104 Conductors. The insulated conductors of Type 
TC cables shall be in sizes 18 AWG to; 1000 kcmil copper, 
moke], or nickel-coatedj copper j and sizes 12 AWG through 
1000 kcmil aluminum or copper-clad aluminum. Insulated 
conductors of sizes 14 AWG, and larger copper, nickel, or 
bickel-coated copp^, and sizes 12 AWG through iOOQ 



70-1 e 



2010 California Electrical Code 



ARTICLE 338 - SERVICE-ENTRANCE CABLE: TYPE SE AND USE 



^38.12 



jtciqiil aluminum or copper-clad aluminum shall be one of 
the types listed in Table 310.13(A) or Table 310.1 3(B) that 
is suitable for branch circuit and feeder circuits or one that 
is identified for such use. 

(A) Fire Alarm Systems. Where used for fire alarm 
systems, conductors shall also be in accordance with 760 .p9] 

(B) Thermocouple Circuits. Conductors in Type TC cable 
used for thermocouple circuits in accordance with Part III 
of Article 725 shall also be permitted to be any of the 
materials used for thermocouple extension wire. 

(C) Class 1 Circuit Conductors. Insulated conductors of 
18 AWG and 16 AWG copper shall also be in accordance 
with 725.49; 

336.116 Jacket. The outer jacket shall be a flame- 
retardant, nonmetallic material. 

336.120 Marking. There shall be no voltage marking on a 
Type TC cable employing thermocouple extension wire. 



■ :; Sferyi|e^]B^itr^^ SE aiid;:XJSi;1:j 

I. General 

338.1 Scope. This article covers the use, installation, and 
construction specifications of service-entrance cable. 

338.2 Definitions. 

Service-Entrance Cable. A single conductor or 
multiconductor assembly provided with or without an 
overall covering, primarily used for services, and of the 
following types: 

Type SE. Service-entrance cable having a flame-retardant, 
moisture-resistant covering. 

Type USE. Service-entrance cable, identified for 
underground use, having a moisture-resistant covering, but 
not required to have a flame-retardant covering. 

II. Installation 

338.10 Uses Permitted. 

(A) Service-Entrance Conductors. Service-entrance cable 
shall be permitted to be used as service-entrance 
conductors and shall be installed in accordance with 230.6, 
230.7, and Parts II, III, and IV of Article 230. 



(B) Branch Circuits or Feeders. 

(1) Grounded Conductor Insulated. Type SE service- 
entrance cables shall be permitted in wiring systems where 
all of the circuit conductors of the cable are of the 
ihermosai or thermoplastic type. 

(2) Grounded Conductor Not Insulated. Type SE 

service -entrance cable shall be permitted for use where the 
insulated conductors are used for circuit wiring and the 
uninsulated conductor is used only for equipment 
grounding purposes. 

Exception: Uninsulated conductors shall be permitted as a 
grounded conductor in accordance with250J2 and 250:140 
'Wh&e th$ uninsulated grounded conductor of jH^^^ 
priginates in service equipmenty and 225.30 through 225.40. 

(3) Temperature Limitations. Type SE service -entrance 
cable used to supply appliances shall not be subject to 
conductor temperatures in excess of the temperature 
specified for the type of insulation involved. 

(4) Installation Methods for Branch Circuits and 
Feeders. 

(a) Interior Installations. In addition to the provisions 
of this article, Type SE service-entrance cable used for 
interior wiring shall comply with the installation 
requirements of Part II of Article 334. 

FPN: See 310.10 for temperature limitation of conductors. 

(b) Exterior Installations. In addition to the 
provisions of this article, service-entrance cable 
used for feeders or branch circuits, where installed 
as exterior wiring, shall be installed in accordance 
with Part I of Article 225. The cable shall be 
supported in accordance with 334.30. Type USE 
cable installed as underground feeder and branch 
circuit cable shall comply with Part II of Article 
340. 



338.12 tlses;Npt Permitted^ 

(A) SeiTvice-Eiitrance Cable* Service-entrance cable (SEJ 
^all hot ;be xised under tihe loilQwing conditims ofinthe 
Ipllowinglpcations: 

(1) ^WSer^ subject to physicaf damage uiileiss^^ 
accordance with 230.50(A) 

(2) Underground with or withaiit a raceway 

(3) For exterior braEi^h circiiits arid feeder wiring unless 
the installation complies; with the provisions of Part I 
of ^tic|e;:225 apd is; in accoriiance with 
=53430; or is ;iusea as; m^^senger-supportedj^^ 
'^kxm^^mj!^ il :6| Ajrticfe 396 



2010 California Electrical Code 



70-189 



338.24 



ARTICLE 340 -UNDERGROUND FEEDER AND BRANCH-CIRUIT CABLE: TYPE UF 



(B) Ujttdergroiittd Se^^ Cable. Underground 

servjce-ealrance cable (USE) shall not be used uader the 
lollowing COTditions pr 1b the jfollowmg tocatiqns: 

(1) Fox intMQOKM^S 

(2) For above^omdriosM 

feimerges from J:hegroimd and k^t^^ an; 

enciosrire at an outdoor location and the cable i$ 
protected in accordance with 300,5(0)! 

(3) 1^ aerial cable jmless it is a .midfeondt*ctof cable 

^ssenger-sn|)£^5djj wto ^in^l^accordance^^^ with 
22510 anCfS^n of Arti 

338.24 Bending Radius. Bends in Types USE and SE 
cable shall be so made that the cable will not be damaged. 
The radius of the curve of the inner edge of any bend, 
during or after installation, shall not be less than five times 
the diameter of the cable. 



III. Construction 

338.100 Construction. Cabled, single-conductor. Type USE 
constructions recognized for underground use shall be 
permitted to have a bare copper conductor cabled with the 
assembly. Type USE single, parallel, or cabled conductor 
assemblies recognized for underground use shall be permitted 
to have a bare copper concentric conductor apphed. These 
constructions shall not require an outer overall covering. 

FPN: See 230.41, Exception, item (2), for directly buried, 
uninsulated service-entrance conductors. 

Type SE or USE cable containing two or more 
conductors shall be permitted to have one conductor 
uninsulated. 

338.120 Marking. Service-entrance cable shall be marked 
as required in 310.11. Cable with the neutral conductor 
smaller than the ungrounded conductors shall be so marked. 

; Underground Feeder and jSrattch^Circiiit 

l\<--: .:. :'^:; ■i!:Cabll€: TypeUF::;::j^:-\; ';■ :'/[':,■■ j 

I. General 

340.1 Scope. This article covers the use, installation, and 
construction specifications for underground feeder and 
branch-circuit cable, Type UF. 

1 340.2 Definition. 

Underground Feeder and Branch- Circuit Cable, Type UF. 
A factory assembly of one or more insulated conductors 



with an integral or an overall covering of nonmetallic 
material suitable for direct burial in the earth. 

340.6 Listing Requirements. Type UF cable shall be listed. 

II. Installation 

340.10 Uses Permitted. Type UF cable shall be permitted 

as follows: 

(1) For use underground, including direct burial in the 
earth. For underground requirements, see 300.5. 

(2) As single-conductor cables. Where installed as single- 
conductor cables, all conductors of the feeder grounded 
conductor or branch circuit, including the grounded 
conductor and equipment grounding conductor, if any, 
shall be installed in accordance with 300.3. 

(3) For wiring in wet, dry, or corrosive locations under the 
recognized wiring methods of this Code. 

(4) Installed as nonmetallic-sheathed cable. Where so 
installed, the installation and conductor requirements 
shall comply with Parts II and III of Article 334 and 
shall be of the multiconductor type. 

(5) For solar photovoltaic systems in accordance with 690.3 1 . 

(6) As single-conductor cables as the nonheating leads for 
heating cables as provided in 424.43. 

(7) Supported by cable trays. Type UF cable supported by 
cable trays shall be of the multiconductor type. 

FPN: See 310.10 for temperature limitation of conductors. 
340.12 Uses Not Permitted. Type UF cable shall not be 
used as follows: 

(1) As service-entrance cable 

(2) In commercial garages 

(3) In theaters and similar locations 

(4) In motion picture studios 

(5) In storage battery rooms 

(6) In hoistways or on elevators or escalators 

(7) In my hazardous (classified) location, eicepj; as 
pftewise permitted^ 

(8) Embedded in poured cement, concrete, or aggregate, 
except where embedded in plaster as nonheating leads 
where permitted in 424.43 

(9) Where exposed to direct rays of the sun, unless 
identified as sunlight resistant 

(10) Where subject to physical damage 

(11) As overhead cable, except where installed as 
messenger-supported wiring in accordance with Part 
II of Article 396 

340.24 Bending Radius. Bends in Type UF cable shall be 
so made that the cable is not damaged. The radius of the 
curve of the inner edge of any bend shall not be less than 
five times the diameter of the cable. 

340.80 Ampacity. The ampacity of Type UF cable shall be 
that of 60°C (140^F) conductors in accordance with 310.15. 



70-190 



2010 California Electrical Code 



ARTICLE 342 - INTERMEDIATE METAL CONDUIT: TYPE IMC 



342.26 



III. Construction Specifications 

340.104 Conductors. The conductors shall be sizes 14 
AWG copper or 12 AWG aluminum or copper-clad 
aluminum through 4/0 AWG. 

340.108 Equipment Grounding jConductpn In addition 
to the insulated conductors, the cable shall be permitted to 
have an insulated or bare equipment grounding conductor. 

340.112 Insulation. The conductors of Type UF shall be one 
of the moisture-resistant types listed in Table 310.13(AJ that is 
suitable for branch-circuit wiring or one that is identified for 
such use. Where installed as a substitute wiring method for NM 
cable, the conductor insulation shall be rated 90°C (194°F). 

340.116 Sheath. The overall covering shall be flame 
retardant; moisture, fungus, and corrosion resistant; and 
suitable for direct burial in the earth. 



„.jr-' ARTICLE.342 
; Ihteiljmediate Metal^ type IMC 

I. General 

342.1 Scope. This article covers the use, installation, and 
construction specifications for intermediate metal conduit 
(IMC) and associated fittings. 

342.2 Definition. 

Intermediate Metal Conduit (IMC). A steel threadable 
raceway of circular cross section designed for the physical 
protection and routing of conductors and cables and for use 
as an equipment grounding conductor when installed with 
its integral or associated coupling and appropriate fittings. 

342.6 Listing Requirements. IMC, factory elbows and 
couplings, and associated fittings shall be listed. 

II. Installation 
342.10 Uses Permitted. 

(A) All Atmospheric Conditions and Occupancies. Use 

of IMC shall be permitted under all atmospheric condidons 
and occupancies. 

(B) Corrosion Environments. IMC, elbows, couplings, 
and fittings shall be permitted to be installed in concrete, in 
direct contact with the earth, or in areas subject to severe 
corrosive influences where protected by corrosion 
protection and judged suitable for the condition. 



(C) Cinder Fill. IMC shall be permitted to be installed in or 
under cinder fill where subject to permanent moisture where 
protected on all sides by a layer of noncinder concrete not 
less than 50 mm (2 in.) thick; where the conduit is not less 
than 450 mm (18 in.) under the fill; or where protected by 
corrosion protection and judged suitable for the condition. 

(D) Wet Locations. All supports, bolts, straps, screws, and 
so forth, shall be of corrosion-resistant materials or 
protected against corrosion by corrosion-resistant materials. 

FPN: See 300.6 for protection against corrosion. 

342.14 Dissimilar Metals, Where practicable, dissimilar 
metals in contact anywhere in the system shall be avoided 
to eliminate the possibility of galvanic action. 

Aluminum fittings and enclosures shall be permitted to 
be used with IMC. 

342.20 Size. 

(A) Minimum. IMC smaller than metric designator 16 
(trade size Vi) shall not be used. 

(B) Maximum. IMC larger than metric designator 103 
(trade size 4) shall not be used. 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

342.22 Number of Conductors. The number of 
conductors shall not exceed that permitted by the 
percentage fill specified in Table 1, Chapter 9. 

Cables shall be permitted to be installed where such use is 
not prohibited by the respective cable articles. The number 
of cables shall not exceed the allowable percentage fill 
specified in Table I, Chapter 9. 

342.24 Bends — How Made. Bends of IMC shall be so 
made that the conduit will not be damaged and the internal 
diameter of the conduit will not be effectively reduced. The 
radius of the curve of any field bend to the centerline of the 
conduit shall not be less than indicated in Table 2, Chapter 9. 

342.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 



2010 California Electrical Code 



70-191 



342,28 



ARTICLE 344 -RIGID METAL CONDUIT: TYPE RMC 



342.28 Reaming and Threading. All cut ends shall be 
reamed or otherwise finished to remove rough edges. Where 
conduit is threaded in the field, a standard cutting die with a 
taper of 1 in 16 (Va in. taper per foot) shall be used. 

FPN: See ANSI/ASME B.1.20.1-1983, Standard for Pipe 
Threads, General Purpose (Inch). 

342.30 Securing and Supporting. IMC shall be installed 
as a complete system in accordance with 300.18 and shall 
be securely fastened in place and supported in accordance 
with 342.30(A) and (B), or pennitted to be xmsupported iri 
accordance with 34230(C). 

(A) Securely Fastened. Each IMC shall be securely 
fastened within 900 mm (3 ft) of each outlet box, junction 
box, device box, cabinet, conduit body, or other conduit 
termination. Fastening shall be permitted to be increased to 
a distance of 1.5 m (5 ft) where structural members do not 
readily permit fastening within 900 mm (3 ft). Where 
approved, conduit shall not be required to be securely 
fastened within 900 mm (3 ft) of the service head for 
above-the-roof termination of a mast. 

(B) Supports. IMC shall be supported in accordance with 
one of the following: 

(1) Conduit shall be supported at intervals not exceeding 3 
m(lOft). 

(2) The distance between supports for straight runs of 
conduit shall be permitted in accordance with Table 
344.30(B)(2), provided the conduit is made up with 
threaded couplings and such supports prevent 
transmission of stresses to termination where conduit 
is deflected between supports. 

(3) Exposed vertical risers from industrial machinery or 
fixed equipment shall be permitted to be supported at 
intervals not exceeding 6 m (20 ft) if the conduit is 
made up with threaded couplings, the conduit is 
supported and securely fastened at the top and bottom 
of the riser, arid no other means of intermediate 
support is readily available. 

(4) Horizontal runs of IMC supported by openings through 
fi-aming members at intervals not exceeding 3 m (10 ft) 
and securely fastened within 900 mm (3 ft) of 
termination points shall be permitted. 

(C) ^tlnsugported - Rac^^^ ^ pyer^ized, 'conceiitrid 
pr eccentric knockouts are not encountered^ Type, IMC) 
shall be permitted to be unsupported where the raceway i^ 
not more than 450 mm (18 in.) ajQd remains in unbroken 
lengths (without coupling); Such raceways shall terminate 
in an outlet box, junction box, device box, cabinet, or oti^i: 
termination at each end of tiie raceway. 



342.42 Couplings and Connectors. 

(A) Threadless. Threadless couplings and connectors used 
with conduit shall be made tight. Where buried in masonry 
or concrete, they shall be the concretetight type. Where 
installed in wet locations, they shall comply with 314.15. 
Threadless couplings and connectors shall not be used on 
threaded conduit ends unless listed for the purpose. 

(B) Running Threads. Running threads shall not be used 
on conduit for connection at couplings. 

342.46 Bushings. Where a conduit enters a box, fitting, or 
other enclosure, a bushing shall be provided to protect the 
wire from abrasion unless the design of the box, fitting, or 
enclosure is such as to afford equivalent protection. 

FPN: See 300.4(G) for the protection of conductors 4 AWG 
and larger at bushings. 

342.56 Splices and Taps. Splices and taps shall be made 
in accordance with 300.15. 

342.60 Grounding. IMC shall be permitted as an 
equipment grounding conductor. 



III. Construction Specifications 

342.120 Marking. Each length shall be clearly and 
durably marked at least every 1.5 m (5 ft) with the letters 
IMC. Each length shall be marked as required in 1 10.21. 

342.130 Standard Lengths. The standard length of IMC 
shall be 3.05 m (10 ft), including an attached coupHng, and 
each end shall be threaded. Longer or shorter lengths with 
or without coupling and threaded or unthreaded shall be 
permitted. 



AI^TIGLE344 
iUgidMetyi Conduits RMC 



I. General 

344.1 Scope. This article covers the use, installation, and 
construction specifications for rigid metal conduit (RMC) 
and associated fittings. 

