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Automobile
Engineering
A General Reference Work
FOR REPAIR MEN, CHAUFFEURS, AND OWNERS; COVERING THE CONSTRUCTION,
CARE, AND REPAIR OF PLEASURE CARS, COMMERCIAL CARS, AND
MOTORCYCLES, WITH ESPECIAL ATTENTION TO IGNITION, START-
ING, AND LIGHTING SYSTEMS, GARAGE EQUIPMENT,
WELDING, FORD CONSTRUCTION AND REPAIR,
AND OTHER REPAIR METHODS
Prepared by a Staff of
AUTOMOBILE EXPERTS, CONSULTING ENGINEERS, AND DESIGNERS OF THE
HIGHEST PROFESSIONAL STANDING
Illustrated with over Fifteen Hundred Engravings
SIX VOLUMES
AMERICAN TECHNICAL SOCIETY
CHICAGO
1921
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COPYRIGHT, 1909. 1910. 1912. 1915. 1916. 1917. 1918, 1919. 1920. 1921
BY
AMERICAN TECHNICAL SOCIETY
Copyrighted in Great Britain
All Rights Reserved
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Authors and Collaborators
CHARLES B. HAYWARD
President and General Manager, The Stirling Press, New York City
Member, Society of Automotive Engineers
Member, The Aeronautical Society
Formerly Secretary, Society of Automotive Engineers
Formerly Engineering Editor, The Automobile
C. T. ZIEGLER
Automobile Engineer
With Inter-State Motor Company, Muncie, Indiana
Formerly Manager, The Ziegler Company, Chicago
MORRIS A. HALL
Editor, Automotive Engineering
Formerly Managing Editor, Motor Life; Editor, The Commercial Vehicle, etc.
Author of "What Every Automobile Owner Should Know"
Member, Society of Automotive Engineers
Member, American Society of Mechanical Engineers
DARWIN S. HATCH, B.S.
Late Editor, Motor Age, Chicago
Formerly Managing Editor, The Light Oar
Member, Society of Automotive Engineers
American Automobile Association
GLENN M. HOBBS, Ph.D.
Formerly Secretary and Educational Director, American School of Correspond-
ence
Formerly Instructor in Physics, The University of Chicago
American Physical Society
HERBERT L. CONNELL, B.S.E.
Late Lecturer, Automobile Division, Milwaukee Central Continuation School
Editorial Representative, Commercial Car Journal and Automobile Trade Journal
Member, Society of Automotive Engineers
Member, Standards Committee of S. A. E.
Formerly Technical Editor, The Light Car
399054
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Authors and Collaborators— Continued
HUGp DIEMER, M.E.
Professor of Industrial Engineering, Pennsylvania State College
American Society of Mechanical Engineers
HERBERT LADD TOWLE, B.A.
Specialist in Technical Advertising
Member, Society of Automotive Engineers
Formerly Associate Editor, The Automobile
ROBERT J. KEHL, M.E.
Consulting Mechanical Engineer, Chicago
American Society of Mechanical Engineers
EDMOND M. SIMON, B.S.
Superintendent, Union Malleable Iron Company, East Moline, Illinois
EDWARD B. WAITE
Formerly Dean and Head, Consulting Department, American School of Cor-
respondence
Member, American Society of Mechanical Engineers
JOHN R. BAYSTON
Head, Automobile Engineering Department, American School of Correspond-
ence
Member, Society of Automotive Engineers
Formerly Lecturer, Federal Association of Automobile Engineers, Chicago
W. R. HOWELL
President, W. R. Howell and Company, London, England
WILLIAM K. GIBBS, B.S.
Associate Editor, Motor Age, Chicago
JESSIE M. SHEPHERD, A.B.
Head, Publication Department, American Technical Society
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Authorities Consulted
THE editors have freely consulted the standard technical litera-
ture of America and Europe in the preparation of these
volumes. They desire io express their indebtedness, particu-
larly, to the following eminent authorities, whose well-known treatises
should be in the library of everyone interested in the Automobile and
allied subjects.
Grateful acknowledgment is here made also for the invaluable
co-operation of the foremost Automobile Firms and Manufacturers
in making these volumes thoroughly representative of the very latest
and best practice in the design, construction, and operation of Auto-
mobiles, Commercial Vehicles, Motorcycles, etc.; also for the valu-
able drawings, data, illustrations, suggestions, criticisms, and other
courtesies.
CHARLES E. DURYEA
Consulting Engineer
First Vice-President, American Motor League
Author of "Roadside Troubles"
OCTAVE CHANUTE
Late Consulting Engineer
Past President of the American Society of Civil Engineers
Author of "Artificial Flight," etc.
E. W. ROBERTS, M.E.
Member, American Society of Mechanical Engineers
Author of "Gas-Engine Handbook," "Gas Engines and Their Troubles," "The
Automobile Pocket-Book," etc.
SANFORD A. MOSS, M.S., Ph.D.
Member, American Society of Mechanical Engineers
Engineer, General Electric Company
Author of "Elements of Gas Engine Design"
GARDNER D. HISCOX, M.E.
Author of "Horseless Vehicles, Automobiles, and Motorcycles," "Gas, Gasoline,
and Oil Engines," "Mechanical Movements, Powers, and Devices," etc.
AUGUSTUS TREADWELL, Jr., E.E.
Associate Member, American Institute of Electrical Engineers
Author of "The Storage Battery : A Practical Treatise on the Construction,
Theory, and Use of Secondary Batteries"
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Authorities Consulted — Continued
BENJAMIN R. TILLSON
Director, H. J. Willard Company Automobile School
Author of "The Complete Automobile Instructor"
THOMAS H. RUSSELL, M.E., LL.B.
Editor, The American Cyclopedia of the Automobile
Author of "Motor Boats," "History of the Automobile," "Automobile Driving,
Self-Taught," "Automobile Motors and Mechanism," "Ignition Timing
and Valve Setting," etc.
CHARLES EDWARD LUCRE, Ph.D.
Mechanical Engineering Department, Columbia University
Author of "Gas Engine Design"
^*
P. M. HELDT
Editor, Horseless Age
Author of "The Gasoline Automobile"
H. DIEDERICHS, M.E.
Professor of Experimental Engineering, Sibley College, Cornell University
Author of "Internal Combustion Engines"
JOHN HENRY KNIGHT
Author of "Light Motor Cars and Voiturettes," "Motor Repairing for Ama-
teurs," etc.
WM. ROBINSON, M.E.
Professor of Mechanical and Electrical Engineering in University College,
Nottingham
Author of "Gas and Petroleum Engines"
W. POYNTER ADAMS
Member, Institution of Automobile Engineers
Author of "Motor-Car Mechanisms and Management"
ROLLA C. CARPENTER, M.M.E., LL.D.
Professor of Experimental Engineering, Sibley College, Cornell University
Author of "Internal Combustion Engines"
ROGER B. WHITMAN
Technical Director, The New York School of Automobile Engineers
Author of "Motor-Car Principles"
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Authorities Consulted— Continued
CHARLES P. ROOT
Formerly Editor, Motor Age
Author of "Automobile Troubles, and How to Remedy Them"
W. HILBERT
Associate Member, Institute of Electrical Engineers
Author of "Electric Ignition for Motor Vehicles"
SIR HIRAM MAXIM
Member, American Society of Civil Engineers
British Association for the Advancement of Science
Chevalier Legion d'Honneur
Author of "Artificial and Natural Flight," etc.
SIGMUND KRAUSZ
Author of "Complete Automobile Record," "A B C of Motoring"
JOHN GEDDES McINTOSH
Lecturer on Manufacture and Application of Industrial Alcohol, at the Poly-
technic Institute, London
Author of "Industrial Alcohol," etc.
FREDERICK GROVER, A.M., Inst.C.E., M.I.Mech.E.
Consulting Engineer
Author of "Modern Gas and Oil Engines"
FRANCIS B. CROCKER, M.E., Ph.D.
Head of Department of Electrical Engineering, Columbia University
Past President, American Institute of Electrical Engineers
Author of "Electric Lighting," Joint Author of "Management of Electrical
Machinery"
A. HILDEBRANDT
Captain and Instructor in the Prussian Aeronautic Corps
Author of "Airships Past and Present"
T. HYLER WHITE
Associate Member, Institute of Mechanical Engineers
Author of "Petrol Motors and Motor Cars"
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Authorities Consulted— Continued
ROBERT H. THURSTON, C.E., Ph.B., A.M., LL.D.
Director of Sibley College, Cornell University
Author of "Manual of the Steam Engine," "Manual of Steam Boilers/' etc.
MAX PEMBERTON
Motoring Editor, The London Sphere
Author of "The Amateur Motorist"
HERMAN W. L. MOEDEBECK
Major and Battalions Kommandeur in Badiscben Fussartillerie
Author of "Pocket-Book of Aeronautics"
EDWARD F. MILLER
Professor of Steam Engineering, Massachusetts Institute of Technology
Author of "Steam Boilers"
ALBERT L. CLOUGH
Author of "Operation, Care, and Repair of Automobiles"
W. F. DURAND
Author of "Motor Boats," etc.
PAUL N. HASLUCK
Editor, Work and Building World
Author of "Motorcycle Building"
JAMES E. HOMANS, A.M.
Author of "Self-Propelled Vehicles"
v»
R. R. MECREDY
Editor, The Encyclopedia of Motoring, Motor News, etc.
S. R. BOTTONE
Author of "Ignition Devices," "Magnetos for Automobiles," etc.
LAMAR LYNDON, B.E., M.E.