344.2 Definition. 

Rigid Metal Conduit (RMC). A threadable raceway of 
circular cross section designed for the physical protection 
and routing of conductors and cables and for use as an 
equipment grounding conductor when installed with its 
integral or associated coupling and appropriate fittings. 
RMC is generally made of steel (ferrous) with protective 
coatings or aluminum (nonferrous). Special use types are 
red brass and stainless steel. 



• 



70-192 



2010 California Electrical Code 



ARTICLE 344 - RIGID METAL CONDUIT: TYPE RMC 



344.30 



344.6 Listing Requirements. RMC, factory elbows and 
couplings, and associated fittings shall be listed. 

II. Installation 

344.10 Uses Permitted. 

(A) Atmospheric Conditions and Occupancies. 

j^i) Galvaiifeed $^^ St^l RMC Galvan^ 

st^el and : stainless steej RMC shall be permitted tinder all 
atmospheric conditions and occupancies. 

{2} Red 6rass SMC Kedbrass RMC shall beperrrritted to be 
installed for direct btirial and swimming pool application^;; 

i(3)'j;Jj^^ RMC.^i^ RMC shaUjbe |}en^^ 

h^^m^^^i .^here judg^;suiy^^^ 

aitMnurn! condiiit enea^Sd in concrete or in direct contact with 
\M eaSh I shall he prnvidift. . ^^i approved si5)piementary 
coitosion protecSon. 

(4) Ferrijus Raceways and |1ttiiigs. Ferrous raceways and 
fittings protected from corrosion solely by enamel shall be 
permitted only indoors and in occupancies not subject to severe 
corrosive influences. 



(BJ Cp>rrtf^^ Environments. 

(ij > Galvkirized StersfaiiUe^ISteel^ and Red Bms 'ftMgi 
Elbows, fcottpffiagi^ and FiMng$. Galvani^ steely stainksd 
steel, andired bra^s RMC elbows, couplings, and fittings shall 
be permitted to be installed in concrete, in direct contact with 
the earth, or in areas subject to severe corrosive influences 
where protected by corrosion protection and judged suitable for 
the condition. 

j(2X_Supplementaix„.F^ I'pt AluiMnyumj;!^ 

Ifiuminum RMjC Jshall provided with approved 

suppiementaiy corrosion 'proifeclion where encased in concrete 
or in direct coo^t with the e^: 

(C) Cinder Fill. Galvanized steel, stainless steel, wd red 

brass RMC shall be permitted to be installed in or under 
cinder fill where subject to permanent moisture where 
protected on all sides by a layer of noncinder concrete not 
less than 50 mm (2 in.) thick; where the conduit is not less 
than 450 mm (18 in.) under the fill; or where protected by 
corrosion protection and judged suitable for the condition. 

(D) Wet Locations. All supports, bolts, straps, screws, and 
so forth, shall be of corrosion-resistant materials or 
protected against corrosion by corrosion-resistant materials. 

FPN: See 300.6 for protection against corrosion. 



344.14 Dissimilar Metals. Where practicable, dissimilar 
metals in contact anywhere in the system shall be avoided 
to ehminate the possibility of galvanic action. Aluminum 
fittings and enclosures shall be permitted to be used with 
steel RMC, and steel fittings and enclosures shall be 
permitted to be used with aluminum RMC where not 
subject to severe corrosive influences. 

344.20 Size. 

(A) Minimum. RMC smaller than metric designator 16 
(trade size Yi) shall not be used. 

Exception: For enclosing the leads of motors as permitted 
in 430.245(B). 

(B) Maximum. RMC larger than metric designator 155 
(trade size 6) shall not be used. 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

344.22 Number of Conductors. The number of 
conductors shall not exceed that permitted by the 
percentage fill specified in Table 1, Chapter 9. 

Cables shall be permitted to be installed where such use is 
not prohibited by the respective cable articles. The number 
of cables shall not exceed the allowable percentage fill 
specified in Table 1, Chapter 9. 

344.24 Bends — How Made. Bends of RMC shall be so 
made that the conduit will not be damaged and so that the 
internal diameter of the conduit will not be effectively 
reduced. The radius of the curve of any field bend to the 
centerline of the conduit shall not be less than indicated in 
Table 2, Chapter 9. 

344.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

344.28 Reaming and Threading. All cut ends shall be 
reamed or otherwise finished to remove rough edges. 
Where conduit is threaded in the field, a standard cutting 
die with a 1 in 16 taper (%-in. taper per foot) shall be used. 

FPN: See ANSI/ASME B. 1.20. 1-1983, Standard for Pipe 
Threads, General Purpose (Inch). 

344.30 Securing and Supporting. RMC shall be installed 
as a complete system in accordance with 300.18 and shall 
be securely fastened in place and supported in accordance 
with 344.30(A) and (B) jor permitted; to be unsupported iri 
jaccordancewfth 34430(C). 



2010 California Electrical Code 



70-193 



344.42 



ARTICLE 348 -FLEXIBLE METAL CONDUIT; TYPE FMC 



(A) Securely Fastened. RMC shall be securely fastened 
within 900 mm (3 ft) of each outlet box, junction box, 
device box, cabinet, conduit body, or other conduit 
termination. Fastening shall be permitted to be increased to 
a distance of 1 .5 m (5 ft) where structural members do not 
readily permit fastening within 900 mm (3 ft). Where 
approved, conduit shall not be required to be securely 
fastened within 900 mm (3 ft) of the service head for 
above-the-roof termination of a mast. 

(B) Supports. RMC shall be supported in accordance with 
one of the following: 

(1) Conduit shall be supported at intervals not exceeding 3 
m(lOft). 

(2) The distance between supports for straight runs of 
conduit shall be permitted in accordance with Table 
344.30(B)(2), provided the conduit is made up with 
threaded couplings and such supports prevent 
transmission of stresses to termination where conduit 
is deflected between supports. 

(3) Exposed vertical risers from industrial machinery or 
fixed equipment shall be permitted to be supported at 
intervals not exceeding 6 m (20 ft) if the conduit is 
made up with threaded coupHngs, the conduit is 
supported and securely fastened at the top and bottom 
of the riser, and no other means of intermediate 
support is readily available. 

(4) Horizontal runs of RMC supported by openings 
through framing members at intervals not exceeding 3 
m (10 ft) and securely fastened within 900 mm (3 ft) of 
termination points shall be permitted. 

Table 344.30(B)(2) Supports for Rigid Metal Conduit 







Maximum Distance 






Between Rigid Metal 


Conduit Size 


Conduit Supports 


Metric 






Designator 


Trade Size 


m ft 


16-21 


Vi-V. 


3.0 10 


27 


1 


3.7 12 


35-^1 


VA-VA 


4.3 14 


53-63 


l-VA 


4.9 16 


78 and larger 


3 and larger 


6.1 20 



^i(Cy;'UrtSttpparte^ ::ilaceway.s* Whete. dyersizei. boilcenfie 
jor eccentric knockputsj atre: pot; bncouiit^ed^ 1)^^ = W:^^ 
sMl b0 ^permitted: to be uii^u|^fted^ where tK^; rac^^v^ is^ 
tot rtiore than 450 mrri 0i;8 ii^i)Jaixd:. remains iniinibrbkiri 
lengths' (without coupling); 'Sucliracewa3fr^ shall ^temiiiiate 
in an outlet box^ junction boxVdevic^box^c^ 
terminaticm at each cMjbf the.^tabev^ 



344.42 Couplings and Connectors. 

(A) Threadless. Threadless couplings and connectors used 
with conduit shall be made tight. Where buried in masonry 
or concrete, they shall be the concretetight type. Where 
installed in wet locations, they shall comply with 314.15. 
Threadless couplings and connectors shall not be used on 
threaded conduit ends unless listed for the purpose. 

(B) Running Threads. Running threads shall not be used 
on conduit for connection at couplings. 

344.46 Bushings. Where a conduit enters a box, fitting, or 
other enclosure, a bushing shall be provided to protect the 
wire from abrasion unless the design of the box, fitting, or 
enclosure is such as to afford equivalent protection. 

FPN: See 300.4(G) for the protection of conductors sizes 4 
AWG and larger at bushings. 

344.56 Splices and Taps. SpUces and taps shall be made 
in accordance with 300.15. 

344.60 Grounding. RMC shall be permitted as an 
equipment grounding conductor. 



III. Construction Specifications 

344.120 Marking. Each length shall be clearly and 
durably identified in every 3 m (10 ft) as required in the 
first sentence of 110.21. Nonferrous conduit of corrosion- 
resistant material shall have suitable markings. 

344.130 Standard Lengths. The standard length of RMC 
shall be 3.05 m (10 ft), including an attached coupling, and 
each end shall be threaded. Longer or shorter lengths with 
or without coupling and threaded or unthreaded shall be 
permitted. 



:;:.;r;:ARTICLE 34R ^- 
Flexible Metk Conduit: l^pfeFlNiC 



I. General 

348.1 Scope. This article covers the use, installation, and 
construction specifications for flexible metal conduit 
(FMC) and associated fittings. 

348.2 Definition. 

Flexible Metal Conduit (FMC). A raceway of circular cross 
section made of helically wound, formed, interlocked metal 
strip. 



70-194 



2010 California Electrical Code 



ARTICLE 348 - FLEXIBLE METAL CONDUIT: TYPE FMC 



348.30 



348.6 Listing Requirements. FMC and associated fittings 
shall be listed. 



II. Installation 

348.10 Uses Permitted. FMC shall be permitted to be 
used in exposed and concealed locations. 

348.12 Uses Not Permitted. FMC shall not be used in the 
following: 

(1) Igv^etfoc^tio'B^ 

(2) In hoistways, other than as permitted in 620.21(A)(1) 

(3) In storage battery rooms 

(4) In any hazardous (classified) location except asi 

permitted % other articles m^^^^ 

(5) Where exposed to materials having a deteriorating 

effect on the installed conductors, such as oil or 
gasohne 

(6) Underground or embedded in poured concrete or 

aggregate 

(7) Where subject to physical damage 

348.20 Size. 

(A) Minimum. FMC less than metric designator 16 (trade 
size Yi) shall not be used unless permitted in 348.20(A)(1) 
through (A)(5) for metric designator 12 (trade size 3/8). 

(1) For enclosing the leads of motors as permitted in 
430.245(B) 

(2) In lengths not in excess of 1.8 m (6 ft) for any of the 
following uses: 

a. For utilization equipment 

b. Aspart of a listed assembly 

c. For tap connections to luminaires as permitted in 

410.;n7(C) 

(3) For manufactured wiring systems as permitted in 
604.6(A) 

(4) In hoistways as permitted in 620.21(A)(1) 

(5) As part of a listed assembly to connect wired luminaire 
sections as permitted in 410.[|||(C) 

Table 348.22 Maximum Number of Insulated Conductors in Metric 



(B) Maximum. FMC larger than metric designator 103 
(trade size 4) shall not be used. 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

348.22 Number of Conductors. The number of 
conductors shall not exceed that permitted by the 
percentage fill specified in Table 1, Chapter 9, or as 
permitted in Table 348.22, or for metric designator 12 
(trade size 3/8). 

Cables shall be permitted to be installed where such 
use is not prohibited by the respective cable articles. The 
number of cables shall not exceed the allowable percentage 
fill specified in Table 1, Chapter 9. 

348.24 Bends — How Made. Bends in conduit shall be made 
so that the conduit is not damaged and the intemal diameter of 
the conduit is not effectively reduced. Bends shall be permitted 
to be made manually without auxiliary equipment. The radius of 
the curve to the centerline of any bend shall not be less than 
shown in Table 2, Chapter 9 using the column "Other Bends." 

348.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

348.28 Trimming. All cut ends shall be trimmed or 
otherwise finished to remove rough edges, except where 
fittings that thread into the convolutions are used. 

348.30 Securing and Supporting. FMC shall be securely 
fastened in place and supported in accordance with 
348.30(A) and (B). 

(A) Securely Fastened. FMC shall be securely fastened in 
place by an approved means within 300 mm (12 in.) of 
each box, cabinet, conduit body, or other conduit 
termination and shall be supported and secured at intervals 
not to exceed 1.4 m (4!/2 ft). 

Designator 12 (Trade Size 3/8) Flexible Metal Conduit* 





Types RFH-2, SF-2 


Types TF, 


XHHW, TW 


Types TFN, THHN, THWN 


Types FEP, FEBP, PF, PGF 


Size 
(AWG) 


Fittings 

Inside 

Conduit 


Fittings 
Outside 
Conduit 


Fittings 

Inside 

Conduit 


Fittings 
Outside 
Conduit 


Fittings 

Inside 

Conduit 


Fittings 
Outside 
Conduit 


Fittings 

Inside 

Conduit 


Fittings 
Outside 
Conduit 


18 


2 


3 


3 


5 


5 


8 


5 


8 


16 


1 


2 


3 


4 


4 


6 


4 


6 


14 


1 


2 


2 


3 


3 


4 


3 


4 


12 


— 


— 


1 


2 


2 


3 


2 


3 


10 


— 


— 


1 


1 


1 


1 


1 


2 



*In addition, one jtisiilated,- covered or bare equipment grounding conductor of the same size shall be permitted. 



2010 California Electrical Code 



70-195 



348.42 



ARTICLE 350 -LIQUIDTIGHT FLEXIBLE METAL CONDUIT: TYPE LFMC 



Exception No. I: Where FMC is fished bep^een access, 
points through concealed spaces, m buildings 6t 

sttuctures arid supporting is impractical. 

Exception No. 2: Where flexibility is necessary after 
imtaUation, lengths shall not exceed the following: 

(1) 900 mm (3 ft) for metric designators 16 through 35 
(trade sizes V2 through I V4) 

(2) 1200 mm (4 ft) for metric designators 41 through 
53 (trade sizes IV2 through 2) 

(3) 1500 mm (5 ft) for metric designators 63 (trade 
size 2V2) and larger 

Exception No. 3: Lengths not exceeding 1.8 m (6 ft) from a 

luminaire terminal connection for tap connections to 

luminaires as permitted in 410.JI?:(C). 

Exception No. 4: Lengths not exceeding 1.8 m (6 ft) from 

the last point where the raceway is securely fastened for 

connections within an accessible ceiling to luminaire(s) or 

other equipment. 

(B) Supports. Horizontal runs of FMC supported by 

openings through framing members at intervals not greater 

than 1.4 m (4/4 fl) and securely fastened within 300 mm 

(12 in.) of termination points shall be permitted. 

348.42 Couplings and Connectors. Angle connectors 

shall not be used for concealed raceway installations. 

348.56 Splices and Taps. Splices and taps shall be made 

in accordance with 300.15. 

348.60 Grounding and Bonding. Where used to connect 

equipment where flexibility is required ;afl;er instaliation, an 

equipment grounding conductor shall be installed. 

Where flexibility is not required after mstaltation, 
FMC shall be permitted to be used as an equipment 
grounding conductor when installed in accordance with 
250.118(5). 

Where required or installed, equipment grounding 
conductors shall be installed in accordance with 
250.134(B). 

Where required or installed, equipment bonding 
jumpers shall be installed in accordance with 250.102. 

■ ^ ARTICLE'350 / 

Liquidtight Flerible Metal Conduit: Type 

'■■■ LFMC-':";;\ 

I. General 

350.1 Scope. This article covers the use, installation, and 
construction specifications for liquidtight flexible metal 
conduit (LFMC) and associated fittings. 



350.2 Definition. 

Liquidtight Flexible Metal Conduit (LFMC). A raceway 
of circular cross section having an outer liquidtight, 
nonmetallic, sunlight-resistant jacket over an inner flexible 
metal core with associated couplings, connectors, and 
fittings for the installation of electric conductors. 

350.6 Listing Requirements. LFMC and associated 
fittings shall be listed. 

II. Installation 

350.10 Uses Permitted. LFMC shall be permitted to be 

used in exposed or concealed locations as follows: 

(1) Where conditions of installation, operation, or 
maintenance require flexibility or protection from 
liquids, vapors, or solids 

(2) As permitted by 501.10(B), 502.10, 503.10, and 504.20 
and in other hazardous (classified) locations where 
specifically approved, and by 553.7(B) 

(3) For direct burial where listed and marked for the 
purpose 

350.12 Uses Not Permitted. LFMC shall not be used as 
follows: 

(1) Where subject to physical damage 

(2) Where any combination of ambient and conductor 
temperature produces an operating temperature in 
excess of that for which the material is approved 

350.20 Size. 

(A) Minimum. LFMC smaller than metric designator 16 
(trade size Vi) shall not be used. 

Exception: LFMC of metric designator 12 (trade size 3/8) 
shall be permitted as covered in 348.20(A). 