Consulting Electrical Engineer
Associate Member, American Institute of Electrical Engineers
Author of "Storage Battery Engineering"
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WAGNER STARTING MOTOR WITH BBNDIX DRIVE EXPOSED, DESIGNED
FOR GRANT CARS
Courtesy of Wagner Electric Manufacturing Company, St, Louie, Missouri
WAGNER GENERATOR DESIGNED FOR GRANT CARS
Courtesy of Wagner Electric Manufacturing Company, St. Louis, Missouri
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Foreword
THE period of evolution of the automobile does not
span many years, but the evolution has been none
the less spectacular and complete. From a creature
of sudden caprices and uncertain behavior, it has become
today a well-behaved thoroughbred of known habits and
perfect reliability. The driver no longer needs to carry war
clothes in momentary expectation of a call to the front.
He sits in his seat, starts his motor by pressing a button
with his hand or foot, and probably for weeks on end will
not need to do anything more serious than feed his animal
gasoline or oil, screw up a few grease cups, and pump up a
tire or two.
^ And yet, the traveling along this road of reliability and
mechanical perfection has not been easy, and the grades
have not been negotiated or the heights reached without
many trials and failures. The application of the internal-
combustion motor, the electric motor, the storage battery,
and the steam engine to the development of the modern
types of mechanically propelled road carriages has been a
far-reaching engineering problem of great difficulty.
Nevertheless, through the aid of the best scientific and me-
chanical minds in this and other countries, every detail
has received the amount of attention necessary to make it
as perfect as possible. Road troubles, except in connection
with tires, have become almost negligible and even the
inexperienced driver, who knows barely enough to keep to
the road and shift gears properly, can venture on long tour-
ing trips without fear of getting stranded. The refinements
in the ignition, starting, and lighting systems have added
greatly to the pleasure in running the car. Altogether, the
automobile as a whole has become standardized, and unless
some unforeseen developments are brought about, future
changes in either the gasoline or the electric automobile
will be merely along the line of greater refinement of the
mechanical and electrical devices used.
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C, Notwithstanding the high degree of reliability already
spoken of, the cars, as they get older, will need the atten-
tion of the repair man. This is particularly true of the
cars two and three seasons old. A special effort, therefore,
has been made to furnish information which will be of value
to the men whose duty it is to revive the faltering action of
the motor and to take care of the other internal troubles
in the machine.
C. Special effort has been made to emphasize the treatment
of the Electrical Equipment of Gasoline Cars, not only be-
cause it is in this direction that most of the improvements
have lately taken place but also because this department of
automobile construction is least familiar to the repair men
and others interested in the details of the automobile. A
multitude of diagrams have been supplied showing the con-
structive features and wiring circuits of the majority of
the systems. In addition to this instructive section, par-
ticular attention is called to the articles on Welding, Shop
Information, Electrical Eepairs, and Ford Construction
and Repair.
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Table of Contents
VOLUME IV
Electrical Equipment for Gasoline Cars (continued) .
By Charles B. Hay ward. Revised by J. R. Bayston t Page *11
Practical Analysis of Electric Starting and lighting Systems (con-
tinued): Leece-Neville System: Generator, Regulation, Starting Motor,
Instruments, Wiring Diagram, Instructions — North East System: Dyna-
motor. Regulation, Protective Devices, Wiring Diagrams, Instructions,
Switch Tests — Remy System: Two-Unit Type, Single-Unit Type —
Slmras-Huff System: Dynamotor, Regulation, Instruments, Dynamotor
Connections, Change of Voltage, Starting Switch, Wiring Diagram,
Instructions — Splitdorf System: Dynamotor, Wiring Diagram, Control,
Regulation, Starting Motor, Instructions— U. S. L. System: Variations,
Generator, Starting Motor, Regulation, Instruments and Protective De-
vices, Wiring Diagrams, Instructions (Touring Switch, Starting Switch,
Brush Pressure, Radial and Angular Brushes, External Regulator, Test-
ing Carbon Pile, Battery Cut-Out, Ammeter), U. S. L. Twelve- Volt System,
U. S. Nelson System — Wagner System : Twelve- Volt, Single-Unit, Two-Wire
Type, Six-Volt, Two-Unit Type (Generator, Regulation, Starting Motor, Con-
trol, Wiring Diagram, Instructions) — Westinghouse System: Twelve- Volt,
Single-Unit, Single-Wire Type, Six-Volt, Double-Unit, Single-Wire Type
(Generators, Regulation, Wiring Diagram, Battery. Cut-Out, Starting
Motors, Instructions) — Special Starting and Lighting Systems for Ford
Cars: Ford System: General Instructions, Removal of Starting Motor,
Removal of Generator, Lighting and Ignition — Gray and Davis System:
Installation, Instructions, Testing Generator with Ammeter — Starting
and Lighting Storage Batteries: Importance of Battery — Careful At-
tention to Battery Necessary — Principles and Construction: Function of
Storage* Battery, Parts of Cell, Specific Gravity, Action of Cell on Charge
and Discharge, Battery Capacity, Construction Details, Edison Cell not
Available — Care of Battery: Adding Distilled Water, Adding Acid,
Hydrometer, Adjusting Specific Gravity, Gassing, Higher Charges for
Cold Weather, Sulphating, Restoring Sulphated Battery, Specific Gravity
Too High, Internal Damage, How to Take Readings, Detecting De-
ranged Cells, Temperature Variations in Voltage Test, Joint Hydrometer
and Voltmeter Tests, Cleaning Battery, Replacing Jar, Overhauling
Battery (Dismounting Cells, Treating Plates, Reassembling Battery.
Checking Connections, Reconnecting Cells, Renewals), Lead Burning,
Installing New Battery, Storing Battery, Charging from Outside. Source,
Equalizing Charges Necessary, Methods of Charging, Care of Battery in
Winter, Testing Rate of Discharge, Testing Rate of Charge, Voltage
Tests, hydrometer and Voltmeter Tests, Cleaning Repair Parts — Summary
of Instructions: Battery: Electrolyte, Hydrometer Tests, Joint Hydrom-
eter-Voltmeter Tests, Gassing:, Sulphating, Voltage Tests, Sediment,
Voltage, Charging from Outside Source, Intermittent and Winter Use,
Edison Battery — Generators: Types and Requirements, Loss of Capacity,
Methods of Regulation, Regulators, Windings, Commutator and Brushes
— Wiring Systems: Different Plans, Faults in Circuit, Proper Conduction —
Protecting and Operative Devices: Fuses, Circuit Breakers, Battery Cut-
Outs, Cqntact Points, Switches — Lighting and Indicators: Lamps, Instru-
ments — Electric Gear Shift
Electrical Repairs . By R. J. Everest and J. R. Bayston Page 307
Ford Magneto: Capacity, Testing, Recharging, Repairing Coil — Polariza-
tion of High-Tension Magnetos: Missing of Sparks, Causes, Proofs, Rem-
edies, Testing and Charging: Astatic Gap, Single Break Test, Special
Dial Gap— Magnet Testing and Charging: Material, Keeper, Testing,
Charger — Ignition Systems: Automatic, G-4, Battery Systems: Atwater-
Kent, Closed-Circuit Type, Open-Circuit Type, Connecticut, Automatic,
North-East, Westinghouse, Horizontal, Vertical — Magneto Systems: Eise-
mann, Dual Impulse Starter*— Bosch, Dual Impulse Starter, Vibrating
Duplex, Two-Spark — Mea Type BK, Type A — Westinghouse Voltage Regu-
lators: Description, Operation — Equipment: Growler, Undercutting Ma-
chine, Magneto Test Stand, Generator Test Stand, Generator Test Stand
Switchboard, Ignition Switchboard, Bearing Puller, Work Bench, Wash
Rack, Small Tools
Index ■ . Page 381
•For page numbers, see foot of pages.
fFor professional standing of authors, see list of Authors and Collabo-
rators at front of volume.
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sS
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ELECTRICAL EQUIPMENT FOR
GASOLINE CARS
PART VI
ELECTRIC STARTING AND LIGHTING
. SYSTEMS— (Continued)
PRACTICAL ANALYSIS OF TYPES— (Continued)
LEECE-NEVILLE SYSTEM
Six-Volt; Two-Unit; Two-Wire
Generator. Standard shunt-wound bipolar type, combined
with ignition timer and distributor driven by a worm gear on the
armature shaft. The generator is mounted on the left side of the
engine and is driven by the pump shaft (Haynes 1913 installation,
and subsequent models to date).
It differs from the standard shunt-wound machine in that the
shunt field is connected to the regulating third brush. This brush
1J ects current from the commutator and excites the field, so that a
strong shunt field is provided at comparatively low speeds. As the
speed increases, the voltage supplied to the shunt field decreases,
even though the total voltage between the main brushes may have
increased. This weakens the field and prevents the output of the
generator from increasing with the increased speed. At higher speeds
it acts somewhat similarly to a bucking-coil winding in that it further
weakens the field arid causes the generator output to decrease still
more. The closer the third brush is set to the main brush just above,
the greater will be the output of the machine; moving it away from
the main brush decreases the output.
Regulation. Generators of the 1915 and 1916 models are con-
trolled by armature reaction through a third brush, the field coils
receiving their exciting current from the armature through this
brush. The position of the latter on the commutator is shown at
B, Fig. 293. A slight rotation of this brush relative to the com-
ll
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444
ELECTRICAL EQUIPMENT
mutator changes the electrical output of the machine. As adjusted
at the factory this brush is set to give a maximum output of 15
amperes at 7\ volts. (All generators
for 6-volt systems are wound to pro-
duce an e.m.f. of 7§ volts, or there-
about, in order that the voltage
of the generator may exceed that of
the battery when the latter is fully
charged. The e.m.f. of generators
for 12-volt and 24-volt systems also
exceeds that of their batteries in
about the same proportion. Other-
wise, the generator would not be able
to force current through the battery.)
Starting Motor. The motor is
of the bipolar series-wound type
driving the engine through a roller
chain and an over-running clutch.
Instruments. An indicating
type of battery cut-out is employed,
thus combining the functions of the
cut-out and ammeter in one device. The details of this device are
shown in Fig. 294. is the winding or coil of the electromagnet
of which the U-shaped bar
8 forms the magnetic circuit.
At 4 is the pivoted armature,
normally held in the OFF
position as shown by a spring,
when no current is passing,
and adapted to be drawn
against the pole pieces of
the magnet when the latter
is excited by the charging
current. As the two-wire sys-
Fig. 294. Details of Leece-Neville Indicator ^ ^ employed> the cut . out
breaks both sides of the battery-charging circuit and it is provided
with six current-carrying contacts on each of the sides of the circuit.
Four of these, which carry most of the current, are copper to bronze,
Fig. 293.
Brushes on Leece-Ne
6- Volt Generator
Diagram of Arrangement of
~~ !vflle
12
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ELECTRICAL EQUIPMENT 445
while those that take the spark in breaking the circuit are cophite to iron
and are actuated by a spring. The indicating target 16 is held in the
OFF position by the spring 19 when no current is passing, and
this reading appears in the opening of the panel on the cover.
When the generator starts and the cut-out closes, the target is
moved to bring the word CHARGING in the opening. The
same panel also carries the three-way lighting switch controlled
by buttons. The central button closes the circuit to the head-
lights and tail lights in the usual manner, while the upper button
throws the headlights in series-parallel connection. As this doubles
the resistance, it halves the voltage passing through the lamps, and
they, accordingly, burn dimly. The lower button controls the cowl
light over the instruments on the dash.
Wiring Diagram. Fig. 295 illustrates the Haynes 1915 installa-
tion. While two wires are employed for connecting all the appara-
tus, it will be noted that the storage battery and the dry-cell battery
are grounded by a common ground connection. This is to permit
using current from the storage battery for ignition, the correspond-
ing ground to complete the circuit being noted at the ignition coil,
close to the distributor. The connections 6? and B on the panel
board are those of the generator and the battery to the indicating
battery cut-out, the connections of three lighting switches being
shown just to the right. In Fig. 296 is shown the Leece-Neville
installation in White cars.
Instructions. Never rim the engine when the generator is dis-
connected from the battery unless the generator is short-circuited,
as otherwise it will be burned out in a very short time. This applies
to all lighting generators except those protected by a fuse in the
field circuit, in which case the fuse will be blown. The Leece-Neville
generator can be short-circuited by taking a small piece of bare
copper wire and connecting the two brush holders together with it.
Instructions for short-circuiting other makes are given in connec-
tion with the corresponding descriptions.
Later models of the Leece-Neville generator are provided with a
circuit-breaker. On the Haynes 12-cylinder models, this is mounted
on top of the generator, while in some cases it is combined with the
ammeter on the dash. To protect the generator and battery, there
is a 5-ampere cartridge fuse under the cover of this circuit-breaker-
13 Digitized by G00gle
446 ELECTRICAL EQUIPMENT
14
ELECTRICAL EQUIPMENT 447
When this fuse blows out, both the generator and the circuit-breaker
become inoperative. Any one of the following conditions may cause
Fig. 296. Wiring Diagram of Leece-Neville System on White Cars
I
Fig. 297. Wiring Diagram of Generator and Circuit-Breaker Circuits for Leece-Neville System
Courtesy of The Leece-Neville Company, Cleveland, Ohio
this fuse to blow out : loose or corroded connections at the battery; an
open circuit in the wiring on the battery side of the cut-out; not
sufficient water in the battery; output of the* generator too high;
15
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448 ELECTRICAL EQUIPMENT
allowing the main brush directly above the third brush to stick in its
holder; a loose connection at the point A 2 , Fig. 297; improper insula-
tion between the wires B\ and B 2 in the connector plug, Fig. 297.
By an open circuit is meant an actual break at a connector or a termi-
nal, or in the wiring itself, while a loose connection signifies an inse-
curely fastened terminal or wire, at a junction box, or at any other part
of the system. If there is a short-circuit in the field winding of the
generator, this also will cause the fuse to blow out.
Testing the Field Winding. While a short-circuit in the field
winding of any generator is a rare fault, there are times when the
trouble cannot be traced to any other part of the system. To test
the Leece-Neville generator for this, connect the negative terminal of
the portable testing ammeter to Fi, Fig. 297, while the positive termi-
nal of the motor must be connected to the positive terminal of a 6- volt
storage battery; the negative terminal of the battery is to be connected
to the third brush when drawn from its holder. If the indication of
the ammeter is above 4 amperes, there is a short-circuit in the field
windings. In such a case, the generator should be returned to the
manufacturers for repairs.
With the engine running) the working of the generator should be
inspected from time to time. In case there is excessive sparking or
"arcing" between the brushes and the commutator, examine the con-
nections at Fi and Ai and see that the screws are perfectly tight,
as these screws sometimes work loose and are responsible for this arc-
ing which is destructive to the commutator. The loosening of the
connections at Fi and A\ will have no effect on the fuse; but if the
connection at A 2 loosens, the fuse will burn out. When inspecting the
operation of the generator, see that the brushes are making good even
contact with the commutator, and wipe away all particles of dust and
grit from around the brushes and their holders. With the engine
stopped, see that the brushes move freely in their holders. This
should always be done where a car has been laid up for some time
(before starting the engine) as the brushes, through disuse, will have
a tendency to stick.
The fuse in the circuit-breaker has no effect whatever on the
output of the generator, so that a larger fuse must not be inserted in
case the generator is not delivering its rated output or more. The
makers supply a 5-ampere fuse for this purpose, and if a fuse of
16
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V % ■ ■ ■"'
r
l
1
17 Digitized by G00gk
Leeoe-NeviUe Starting and Lighting System on White Cars, Model G-M
Courtesy of Leece~NeriU* Company, Cleveland, Ohio
18
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ELECTRICAL EQUIPMENT 449
heavier capacity is employed, it will cause both the circuit-breaker
and the generator to burn out. This will be the case also where a
"jumper" is resorted to, i.e., a piece of wire or other metal bridging
the fuse clips so that the fuse is cut out of the circuit. It must be
borne in mind, however, that these fuses are more or less fragile and
are likely to become damaged by careless handling. A fuse whose
connections have been loosened up is likely to blow out on that
account, so before inserting a fuse in the clips of the circuit, it should
be examined to see that the ferrules on each end of the cartridge are
perfectly tight. Where a good fuse has been inserted and it blows out,
the cause should be ascertained before inserting another fuse.
Regulating Brush. In case the generator output falls off as
shown by its inability to keep the battery properly charged, the
battery itself and all connections being in good condition, and a
proper amount of day running being done to provide the necessary
charging current, the trouble may be in the regulating brush of the
generator. Test by inserting an ammeter, such as the Weston
portable or any other good instrument with a scale reading to 30
amperes, in the line between the generator and the battery. Run
the engine at a speed corresponding to 20 miles per hour, at which
rate the ammeter should record a current of approximately 15
amperes. If the ammeter needle butts against the controlling pin
at the left end of the scale instead of showing a reading, it indicates
that the polarity is wrong, and the connections should be reversed.
Should there be no current whatever, the needle will stay perfectly
stationary except as influenced by vibration. If the ammeter shows
a reading of less than 15 amperes, the current output of the gener-
ator may be increased by loosening the set screw holding the third
brush and rotating the brush slightly in the same direction as the
rotation of the armature. This should be done with the generator
running and the ammeter in circuit, noting the effect on the reading
as the brush is moved. To decrease the output, it should be moved
in the opposite direction until the proper reading is obtained, after
which the brush must be sanded-in to a good fit on the commutator.
It may sometimes occur that sufficient movement cannoj; be given
the third brush without bringing it into contact with one of the
main brushes. This must be avoided by loosening the two set
screws E, Fig. 293, and moving the main brush holder away
19
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450 ELECTRICAL EQUIPMENT
from the third brush until there is no danger of their touching.
After securing the desired adjustment, fasten the third brush in
place again, stop the engine, and then reconnect ths generator to the
battery. Do not cut the ammeter out of the circuit while the gen-
erator is running.
To Adjust Third Brush. Before making any adjustment of the
third brush when it is suspected that any trouble with the current
supply is due to the generator, the output of the generator should be
tested. On a car equipped witl\ lamps totaling 250 candle power or
more (this refers to White busses), the generator should produce 20
amperes. Run the engine at a speed sufficient to drive the car 15
o 16 miles per hour on direct drive and note the reading of the dash
ammeter. In case the car has seen considerable service, it may be
well to check the dash ammeter with the more accurate portable
ammeter described in connection with other tests in previous and
subsequent sections. Where the car lighting system totals 250 c.p.
or over, and the ammeter reading shows more than four amperes above
or below 20, the generator should be adjusted to give its rated capacity
of 20 amperes — as every 15 c.p. less than 250 c.p. used on the car,
lower the output of the generator by one ampere. By making the
adjustments in this manner, the storage battery will be amply
protected.
Before making any generator adjustments, test the storage bat-
tery with the hydrometer. Do not add any distilled water just pre-
vious to making this test unless the level of electrolyte is right down to
the plates so that sufficient liquid cannot be drawn into the hydrome-
ter; in this case, add water and charge the battery for at least one hour
before making the hydrometer test. If the specific gravity of the elec-
trolyte is 1.250 or over, and the generator is found to be delivering less
than the rated lamp load, no adjustment of the generator should
be made.