(B) Maximum. The maximum size of LFMC shall be 
metric designator 103 (trade size 4). 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

350.22 Number of Conductors or Cables. 

(A) Metric Designators 16 through 103 (Trade Sizes Vi 
through 4). The number of conductors shall not exceed that 
permitted by the percentage fill specified in Table 1 , Chapter 9. 

Cables shall be permitted to be installed where such use is 
not prohibited by the respective cable articles. The number 
of cables shall not exceed the allowable percentage fill 
specified in Table 1, Chapter 9. 



70-196 



2010 Califomia Electrical Code 



ARTICLE 352 - RIGID POLYVINYL CHLORIDE CONDUIT: TYPE PVC 



352.10 



(B) Metric Designator 12 (Trade Size 3/8). The number 
of conductors shall not exceed that permitted in Table 
348.22, "Fittings Outside Conduit" columns. 

350.24 Bends — How Made. Bends in conduit shall be so 
made that the conduit will not be damaged and the internal 
diameter of the conduit will not be effectively reduced. 
Bends shall be permitted to be made manually without 
auxiliary equipment. The radius of the curve to the 
centerline of any bend shall not be less than required in 
Table 2, Chapter 9 using the column "Other Bends." 

350.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

350.30 Securing and Supporting. LFMC shall be 
securely fastened in place and supported in accordance 
with 350.30(A) and (B). 

(A) Securely Fastened. LFMC shall be securely fastened 
in place by an approved means within 300 mm (12 in.) of 
each box, cabinet, conduit body, or other conduit 
termination and shall be supported and secured at intervals 
not to exceed 1.4 m (AVi ft). 

Exception No. 1: Where LFMC is fished between access 
points thfpugh concealed spaces in finished buildings or 
stnicture^and supporting is imprgcticql 

Exception No, 2: Where flexlbiHty is jiecessary after 
installatiSn, lengths shall not excmd the fal^^ 

(1) 9Q0 mm (3 ft) for metric designators ,1 6 through SS 

(trade sizes ¥2 through ^ / §| 

'63ftrgde}izesJJ£thr^^^ 

(3) \l5d0 mm Q ft) for metric designators 63 (trade^ 

'size Ifij: dnd^ Idf^^K 

Exception No. 3: Lengths not exceeding L8 m (6 ft) from a 
luminaire terminal connection for tap conductors to 
luminaires, as permitted in 410Ai{^C). 

Exception No. 4: Lengths not exceeding L8 m (6 ft) from 
the last point where the raceway is securely fastened for 
connections within an accessible ceiling to luminaire(s) or 
other equipment. 

(B) Supports. Horizontal runs of LFMC supported by 
openings through framing members at intervals not greater 
than 1.4 m {AVi ft) and securely fastened within 300 mm 
(12 in.) of termination points shall be permitted. 

350.42 Couplings and Connectors. Angle connectors 
shall not be used for concealed raceway installations. 



350.56 Splices and Taps. Splices and taps shall be made 
in accordance with 300.15. 

350.60 Grounding and Bonding. Where used to connect 
equipment where flexibility is required iafter;iipistkliat^ an 
equipment grounding conductor shall be installed. 

Where flexibility is not required after jinstajto 
LFMC shall be permitted to be used as an equipment 
grounding conductor when installed in accordance with 
250.118(6). 

Where required or installed, equipment grounding 
conductors shall be installed in accordance with 
250.134(B). 

Where required or installed, equipment bonding 
jumpers shall be installed in accordance with 250.102. 

FPN: See 501.30(B), 502.30(B), 503.30(B), 505.25(B)J;,and 
506J25(B) for types of equipment grounding conductors. 

III. Construction Specifications 

350.120 Marking. LFMC shall be marked according to 
110.21. The trade size and other information required by 
the listing shall also be marked on the conduit. Conduit 
suitable for direct burial shall be so marked. 



ARTICLE 352 

Rigid Polyvinyl Chloride Conduit: tj^^^ 

I. General 

352.1 Scope. This article covers the use, installation, and 
construction specifications for rigid pQiyyinyi chloride 
conduit (PyC) and associated fittings. 

FFN; Refer to Article 353 for j&igh Density Polyethylene 
CoTi&itt: Type HDPEj and Article 355 for Reinforced 
Thermosetting Resin Conduit: Type RTRC j 

352.2 Definition. 

Rigid jPolyvinyl , Chloride' Conduit i(PyC);.; A rigiS 
nonmetallic condiujt (RNC) of circular cross section, with 
integral or associated couplings, connectors, and fittings for 
the installation of electrical conductors and cables. 

352.6 Listing Requirements. PVC conduit, factory 
elbows, and associated fittings shall be listed. 

II. Installation 

352.10 Uses Permitted. The use of PVC'^O^Mt shall be 
permitted in accordance with 352.10(A) through (H). 



2010 California Electrical Code 



70-197 



352.12 



ARTICLE 352 -RIGID POLYVINYL CHLORIDE CONDUIT: TYPE PVC 



c 

A 
C 
A 
C 



FPN: Extreme cold may cause some nonmetallic conduits to 
become brittle and, therefore, more susceptible to damage 
from physical contact. 

(A) Concealed. FVC c^^S^ shall be permitted in walls, 
floors, and ceilings. __ 

(B) Corrosive Influences. Pyc!poii(juil shall be permitted 
in locations subject to severe corrosive influences as 
covered in 300.6 and where subject to chemicals for which 
the materials are spe cifically approved. 

(C) Cinders-iPy^G^onduit shall be permitted in cinder fill. 

(D) Wet Locations. PVC^lcpTKlmt shall be permitted in 
portions of dairies, laundries, canneries, or other wet 
locations, and in locations where walls are frequently 
washed, the entire conduit system, including boxes and 
fittings used therewith, shall be installed and equipped so 
as to prevent water from entering the conduit. All supports, 
bolts, straps, screws, and so forth, shall be of corrosion- 
resistant materials or be protected against corrosion by 
approved corrosion-resistant materials. 

(E) Dry and Damp Locations. I^CJgcpi&ii shall be 
permitted for use in dry and damp locations not prohibited 
by 352.12. 

(F) Exposed. PVC conduil shall be permitted for exposed 
work. PVC conduit used exposed iti aieas; of physidat 
damage shall be identified for theusei 

'fPN:J>VC' Conduit,: Tyi0^.S€^^:m,]-^:''id^^ 

atea%6tp.^y&i<?^ d|t.mageJ 
(G)Underground Installations. For underground 
installations,^ fo and. n6fiKomogerious'PVC;^hali 

i>e permitted for; difect^b aild undetgrouiid eticased in 
boiictetej See 300.5 and 300.50! 

(H) Support of Conduit Bodies. PVG conduit shall be 
permitted to support nonmetallic conduit bodies not larger 
than the largest trade size of an entering raceway. These 
conduit bodies shall not support luminaires or other 
equipment and shall not contain devices other than splicing 
devices as permitted by 110.14(B) and 314.16(C)(2). 
352.12 Uses Not Permitted. RNC shall not be used under the 
following conditions. 

[OSHPD I 2, 3 & 4] PVC conduit shall not be used under the 
conditions specified in 352.12 (A) through (F) 

(A) Hazardous (Classified) Locations. In any hazardous 
(classified) location, except as permitted bj^tithe^jgrt^ 

# 

(B) Support of Luminaires. For the support of luminaires 
or other equipment not described in 352.10(H). 

(C) Physical Damage. Where subject to physical damage 
unless identified for such use. 

(D) Ambient Temperatures, Where subject to ambient 
temperatures in excess of 50°C (122^F) unless listed 
otherwise. 

(E) Insulation Temperature Limitations. For conductors 

or cables operating at a temperature higher than the PVC 
conduit listed operating temperature rating. 



Exception: Conductors or cables rated at a temperature 
higher than the 'PVC^con^uii^ listed temperature rating 
shall be permitted to be installed in ^^&4p^^^M^ provided 
they are not operated at a temperature higher than the 
¥Y^j^P^4'^ii listed temperature rating. 

(F) Theaters and Similar Locations. In theaters and 
similar locations, except as provided in 518.4 and 520.5. 

352.20 Size. 

(A) Minimum. IPVp condiiii smaller than metric 
designator 16 (trade size Vi) shall not be used. 



(B) Maximum. fNC cpk&M larger than metric designator 
155 (trade size 6) shall not be used. 

FPN: The trade sizes and metric designators are for 
identification purposes only and do not relate to actual 
dimensions. See 300.1(C). 

352.22 Number of Conductors. The number of 
conductors shall not exceed that permitted by the 
percentage fill specified in Table 1, Chapter 9. 

Cables shall be permitted to be installed where such use is 
not prohibited by the respective cable articles. The number 
of cables shall not exceed the allowable percentage fill 
specified in Table 1, Chapter 9. 

352.24 Bends — How Made. Bends shall be so made that 
the conduit will not be damaged and the internal diameter 
of the conduit will not be effectively reduced. Field bends 
shall be made only with bending equipment identified for 
the purpose. The radius of the curve to the centerline of such 
bends shall not be less than shown in Table 2, Chapter 9. 

352.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

352.28 Trimming. All cut ends shall be trimmed inside 
and outside to remove rough edges. 

352.30 Securing and Supporting. PVG^condu^ shall be 
installed as a complete system as provided in 300.18 and 
shall be fastened so that movement from thermal expansion 
or contraction is permitted. iKjOiS^^sl ^^^^^ be securely 
fastened and supported in accordance with 352.30(A) and 
(B) lor ^pei™fed--tb^':;|ejj^ 



70-198 



2010 California Electrical Code 



ARTICLE 352 - RIGID POLYVINYL CHLORIDE CONDUIT: TYPE PVC 



352,56 



(A) Securely Fastened. PTGJcoMmt shall be securely 
fastened within 900 mm (3 ft) of each outlet box, junction 
box, device box, conduit body, or other conduit 
termination. Conduit listed for securing at other than 900 
mm (3 ft) shall be permitted to be installed in accordance 
with the listing. 

(B) Supports. PVC comiuit shall be supported as required 
in iTaBlel 35230. Conduit listed for support at spacings 
other than as shown in Tabl^:352 J^^ shall be permitted to 
be installed in accordance with the listing. Horizontal runs 
^f WiSj&lMM supported by openings through framing 
members at intervals not exceeding those in Table 352.30 
and securely fastened within 900 mm (3 ft) of termination 
points shall be permitted. 

Table 352.30 Support of Rigid Polyvinyl Chloride Conduit (PVC) 







Maximum Spacing 


Between 


Conduit Size 


Supports 




Metric 








Designator 


Trade Size 


mm or m 


ft 


16-27 


Vi-l 


900 mm 


3 


35-53 


l%-2 


1.5 m 


5 


63-78 


2^/2-3 


1.8 m 


6 


91-129 


31/2-5 


2.1m 


7 


155 


6 


2.5 m 


8 



]?^:J!9§^fi^S!.fe?pfews^^are^ not enc6tin&e4^J-FVC 

not mo^e Ijim and remattis in unbroken 

lengths (wtHoTJl; coupiia^^^ Sii^h raceway sh^il fcOTinate in 
an outlet bqxj. junction box^ device box^; cabinet, or. ^^^^^ 
termination at each end of th^ 

352.44 Expansion Fittings. Expansion fittings for PVC 
conduit shall be provided to compensate for thermal expansion 
and contraction where the length change, in accordance with 
Table! 3 §2:44] is expected to be 6 mm (% in.) or greater in a 
straight run between securely mounted items such as boxes, 
cabinets, elbows, or other conduit terminations. 

352.46 Bushings. Where a conduit enters a box, fitting, or 
other enclosure, a bushing or adapter shall be provided to 
protect the wire from abrasion unless the box, fitting, or 
enclosure design provides equivalent protection. 

FPN: See 300.4(G) for the protection of conductors 4 AWG 
and larger at bushings. 

352.48 Joints. All joints between lengths of conduit, and 
between conduit and couplings, fittings, and boxes, shall be 
made by an approved method. 

352.56 Splices and Taps. Splices and taps shall be made 
in accordance with 300.15. 



Table 352.44 Expansion Characteristics of PVC Rigid Nonmetallic Conduit Coefficient of Thermal Expansion 
mm/mm/°C (3.38 x l0-5 in./in./°F) 



6.084 X 10-5 



Temperature 


Length 




Temperature 


Length 


Temperature 


Length Change of PVC Conduit 


Change 


Change of 




Change 


Change of 


Change 


(in./100 ft) 


(°C) 


PVC Conduit 
(mm/m) 




(-F) 


PVC Conduit 
(in./100 ft) 


(°F) 




5 


0.30 




5 


0.20 


105 


4.26 


10 


0.61 




10 


0.41 


110 


4.46 


15 


0.91 




15 


0.61 


115 


4.66 


20 


1.22 




20 


0.81 


120 


4.87 


25 


1.52 




25 


1.01 


125 


5.07 


30 


1.83 




30 


1.22 


130 


5.27 


35 


2.13 




35 


1.42 


135 


5.48 


40 


2.43 




40 


1.62 


140 


5.68 


45 


2.74 




45 


1.83 


145 


5.88 


50 


3.04 




50 


2.03 


150 


6.08 


55 


3.35 




55 


2.23 


155 


6.29 


60 


3.65 




60 


2.43 


160 


6.49 


65 


3.95 




65 


2.64 


165 


6.69 


70 


4.26 




70 


2.84 


170 


6.90 


75 


4.56 




75 


3.04 


175 


7.10 


80 


4.87 




80 


3.24 


180 


7.30 


85 


5.17 




85 


3.45 


185 


7.50 


90 


5.48 




90 


3.65 


190 


7.71 


95 


5.78 




95 


3.85 


195 


7.91 


100 


6.08 




100 


4.06 


200 


8.11 



2010 California Electrical Code 



70-199 



352.60 



ARTICLE 353 -HIGH DENSITY POLYETHYLENE CONDUIT: TYPE HDPE CONDUIT 



352.60 Grounding. Where equipment grounding is 
required, a separate equipment grounding conductor shall 
be installed in the conduit. 

Exception No. I: As permitted in 250.134(B), Exception 
No. 2, for dc circuits and 250.134(B), Exception No. 1, for 
separately run equipment grounding conductors. 
Exception No. 2: Where the grounded conductor is used to 
ground equipment as permitted in 250.142. 

III. Construction Specifications 



352,lOCLConstructi0B. ^FVC conduit shall be imde of 
ngid Jnonplasticized) polyvinyl ch lo ride (PVC). PVC 
bonduit and fittings shall be composed of suitable 
nonmetallic material that is resistant to moisture and 
chemical atmospheres. For use aboveground, it shall also 
be flame retardant, resistant to impact and crushing, 
resistant to distortion from heat under conditions likely to 
be encountered in service, and resistant to low temperature 
and sunlight effects. For use underground, the material 
shall be acceptably resistant to moisture and corrosive 
agents and shall be of sufficient strength to withstand 
abuse, such as by impact and crushing, in handling and 
during installation. Where intended for direct burial, 
without encasement in concrete, the material shall also be 
capable of withstanding continued loading that is likely to 
be encountered after installation. 

352.120 Marking. Each length of i>VC oonduit shall be 
clearly and durably marked at least every 3 m (10 ft) as 
required in the first sentence of 110.21. The type of 
material shall also be included in the marking unless it is 
visually identifiable. For conduit recognized for use 
aboveground, these markings shall be permanent. For 
conduit limited to underground use only, these markings 
shall be sufficiently durable to remain legible until the 
material is installed. Conduit shall be permitted to be 
surface marked to indicate special characteristics of the 
material. 

FPN: Examples of these markings include but are not 
limited to "limited smoke" and "sunlight resistant." 

■■;:;. ;;;::'';\'-' ARTICLE 3^^^^^^ 

Higli Density Polyethylene Conduit: Type 

I. General 

353.1 Scope. This article covers the use, installation, and 
construction specifications for high density polyethylene 
(HDPE) conduit and associated fittings. 



'Gpnim£^\Jf^ /or ,:Reinforced 

llhermgsettjigR^^ TyM^^fefRCl 

353.2 Definition. A nonmetallic raceway of circular cross 
section, with associated couplings, connectors, and fittings 
for the installation of electrical conductors. 



HDPE conduit and 



353.6 Listing Requirements. 

associated fittings shall be listed. 

II. Installation 



353.10 Uses Permitted. The use of HDPE conduit shall be 
permitted under the following conditions: 

(1) In discrete lengths or in continuous lengths from a reel 

(2) In locations subject to severe corrosive influences 
as covered in 300.6 and where subject to chemicals for 
which the conduit is listed 

(3) In cinder fill 

(4) In direct burial installations in earth or concrete 

FPN to (4): Refer to 300.5 and 300.50 for 
underground installations. 