To increase the output of the generator, rotate the third brush
in the direction of rotation of the armature; to decrease the output,
move the brush against the direction of rotation. Adjustments
should be made with the engine standing. Loosen the screw at the
rear of the commutator housing shown at the point F, Fig. 293.
This releases the third brush holder, and the brush may then be moved
in the direction desired. It should be moved only a short distance,
20
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ELECTRICAL EQUIPMENT 451
and the generator then should be tested until the desired output is
secured. In case the third brush should come in contact with the
main brush above in the course of adjustment, it will be necessary to
move the main brushes. To do this, loosen the two set screws E,
Fig. 293, and move the main brush holder far enough away from
the third brush so that there is no possibility of contact between them.
When the desired location is found, sand-in the third brush to the com-
mutator and also clean the commutator with a piece of worn sand-
paper as described in the section on Sanding-In the Brushes (Delco
instructions) ; if it has been necessary to move the main brushes, they
should be sanded-in also. The brush holder screws should be well
tightened after making any adjustments to prevent any possibility of
the vibration and jolting loosening them up and throwing the gener-
ator out of adjustment again.
Brush Replacements. Never replace any of the brushes on
either the generator or starting motor with any but those supplied
by the manufacturer of the system for this purpose. Motors and
generators adapted for use on electric-lighting circuits are usually
fitted with plain carbon brushes. These are not suitable for use on
automobile generators or starting motors owing to their resistance
being much higher. Due to the low voltage of electric apparatus
on the automobile, special brushes of carbon combined with soft
copper are usually employed. Brushes also differ greatly in hard-
ness, and a harder brush than that for which the commutator is
designed will be liable to score it badly besides producing a great deal
of carbon dust, which is dangerous to the windings. This, of course,
applies to all makes of apparatus and not merely to that under
consideration.
Generator or Motor Failure. For failure of the generator or of
the starting motor, see instructions under Auto-Lite, Delco, and
Gray & Davis, bearing in mind, however, that the system under
consideration is of the two-wire type, so that in using the test lamp
to locate short-circuits a connection to the frame or ground is not
always necessary. The short-circuit may be between two adjacent
wires of different circuits. Given properly installed wires and
cables, there is less likelihood of short-circuits in the wiring of a two-
wire system. Defective lamps will not infrequently prove to be the
cause, as, in burning out, a lamp often becomes short-circuited.
21
452 ELECTRICAL EQUIPMENT
NORTH EAST SYSTEM*
Twelve- Volt, Sixteen-Volt; or Twenty-Four-Volt; Single-Unit; Single-
Wire or Two-Wire, According to the Installation
Dynamotor. The dynamotor is of the four-pole type, with both
windings connected to the same, commutator. It is designed for
installation either with silent-chain drive — as on the Dodge, Fig. 298,
in which case the drive is direct either as a generator or as a motor—
or with a special reducing gear and clutch for driving from the
pump or magneto shaft of the engine. In the latter type, the start-
ing switch is mounted on the gear housing, which is integral with
Fig. 298. North East Dynamotor with Silent-Chain Drive. Starting
Switch Shown at Right
Courtesy of North East Electric Company, Rochester, New York
the bedplate of the dynamotor. In this case the drive as a gener-
ator is 1\ times engine speed, while as a starting motor the
reduction through the gear is approximately 40 : 1.
Regulation. The regulation is by means of a differential wind-
ing or bucking coil, in connection with an external resistance auto-
matically cut into the shunt-field circuit by a relay in series with the
battery cut-out. See "limiting relay", Fig. 299. The "master
relay" is the battery cut-out, and the condenser is to reduce sparking
at the contacts of these relays.
Protective Devices. There is a fuse in the field circuit of the
generator, but fuses are not employed on the lighting circuits.
♦ The voltage of any system may be determined by counting the number of cells in the
storage battery, and multiplying by 2 in the case of a lead battery, or multiplying by IX where
an Edison battery is used.
22
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To Battery.
<3) HAJ2NG 3WI tCH.
)5. Oa
Block
O CONDENSE* O
,:k
v , ,y
1 — D*
•f:
W^>
Red.
r ^rT^ 1 -
RE&SmNCE. urtmNo
RELPT.
rnsTER
RELJMT.
RES&mNCE
Fig. 209. Diagrammatic Section of North East Dynamotor, Showing Regulator (Limiting
Relay) and C»+-Out (Master Relay)
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454 ELECTRICAL EQUIPMENT
Wiring Diagrams. A graphic diagram of the North East
§
©
it
§e
'Si
1 J
IS
°J
a
installation on the Dodge is shown in Fig. 300. This is a 6-cell or
12-volt system single-wire type. The sDrocket on the forward end
24
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456
ELECTRICAL EQUIPMENT
I L ^ c J , y rcw l
of the machine drives from a similar but much larger sprocket on
the forward end of the crankshaft of the engine through a silent
chain. The wiring diagram of the Krit 1915, Fig. 301, will be
recognized as being the
same as the Dodge, except
for the use of two wires
throughout. Fig. 302
show's the wiring diagram
of an 8-cell or 16-volt
system, but the battery is
divided for the lighting
circuits so that 8J — 9-volt
lamps are used, whereas
14-volt bulbs are necessary
on the Dodge installation
as the entire battery is
used in series for lighting.
The wiring of the 12-cell
or 24-volt system is shown
in Fig. 303. In this case
the battery is divided for
lighting so that 7-volt
lamps are employed. Such
a system is usually desig-
nated as 24 — 6-volt, while
the previous one would be
a 16— 6-volt. The North
East installation for Ford
cars is 24 — 14-volt. With
the exception of the Dodge,
the two-wire system is
employed on the instal-
lations mentioned.
Instructions. The
indicator shows when the
battery is charging or dis-
charging and accordingly
should indicate OFF when
!!
i*'i
fig. 302. Wiring Diagram for 16-Volt North East
System Using 8M— 9-Volt Lamp*
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ELECTRICAL EQUIPMENT 457
v
i
3d
xn
TAIULAMP
Fig. 303. Wiring Diagram for 24-Volt North East System Using 7-Volt Lamps
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458 ELECTRICAL EQUIPMENT
the engine is idle and no lamps are lighted. A discharge reading under
such conditions would indicate the presence of a ground, short-circuit,
or failure of the battery cut-out to release. Should the generator fail
to charge the battery, note whether the field fuse has been blown by
short-circuiting the fuse clips with the pliers or a piece of wire while
the engine is running at a moderate speed. Look for cause of failure
before replacing the fuse. If the fuse has not blown, see whether
battery cut-out is operating; look for loose connections at generator,
cut-out, and battery. If the battery is properly charged, loose con-
nections are also most likely to be the cause of failure of the starting
motor; or, any of the instructions covering brushes, commutator, etc.,
as given previously, may apply.
Battery Cvt-Ovi and Regulator (Relays) . In every case where it is
necessary to make repairs on starter-generators equipped with the
earlier type cut-out and regulator (relays), 1283 (12-volt), 1860
(16-volt), 2501 (24-volt), 1900 (16-volt), and 2503 (12 and 24-volt),
it is advisable to replace the cut-out entirely, installing a later and
improved type, 1196 (12-volt), or 1197 (24-volt and 16-volt). In
order to adapt the starter-generator to the 1196 and 1197 cut-out, or
relay units, it is necessary to cut out the bosses on the commutator
end bearing in which the studs holding the original relay were
screwed. This will provide the clearance required to prevent ground-
ing of the nuts which secure the units to their baseboard. As a
further precaution against grounding, it will be necessary to cut away
that portion of the gasket retainer which would be liable to come
into contact with the armature of the master relay.
Fasten down the baseboard which carries the relays by screwing
the resistance unit studs into the holes which were used for the former
resistance studs. Before making connections on the relay, draw
tight all leads which come from inside the starter-generator so as to
take up whatever slack they have^ then tie them together with string
to prevent their slipping back. No loose wire must be left inside the
starter-generator, because of its tendency to be drawn in between the
armature and the pole pieces. The connections on the four-terminal
type starter-generator are made as follows :
Looking at the starter-generator from the driving sprocket end,
the main terminals 1, 2, 4, and 3 of the starter-generator are consid-
ered as being numbered in anti-clockwise rotation, Fig. 304. Viewing
28
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13
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ELECTRICAL EQUIPMENT
459
the relay unit as mounted on the starter-generator with the larger, or
master relay, at the left, the four binding posts a, b, c, and d are
designated from left to right in the same illustration. To relay bind-
ing post a, connect lead (red) coming from starter-generator terminal
2. To relay binding post b,
connect lead (black) coming
direct from starter-generator
terminal 3. To relay binding
post c, connect lead (green)
from starter-generator ter-
minal 4. To relay binding
post d, connect lead (yellow)
from starter-generator shunt-
field coils. It is always advis-
able to check the identity of the
leads by inspection and test.
In order to make a posi-
tive distinction between the d
lead and the b lead, both of
which are in electrical connec-
tion with the starter-generator
terminal 3, the following test
should be made: Using the
test-lamp outfit, send current
from starter-generator ter-
minals, through each of these
wires in turn, and note appear-
ance of the lamp. When the
direct lead (6 lead) is in circuit,
the lamp will burn with full
brilliance, but when the d lead,
which includes the starter-generator shunt-field coils, is in circuit, the
lamp will be noticeably dimmer.