(5) Kfeoye kbund, except as prohibited in 353.12, wherg 
encasedTn. not less than 50 mm (2 in,) of concr§eJ 

353.12 Uses Not Permitted. HDPE conduit shall not be 
used under the following conditions: 

(1) Where exposed 

(2) Within a building 

(3) In any hazardous (classified) location, except as 
permitted bjnother articles in this Codi 

(4) Where subject to ambient temperatures in excess of 
50°C (122°F) unless listed otherwise 

(5) For conductors or cables operating at a temperature higher 
than the HDPE conduit listed operating temperature rating 

Exception: Conductors or cables rated at a temperature 
higher than the HDPE conduit listed temperature rating 
shall he permitted to be installed in HDPE conduit, 
provided they are not operated at a temperature higher 
than the HDPE conduit listed temperature rating. 

353.20 Size. 

(A) Minimum. HDPE conduit smaller than metric 
designator 16 (trade size Vi) shall not be used. 



(B) Maximum. HDPE conduit larger than 

designator ;155 {£ade si|e 6J shall not be used. 



metric 



70-200 



2010 California Electrical Code 



ARTICLE 354 - NONMETALLIC UNDERGROUND CONDUIT WITH CONDUCTORS: TYPE NUCC 



354.10 



FPN: The trade sizes and metric designators are for 
identification purposes only and do not relate to actual 
dimensions. See 300.1(C). 

353.22 Number of Conductors. The number of 
conductors shall not exceed that permitted by the 
percentage fill specified in Table 1, Chapter 9. 

Cables shall be permitted to be installed where such 
use is not prohibited by the respective cable articles. The 
number of cables shall not exceed the allowable percentage 
fill specified in Table 1, Chapter 9. 

353.24 Bends — How Made. Bends shall be so made that 
the conduit will not be damaged and the internal diameter 
of the conduit will not be effectively reduced. Bends shall 
be permitted to be made manually without auxiliary 
equipment, and the radius of the curve to the centerline of 
such bends shall not be less than shown in Table 354.24. 

353.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

353.28 Trimming. All cut ends shall be trimmed inside 
and outside to remove rough edges. 

353.46 Bushings. Where a conduit enters a box, fitting, or 
other enclosure, a bushing or adapter shall be provided to 
protect the wire from abrasion unless the box, fitting, or 
enclosure design provides equivalent protection. 

FPN: See 300.4(G) for the protection of conductors 4 AWG 
and larger at bushings. 

353.48 Joints. All joints between lengths of conduit, and 
between conduit and couplings, fittings, and boxes, shall be 
made by an approved method. 

FFN: HpPfe conduit mii be joiii^^ usmg^ eitih^^ 
bfectSSfijjsion, or mechanical 4iipBsj 

353.56 Splices and Taps. SpHces and taps shall be made 
in accordance with 300.15. 

353.60 Grounding. Where equipment grounding is 
required, a separate equipment grounding conductor shall 
be installed in the conduit. 

Exception No. 1: The equipment grounding conductor shall be 
permitted to he run separately from the conduit where used for 
grounding dc circuits as permitted in 2 50 J 34, Exception No. 2. 

Exception No. 2: The equipment grounding conductor 
shall not be required where the grounded conductor is used 
to ground equipment as permitted in 250.142. 



III. Construction Specifications 

353.100 Construction. HDPE conduit shall be composed 
of high density polyethylene that is resistant to moisture 
and chemical atmospheres. The material shall be resistant 
to moisture and corrosive agents and shall be of sufficient 
strength to withstand abuse, such as by impact and 
crushing, in handling and during installation. Where 
intended for direct burial, without encasement in concrete, 
the material shall also be capable of withstanding continued 
loading that is likely to be encountered after installation. 

353.120 Marking. Each length of HDPE shall be clearly and 
durably marked at least every 3 m (10 ft) as required in 1 10.21. 
The type of material shall also be included in the marking. 



J ; Nonm^taliic Utiderground Coiidwit w ] 

I. General 

354.1 Scope. This article covers the use, installation, and 
construction specifications for nonmetaUic underground 
conduit with conductors (NUCC). 

354.2 Definition. 

NonmetaUic Underground Conduit with Conductors 
(NUCC). A factory assembly of conductors or cables inside 
a nonmetaUic, smooth wall conduit with a circular cross 
section. 



354.6 Listing Requirements. 

fittings shall be listed. 



NUCC and associated 



II. Installation 

354.10 Uses Permitted. The use of NUCC and fittings 
shall be permitted in the following: 

(1) For direct burial underground installation (For 
minimum cover requirements, see Table 300.5 and 
Table 300.50 under Rigid NonmetaUic Conduit.) 

(2) Encased or embedded in concrete 

(3) In cinder fill 

(4) In underground locations subject to severe corrosive 
influences as covered in 300.6 and where subject to 
chemicals for which the assembly is specifically 
approved 

(5) jteove^t^^ '-pm\kMi^^'\\n^^^ 
^^:^^^mm^_ :i^ss;||M50 .nam (2 ;y|.:of oog^^ 



2010 California Electrical Code 



70-201 



354.12 



ARTICLE 354 -NONMETALLIC UNDERGROUND CONDUIT WITH CONDUCTORS: TYPE NUCC 



354.12 Uses Not Permitted. NUCC shall not be used in 
the following: 

(1) In exposed locations 

(2) Inside buildings 

Exception: The conductor or the cable portion of the 
assembly, where suitable, shall be permitted to extend 
within the building for termination purposes in accordance 
with 300.3. 

(3) In btiy hazardous (classified) location, except as 
permitted by otliei: articles of this Cof/e 

354.20 Size. 

(A) Minimum. NUCC smaller than metric designator 16 
(trade size Vi) shall not be used. 

(B) Maximum. NUCC larger than metric designator 103 
(trade size 4) shall not be used. 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

354.22 Number of Conductors. The number of 
conductors or cables shall not exceed that permitted by the 
percentage fill in Table 1, Chapter 9. 

354.24 Bends — How Made. Bends shall be manually 
made so that the conduit will not be damaged and the 
internal diameter of the conduit will not be effectively 
reduced. The radius of the curve of the centerline of such 
bends shall not be less than shown in Table 354.24. 



Table 354.24 Minimum Bending Radius for Nonmetallic 
Underground Conduit with Conductors (NUCC) 







Minimum Bending 


Conduit Size 


Radius 




Metric 








Designator 


Trade Size 


mm 


in. 


16 


'/2 


250 


10 


21 


\ 


300 


12 


27 


1 


350 


14 


35 


VA 


450 


18 


41 


V/2 


500 


20 


53 


2 


650 


26 


63 


Vh 


900 


36 


78 


3 


1200 


48 


103 


4 


1500 


60 



354.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between termination points. 



354.28 Trimming. For termination, the conduit shall be 
trimmed away from the conductors or cables using an 
approved method that will not damage the conductor or 
cable insulation or jacket. All conduit ends shall be 
trimmed inside and out to remove rough edges. 

354.46 Busliings. Where the NUCC enters a box, fitting, or 
other enclosure, a bushing or adapter shall be provided to 
protect the conductor or cable from abrasion unless the design 
of the box, fitting, or enclosure provides equivalent protection. 

FPN: See 300:4(G) for the protection of conductors size 4 
AWG or larger. 

354.48 Joints. All joints between conduit, fittings, and 
boxes shall be made by an approved method. 

354.50 Conductor Terminations. All terminations between 
the conductors or cables and equipment shall be made by an 
approved method for that type of conductor or cable. 

354.56 Splices and Taps. Splices and taps shall be made 
injunction boxes or other enclosures. 

354.60 Grounding. Where equipment grounding is 
required, an assembly containing a separate equipment 
grounding conductor shall be used. 



III. Construction Specifications 
354.100 Construction. 

(A) General. NUCC is an assembly that is provided in 
continuous lengths shipped in a coil, reel, or carton. 

(B) Nonmetallic Underground Conduit. The nonmetallic 
underground conduit shall be listed and composed of a 
material that is resistant to moisture and corrosive agents. It 
shall also be capable of being supplied on reels without 
damage or distortion and shall be of sufficient strength to 
withstand abuse, such as impact or crushing, in handling and 
during installation without damage to conduit or conductors. 

(C) Conductors and Cables. Conductors and cables used 
in NUCC shall be Hsted and shall comply with 310.8(C). 
Conductors of different systems shall be installed in 
accordance with 300.3(C). 

(D) Conductor Fill. The maximum number of conductors 
or cables in NUCC shall not exceed that permitted by the 
percentage fill in Table 1, Chapter 9. 

354.120 Marking. NUCC shall be clearly and durably marked 
at least every 3.05 m (10 ft) as required by 1 10.21. The type of 
conduit material shall also be mcluded in the marking. 



• 



70-202 



2010 California Electrical Code 



ARTICLE 355 ~ REINFORCED THERMOSETTING RESIN CONDUIT; TYPE RTRC 



355.20 



Identification of conductors or cables used in the 
assembly shall be provided on a tag attached to each end of 
the assembly or to the side of a reel. Enclosed conductors 
or cables shall be marked in accordance with 310.1 L 



Reiiilprced Ther mosettiiig Resin Coiidiiit: 



Type RTRC 



I. General 

355.1 Scope. This article covers the use, installation, and 
construction specification for reinforced thermosetting 
resin conduit (RTRC) and associated fittings. 

FPN: Refer to Article 352 for Rigid Polyvinyl Chloride 
Conduit: Type PVC, and Article 353 for High Density 
Polyethylene Conduit: Type HDPE. 

355.2 Definition. 

Reinforced Thermosetting Resin Conduit (RTRC). A 

rigid nonmetallic conduit (RNC) of circular cross section, 
with integral or associated couplings, connectors, and fittings 
for the installation of electrical conductors and cables. 

355.6 Listing Requirements. RTRC, factory elbows, and 
associated fittings shall be listed. 



II. Installation 

355.10 Uses Permitted. The use of RTRC shall be 
permitted in accordance with 355.10(A) through (H). 

(A) Concealed. RTRC shall be permitted in walls, floors, 
and ceilings. 

(B) Corrosive Influences. RTRC shall be permitted in 
locations subject to severe corrosive influences as covered 
in 300.6 and where subject to chemicals for which the 
materials are specifically approved. 

(C) Cinders. RTRC shall be permitted in cinder fill. 

(D) Wet Locations. RTRC shall be permitted in portions 
of dairies, laundries, canneries, or other wet locations, and 
in locations where walls are frequently washed, the entire 
;onduit system, including boxes and fittings used 
.herewith, shall be installed and equipped so as to prevent 
water from entering the conduit. All supports, bolts, straps, 
screws, and so forth, shall be of corrosion-resistant 
materials or be protected against corrosion by approved 
corrosion-resistant materials. 



(E) Dry and Damp Locations. RTRC shall be permitted for 
use in dry and damp locations not prohibited by 355. 12. 

(F) Exposed. RTRC shall be permitted for exposed work where 
not subject to physical damage if identified for such use. 

(G) Underground Installations. For underground installations, 
see 300.5 and 300.50. 

(H) Support of Conduit Bodies. RTRC shall be permitted to 
support nonmetalHc conduit bodies not larger than the largest 
trade size of an entering raceway. These conduit bodies shall not 
support luminaires or other equipment and shall not contain 
devices other than splicing devices as permitted by 110.14(B) 
and 3 14.16(C)(2). 



355.12 Uses Not Permitted. 

under the following conditions. 



RTRC shall not be used 



(A) Hazardous (Classified) Locations. 

(1) In any hazardous (classified) location, except as 
permitted by other articles in this Code 

(2) In Class I, Division 2 locations, except as permitted in 
501.10(B)(3) 

(B) Support of Luminaires. For the support of luminaires 
or other equipment not described in 355.10(H). 

(C) Physical Damage. Where subject to physical damage 
unless identified for such use. 

(D) Ambient Temperatures. Where subject to ambient 
temperatures in excess of 50'^C (122°F) unless listed 
otherwise. 

(E) Insulation Temperature Limitations. For conductors 
or cables operating at a temperature higher than the RTRC 
listed operating temperature rating. 

Exception: Conductors or cables rated at a temperature 
higher than the RTRC listed temperature rating shall be 
permitted to be installed in RTRC, provided they are not 
operated at a temperature higher than the RTRC listed 
temperature rating. 

(F) Theaters and Similar Locations. In theaters and 
similar locations, except as provided in 518.4 and 520.5. 

355.20 Size. 

(A) Minimum. RTRC smaller than metric designator 16 
(trade size Vi) shall not be used. 

(B) Maximum. RTRC larger than metric designator 155 
(trade size 6) shall not be used. 



2010 California Electrical Code 



70-203 



355.22 



ARTICLE 355 -REINFORCED THERMOSETTING RESIN CONDUIT: TYPE RTRC 



FPN: The trade sizes and metric designators are for 
identification purposes only and do not relate to actual 
dimensions. See 300.1(C). 

355.22 Number of Conductors. The number of conductors 
shall not exceed that permitted by the percentage fill specified 
in Table 1, Chapter 9. Cables shall be permitted to be installed 
where such use is not prohibited by the respective cable 
articles. The number of cables shall not exceed the allowable 
percentage fill specified in Table 1, Chapter 9. 

355.24 Bends - How Made. Bends shall be so made that 
the conduit will not be damaged and the internal diameter of 
the conduit will not be effectively reduced. Field bends shall 
be made only with bending equipment identified for the 
purpose. The radius of the curve to the centerline of such 
bends shall not be less than shown in Table 2, Chapter 9. 

355.26 Bends ~ Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

355.28 Trimming. All cut ends shall be trimmed inside 
and outside to remove rough edges. 

355.30 Securing and Supporting. RTRC shall be 
installed as a complete system in accordance with 300.18 
and shall be securely fastened in place and supported in 
accordance with 355.30(A) and (B) or permitted to be 
unsupported in accordance with 355.30(C). 

(A) Securely Fastened. RTRC shall be securely fastened 
within 900 mm (3 ft) of each outlet box, junction box, 
device box, conduit body, or other conduit termination. 
Conduit listed for securing at other than 900 mm (3 ft) shall 
be permitted to be installed in accordance with the H sting. 

(B) Supports. RTRC shall be supported as required in Table 
355.30. Conduit listed for support at spacing other than as 
shown in Table 355.30 shall be permitted to be installed in 
accordance with the listing. Horizontal runs of RTRC 
supported by openings through fi*aming members at intervals 
not exceeding those in Table 355.30 and securely fastened 
within 900 mm (3 ft) of termination points shall be permitted. 

(C) Unsupported Raceways. Where oversized, concentric 
or eccentric knockouts are not encountered. Type RTRC 
shall be permitted to be unsupported where the raceway is 
not more than 450 mm (18 in.) and remains in unbroken 
lengths (without coupling). Such raceways shall terminate 
in an outlet box, device box, cabinet, or other termination 
at each end of the raceway. 

355.44 Expansion Fittings. Expansion fittings for RTRC 
shall be provided to compensate for thermal expansion and 



Table 355.30 Support of Reinforced Thermosetting 
Resin Conduit (RTRC) 



Conduit Size 



Maximum Spacing Between 
Supports 



Metric 
Designator 



16-27 

35-53 

63-78 

91-129 

155 



Trade Size 



Vi-i 
VA-2 



mm or m 



900 mm 
1.5 m 
1.8 m 
2.1m 
2.5 m 



contraction where the length change, in accordance with 
Table 355.44, is expected to be 6 mm (!4 in.) or greater in a 
straight run between securely mounted items such as boxes, 
cabinets, elbows, or other conduit terminations. 

355.46 Bushings. Where a conduit enters a box, fitting, or 
other enclosure, a bushing or adapter shall be provided to 
protect the wire fi*om abrasion unless the box, fitting, or 
enclosure design provides equivalent protection. 

FPN; See 300.4(G) for the protection of conductors 4 AWG 
and larger at bushings. 

355.48 Joints. All joints between lengths of conduit, and 
between conduit and couplings, fitting, and boxes, shall be 
made by an approved method. 

355.56 Splices and Taps. Splices and taps shall be made 
in accordance with 300.15. 

355.60 Grounding. Where equipment grounding is 
required, a separate equipment grounding conductor shall 
be installed in the conduit. 

Exception No. 1: As permitted in 250.134(B), Exception 
No. 2, for dc circuits and 250.134(B), Exception No. 1, for 
separately run equipment grounding conductors. 

Exception No. 2: Where the grounded conductor is used to 
ground equipment as permitted in 250. 142. 