Five- Terminal Type Unit. The connections on the five-terminal
type generator-starter unit are made as follows: Looking at the
starter-generator, Fig. 305, from the driving sprocket end, the main
terminals 1, 5, 2, 4, and 3, respectively, of the unit are numbered in
anti-clockwise rotation (to the left). Viewing the relay unit as
JT/7JPTER-0ZMZXJ7TQR
Fig. 304. Internal Wiring Diagram for North East
Model "D" Starter-Generator
31
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460
ELECTRICAL EQUIPMENT
mounted on.the starter-generator with the master relay at the left,
the four binding posts a, b, c, and d are designated from left to right
as shown in the illustration. Proceed with the instructions as given
for the four-terminal type starter-generator as given. The new type
relays 1196 and 1197 are regularly furnished with local connec-
tions, as shown in Fig. 304,
s^^-^Qj/tf/lpY cr*'A«5fc/y but it will be necessary to
~~ make the following altera-
tions when applied to the
five-terminal type starter-
generator, so that the relay
connections will conform to
the 'diagram in Fig. 305.
Remove the jumper lead that
connects the frame of the
master relay to the rear con-
tact terminal on the limiting
relay; remove from relay
binding post a the left-hand
resistance-unit lead.
Lengthen this lead by splic-
ing a piece of the same kind
of wire to it, and solder it to
the limiting relay contact ter-
minal, from which the jumper
has been removed. To this
terminal must also be sol-
dered the lead coming from
starter-generator terminal 5.
(In some starter-generators
this lead includes the field
fuse.)
The condenser in the early models is mounted between the field
coils. One condenser lead must either be connected to the relay
binding post a as shown in either Fig. 304 or Fig. 305 or be spliced
to the wire leading to it. The other condenser lead must either be
connected to the relay binding post d or spliced to the shunt-field
wire leading to it.
STARTER- GENERATOR
c-z^zz
AZLJJY C/NfT
Fig. 305. Internal Wiring Diagram for
Model "B" Starter-Generator
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462
ELECTRICAL EQUIPMENT
Ratchet
Starting Switch. When its operation indicates that the con-
tactor blades have worn, the starting switch should be dismounted,
and, if necessary, new blades should be inserted. To disassemble the
switch, proceed as follows: (1) Remove the spring 2265, Fig. 306, on
the switch case 2365; (2) remove the cotter pin from the collar 2416;
(3) withdraw the shaft and lever 2401, together with the spring
1818; (4) remove the three screws which hold the cover 2404 in place,
and remove the cover;
(5) remove the stop 2457;
and (6) disconnect the
spring 1813 from the arm
of the ratchet and re-
move the contactor mem-
ber 2344.
If, upon inspection,
the contacts are found to
be in such a condition
that their renewal is nec-
essary, make a replace-
ment of the entire cover
member 2404 and the
entire contactor 2344.
Before placing these new
parts in the switch, the
following points should
receive careful attention:
the front edges of the contact blocks should be slightly rounded so
as to eliminate the possibility of these edges catching on each other
when the switch is being operated. The supports on the cover
must be adjusted so that they lie parallel with the faces of the
contact blocks.
The upper surfaces of the supports must be .010 to .015 inch
lower than the contact surface of the block. Care should be taken
that the upper surface of the contact blocks are fV inch above the
inner surface of the cover. A small steel straightedge laid upon
the face of the contact block and extended over the supports,
as shown in Fig. 307 (a), will serve as a means of checking these
dimensions.
Jtig/tfs/c/e MOJ
up/tkf t/tii _ //At Mis
Tbp+bottom Ufa*/ of stop
(c)
Fig. 307. Assembly of Starting Switch
Courtesy of North East Electric Company, Rochester, New York
34
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' ELECTRICAL EQUIPMENT 463
Before placing in service, the contact surfaces must be carefully
cleaned and lubricated with a very small quantity of vaseline. To
reassemble the switch: (1) Connect the spring 1813, Fig. 306, to the
arm of the ratchet; (2) place the contactor member 2344 in
the switch case in such a position that the ratchet will lie against the
pawl 1830; and (3) hold the switch case in the left hand, lever side up,
and insert the right forefinger through the hole in the switch case
and introduce the pawl into the first notch of the ratchet, Fig. 307 (b) ;
(4) hold these parts carefully in position and replace the cover 2404,
Fig. 306, fastening it to the switch case by means of the three screws;
(5) insert the stop through the hole in the switch case and replace it
upon the ratchet plate in such a position that the elongated portion
of the stop will lie between the raised projection which is found on
the ratchet plate and the end of the short lever on the pawl as shown in
Fig. 307 (c). It is very important that the stop be placed in the
switch right side up, Fig. 307 (d) illustrating the proper method of
doing this. (6) Place the spring on the shaft and replace the shaft in
the switch, taking care while entering the shaft not to disturb the
arrangement of any of the switch parts; (7) replace the collar and the
cotter pin; and (8) connect the spring 2265 with the lug on the switch
case. A drop of light oil should be applied to the bearing point at each
end of the switch shaft 2401.
Switch Tests. To determine whether the switch has been
assembled correctly, pull the lever through the full length of its stroke
and allow it to return slowly to its initial position. If the switch
is properly assembled, three distinct clicks will be heard while the lever
is being moved through its stroke, and a snap will occur just before
the lever comes back to its initial position. The switch should be
tested electrically, as follows:
Ground Test. Using the lamp-test set as shown in Fig. 263
and following Part V, hold one contact point on the switch case and
then connect the other to the two contact studs. The test lamp will
not light unless there is a ground.
Operation Test. Hold one of the test points in contact with each
of the two studs, and turn the lever through its stroke. If the switch
is in proper working condition, the test lamp will light up just after
the first dick of the switch and continue to burn until the final
snap occurs.
35
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ELECTRICAL EQUIPMENT
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ELECTRICAL EQUIPMENT
Replacing Dodge Chain. When the driving chain on any equip-
ment operated in this manner has worn to a point where it no longer
makes proper contact with the sprockets (the chain being adjusted to
the correct tension), it will be necessary to replace it. While the
following instructions for "fishing" the chain through the housing
apply particularly to the Dodge car, with little modifications
here and there they will be found equally applicable to all similar
installations.
Having removed the old chain, pass a short piece of wire through
the end of the new chain, Fig. 308. Then start the chain on the
lower side of the sprocket, as shown in the illustration, hooking the
wire through the sprocket to keep the chain in mesh, and slowly turn
the engine over by hand until the chain appears at the top of the
sprocket. Then remove the wire from the sprocket, hold the end of
the chain, and continue to turn the engine over until the chain is in
v , a position to apply the
J f \ / rr f>**T QPEHAT/ar*
_sy V J /^y r Arss3fiartpitctofHr/r*fftrot/eA
^ \. J / rr [ *i4efc/tabtarr€t&*ncft*tto
> ^-— ^y v^ *yjf I /brm of staple.
master link.
Mechanical and Elec-
trical Characteristics.
When it is desired to
make bench tests of any
of the North East appa-
ratus with the aid of the
outfit described in connec-
tion with the Gray &
Davis tests, the data
shown in Table V will
be found valuable for
Jccohd Qficjgjrr/oj*
SAerrf cAerfst on f—»*r s/efe of
jprocXef to Arffp rAafsr Or to
nd torn Mo/tte w/tAr sktrftht
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sr ^ *V>ofSf>roeA*f, frofd osTeTof cA<r<>i
A flrjposWorr far apfifyfny ****&-//**.
Fig. 308. — Diagram Showing Method of Inserting
Chain in North East Equipment on Dodge Cars
checking purposes. The
left-hand columns give
the mechanical charac-
teristics, with the aid of
which the unit may be
identified, while the right-hand columns give the electrical character-
istics, such as the charging rate, torque in foot-pounds with given
current input, cutting-in and cutting-out points of the master relay
(battery cut-out), air gaps for the limitation relay, and the resistance
of the units.
38
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REMY SYSTEM
Six-Volt; Two-Unit; Single-Wire
Generator. Of the multipolar (four-pole) shunt-wound type
of generator combined with ignition timer and distributor and
designed to be driven at 1§ times crankshaft speed, several models
are made, of which one is shown in Fig. 309. In this case, both the
regulator for the generator and the battery cut-out are mounted
directly on the generator. On some of the models only the regu-
lator is so mounted, the cut-out being placed on the dash of the car,
while on others no
independent regu-
lating device is
required as the
third-brush type
of regulation is
employed (on bi-
polar generator).
Regulation.
In accordance
with the model of
generator and the
requirements Of ^ 309 j^y i gn ition Generator and Distributor
the engine tO Courtesy of Remy Electric Company, Anderson, Indiana
which it is to be fitted, either the constant-voltage method of
regulation using a vibrating regulator mounted on the generator
or the third-brush method is employed.
Constant-Voltage Method. The regulator for the generator is
similar in principle to that described in connection with the Bijur
system. It consists of an electromagnet; two sets of contact points,
two of which are mounted on springs; a pivoted armature which may
move to make or break the circuit; and a resistance unit. When
running at too slow a speed to produce its maximum output, the
generator field is supplied with current passing directly through the
regulator contact points, which are held together by a spring. As
soon, however, as the speed of the generator increases to a point
where it tends to cause its output to exceed the predetermined
maximum, the charging current which is flowing through the coil
of the electromagnet energizes it so such an extent as to cause it to
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pull th$ armature down. This separates the contacts and causes
the field current to pass through the resistance unit, thus decreasing
the field current and, in turning, decreasing the generator output,
which reduces the exciting effect on the electromagnet and causes
it to release its armature, cutting the resistance out of the field cir-
cuit. The latter immediately builds up again, and the operation is
repeated as long as the speed remains excessive for the generator,
which is thus supplied with a pulsating current to excite its fields,
and its output is held at a practically constant value.
Third-Brush Method. The third-brush method of regulation is
based upon the distortion of the magnetic field of a generator at
high speeds. When running at low speeds, the magnetic flux of a
generator is evenly distributed along the faces of its field pole pieces,
but at high speeds there is a tendency to drag it out of line in the
direction of the rotation of the armature. It is then said to be
distorted. The third brush, which supplies the exciting current to
the field winding, is so located with relation to the main-line brush
of opposite polarity that this distortion of the magnetic flux reduces
the current which it supplies to the fields. This decrease in the
exciting current of the field causes a corresponding decrease in
the output of the generator, and as the distortion of the magnetic flux
is proportional to the increase in speed, the generator output falls
off rapidly the faster it is driven above a certain point, so that it is
not damaged when the automobile engine is raced.
Thermostatic Switch. More of the current produced by the
generator is used for lighting purposes in winter than in summer, in
the proportion that the demands for house lighting vary with the
change of the seasons. Added to the decreased efficiency of the stor-
age battery in cold weather, this tends to place a greatly increased
load on the generator in the winter months. If the generator, as
installed, were regulated to produce sufficient current to take care of
this maximum demand, it would keep the storage battery in a con-
stant state of overcharge in summer and would be likely to ruin the
plates through excessive gassing. The Remy engineers have accord-
ingly developed a method of regulation that will automatically com-
pensate for the difference in the demand with the changing seasons,
consisting of a thermostatic switch in connection with the third-brush
control; it will be found, among others, on the Reo 1917 models.
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To gain a clear idea of the action of an electric thermostat, the
heating effect of the current must be kept in mind; also that different
metals have different coefficients of expansion, i.e., some will expand
more than others under the influence of the same degree of heat.
Electric thermostats have been
in use for years as automatic
fire alarms and as temperature-
controlling devices in incubators
and for residence heating, and
within the past few years they
have come into use on the auto-
mobile to control the circulation
of the cooling water and the f <*- r
suction of the engine in accord- p^^/vmaw^a^w^/
ance. with variations in the tern- ' C z y •
ance x with variations in the tem-
perature. The device consists
of a thermal member, or blade, of
two different metals riveted together at their ends,
held fast at one end and at the other it carries
Fig. 310. Details of Remy Thermostatic
Switch
This member is
a contact point,
designed to complete the circuit by touching a stationary contact.
Under the influence of an increase in temperature, one of the metals
Fig. 311. Wiring Diagram of Switch Connections
expands more than the other and thus springs this member, or blade,
away from the stationary contact.
The details of the Remy thermostat are shown in Fig. 310. B is
the thermo-member carrying the silver contact C, and is supported on
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a strip of steel A. A also carries the resistance unit E, which is a
short coil of high-resistance wire wound on heavy mica insulation.
A and B are riveted together at the end D so as to insulate them from
each other. The two metals composing B are spring brass and nickel
steel, the strip of spring brass being placed on the lower side of
the blade. Sufficient tension is placed on this strip, by means of the
adjusting nut F, to keep the points firmly in contact at temperatures
below 150° F. This adjustment is made by the manufacturer and is
permanent.
As shown in the wiring diagram, Fig. 311, which illustrates the
relation of the thermo-switch to the third-brush method of regulation,
it will be noticed that the switch is placed near the commutator of the
generator, as that is the hottest part of the machine when it is in
*~ ' ' — ' ^~i
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1 /T-orrt f*n*fafoT- ArusJi
T/fCBMOSTJJT CLOSED
yf To g*rt+r**tfor- /r'elcf
V. fs-om geTterafor SrusA
TffEBM05r/!T OPEN
Fig. 312. Photographic Reproductions and Diagrams of Action of Thermostatic Switch
When Closed and Opened
Courtesy of Remy Electric Company, Anderson, Indiana
operation. It will be noticed also that when the contact points of the
thermo-switch are open, as shown in the illustration, the current
supplied to the field by the third brush must pass through the resist-
ance unit of the switch, thus cutting it down. This is the position
for warm-weather running, when not so much of the current is required
for lighting, and when the storage battery is at its best. When the
temperature of the air about the thermo-switch exceeds 150° F., the
movable blade is warped upward, owing to the greater coefficient of
expansion of the brass as compared with that of the nickel steel. The
contact points will accordingly remain open as long as the temperature
exceeds this degree. When it falls below that point, the quicker
contraction of the brass pulls the blade down, and the points again ,
make contact, cutting out the resistance and increasing the output
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ELECTRICAL EQUIPMENT
471
of the generator, diagrams of the thermo-switch in its closed and open
positions being shown at the right, and a halftone of the switch at the
left in Fig. 312, while the curves, Fig. 313, show the increase in the
current output brought about by the closing of the thermo-switch
points. The path taken by the current when the points are open and
when they are closed is
indicated by the dotted
lines in the diagrams, Fig.
312. The curves show
that with the thermo-
switch open, the maxi-
mum current output of
the generator is limited
to 14 to 15 amperes,
while with the switch
closed it rises to 20 to *** 313 -
22 amperes. The switch will normally remain closed after the engine
has been idle for any length of time; but in summer it will open after
driving ,a few miles, while in winter it will probably remain closed,
no matter how much the car is driven.
Starting Motor. The motor is the 6-volt 4-pole series-wound
type, illustrated in Fig. 314, mounted either with gear reduction
Output Curves of Remy Patented Generator
Fig. 314. Remy Starting Motor with Outboard Type Bendiz Pinion
&»/d over-running clutch, or with automatically engaging pinion for
direct engagement with flywheel gear, as described in connection
with the Auto-Lite. The latter is known as the Bendix gear. The
control is by independent switch.
Instruments and Protective Devices. An indicator, or telltale,
shows when the battery is charging or discharging, and also serves
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472 'ELECTRICAL EQUIPMENT
to indicate any discharge, in all except the starting-motor circuit,
due to grounds or short-circuits. All lamp circuits are fused, and a
fuse is inserted in the regulator circuit.
Remy Single-Unit
A Mechanical Combination. While termed a single-unit type,
this is actually two independent units combined, mechanically and not
electrically, so that it bears no resemblance to the single unit on which
both field and armature windings are carried on the same pole pieces
and armature core. The field frame for the two units is a single
casting, Fig. 315, but the
magnetic circuits of both
the generator and the motor
are entirely independent, and
each is a separate unit. They
are combined in this manner
solely for convenience in
mounting where space is
lim ited . The vibrating type
of voltage regulator is em-
ployed in connection with
the generator, while the start-
ing motor operates through
a train of reducing gears
and an over-running clutch.
Apart from the combination
of the two units and the
Fig. 315. Combined Field Frame of Generator method of Starting drive
and Motor for B*my Single-Unit System wh j ch ^ ^^ the gys _
tern is the same in its essentials as where the units are mounted
independently.
Wiring Diagrams. Velie. Fig. 316 shows the installation on
Velie, Model 22, and the details will be plain with further explanation.
The "ratchet reversing switch", shown in the diagram, is for
controlling the ignition current, and it is designed to reverse the
direction of this current each time the switch is turned on in order to
prevent the formation of a crater and cone on the ignition interrupter
contacts, as previously described, thus keeping the points in good work-
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ELECTRICAL EQUIPMENT 473
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ing order for a much longer period. The dash and tail lights are 3 J-
. volt lamps, wired in series, so that the failure of one puts the other out,
thus giving an indication at the dash of the failure of the tail light.
Oakland. The Remy installation on Oakland Model 32 is
shown in Fig. 317. The chief distinction between this and the pre-
vious diagram is the employment of a single 10-ampere fuse on the
lighting circuits instead of independent fuses on each circuit.
"Breaker box" refers to the ignition-circuit contact-breaker, or
interrupter, as it is variously termed. The starting motor in this
case is fitted with the Bendix drive.
Reo. On the Reo installation, Fig. 318, the starting motor is
mounted on the transmission housing and drives to a shaft of the
latter through a worm gear. In this case the starting switch is
mounted directly on the starting motor, and an ammeter is supplied
on the charging circuit instead of a telltale, or indicator.
National. A typical installation of the single unit, or so-called
double-deck unit, is shown in Fig. 319. This is on the National
six-cylinder model, and is a two-wire system. It is not intercon-
nected with the ignition system, so there are no ground connections,
and no fuses are employed.
Instructions. These instructions cover the systems which
include the ignition. For instructions applying to the double-wire
system on cars having an entirely independent ignition system, like
the National, see instructions under Auto-Lite, Delco, Gray &
Davis, and others, for failure of generator or motor, short-circuits,
and the like.
Battery Discharge. In systems of this type, discharge of the
battery may be due to failure to open the ignition switch after
stopping the car. The amount of current consumed is small but
in time it will run the battery down. The indicator or the ammeter,
according to which is fitted, will show a discharge. An entire fail-
ure of the current may indicate: a loose connection at battery ter-
minals, at battery side of starting switch in connection with a blown
main fuse (Oakland), or a loose battery ground connection; a loose
connection at motor side of starting switch or at starting motor,
or a broken wire between the switches. (See previous instructions
on other makes for testing with lamp set for broken or grounded
circuits.)
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Failure of Lighting, Ignition, Starting. When the lights and
ignition fail but the starting motor operates, it indicates a short
or open circuit between the starting switch and the main fuse (Oak-
land). This fuse should first be examined and, if blown, a search
should be made for the ground or short-circuit causing it, before
putting in a new fuse. The fault will be in the wiring between the
switch, lights, and ignition distributor. See that all connection^
including those on fuse block, are tight. When the lights fail but
the ignition and starting motor operate, the trouble will be found
either in the circuits between the lighting switch and lamps; in the
lamps themselves, as a burned-out bulb causes a short-circuit; or
from loose connections in these circuits. Failure of the ignition,
with the remainder of the system operating, may he traced to loose
connections at the ignition switch, coil, or distributor; poor ground-
ing of the ignition switch on the speedometer support screw; or t<k
open or short-circuits between the ignition switch and the distributor.