III. Construction Specifications 

355.100 Construction. RTRC and fittings shall be composed of 
suitable nonmetallic material that is resistant to moisture and 
chemical atmospheres. For use aboveground, it shall also be 
flame retardant, resistant to impact and crushing, resistant to 
distortion fi*om heat under conditions likely to be encountered in 
service, and resistant to low temperature and sunhght effects. For 
use undergroimd, the material shall be acceptably resistant to 
moisture and corrosive agents and shall be of sufficient strength to 
withstand abuse, such as by impact and crushing, in handling and 



• 



a 



70-204 



2010 California Electrical Code 



ARTICLE 356 - LIQUIDTIGHT FLEXIBLE NONMETALLIC CONDUIT: TYPE LFNC 



356.2 



Table 355.44 Expansion Characteristics of Reinforced Tiiermosetting Resin Conduit (RTRC) Coefficient of Thermal Expansion = 
2.7 X 10-5 mm/mm/°C (1.5 x 10-5 in./in./°F) 



Temperature 
Change fC) 


Length Change of 

RTRC Conduit 

(mm/m) 




Temperature 
Change (°F) 


Length Change of 

RTRC Conduit 

(in./100 ft) 


Temperature 
Change (°F) 


Length Change of 

RTRC Conduit 

(in./100 ft) 


5 


0.14 




5 


0.09 


105 


1.89 


10 


0.27 




10 


0.18 


110 


1.98 


15 


0.41 




15 


0.27 


115 


2.07 


20 


0.54 




20 


0.36 


120 


2.16 


25 


0.68 




25 


0.45 


125 


2.25 


30 


0.81 




30 


0.54 


130 


2.34 


35 


0.95 




35 


0.63 


135 


2.43 


40 


1.08 




40 


0.72 


140 


2.52 


45 


1.22 




45 


0.81 


145 


2.61 


50 


1.35 




50 


0.90 


150 


2.70 


55 


1.49 




55 


0.99 


155 


2.79 


60 


1.62 




60 


1.08 


160 


2.88 


65 


1.76 




65 


1.17 


165 


2.97 


70 


1.89 




70 


1.26 


170 


3.06 


75 


2.03 




75 


1.35 


175 


3.15 


80 


2.16 




80 


1.44 


180 


3.24 


85 


2.30 




85 


1.53 


185 


3.33 


90 


2.43 




90 


1.62 


190 


3.42 


95 


2.57 




95 


1.71 


195 


3.51 


100 


2.70 




100 


1.80 


200 


3.60 



during installation. Where intended for direct burial, 
without encasement in concrete, the material shall also be 
capable of withstanding continued loading that is likely to 
be encountered after installation. 

355.120 Marking. Each length of RTRC shall be clearly 
and durably marked at least every 3 m (10 ft) as required in 
the first sentence of 110.21. The type of material shall also 
be included in the marking unless it is visually identifiable. 
For conduit recognized for use aboveground, these 
markings shall be permanent. For conduit limited to 
underground use only, these markings shall be sufficiently 
durable to remain legible until the material is installed. 
Conduit shall be permitted to be surface marked to indicate 
special characteristics of the material. 

FPN: Examples of these markings include but are not 
limited to "limited smoke" and "sunlight resistant." 



ARTICLE 356 

Liquidtight flexible Nomnetallk Condtiit : 

Ik;.;.' -^ ■ ■■ .: ..l-L^STP^LFNC./rk: = :'^..^^:::L£ 

I. General 

356.1 Scope. This article covers the use, installation, and 
construction specifications for liquidtight flexible 
nonmetallic conduit (LFNC) and associated fittings. 

356.2 Dennition. 

Liquidtight Flexible NonmetalHc Conduit (LFNC). A 
raceway of circular cross section of various types as 
follows: 

(1) A smooth seamless inner core and cover bonded 
together and having one or more reinforcement layers 
between the core and covers, designated as Type 
LFNC-A 

(2) A smooth inner surface with integral reinforcement 
within the conduit wall, designated as Type LFNC-B 

(3) A corrugated internal and external surface without 
integral reinforcement within the conduit wall, 
designated as LFNC-C 

LFNC is flame resistant and with fittings and is approved 
for the installation of electrical conductors. 

FPN: FNMC is an altemative designation for LFNC. 



2010 California Electrical Code 



70-205 



356.6 



ARTICLE 356 -LIQUIDTIGHT FLEXIBLE NQNMETALLIC CONDUIT: TYPE LFNC 



356.6 Listing Requirements. 

fittings shall be listed. 



LFNC and associated 



II. Installation 

356.10 Uses Permitted. LFNC shall be permitted to be used 
in exposed or concealed locations for the following purposes: 

FPN: Extreme cold may cause some types of nonmetallic 
conduits to become brittle and therefore more susceptible to 
damage from physical contact. 

(1) Where flexibility is required for installation, operation, 
or maintenance. 

(2) Where protection of the contained conductors is 
required from vapors, Hquids, or solids. 

(3) For outdoor locations where listed and marked as 
suitable for the purpose. 

(4) For direct burial where listed and marked for the 
purpose. 

(5) Type LFNC-B shall be permitted to be installed in 
lengths longer than 1 .8 m (6 ft) where secured in 
accordance with 356.30. 

(6) Type LFNC-B as a listed manufactured prewired 
assembly, metric designator 1 6 through 27 (trade size 
V2 through 1) conduit. 

(7) For encasemeiit in Goncrete where listed for cHtect 
biirial and jnsj^led in comgl w^e with 356 .42 ; 

356.12 Uses Not Permitted. LFNC shall not be used as 
follows: 

(1) Where subject to physical damage 

(2) Where any combination of ambient and conductor 
temperatures is in excess of that for which the LFNC is 
approved 

(3) In lengths longer than 1.8 m (6 ft), except as permitted 
by 356. 10(5) or where a longer length is approved as 
essential for a required degree of flexibility 

(4) Where the operating voltage of the contained 
conductors is in excess of 600 volts, nominal, except 
as permitted in 600.32(A) 

(5) In any hazardous (classified) location, bccept as| 
permtjed by other articles in ihbCqd^^ 

356.20 Size. 

(A) Minimum. LFNC smaller than metric designator 16 (trade 
size Yi) shall not be used unless permitted in 356.20(A)(1) or 
(A)(2) for metric designator 12 (trade size 3/8). 

(1) For enclosing the leads of motors as permitted in 
430.245(B) 

(2) In lengths not exceeding 1.8 m (6 ft ) as part of a listed 
assembly for tap connections to luminaires as required 
in 4l0.ln2(O' ^^ f*o^ utilization equipment 



(B) Maximum, LFNC larger than metric designator 103 
(trade size 4) shall not be used. 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

356.22 Number of Conductors. The number of 
conductors shall not exceed that permitted by the 
percentage fill specified in Table 1, Chapter 9. 

Cables shall be permitted to be installed where such 
use is not prohibited by the respective cable articles. The 
number of cables shall not exceed the allowable percentage 
fill specified in Table 1, Chapter 9. 

356.24 Bends — How Made. Bends in conduit shall be so 
made that the conduit is not damaged and the internal 
diameter of the conduit is not effectively reduced. Bends 
shall be permitted to be made manually without auxiliary 
equipment. The radius of the curve to the centerline of any 
bend shall not be less than shown in Table 2, Chapter 9 
using the column "Other Bends." 

356.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

356.28 Trimming. All cut ends of conduit shall be 
trimmed inside and outside to remove rough edges. 

356.30 Securing and Supporting. Type LFNC-B shall be 
securely fastened and supported in accordance with one of 
the following: 

(1) Where installed in lengths exceeding 1.8 m (6 ft), the 
conduit shall be securely fastened at intervals not 
exceeding 900 mm (3 ft) and within 300 mm (12 in.) on 
each side of every outlet box, junction box, cabinet, or 
fitting. 

(2) Securing or supporting of the conduit shall not be required 
where it is fished, installed in lengths not exceeding 900 
mm (3 ft) at terminals where flexibiUty is required, or 
installed in lengths not exceeding 1.8 m (6 ft) from a 
luminaire terminal connection for tap conductors to 
luminaires permitted in 4 1 0.1 1 7(C). 

(3) Horizontal runs of LFNC supported by openings through 
framing members at intervals not exceeding 900 mm (3 ft) 
and securely fastened within 300 mm (12 in.) of 
termination points shall be permitted. 

(4) Securing or supporting of LFNC-B shall not be required 
where installed in lengths not exceeding 1.8 m (6 ft) from 
the last point where the raceway is securely fastened for 
connections within an accessible ceiling to luminau'e(s) or 
other equipment. 



# 



70-206 



2010 California Electrical Code 



ARTICLE 358 - ELECTRICAL METALLIC TUBING: TYPE EMT 



358.20 



356.42 Couplings and Connectors. Only fittings listed for use 
with LFNC shall be used. Angle connectors shall not be used 
for concealed raceway installations. Straight LFNC fittings are 
permitted for direct burial or encasement in concrete. 

356.56 Splices and Taps. Splices and taps shall be made 
in accordance with 300.15. 

356.60 Grounding and Bonding. Where used to connect 
equipment where flexibility is required, an equipment 
grounding conductor shall be installed. 

Where required or installed, equipment grounding 
conductors shall be installed in accordance with 

250.134(B). 

Where required or installed, equipment bonding jumpers 
shall be installed in accordance with 250.102. 



III. Construction Specifications 

356.100 Construction. LFNC-B as a prewired 
manufactured assembly shall be provided in continuous 
lengths capable of being shipped in a coil, reel, or carton 
without damage. 

356.120 Marking. LFNC shall be marked at least every 
600 mm (2 ft) in accordance with 110.21. The marking 
shall include a type designation in accordance with 356.2 
and the trade size. Conduit that is intended for outdoor use 
or direct burial shall be marked. 

The type, size, and quantity of conductors used in 
prewired manufactured assemblies shall be identified by 
means of a printed tag or label attached to each end of the 
manufactured assembly and either the carton, coil, or reel. 
The enclosed conductors shall be marked in accordance 
with 310.11. 



■ ■ ■ ' . ■ . Electrical Metallic Tubiiig: 'Type lEMt ; ■ . ■ 

I. General 

358.1 Scope. This article covers the use, installation, and 
construction specifications for electrical metallic tubing 
(EMT) and associated fittings. 

358.2 Definition. 

Electrical Metallic Tubing (EMT). An unthreaded thinwall 
raceway of circular cross section designed for the physical 
protection and routing of conductors and cables and for use 
as an equipment grounding conductor when installed 
utilizing appropriate fittings. EMT is generally made of 
steel (ferrous) with protective coatings or aluminum 
(nonferrous). 



358.6 Listing Requirements. EMT, factory elbows, and 
associated fittings shall be listed. 

II. Installation 

358.10 Uses Permitted. 

(A) Exposed and Concealed. The use of EMT shall be 
permitted for both exposed and concealed work. 

(B) Corrosion Protection. Ferrous or nonferrous EMT, 
elbows, couplings, and fittings shall be permitted to be 
installed in concrete, in direct contact with the earth, or in 
areas subject to severe corrosive influences where protected 
by corrosion protection and judged suitable for the condition. 

(C) Wet Locations. All supports, bolts, straps, screws, and 
so forth shall be of corrosion-resistant materials or 
protected against corrosion by corrosion-resistant materials. 

FPN: See 300.6 for protection against corrosion. 

358.12 Uses Not Permitted. EMT shall not be used under 
the following conditions: 

(1) Where, during installation or afterward, it will be 
subject to severe physical damage. 

(2) Where protected from corrosion solely by enamel. 

(3) In cinder concrete or cinder fill where subject to 
permanent moisture unless protected on all sides by a 
layer of noncinder concrete at least 50 mm (2 in.) thick 
or unless the tubing is at least 450 mm (18 in.) under 
the fill. 

(4) In any hazardous (classified) location except as 
permitted by j6ther:aWi;cle$:iB iimCdde. 

(5) For the support of luminaires or other equipment 
except conduit bodies no larger than the largest trade 
size of the tubing. 

(6) Where practicable, dissimilar metals in contact 
anywhere in the system shall be avoided to eliminate 
the possibility of galvanic action. 

Exception: Aluminum fittings and enclosures shall be 
permitted to he used with steel EMT where not subject to 
severe corrosive influences. 

358.20 Size. 

(A) Minimum. EMT smaller than metric designator 16 
(trade size Vi) shall not be used. 



2010 California Electrical Code 



70-207 



358.22 



ARTICLE 360 -FLEXIBLE METALLIC TUBING: TYPE FMT 



Exception: For enclosing the leads of motors as permitted 
in 430.245(B). 

(B) Maximum. The maximum size of EMT shall be metric 
designator 103 (trade size 4). 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

358.22 Number of Conductors. The number of 
conductors shall not exceed that permitted by the 
percentage fill specified in Table 1, Chapter 9. 

Cables shall be permitted to be installed where such use is 
not prohibited by the respective cable articles. The number 
of cables shall not exceed the allowable percentage fill 
specified in Table 1, Chapter 9. 

358.24 Bends — How Made. Bends shall be made so that 
the tubing is not damaged and the internal diameter of the 
tubing is not effectively reduced. The radius of the curve of 
any field bend to the centerline of the tubing shall not be 
less than shown in Table 2, Chapter 9 for one-shot and full 
shoe benders. 

358.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

358.28 Reaming and Threading. 

(A) Reaming. All cut ends of EMT shall be reamed or 
otherwise finished to remove rough edges. 

(B) Tlireading. EMT shall not be threaded. 

Exception: EMT with factory threaded integral couplings 
complying with 358.100. 

358.30 Securing and Supporting. EMT shall be installed 
as a complete system in accordance with 300.18 and shall 
be securely fastened in place and supported in accordance 
with 358.30(A) and (B) or perrnitteil to be uhsuppprted in 
accordance with 358.30(C). 

(A) Securely Fastened. EMT shall be securely fastened in 
place at least every 3 m (10 ft). In addition, each EMT run 
between termination points shall be securely fastened 
within 900 mm (3 ft) of each outlet box, junction box, 
device box, cabinet, conduit body, or other tubing 
termination. 

Exception No. 1: Fastening of unbroken lengths shall be 
permitted to be increased to a distance of 1.5 m (5 ft) 
where structural members do not readily permit fastening 
within 900 mm (3 ft). 

Exception No. 2: For concealed work in finished buildings 
or prefinished wall panels where such securing is 



impracticable, unbroken lengths (without coupling) of EMT 
shall be permitted to be fished. 

(B) Supports. Horizontal runs of EMT supported by 
openings through framing members at intervals not greater 
than 3 m (10 ft) and securely fastened within 900 mm (3 ft) 
of termination points shall be permitted. 

(C) :tlBSiippprted Raceways.: Whaire^ avei^ized, 'cptxcQuinp. 
pt: eccentric: iaiockou|s..are.pot ^encountered. Type -EMT 
shall be pertoitted to be misuppoited wte^^ raceway i^ 
ii&t^.iMr^,:tM ni|i^|i|an.)__ andjre^ 

lengths (mXhouim §ijch raceways s^^^ 

ih an outlet box^ device Jipx^ cabinet, or 6t%r term 

^teach end ot tlie. raceway; 

358.42 Couplings and Connectors. Couplings and 
connectors used with EMT shall be made up tight. Where 
buried in masonry or concrete, they shall be concretetight 
type. Where installed in wet locations, they shall comply 
with 314.15. 

358.56 Splices and Taps. Sphces and taps shall be made 
in accordance with 300.15. 

358.60 Grounding. EMT shall be permitted as an 
equipment grounding conductor. 

III. Construction Specifications 

358.100 Construction. Factory-threaded integral 

couplings shall be permitted. Where EMT with a threaded 
integral coupling is used, threads for both the tubing and 
coupling shall be factory-made. The coupling and EMT 
threads shall be designed so as to prevent bending of the 
tubing at any part of the thread. 

358.120 Marking. EMT shall be clearly and durably 
marked at least every 3 m (10 ft) as required in the first 
sentence of 110.21. 



ARTICLE 360 

Flexible Metallic Tubing: Type FMT 

I. General 

360.1 Scope. This article covers the use, installation, and 
construction specifications for flexible metallic tubing 
(FMT) and associated fittings. 

360.2 Definition. 

Flexible Metalhc Tubing (FMT). A raceway that is circular 
in cross section, flexible, metalhc, and hquidtight without a 
nonmetallic jacket. 



70-208 



2010 California Electrical Code 



ARTICLE 360 - FLEXIBLE METALLIC TUBING: TYPE FMT 



360.120 



360.6 Listing Requirements. FMT and associated fittings 
shall be listed. 

11. Installation 

360.10 Uses Permitted. FMT shall be permitted to be 
used for branch circuits as follows: 

(1) In dry locations 

(2) Where concealed 

(3) In accessible locations 

(4) For system voltages of 1000 volts maximum 

360.12 Uses Not Permitted. FMT shall not be used as 
follows: 

(1) In hoistways 

(2) In storage battery rooms 

(3) In hazardous (classified) locations unless otherwise 
permitted under other articles in this Code 

(4) Underground for direct earth burial, or embedded in 
poured concrete or aggregate 

(5) Where subject to physical damage 

(6) In lengths over 1.8 m (6 ft) 
360.20 Size. 

(A) Minimum. FMT smaller than metric designator 16 
(trade size V2) shall not be used. 

Exception No. 1: FMT of metric designator 12 (trade size 
3/8) shall he permitted to be installed in accordance with 
300.22(B) and (C). 

Exception No. 2: FMT of metric designator 12 (trade size 3/8) 
shall be permitted in lengths not in excess of 1.8 m (6 ft) as 
part of a listed assembly or for luminaires. See 41 Oil 17(C). 

(B) Maximum. The maximum size of FMT shall be metric 
designator 21 (trade size Va). 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

360.22 Number of Conductors. 

(A) FMT — Metric Designators 16 and 21 (Trade Sizes 

Vi and V4), The number of conductors in metric designators 
1 6 (trade size Vi) and 2 1 (trade size Va) shall not exceed that 
permitted by the percentage fill specified in Table 1, 
Chapter 9. 

Cables shall be permitted to be installed where such 
use is not prohibited by the respective cable articles. The 



number of cables shall not exceed the allowable percentage 
fill specified in Table 1, Chapter 9. 

(B) FMT — Metric Designator 12 (Trade Size 3/8). The 

number of conductors in metric designator 12 (trade size 
3/8) shall not exceed that permitted in Table 348.22, 

360.24 Bends. 

(A) Infrequent Flexing Use. Where FMT may be 

infrequently flexed in service after installation, the radii of 
bends measured to the inside of the bend shall not be less 
than specified in Table 360.24(A). 

Table 360.24(A) Minimum Radii for Flexing Use 

Minimum Radii for Flexing 
Use 



Metric 



j^esignaiur 


Trade Size 


mm 


in. 


12 


V, 


25.4 


10 


16 


Vi 


317.5 


12'/2 


21 


Ya 


444.5 


17^2 



(B) Fixed Bends. Where FMT is bent for installation 
purposes and is not flexed or bent as required by use after 
installation, the radii of bends measured to the inside of the 
bend shall not be less than specified in Table 360.24(B). 



Table 360.24(B) Minimum Radii for Fixed Bends 





Trade Size 


Minimum Radii for Fixed 
Bends 


Metric 
Designator 


mm 




in. 


12 
16 
21 


^8 

Va 


88.9 
101.6 
127.0 




V/2 

4 
5 



360.40 Boxes and Fittings. Fittings shall effectively close 
any openings in the connection. 

360.56 Splices and Taps. Splices and taps shall be made 
in accordance with 300. 15. 

360.60 Grounding. FMT shall be permitted as an 
equipment grounding conductor where installed in 
accordance with 250.1 18(7). 



TIL Construction Specifications 

360.120 Marking. FMT shall be marked according to 1 10.21. 



2010 California Electrical Code 



70-209 



362.1 



ARTICLE 362 -ELECTRICAL NONMETALLIC TUBING: TYPE ENT 






I. General 

362.1 Scope. This article covers the use, installation, and 
construction specifications for electrical nonmetallic tubing 
(ENT) and associated fittings. 

362.2 Definition. 

Electrical Nonmetallic Tubing (ENT). A nonmetallic, 
pliable, corrugated raceway of circular cross section with 
integral or associated couplings, connectors, and fittings for 
the installation of electrical conductors. ENT is composed 
of a material that is resistant to moisture and chemical 
atmospheres and is flame retardant. 

A pliable raceway is a raceway that can be bent by 
hand with a reasonable force but without other assistance. 

362.6 Listing Requirements. ENT and associated fittings 
shall be listed. 



II. Installation 

362.10 Uses Permitted. For the purpose of this article, the 
first floor of a building shall be that floor that has 50 
percent or more of the exterior wall surface area level with 
or above finished grade. One additional level that is the 
first level and not designed for human habitation and used 
only for vehicle parking, storage, or similar use shall be 
permitted. The use of ENT and fittings shall be permitted 
in the following: 

(1) In any building not exceeding three floors above grade 
as follows: 

a. For exposed work, where not prohibited by 362.12 

b. Concealed within walls, floors, and ceilings 

(2) In any building exceeding three floors above grade, 
ENT shall be concealed within walls, floors, and 
ceilings where the walls, floors, and ceilings provide a 
thermal barrier of material that has at least a 15 -minute 
finish rating as identified in listings of fire-rated 
assemblies. The 15 -minute-finish-rated thermal barrier 
shall be permitted to be used for combustible or 
noncombustible walls, floors, and ceilings. 

Exception to (2): Where a fire sprinkler system(s) is 
installed in accordance with NFPA 13-2007, Standard for 
the Installation of Sprinkler Systems, on all floors, ENT 
shall be permitted to be used within walls, floors, and 
ceilings, exposed or concealed, in buildings exceeding 
three floors abovegrade. 

FPN: A finish rating is established for assemblies 
containing combustible (wood) supports. The finish rating 
is defined as the time at which the wood stud or wood joist 
reaches an average temperature rise of 121°C (250°F) or an 



individual temperature of 163°C (325°F) as measured on 
the plane of the wood nearest the fire. A finish rating is not 
intended to represent a rating for a membrane ceiling. 

(3) In locations subject to severe corrosive influences as 
covered in 300.6 and where subject to chemicals for which 
the materials are specifically approved. 

(4) In concealed, dry, and damp locations not prohibited by 
362.12. 

(5) Above suspended ceilings where the suspended ceilings 
provide a thermal barrier of material that has at least a 15- 
minute finish rating as identified in listings of fire-rated 
assemblies, except as permitted in 362.10(l)(a). 

Exception to (5): ENT shall be permitted to be used above 
suspended ceilings in buildings exceeding three floors 
above grade where the building is protected throughout by 
afire sprinkler system installed in accordance with NFPA 
13-2007, Standard for the Installation of Sprinkler Systems. 

(6) Encased in poured concrete, or embedded in a concrete 
slab on grade ivhere ENT is placed on sand or 
approved screenings, provided fittings identified for 
this purpose are used for connections. 

(7) For wet locations indoors as permitted in this section or 
in a concrete slab on or belowgrade, with fittings Hsted 
for the purpose. 

(8) Metric designator 16 through 27 (trade size Vi through 
1) as listed manufactured prewired assembly. 

FPN: Extreme cold may cause some types of nonmetallic 
conduits to become brittle and therefore more susceptible to 
damage from physical contact. 

362.12 Uses Not Permitted. ENT shall not be used in the 
following: 

(1) In §if hazardous (classified) location, except as 
permitted by &iheilarticlgs in^ ^^ 

(2) For the support of luminaires and other equipment 

(3) Where subject to ambient temperatures in excess of 
50°C (122°F) unless Hsted otherwise 

(4) For conductors or cables operating at a temperature 
higher than the ENT listed temperature rating 

Exception to (4): Conductors or cables rated at a 
temperature higher than the ENT listed temperature rating 
shall be permitted to be installed in ENT, provided they are 
not operated at a temperature higher than the ENT listed 
temperature rating. 

(5) For direct earth burial 

(6) Where the voltage is over 600 volts 

(7) In exposed locations, except as permitted by 362.10(1), 

362.10(5), and 362.10(7) 



70-210 



2010 Califomia Electrical Code 



ARTICLE 362 - ELECTRICAL NONMETALLIC TUBING: TYPE ENT 



362.120 



(8) In theaters and similar locations, except as provided in 
518.4 and 520.5 

(9) Where exposed to the direct rays of the sun, unless 
identified as sunlight resistant 

(10) Where subject to physical damage 
362.20 Size. 

(A) Minimum. ENT smaller than metric designator 16 
(trade size Vi) shall not be used. 

(B) Maximum. ENT larger than metric designator 53 
(trade size 2) shall not be used. 

FPN: See 300.1(C) for the metric designators and trade 
sizes. These are for identification purposes only and do not 
relate to actual dimensions. 

362.22 Number of Conductors. The number of 
conductors shall not exceed that permitted by the 
percentage fill in Table 1, Chapter 9. 

Cables shall be permitted to be installed where such use is 
not prohibited by the respective cable articles. The number 
of cables shall not exceed the allowable percentage fill 
specified in Table 1, Chapter 9. 

362.24 Bends — How Made. Bends shall be so made that 
the tubing will not be damaged and the internal diameter of 
the tubing will not be effectively reduced. Bends shall be 
permitted to be made manually without auxiliary 
equipment, and the radius of the curve to the centerline of 
such bends shall not be less than shown in Table 2, Chapter 
9 using the column "Other Bends," 

362.26 Bends — Number in One Run. There shall not be 
more than the equivalent of four quarter bends (360 
degrees total) between pull points, for example, conduit 
bodies and boxes. 

362.28 Trimming. All cut ends shall be trimmed inside 
and outside to remove rough edges. 

362.30 Securing and Supporting. ENT shall be installed 
as a complete system in accordance with 300.18 and shall 
be securely fastened in place and supported in accordance 
with 362.30(A) and (B). 

(A) Securely Fastened. ENT shall be securely fastened at 
intervals not exceeding 900 mm (3 ft). In addition, ENT 
shall be securely fastened in place within 900 mm (3 ft) of 
each outlet box, device box, junction box, cabinet, or fitting 
where it terminates. 

Exception No, I: Lengths not exceeding a distance of 1.8 
m (6 ft) from a luminaire terminal connection for tap 
connections to lighting luminaires shall he permitted 



without being secured. 

Exception No. 2: Lengths not exceeding L8 m (6 ft) from 
the last point where the raceway is securely fastened for 
connections within an accessible ceiling to luminaire(s) or 
other equipment. 

Exception No. 3: For concealed work in finished bmldings 
or. prefinisked yvaii panels where .such securing is 
impracticable, vnhroken lengths (without coupling) of ENT 
shall be permitted to be fished 

(B) Supports. Horizontal runs of ENT supported by 
openings in framing members at intervals not exceeding 
900 mm (3 ft) and securely fastened within 900 mm (3 ft) 
of termination points shall be permitted. 

362.46 Bushings. Where a tubing enters a box, fitting, or 
other enclosure, a bushing or adapter shall be provided to 
protect the wire from abrasion unless the box, fitting, or 
enclosure design provides equivalent protection. 

FPN: See 300.4(G) for the protection of conductors size 4 
AWG or larger. 

362.48 Joints. All joints between lengths of tubing and 
between tubing and couplings, fittings, and boxes shall be 
by an approved method. 

362.56 Splices and Taps. Splices and taps shall be made 
only in accordance with 300.15. 

FPN: See Article 3 14 for rules on the installation and use of 
boxes and conduit bodies. 

362.60 Grounding. Where equipment grounding is 
required, a separate equipment grounding conductor shall 
be installed in the raceway in compliancg ^dth Artk^ 250; 
Pail; VI; 



III. Construction Specifications 

362.100 Construction. ENT shall be made of material that 
does not exceed the ignitibility, flammability, smoke 
generation, and toxicity characteristics of rigid 
(nonplasticized) polyvinyl chloride. 

ENT, as a prewired manufactured assembly, shall be 
provided in continuous lengths capable of being shipped in 
a coil, reel, or carton without damage. 

362.120 Marldng. ENT shall be clearly and durably 
marked at least every 3 m (10 ft) as required in the first 
sentence of 110.21. The type of material shall also be 
included in the marking. Marking for limited smoke shall 
be permitted on the tubing that has limited smoke- 
producing characteristics. 



2010 California Electrical Code 



70-211 



366.1 



ARTICLE 366 -AUXILIARY GUTTERS 



The type, size, and quantity of conductors used in 
prewired manufactured assemblies shall be identified by 
means of a printed tag or label attached to each end of the 
manufactured assembly and either the carton, coil, or reel. 
The enclosed conductors shall be marked in accordance 
with 310.11. 

Auxiliary Gutters 



I. General 

366.1 Scope. This article covers the use, installation, and 
construction requirements of metal auxiliary gutters and 
nonmetallic auxiliary gutters and associated fittings. 

366.2 Definitions. 

Metallic Auxiliary Gutter. A sheet metal enclosure used 
to supplement wiring spaces at m^ter centers, distiibi^itioti 
jcenters; switchboards, and similar points of wiriiig systems. 
The enclosure has hinged ox jretnovable covers for housing 
and protecting electrical wires^ cable, and busbars: The 
enclosure is designed for conductors to be laid or set inj 
place after the enclosures have l^een installed as a complete 
systerril 

Nonmetallic Auxiliary Gutter. A flame i^etardaatj- 
nonmetallic enclosure used to supplement wiring spaces a^ 
meter centers, distribution; centers, switcliboardsi V^Piid 
similar points of v;^iring systenas* The enclosure has hinged 
or removable covers for housing and ptotecting electrical 
wires, cable, and busbars. The enclosure is designed fdd 
/conductors to be laid or set -inTplace after the^e^^^ 
kaye been installed as a coniplbte systetnl 

366.6 Listing Requirements. 

(A) Outdoors. Nonmetallic auxiliary gutters installed 
outdoors shall comply with the following: 

(1) Be listed as suitable for exposure to sunUght 

(2) Be listed as suitable for use in wet locations 

(3) Be listed for maximum ambient temperature of the 
installation 

(B) Indoors. Nonmetallic auxihary gutters installed 
indoors shall be listed for the maximum ambient 
temperature of the installation. 

II. Installation 
366.10 Uses Permitted. 

m 
(A) Sheet Metal Auxiliary Gutters. 

(1) Indoor and Outdoor Use. Sheet metal auxiliary 
gutters shall be permitted for indoor and outdoor use. 

(2) Wet Locations. Sheet metal auxiliary gutters installed 
in wet locations shall be suitable for such locations. 



(B) Nonmetallic Auxiliary Gutters. Nonmetallic auxiliary 
gutters shall be listed for the maximum ambient 
temperature of the installation and marked for the installed 
conductor insulation temperature rating. 

(1) Outdoors. Nonmetallic auxiliary gutters shall be 
permitted to be installed outdoors where listed and marked 
as suitable for the purpose. 

FPN: Extreme cold may cause nonmetallic auxiliary gutters 
to become brittle and therefore more susceptible to damage 
from physical contact. 

(2) Indoors. Nonmetallic auxiliary gutters shall be 
permitted to be installed indoors. 

366.12 Uses Not Permitted. Auxiliary gutters shall not be 
used under the following conditions: 

(1) To enclose switches, overcurrent devices, appHances, 
or other similar equipment 

(2) To extend a greater distance than 9 m (30 ft) beyond 
the equipment that it supplements 

Exception: As permitted in 620.35 for elevators, an 
auxiliary gutter shall be permitted to extend a distance 
greater than 9 m (30 ft) beyond the equipment it 
supplements. 

FPN: For wireways, see Articles 376 and 378. For busways, 

see Article 368. 

366.22 Number of Conductors. 

(A) Sheet Metal Auxiliary Gutters. The sum of the cross- 
sectional areas of all contained conductors at any cross 
section of a sheet metal auxiliary gutter shall not exceed 20 
percent of the interior cross-sectional area of the sheet 
metal auxiliary gutter. The derating factors in 
310.15(B)(2)(a) shall be applied only where the number of 
current-carrying conductors, including neutral conductors 
classified as current-carrying under the provisions of 
310.15(B)(4), exceeds 30. Conductors for signaling circuits 
or controller conductors between a motor and its starter and 
used only for starting duty shall not be considered as 
current-carrying conductors. 

(B) Nonmetallic Auxiliary Gutters. The sum of cross- 
sectional areas of all contained conductors at any cross 
section of the nonmetallic auxiliary gutter shall not exceed 
20 percent of the interior cross-sectional area of the 
nonmetallic auxiliary gutter. 

366.23 Ampacity of Conductors. 

(A) Sheet Metal Auxiliary Gutters. Where the number of 
current-carrying conductors contained in the sheet metal 
auxiliary gutter is 30 or less, the |dj:U|tmeiit factors 
specified in 310.15(B)(2)(a) shall not apply. The current 
carried continuously in bare copper bars in sheet metal 
auxiliary gutters shall not exceed 1.55 amperes/mm2 (1000 
amperes/in.2) of cross section of the conductor. For 
aluminum bars, the current carried continuously shall not 
exceed 1.09 amperes/mm2 (700 amperes/in.2) of cross 
section of the conductor. 