Further detail instructions on ignition are given in Ignition, Part II.
Dim Lights. When all the lights burn dimly, the most prob-
able cause is the battery, but if a test shows this to be properly
charged, a ground between the battery and the starting switch or
between the latter and the generator may be responsible for leakage.
Other causes are the use of higher candle-power lamps than those
specified, the use of low efficiency carbon-filament bulbs, or failure
of the generator to charge properly.
Examine generator-field fuse and if blown, look for short-
circuits before replacing, as previously instructed. A simple test of
the generator may be made by switching on all the lights with the
engine standing. Start the engine and run at a speed equivalent
to 15 miles per hour or over. If the lights then brighten percepti-
bly, the generator is operating properly. This test must be made,
in the garage or preferably at night, as the difference would not be
sufficiently noticeable in daylight.
If the generator fuse is intact, examine the regulator relay con-
tacts. If the points are stuck together, open by releasing the relay
blade with the finger. Clean and true up points as previously
instructed and clean out all dust or dirt from relay before replacing
cover. Particles of dirt lodged between the points will prevent
the generator from charging properly.
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ELECTRICAL EQUIPMENT 479
The failure, flickering, or dim burning of any single lamp will
be due to a burned-out bulb, to loose or frayed connections at lamp
or switch, to a bulb loose in* its socket, or to an intermittent ground
or short-circuit in the wiring of that particular Tamp, ot to the frame
of the lamp nor being . grounded properly. Where" dash and tail
lamps are in series^ examine bot^buJbs.apd replace the one that
has burned out. Test with two dry cells connected in series.
Ammeter. When the indicator, or ammeter, does not register a
charge with the engine running with all the lights out, stop the engine
and switch on the lights. If the instrument gives no discharge
reading, it is faulty. If it shows a discharge, the trouble is in the
generator or connections. In case the ammeter registers a discharge
with all the lights off,, ignition switch open, and engine idle, examine
relay contacts to see if they remain closed. If not, disconnect the
battery. This should cause the ammeter hand to return to zero; if
it does not, the instrument is out of adjustment. With the ammeter,
or indicator, working properly, and the relay contacts in good con-
dition, a discharge then indicates a ground or short-circuit. When
examining the relay 'for trouble, do not change the adjustment of
the relay blade.
SIMMS-HUFF SYSTEM
Twelve- Volt; Single-Unit; Single-Wire
Dynamotor. The dynamotor is of the multipolar type having
six poles, as illustrated in Fig. 320, which shows the field frame, coils,
and poles. Fig. 322 illustrates the assembled brush rigging, while
Fig. 321 shows the complete unit with the commutator housing plates
removed. *
Regulation. Regulation is by reversed series field, in connection
with a combination cut-out and regulator. The regulator is of the
constant-potential type and is combined with the battery cut-out.
It is connected in circuit with the shunt field of the generator, and the
vibrating.contacts of the regulator cut extra resistance into this circuit
when the speed exceeds the normal generating rate. There is also
a differential compound winding of the fields, the two halves of which
oppose each other at high speeds.
• Instruments. An ammeter is supplied, showing charge and
discharge.
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480 ELECTRICAL EQUIPMENT
Dynamotor Connections. The dynamotor has two connections,
one at the bottom of the forward end plate, marked DYN+, and
the other on top of the field yoke designated as FILED. Astthe
system is a single-wire type, the opposite sides of both circuits are
grounded within the machine itself. The terminals on the' cut-
out are marked BAT+, DYN+, and DYN-, BAT-, and FLD.
Fig. 320. Field Frame, Poles, and Windings Fig. 321. Brush Rigging for
for Simms-Huff Dynamotor Simms-Huff Dynamotor
Fig. 322. Simms-Huff Dynamotor with Commutator Housing
Plates Removed
Courtesy of Simnu Magneto Company, East Orange, New Jersey
BAT+ connects through a 12-gage wire to the negative side of the
ammeter and thence to a terminal on the starting switch. This con-
nects it permanently to +R of the battery through the ammeter.
This wire supplies the current to the distributing panel, from which
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ELECTRICAL EQUIPMENT
481
current is supplied to the lamps and hom. DYN+ connects through
a similar wire to the plus terminal of the dynamo, while DYN— and
Chorogno.
« Starting. -s
Fig. 323. Wiring Diagram for Simms-Huff Starting and Lighting Systems
BAT— connect with the — L terminal of the storage battery through
a wire of the same size.
Change of Voltage. The system is known as 6 — 12-voIt type,
signifying that the current is generated at 6 volts, but is employed for
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482 ELECTRICAL EQUIPMENT
starting at 12 volts. There are accordingly 6 cells in the storage
battery, and the latter is charged by placing the two halves of it,
consisting of two 3-cell units, in parallel. This is indicated in the
ft/G//r HEAD L/RMP
LEFT HE/ID LAMP
Fig. 324a. Complete Wiring Diagram for 1916-17 Maxwell Cars (see Fig. 324b)
/ Courtesy of Simms Magneto Company, East Orange, New Jersey
upper diagram, Fig. 323, also in the middle diagram, which shows the
connections for charging. In the lower diagram of the figure are
shown the starting connections, the switch being connected to throw
the 6 cells of the battery in series, so that the unit receives current at
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ELECTRICAL EQUIPMENT 483
12 volts for starting, thus doubling its power. . Six-volt lamps are
employed and are supplied with current from the left-hand section of
the battery, marked 1, as shown in the upper part of the diagram.
Fig. 324b. Complete Wiring Diagram for 1916-17 Maxwell Cars, Showing Details of Dash
Panel and Batteries
Courtesy of Simms Magneto Company, East Orange, New Jersey
Starting Switch. This is mounted on the left side of the gear-
box housing (Maxwell) and is so arranged as to connect the entire
battery in series for starting, thus giving current at 12 volts for this
purpose. The same movement of the starting switch also puts the
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battery in circuit with the ignition system so that, as soon as the
engine starts and the switch is released, it automatically disconnects
the battery from the ignition, and the engine then runs on the magneto
(dual ignition system).
Wiring Diagram. Fig. 324a and Fig. 3246 show the wiring
diagram complete of the ignition, starting, and lighting systems as
installed on the 1916 and 1917 Maxwell cars. The heavy lines indicate
the starting-system connections, while the light lines are the wires
leading from the generator to the battery (through the regulator and
cut-out), and the various connections for the ignition and the lamps.
They show very plainly, upon tracing them out, the relation of the
regulator and cut-out to the generator and the battery, as well as the
method of dividing the six cells of the battery into two units for light-
ing service, and the coupling of all the cells in series for starting. It
will be noted also that the storage battery is not utilized for ignition,
as the starting switch closes the circuit of a dry battery of four cells
for ignition when starting the engine. As the starting switch auto-
matically opens this circuit when released, there is no danger of this
battery being inadvertently left in circuit.
At the upper left-hand corner of the diagram, complete details of
the ignition circuit and of the magneto itself are shown. The
magneto (Simms) is of the true high-tension type, having primary
and secondary windings on the armature core, as well as a condenser
incorporated in it. As this sketch shows not only the relation of high-
tension type of magneto to the plugs but also that of the essential
parts of the magneto, as well as the relation of the ignition system to
the starting and lighting systems through the combination starting
and ignition switch, it will repay close study. The number of wires
makes it appear as if this were a two-wire system, but upon noting
the ground connections at the various terminals it will be evident
that it is not.
Instructions. The Simms-Huff system as above described is
standard equipment on the Maxwell cars. The combination cut-
out and regulator is mounted on the rear of the dash panel carrying
the ammeter and switch. It consists of two distinct devices, the
cut-out serving the usual purpose of protecting the battery when
the generator voltage drops, and the regulator limiting the current
output of the dynamo as the engine speed increases. In connection
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8immfl-Huff Ignition, Starting, and Lighting Installation on Maxwell 1918 Cars
Courtesy of Maxwell Motor Company, Detroit, Michigan
83
LEFT HEAD LAMP RICHJ HEADLAMP
Wiring Diagram for Simms-Huff Starting and Lighting Installation on Maxwell 1918 Cars
Courtesy of Maxwell Motor Company, Detroit, Michigan
84
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ELECTRICAL EQUIPMENT 485
with it a special regulator switch is provided. This is located on
the right side of the dash panel and has two positions, HIGH
and LOW, the latter inserting additional resistance in the field
circuit of the dynamo to further limit its output when the car is
driven steadily at high speed on long runs. This switch is kept in
the HIGH position for all ordinary driving and only shifted to
LOW as above mentioned.
Failure of Cut-Out or of Regulator. Should the ammeter pointer
go to the limit of its travel on the discharge side, this indicates that
the cut-out contact points have failed to release on the slowing
down of the generator. The latter also will continue to run as a
motor after the engine is stopped. Disconnect the two wires from
the terminals on the generator and wrap them with friction tape
to prevent their coming in contact with any metal parts of the car.
Clean and true up contact points as outlined in previous instruc-
tions. An unusually high reading on the charge side of the ammeter
will indicate a failure of the regulator to work. If an inspection
shows no sign of broken or crossed wires, loose connections, or other
obvious trouble, the manufacturers recommend that the unit be sent
to them. In the case of the owner, it is recommended that no
attempt be made to correct faults in the cut-out or in the regulator,
but that it be referred to the maker of the device or to the nearest
service station.