70-212 



2010 Califomia Electrical Code 



ARTICLE 366 - AUXILIARY GUTTERS 



366.120 



(B) Nonmetallic Auxiliary Gutters. The derating factors 
specified in 310.15(B)(2)(a) shall be applicable to the 
current-carrying conductors in the nonmetallic auxiliary 
gutter. 

366.30 Securing and Supporting. 

(A) Sheet Metal Auxiliary Gutters. Sheet metal auxiliary 
gutters shall be supported throughout their entire length at 
intervals not exceeding 1.5 m (5 ft). 

(B) Nonmetallic Auxiliary Gutters. Nonmetallic auxiliary 
gutters shall be supported at intervals not to exceed 900 
mm (3 ft) and at each end or joint, unless listed for other 
support intervals. In no case shall the distance between 
supports exceed 3 m (10 ft). 

366.44 Expansion Fittings. Expansion fittings shall be 
installed where expected length change, due to expansion 
and contraction due to temperature change, is more than 6 
mm (0.25 in.). 

366.56 Splices and Taps. Splices and taps shall comply 
with 366.56(A) through (D). 

(A) Within Gutters. Splices or taps shall be permitted 
within gutters where they are accessible by means of 
removable covers or doors. The conductors, including 
splices and taps, shall not fill the gutter to more than 75 
percent of its area. 

(B) Bare Conductors. Taps from bare conductors shall 
leave the gutter opposite their terminal connections, and 
conductors shall not be brought in contact with uninsulated 
current-carrying parts of different potential. 

(C) Suitably Identified. All taps shall be suitably 
identified at the gutter as to the circuit or equipment that 
they supply. 

(D) Overcurrent Protection. Tap connections from 
conductors in auxiliary gutters shall be provided with 
overcurrent protection as required in 240.21. 

366.58 Insulated Conductors. 

(A) Deflected Insulated Conductors. Where insulated 
conductors are deflected within an auxiliary gutter, either at 
the ends or where conduits, fittings, or other raceways or 
cables enter or leave the gutter, or where the direction of 
the gutter is deflected greater than 30 degrees, dimensions 
corresponding to one wire per terminal in Table 312.6(A) 
shall apply. 

(B) Auxiliary Gutters Used as Pull Boxes. Where 
insulated conductors 4 AWG or larger are pulled through 
an auxiliary gutter, the distance between raceway and cable 



entries enclosing the same conductor shall not be less than 
that required in 314,28(A)(1) for straight pulls and 
314.28(A)(2) for angle pulls. 

366.60 Grounding. Metal auxiliary gutters shall be 
Qomecie&jq m^e^^ 

Iquipmept !?OT^ or to j the groiinded couiiwtoi 

Wh^pi^rr^^^ or mqiSedby 250.92(B)(1^^ 



III. Construction Specifications 
366.100 Construction. 

(A) Electrical and Mechanical Continuity. Gutters shall 
be constructed and installed so that adequate electrical and 
mechanical continuity of the complete system is secured. 

(B) Substantial Construction. Gutters shall be of 
substantial construction and shall provide a complete 
enclosure for the contained conductors. All surfaces, both 
interior and exterior, shall be suitably protected from 
corrosion. Comer joints shall be made tight, and where the 
assembly is held together by rivets, bolts, or screws, such 
fasteners shall be spaced not more than 300 mm (12 in.) 
apart. 

(C) Smooth Rounded Edges. Suitable bushings, shields, 
or fittings having smooth, rounded edges shall be provided 
where conductors pass between gutters, through partitions, 
around bends, between gutters and cabinets or junction 
boxes, and at other locations where necessary to prevent 
abrasion of the insulation of the conductors. 

(D) Covers. Covers shall be securely fastened to the gutter. 

(E) Clearance of Bare Live Parts. Bare conductors shall 
be securely and rigidly supported so that the minimum 
clearance between bare current-carrying metal parts of 
different potential mounted on the same surface will not be 
less than 50 mm (2 in.), nor less than 25 mm (1 in.) for 
parts that are held free in the air. A clearance not less than 
25 mm (I in.) shall be secured between bare current- 
carrying metal parts and any metal surface. Adequate 
provisions shall be made for the expansion and contraction 
of busbars. 

366.120 Marking. 

(A) Outdoors. Nonmetallic auxiliary gutters installed 
outdoors shall have the following markings: 

(1) Suitable for exposure to sunlight 

(2) Suitable for use in wet locations 

(3) Installed conductor insulation temperature rating 



2010 California Electrical Code 



70-213 



368.1 



ARTICLE 368 - BUSWAYS 



(B) Indoors. Nonmetallic auxiliary gutters installed 
indoors shall have the following markings: 

(1) Installed conductor insulation temperature rating 

^{'■^Jk ^ ■ -D .ARTICLE '3^8; :';;-^ ■■■:;/■::■:. 

[- . .'; : ■■.■■;■'■ Busways ■ : ■ ■ ■■; 

I. General Requirements 

368.1 Scope. This article covers service-entrance, feeder, 
and branch-circuit busways and associated fittings. 

368.2 Definition. 

Busway. A grounded metal enclosure containing factory- 
mounted, bare or insulated conductors, which are usually 
copper or aluminum bars, rods, or tubes. 

FPN: For cablebus, refer to Article 370. 

II. Installation 

368.10 Uses Permitted. Busways shall be permitted to be 
installed where they are located in accordance with 
368.10(A) through (C). 

(A) Exposed. Busways shall be permitted to be located in 
the open where visible, except as permitted in 368. 10(C). 

(B) Concealed. Busways shall be permitted to be installed 
behind access panels, provided the busways are totally 
enclosed, of nonventilating-type construction, and installed 
so that the joints between sections and at fittings are 
accessible for maintenance purposes. Where installed 
behind access panels, means of access shall be provided, 
and either of the following conditions shall be met: 

(1) The space behind the access panels shall not be used 
for air-handling purposes. 

(2) Where the space behind the access panels is used for 
environmental air, other than ducts and plenums, there 
shall be no provisions for plug-in connections, and the 
conductors shall be insulated. 

(C) Through Walls and Floors. Busways shall be 
permitted to be installed through walls or floors in 
accordance with (C)(1) and (C)(2). 

(1) Walls. Unbroken lengths of busway shall be permitted 
to be extended through dry walls. 

(2) Floors. Floor penetrations shall comply with (a) and (b): 

(a) Busways shall be permitted to be extended 
vertically through dry floors if totally enclosed 
(unventilated) where passing through and for a minimum 



distance of 1.8 m (6 ft) above the floor to provide adequate 
protection from physical damage. 

(b) In other than industrial establishments, where a 
vertical riser penetrates two or more dry floors, a minimum 
100-mm (4-in.) high curb shall be installed around all floor 
openings for riser busways to prevent liquids from entering 
the opening. The curb shall be installed within 300 mm (12 
in.) of the floor opening. Electrical equipment shall be 
located so that it will not be damaged by liquids that are 
retained by the curb. 

FPN: See 300.21 for information concerning the spread of 
fire or products of combustion. 

368.12 Uses Not Permitted. 

(A) Physical Damage. Busways shall not be installed 
where subject to severe physical damage or corrosive 
vapors. 

(B) Hoistways. Busways shall not be installed in 
hoistways. 

(C) Hazardous Locations. Busways shall not be installed 
in any hazardous (classified) location, unless specifically 
approved for such use. 

FPN: See 501.10(B). 

(D) Wet Locations. Busways shall not be installed 
outdoors or in wet or damp locations unless identified for 
such use. 

(E) Working Platform. Lighting busway and trolley 
busway shall not be installed less than 2.5 m (8 ft) above 
the floor or working platform unless provided with a cover 
identified for the purpose. 

368.17 Overcurrent Protection. Overcurrent protection shall 
be provided in accordance with 368.17(A) through (D). 

(A) Rating of Overcurrent Protection — Feeders. A 

busway shall be protected against overcurrent in 
accordance with the allowable current rating of the busway. 

Exception No. 1: The applicable provisions of 240.4 shall 
he permitted. 

Exception No. 2: Where used as transformer secondary 
ties, the provisions of 450.6(A)(3) shall be permitted. 

(B) Reduction in Ampacity Size of Busway. Overcurrent 
protection shall be required where busways are reduced in 
ampacity. 

Exception: For industrial establishments only, omission of 
overcurrent protection shall be permitted at points where 
busways are reduced in ampacity, provided that the length 
of the busway having the smaller ampacity does not exceed 
15 m (50 ft) and has an ampacity at least equal to one-third 
the rating or setting of the overcurrent device next back on 
the line, and provided that such busway is free from 
contact with combustible material. 



• 



70-214 



2010 California Electrical Code 



ARTICLE 368 - BUSWAYS 



368.234 



(C) Feeder or Branch Circuits. Where a busway is used 
as a feeder, devices or plug-in connections for tapping off 
feeder or branch circuits from the busway shall contain the 
overcurrent devices required for the protection of the feeder 
or branch circuits. The plug-in device shall consist of an 
externally operable circuit breaker or an externally 
operable fusible switch. Where such devices are mounted 
out of reach and contain disconnecting means, suitable 
means such as ropes, chains, or sticks shall be provided for 
operating the disconnecting means from the floor. 
Exception No. 1: As permitted in 240.21. 

Exception No. 2: For fixed or semifixed luminaires, where 
the branch- circuit overcurrent device is part of the 
luminaire cord plug on cord-connected luminaires. 
Exception No. 3: Where luminaires without cords are 
plugged directly into the busway and the overcurrent 
device is mounted on the luminaire. 

(D) Rating of Overcurrent Protection — BrancJi 
Circuits. A busway used as a branch circuit shall be 
protected against overcurrent in accordance with 210.20. 
368.30 Support. Busways shall be securely supported at 
intervals not exceeding 1.5 m (5 ft) unless otherwise 
designed and marked. 

368.56 Branches from Busways. Branches from busways 
shall be permitted to be made in accordance with 
368.56(A), (B), and (C). 

(A) General. Branches from busways shall be permitted to 
use any of the following wiring methods: 

1) Type AC armored cable 

2) Type MC metal-clad cable 

3) Type MI mineral-insulated, metal-sheathed cable 

4) Type IMC intermediate metal conduit 

5) Type RMC rigid metal conduit 

6) Type FMC flexible metal conduit 

7) Type LFMC liquidtight flexible metal conduit 

8) Type WC rigid p(>lyvinyl chloride conduit 

9) Type RTRC remfof ced thermosgk^^^ 

I) TypelLFNCliqiiidtight flexible a^^ conduit Q 

II) Type EMT electrical metaUic tubing 

12) Type ENT electrical nonmetaUic tubing 

13) Busways 

14) Strut-type channel raceway 

15) Surface metal raceway 

16) Surface nonmetaUic raceway 

Where a separate equipment grounding conductor is used, 
connection of the equipment grounding conductor to the 
busway shall comply with 250.8 and 250.12. 

(B) Cord and Cable Assemblies. Suitable cord and cable 
assemblies approved for extra-hard usage or hard usage and 
listed bus drop cable shall be permitted as branches from 
busways for the connection of portable equipment or the 



connection of stationary equipment to facilitate their 
interchange in accordance with 400.7 and 400.8 and the 
following conditions: 

(1) The cord or cable shall be attached to the building by 
an approved means. 

(2) The length of the cord or cable from a busway plug-in 
device to a suitable tension take-up support device 
shall not exceed 1 .8 m (6 ft). 

(3) The cord and cable shall be installed as a vertical riser 
from the tension take-up support device to the 
equipment served. 

(4) Strain relief cable grips shall be provided for the cord 
or cable at the busway plug-in device and equipment 
terminations. 

Exception to (B)(2): In industrial establishments only, 
where the conditions of maintenance and supervision 
ensure that only qualified persons service the installation, 
lengths exceeding 1.8 m (6 ft) shall be permitted beP\^^een 
the busway plug-in device and the tension take-up support 
device where the cord or cable is supported at intervals not 
exceeding 2.5 m (8 ft). 

(C) Branches from Trolley-Type Busways. Suitable cord 
and cable assemblies approved for extra-hard usage or hard 
usage and listed bus drop cable shall be permitted as 
branches from trolley-type busways for the connection of 
movable equipment in accordance with 400.7 and 400.8. 
368.58 Dead Ends. A dead end of a busway shall be 
closed. 

368.60 Grounding. Busway shall be bdniaected to: an 
feqiiipment growditig cotiductc)r(s)j to an equipjaiertt 
boiiding jumper, or to the grounded conductor where 
j^itted Of requjtM Jby :25O.92(®0 250. 142] 

III. Construction 

368.120 Marking. Busways shall be marked with the 
voltage and current rating for which they are designed, and 
with the manufacturer's name or trademark in such a 
manner as to be visible after installation. 

IV. Requirements for Over 600 Volts, Nominal 
368.214 Adjacent and Supporting Structures. Metal- 
enclosed busways shall be installed so that temperature rise 
from induced circulating currents in any adjacent metallic 
parts will not be hazardous to personnel or constitute a fire 
hazard. 

368.234 Barriers and Seals. 

(A) Vapor Seals. Busway runs that have sections located 
both inside and outside of buildings shall have a vapor seal 
at the building wall to prevent interchange of air between 
indoor and outdoor sections. 

Exception: Vapor seals shall not be required in forced- 
cooled bus. 



2010 California Electrical Code 



70-215 



368.236 



ARTICLE 370 ~ CABLEBUS 



(B) Fire Barriers. Fire barriers shall be provided where 
fire walls, floors, or ceilings are penetrated. 

FPN: See 300.21 for information concerning the spread of 

fire or products of combustion. 

368.236 Drain Facilities. Drain plugs, filter drains, or 
similar methods shall be provided to remove condensed 
moisture from low points in busway run. 

368.237 Ventilated Bus Enclosures. Ventilated busway 
enclosures shall be installed in accordance with Article 
no, Part III, and 490.24. 

368.238 Terminations and Connections. Where bus 
enclosures terminate at machines cooled by flammable gas, 
seal-off bushings, baffles, or other means shall be provided 
to prevent accumulation of flammable gas in the busway 
enclosures. 

All conductor termination and connection hardware 
shall be accessible for installation, connection, and 
maintenance. 

368.239 Switches. Switching devices or disconnecting 
links provided in the busway run shall have the same 
momentary rating as the busway. Disconnecting links shall 
be plainly marked to be removable only when bus is de- 
energized. Switching devices that are not load-break shall 
be interlocked to prevent operation under load, and 
disconnecting link enclosures shall be interlocked to 
prevent access to energized parts. 

368.240 Wiring 600 Volts or Less, Nominal. Secondary 
control devices and wiring that are provided as part of the 
metal-enclosed bus run shall be insulated by fire-retardant 
barriers from all primary circuit elements with the 
exception of short lengths of wire, such as at instrument 
transformer terminals. 

368.244 Expansion Fittings. Flexible or expansion 
connections shall be provided in long, straight runs of bus 
to allow for temperature expansion or contraction, or where 
the busway run crosses building vibration insulation joints. 
368.258 Neutral Gpnduciori Neutral bus, where required, 
shall be sized to carry all neutral load current, including 
harmonic currents, and shall have adequate momentary and 
short-circuit rating consistent with system requirements. 
368.260 Grounding. Metal-enclosed busway shall be 
grounded. 

368.320 Marking. Each busway run shall be provided 
with a permanent nameplate on which the following 
information shall be provided: 

(1) Rated voltage. 

(2) Rated continuous current; if bus is forced-cooled, both 
the normal forced-cooled rating and the self-cooled 
(not forced-cooled) rating for the same temperature 
rise shall be given. 

(3) Rated frequency. 

(4) Rated impulse withstand voltage. 

(5) Rated 60-Hz withstand voltage (dry). 

(6) Rated momentary current. 

(7) Manufacturer's name or trademark. 



FPN: See ANSI C37.23-1987 (R1991), Guide for Metal- 
Enclosed Bus and Calculating Losses in Isolated-Phase 
Bus, for construction and testing requirements for metal- 
enclosed buses. 

■ ARTICLE 370 



370.1 Scope. This article covers the use and installation 
requirements of cablebus and associated fittings. 

370.2 Definition. 

Cablebus. An assembly of insulated conductors with 
fittings and conductor terminations in a completely 
enclosed, ventilated protective metal housing. Cablebus is 
ordinarily assembled at the point of installation from the 
components furnished or specified by the manufacturer in 
accordance with instructions for the specific job. This 
assembly is designed to carry fault current and to withstand 
the magnetic forces of such current. 

370.3 Use. Approved cablebus shall be permitted at any 
voltage or current for which spaced conductors are rated 
and shall be installed only for exposed work, except as 
permitted in 370.6. Cablebus installed outdoors or in 
corrosive, wet, or damp locations shall be identified for 
such use. Cablebus shall not be installed in hoistways or 
hazardous (classified) locations unless specifically 
approved for such use. Cablebus shall be permitted to be 
used for branch circuits, feeders , and services. 

Cablebus framework, where bonded, shall be 
permitted to be used as the equipment grounding conductor 
for branch circuits and feeders. 

370.4 Conductors. 

(A) Types of Conductors. The current-carrying 
conductors in cablebus shall have an insulation rating of 
75°C (167°F) or higher and be an approved type suitable 
for the application. 

(B) Ampacity of Conductors. The ampacity of conductors 
in cablebus shall be in accordance with Table 310.17 and 
Table 310.19, or with Table 310.69 and Table 310.70 for 
installations over 600 volts. 

(C) Size and Number of Conductors. The size and 
number of conductors shall be that for which the cablebus 
is designed, and in no case smaller than 1/0 AWG. 

(D) Conductor Supports. The insulated conductors shall 
be supported on blocks or other mounting means designed 
for the purpose. 

The individual conductors in a cablebus shall be 
supported at intervals not greater than 900 mm (3 ft) for 
horizontal runs and 450 mm (Wi ft) for vertical runs. 
Vertical and horizontal spacing between supported 
conductors shall not be less than one conductor diameter at 
the points of support. 



70-216 



2010 California Electrical Code 



ARTICLE 372 - CELLULAR CONCRETE FLOOR RACEWAYS 



372.2 



370.5 Overcurrent Protection. Cablebus shall be 
protected against overcxirrent in accordance with the 
allowable ampacity of the cablebus conductors in 
accordance with 240.4. 

Exception: Overcurrent protection shall be permitted in 
accordance with 240 J 00 and 240.101 for over 600 volts, 
nominal 

370.6 Support and Extension Through Walls and 
Floors. 

(A) Support. Cablebus shall be securely supported at 

intervals not exceeding 3.7 m (12 ft). 

Exception: Where spans longer than 5.7 m (12 ft) are 
required, the structure shall be specifically designed for the 
required span length. 

(B) Transversely Routed. Cablebus shall be permitted to 
extend transversely through partitions or walls, other than 
fire walls, provided the section within the wall is 
continuous, protected against physical damage, and 
unventilated. 

(C) Through Dry Floors and Platforms. Except where 
firestops are required, cablebus shall be permitted to extend 
vertically through dry floors and platforms, provided the 
cablebus is totally enclosed at the point where it passes 
through the floor or platform and for a distance of 1.8 m (6 
ft) above the floor or platform. 

(D) Through Floors and Platforms in Wet Locations. 

Except where firestops are required, cablebus shall be 
permitted to extend vertically through floors and platforms 
in wet locations where (1) there are curbs or other suitable 
means to prevent waterflow through the floor or platform 
opening, and (2) where the cablebus is totally enclosed at 
the point where it passes through the floor or platform and 
for a distance of 1 .8 m (6 ft) above the floor or platform. 

370.7 Fittings. A cablebus system shall include approved 
fittings for the following: 

(1) Changes in horizontal or vertical direction of the run 

(2) Deadends 

(3) Terminations in or on connected apparatus or 
equipment or the enclosures for such equipment 

(4) Additional physical protection where required, such as 
guards where subject to severe physical damage 

370.8 Conductor Terminations. Approved terminating 
means shall be used for connections to cablebus 
conductors. 



370.9 Grounding. A cablebus installation shall be 
grounded and bonded in accordance with Article 250, 
excluding 250.86, Exception No. 2. 

370.10 Marking. Each section of cablebus shall be 
marked with the manufacturer's name or trade designation 
and the maximum diameter, number, voltage rating, and 
ampacity of the conductors to be installed. Markings shall 
be located so as to be visible after installation. 



CeUular Concrete JTjppr 



372.1 Scope. This article covers cellular concrete floor 
raceways, the hollow spaces in floors constructed of 
precast cellular concrete slabs, together with suitable metal 
fittings designed to provide access to the floor cells. 

372.2 Definitions. 

Cell. A single, enclosed tubular space in a floor made of 
precast cellular concrete slabs, the direction of the cell 
being parallel to the direction of the floor member. 

Header. Transverse metal raceways for electrical 
conductors, providing access to predetermined cells of a 
precast cellular concrete floor, thereby permitting the 
installation of electrical conductors from a distribution 
center to the floor cells. 

372.4 Uses Not Permitted. Conductors shall not be 
installed in precast cellular concrete floor raceways as 
follows: 

(1) Where subject to corrosive yapor 

(2) In any hazardous (classified) location, except as 
permitted by ^§^^-M^^^M.^^M^ 

(3) In commercial garages, other than for supplying ceiling 
outlets or extensions to the area below the floor but not 
above 

FPN: See 300.8 for installation of conductors with other 
systems. 

372.5 Header. The header shall be installed in a straight 
line at right angles to the cells. The header shall be 
mechanically secured to the top of the precast cellular 
concrete floor. The end joints shall be closed by a metal 
closure fitting and sealed against the entrance of concrete. 
The header shall be electrically continuous throughout its 
entire length and shall be electrically bonded to the 
enclosure of the distribution center. 



2010 California Electrical Code 



70-217 



372.6 



ARTICLE 374 - CELLULAR METAL FLOOR RACEWAYS 



372.6 Connection to Cabinets and Other Enclosures. 

Connections from headers to cabinets and other enclosures 
shall be made by means of listed metal raceways and listed 
fittings. 

372.7 Junction Boxes. Junction boxes shall be leveled to 
the floor grade and sealed against the free entrance of water 
or concrete. Junction boxes shall be of metal and shall be 
mechanically and electrically continuous with the header. 

372.8 Markers. A suitable number of markers shall be 
installed for the future location of cells. 

372.9 Inserts. Inserts shall be leveled and sealed against 
the entrance of concrete. Inserts shall be of metal and shall 
be fitted with grounded-type receptacles. A grounding 
conductor shall connect the insert receptacles to a positive 
ground connection provided on the header. Where cutting 
through the cell wall for setting inserts or other purposes 
(such as providing access openings between header and 
cells), chips and other dirt shall not be allowed to remain in 
the raceway, and the tool used shall be designed so as to 
prevent the tool from entering the cell and damaging the 
conductors. 

372.10 Size of Conductors. No conductor larger than 1/0 
AWG shall be installed, except by special permission. 

372.11 Maximum Number of Conductors. The 

combined cross-sectional area of all conductors or cables 
shall not exceed 40 percent of the cross-sectional area of 
the cell or header. 

372.12 Splices and Taps. Splices and taps shall be made 
only in header access units or junction boxes. 

For the purposes of this section, so-called loop wiring 
(continuous unbroken conductor connecting the individual 
outlets) shall not be considered to be a splice or tap. 

372.13 Discontinued Outlets. When an outlet is 
abandoned, discontinued, or removed, the sections of 
circuit conductors supplying the outlet shall be removed 
from the raceway. No splices or reinsulated conductors, 
such as would be the case of abandoned outlets on loop 
wiring, shall be allowed in raceways. 

372,17 Ampacity of Conductors. The ampacity 
adjustment factors, provided in 310.15(B)(2), shall apply to 
conductors installed in cellular concrete floor raceways. 



;.|:ARTICtE:3j4^^ 
CeUular McJtai FlcMi^R^cew 



374.1 Scope. This article covers the use and installation 
requirements for cellular metal floor raceways. 

374.2 Definitions. 

Cellular Metal Floor Raceway. The hollow spaces of 
cellular metal floors, together with suitable fittings, that 
may be approved as enclosures for electrical conductors. 

Cell A single enclosed tubular space in a cellular metal 
floor member, the axis of the cell being parallel to the axis 
of the metal floor member. 

Header. A transverse raceway for electrical conductors, 
providing access to predetermined cells of a cellular metal 
floor, . thereby permitting the installation of electrical 
conductors from a distribution center to the cells. 

374.3 Uses Not Permitted. Conductors shall not be 
installed in cellular metal floor raceways as follows: 

(1) Where subject to corrosive vapor 

(2) In any hazardous (classified) location, except as 
permitted by other attiotes in this: Gc?<fe 

(3) In commercial garages, other than for supplying 
ceiling outlets or extensions to the area below the 
floor but not above 

FPN: See 300.8 for installation of conductors with other 
systems. 



I. Installation 

374.4 Size of Conductors. No conductor larger than I/O 
AWG shall be installed, except by special permission. 

374.5 Maximum Number of Conductors in Raceway. 

The combined cross-sectional area of all conductors or 
cables shall not exceed 40 percent of the interior cross- 
sectional area of the cell or header. 

374.6 Splices and Taps. Splices and taps shall be made 
only in header access units or junction boxes. 

For the purposes of this secfion, so-called loop wiring 
(continuous unbroken conductor connecting the individual 
outlets) shall not be considered to be a spHce or tap. 

374.7 Discontinued Outlets. When an outlet is 
abandoned, discontinued, or removed, the sections of 
circuit conductors supplying the outlet shall be removed 
from the raceway. No splices or reinsulated conductors, 
such as would be the case with abandoned outlets on loop 
wiring, shall be allowed in raceways. 



70-218 



2010 California Electrical Code 



ARTICLE 376 - METAL WIREWAYS 



376.10 



374.8 Markers. A suitable number of markers shall be 
installed for locating cells in the future. 

374.9 Junction Boxes. Junction boxes shall be leveled to 
the floor grade and sealed against the free entrance of water 
or concrete. Junction boxes used with these raceways shall 
be of metal and shall be electrically continuous with the 
raceway. 

374.10 Inserts. Inserts shall be leveled to the floor grade 
and sealed against the entrance of concrete. Inserts shall be 
of metal and shall be electrically continuous with the 
raceway. In cutting through the cell wall and setting inserts, 
chips and other dirt shall not be allowed to remain in the 
raceway, and tools shall be used that are designed to 
prevent the tool from entering the cell and damaging the 
conductors. 

374.11 Connection to Cabinets and Extensions from 
Cells. Connections between raceways and distribution 
centers and wall outlets shall be made by means of 
liquidtight flexible metal conduit, flexible metal conduit 
where not installed in concrete, rigid metal conduit, 
intermediate metal conduit, electrical metallic tubing, or 
approved fittings. Where there are provisions for the 
termination of an equipment grounding conductor, 
nonmetallic conduit, electrical nonmetallic tubing, or 
liquidtight flexible nonmetallic conduit shall be permitted. 
Where installed in concrete, Hquidtight flexible nonmetallic 
conduit shall be listed and marked for direct burial. 

FPN: Liquidtight flexible metal conduit and liquidtight 
flexible nonmetallic conduit that is suitable for installation 
in concrete is listed and marked for direct burial. 

374.17 Ampacity of Conductors. The ampacity 
adjustment factors in 310.15(B)(2) shall apply to 
conductors installed in cellular metal floor raceways. 



II. Construction SpeciHcations 

374.100 General. Cellular metal floor raceways shaU be 
constructed so that adequate electrical and mechanical 
continuity of the complete system will be secured. They 
shall provide a complete enclosure for the conductors. The 
interior surfaces shall be free from burrs and sharp edges, 
and surfaces over which conductors are drawn shall be 
smooth. Suitable bushings or fittings having smooth 
rounded edges shall be provided where conductors pass. 



ARTICLE 376 

Metal Wireways 



I. General 

376.1 Scope. This article covers the use, installation, and 
construction specifications for metal wireways and 
associated fittings. 

376.2 Definition. 

Metal Wireways. Sheet metal troughs with hinged or 
removable covers for housing and protecting electrical 
wires and cable and in which conductors are laid in place 
after the wire way has been installed as a complete system. 



II. Installation 

376.10 Uses Permitted. The use of metal wireways shall 
be permitted in the following: 

(1) For exposed work 

(2) In concealed spaces as permitted in 376.10(4) 

(3) In hazardous (classified) locations as permitted by 
501.10(B) for Class I, Division 2 locations; 502.10(B) 
for Class II, Division 2 locafions; and 504.20 for 
intrinsically safe wiring. Where installed in wet 
locations, wireways shall be listed for the purpose. 

(4) As extensions to pass transversely through walls if the 
length passing through the wall is unbroken. Access to 
the conductors shall be maintained on both sides of the 
wall. 

376.12 Uses Not Permitted. Metal wireways shall not be 
used in the following: 

(1) Where subject to severe physical damage 

(2) Where subject to severe corrosive environments 

376.21 Size of Conductors. No conductor larger than 
that for which the wireway is designed shall be installed 
in any wireway. 

376.22 Number of Conductors and Ampacity. The 

number of condqctors and their ampacity shall comply with 

376.22(A)' and'^5 ' 

(A|) Crpis-Secti^^ of Wirewayj The sum of the 

cross-sectional areas of all contained conductors at any 
cross section of a wireway shall not exceed 20 percent of 
the interior cross-secfional area of the wireway. 



2010 California Electrical Code 



70-219 



376.12 



ARTICLE 376 - METAL WIREWAYS 



(§) ^i^mtmeii^"^fMCim$l, The adJustt^S factors in 
310.15(B)(2)(a) shall be applied only where the number of 
current-carrying conductors, including neutral conductors 
classified as current-carrying under the provisions of 
310.15(B)(4), exceeds 30. Conductors for signaling circuits 
or controller conductors between a motor and its starter and 
used only for starting duty shall not be considered as 
current-carrying conductors. r 

376.23 Insulated Conductors. Insulated conductors 
installed in a metallic wireway shall comply with 
376.23(A) and (B). 

(A) Deflected Insulated Conductors. Where insulated 
conductors are deflected within a metallic wireway, either 
at the ends or where conduits, fittings, or other raceways or 
cables enter or leave the metallic wireway, or where the 
direction of the metallic wireway is deflected greater than 
30 degrees, dimensions corresponding to one wire per 
terminal in Table 312.6(A) shall apply. 

(B) Metallic Wireways Used as Pull Boxes. Where 
insulated conductors 4 AWG or larger are pulled through a 
wireway, the distance between raceway and cable entries 
enclosing the same conductor shall not be less than that 
required by 314.28(A)(1) for straight pulls and 
314.28(A)(2) for angle pulls. When transposing cable size 
into raceway size, the minimum metric designator (trade 
size) raceway required for the number and size of 
conductors in the cable shall be used. 

376.30 Securing and Supporting. Metal wireways shall 
be supported in accordance with 376.30(A) and (B). 

(A) Horizontal Support. Wireways shall be supported 
where run horizontally at each end and at intervals not to 
exceed 1.5 m (5 ft) or for individual lengths longer than 1.5 
m (5 ft) at each end or joint, unless listed for other support 
intervals. The distance between supports shall not exceed 3 
m(lOft). 

(B) Vertical Support. Vertical runs of wireways shall be 
securely supported at intervals not exceeding 4.5 m (15 ft) 
and shall not have more than one joint between supports. 
Adjoining wireway sections shall be securely fastened 
together to provide a rigid joint. 

376.56 Splices, Taps, and Power Distribution Blocks. 

(A) Splices and Taps. Splices and taps shall be permitted 
within a wireway, provided they are accessible. The 
conductors, including splices and taps, shall not fill the 
wireway to more than 75 percent of its area at that point. 



(B) Power Distribution Blocks. 

(1) Installation. Power distribution blocks installed in 
metal wireways shall be listed. 

(2) Size of Enclosure. In addition to the wiring space 
requirement in 376.56(A), the power distribution block 
shall be installed in a wireway with dimensions not smaller 
than specified in the installation instructions of the power 
distribution block. 

(3) Wire Bending Space. Wire bending space at the terminals 
of power distribution blocks shall comply with 3 12.6(B). 

(4) Live Parts. Power distribution blocks shall not have 

uninsjjl^^ live parts ^tpp^d^m& 
!?LIM?L§^lwirewa]^^^ 

376.58 Dead Ends. Dead ends of metal wireways shall be 
closed. 

376.70 Extensions from Metal Wireways. Extensions 
from wireways shall be made with cord pendants installed 
in accordance with 400.10 or with any wiring method in 
Chapter 3 that includes a means for equipment grounding. 
Where a separate equipment grounding conductor is 
employed, connection of the equipment grounding 
conductors in the wiring method to the wireway sha