Generator Tests. To determine whether a short-circuit or. a
ground exists in the brush holder, pull up all the brushes and with the
aid of the lamp-test set, test by applying one end to the frame and
the other to the main terminal post. The lamp will light if there is a
short-circuit or a ground between the brush holder and the frame.
A similar test- may be made for the armature by pulling up all the
brushes (or heavy paper may be inserted between them and the com-
mutator) and placing one point on the commutator and the other on
the shaft. The lighting of the lamp will indicate that the armature is
grounded. In all tests of this nature where the lamp does not light
at the first contact, it should not be taken for granted at once that
there is no fault. Touch various parts of both members on clean
bright metal. See that the points of the test set are clean, that
the lamp filament has not been broken, and that the lamp itself has
not become unscrewed sufficiently to break the circuit between it and
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486 ELECTRICAL EQUIPMENT
the socket. A good rule is always to test the lamp itself first; some-
times the connecting plug of the set is not properly screwed into the
socket.
While the above test for the armature, if properly carried out, will
show whether the latter is grounded or not, it will not give any indi-
cation of an internal short-circuit in the armature itself. To deter-
mine this, connect the shunt fields and run the unit idle as a motor,
with the portable ammeter in the circuit, using the 30-ampere shunt.
While running without any load the motor should not consume more
than 7 amperes at 6 volts, i.e., using half the battery. Tests for
grounds in the shunt field may be made with the lamp-test set, but to
determine whether there is a short-circuit in the field, it is necessary
to measure the resistance of its windings. If there is neither a short-
circuit nor a ground in the field, the resistance of the windings should
calculate approximately 6? ohms on units with serial numbers up to
27,000, and approximately 4.8 ohms on starters above this serial
number.
The Simms-Huff is one of the very few, if not the only unit, that
is belt-driven as a generator. Its normal output is 10 to 15
amperes; so when the dash ammeter shows any falling off in this
rate, with the engine running at the proper speed to give the
maximum charging current, the belt drive of the generator should be
inspected. If the ammeter reading falls off as the engine speed
increases, it is a certain indication that the belt is slipping and that
the generator itself is not being driven fast enough. Adjust the
tension of the belt and test again. If this does not increase the output
to normal, inspect the commutator and brushes, brush connections
and springs, etc. See that the brushes have not worn down too far,
and if necessary, sand-in. Failing improvement from any of these
expedients, inspect the regulator. This should not be adjusted to give
more current until every other possible cause has been eliminated;
and before making any change in the adjustment of the contacts, see
if cleaning and truing them up will not remedy the trouble. If
necessary to adjust, do so very carefully, as increasing the current
output by this means will also increase the voltage, and if the voltage
exceeds the normal by any substantial percentage,' all the lamps will
be burned out at once. Trouble in the electrical unit itself will be
most likely to appear in the brush holder.
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ELECTRICAL EQUIPMENT 487
Whenever it is necessary to remove the front end plate over the
commutator to inspect the commutator or the brushes, be sure that
this plate is put back the same way, and not accidentally turned round
a sixth of a revolution, which would cause the motor to run backward.
There is a slot in the front end of this plate to permit the brush holder
to be moved backward or forward so as to give the best brush setting
as a generator and as a motor. On most of the Simms-Huff units, a
chisel mark will be found on each side of the fiber insulator under the
main terminal post, indicating the factory brush setting. Checking
this brush setting should be one of the further tests undertaken before
resorting to adjustment of the regulator. To do this, connect the
portable ammeter in the charging circuit (30-ampere shunt) or, if
one of these instruments is not available, the dash ammeter may be
relied upon.
Run the engine at a speed high enough for the maximum normal
output; loosen the brush holder and move very slowly backward and
forward, meanwhile noting the effect on the reading of the ammeter;
and mark the point at which the best output is obtained. To test
as a motor, connect the ammeter in circuit with half of the battery
and run idle. Move brush holder backward or forward to obtain best
setting point, as shown by the ammeter reading, which, in this case,
will be the minimum instead of the maximum. The unit should not
draw more than 7 amperes when tested in this manner. If the best
points for generating and running as a motor, as shown by these tests,
are separated by any considerable distance, a compromise must be
effected by placing the brush holder midway between them. If the
dash ammeter does not appear to be correct, check it with the portable
instrument or with another dash ammeter.
SPLITDORF SYSTEM
Twelve— Six-Volt; Single-Unit; Two-Wire
Dynamotor. Both windings are, connected to the same com-
mutator on the dynamotor, which is of the bipolar type.
Wiring Diagram. As the lamps are run on 6 volts, the 6-cell
battery is connected as two units of 3 cells each for lighting, and these
units are connected in series-parallel for charging, as the dynamotor
produces current at 6 volts. The remaining details of the connections
will be clear in the wiring diagram, Fig. 325.
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ELECTRICAL EQUIPMENT
Six-Volt; Two-Unit
Control. Switch. The starting switch is mounted on the
starting motor. This switch automatically breaks the circuit as
soon as the engine starts. The starting gear slides on spiral splines
on the armature shaft, so that when the engine gear over-runs it,
the starting gear is forced out of engagement. This gear is connected
to a drive rod which also engages a switch rod, so that when the
gear is forced out of mesh with the flywheel, it carries the switch
rod with it and automatically opens the circuit. The switch contacts
cannot stick, and no damage can result from holding down the switch
pedal after the engine has started.
Regulation. On the earlier models, a vibrating regulator was
built in the generator, as illustrated in the section on Constant-
88
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ELECTRICAL EQUIPMENT 489
Potential Generators, but in later models an external regulator com-
bined with the battery cut-out is employed. This is a constant
voltage control of the vibrating type, similar to that described in detail
in connection with the Bijur system, i.e., an electromagnet operating
two spring-mounted armatures carrying contacts.
Instructions. Should a discharge of 3 amperes or more be indi-
cated on the ammeter when the engine is idle and all lights are off,
this can be eliminated by slightly increasing the tension of the spring
at the rear end of the cut-in armature.
Too great an increase in the tension of this spring will cause the
cut-in, or charging point, to be raised too high, as indicated by
the ammeter, which should
be noted when making the
adjustment.
The voltage regulator
as set at the factory is
adjusted to limit the output
of the generator to from 7
to 10 amperes. Should it be
necessary to increase this
for winter runnine or for Fig. 326. s P utdorf vr Regulator
1UI Winter running Ul 1U1 Courtesy of Spiitdorf Electric Company,
any Other reason, it. may Newark, New Jersey
be done by increasing the tension of the spring armature. The
amount of movement of the adjusting screw at the rear end of the
armature that is necessary will be indicated by the reading of
the ammeter. The passage of current at the regulating contacts,
which are in constant vibration while the engine is running above a
certain speed, tends to roughen them. m In time this may affect the
charging rate and cause the points to stick together, which will be
indicated by the ammeter showing a permanent increase in the charg-
ing rate. If the latter becomes excessive, the cover of the regulator
should be removed, and a thin dental file passed between the contacts
on the stationary screw R, Fig. 326, and the movable contact on the
regulating armature until both become smooth. In case it is neces-
sary to remove the contact screw R for the purpose of smoothing its
point, be sure to replace it at the same position, taking care that the
ammeter reading does not exceed 7 to 10 amperes and that the lock-
nut N is fastened securely. Under ordinary conditions, these con-
89
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490
ELECTRICAL EQUIPMENT
tacts should not require attention on an average oftener than once
a year, but it would be well to examine them occasionally.
ftefef Circuit <s-*-s -jr*n-J9**
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Kg. 327. Wiring Diagram of Splitdorf Lighting Generator and VR Regulator
By referring to Fig. 327, which is a diagram of the wiring of the
generator and battery, the relation of these essentials to the regulator
and cut-out are made clear. The field fuse shown on this diagram is
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ELECTRICAL EQUIPMENT 491
also indicated at F in Fig. 326. This fuse is a small piece of soft-alloy
wire mounted between the post F and the contact-breaker. By
referring to the wiring diagram, it will be noted that this fuse is in the
shunt-field circuit, so that if it has been blown, the machine will not
generate. It is designed to blow only at high speed with the battery
off the line and the vibrator contact R stuck. In actual practice,
the regulator cut-out is mounted directly on the generator itself.
The colors mentioned alongside the different wires are for purposes of
identification so that there will be no mistakes in making the
various connections.
Starting Motor. The starting motor is of the series-wound type
and is similar in design to the generator. It is supplied with a Bendix
drive as shown in Fig.. 328.
The starting motor is constructed so that when the operator
presses the starting switch, the starting circuit is completed and
Fig. 328. Splitdorf SU Starting Motor
Courtesy of Splitdorf Electric Company, Newark, New Jersey
the armature speeds up very rapidly. As the gear is counter
weighted and is mounted on a spiral cut sleeve, it is "threaded"
into mesh with the flywheel gear when the armature revolved.
This spiral cut sleeve holds the gear in mesh while the motor is
being cranked. As soon as the engine picks up it turns faster
than the starter pinion which is now operated from the flywheel,
and on account of the spiral cut sleeve the pinion is forced out of
mesh with the flywheel gear. This sleeve, mounted on the armature
shaft, is connected to a coil spring, the other end fastened to the
armature shaft. The spring takes up the shock.
The feature of this construction is, that no matter how long the
operator may hold his foot on the starting pedal, the current is broken
when the engine starts, as in the manner previously described. The
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492 ELECTRICAL EQUIPMENT
amount of current actually required for turning over the engine is
thus controlled by the engine itself, and on account of the positive
connection between one element of the switch and the starting
gear, all possibility of the jaws of the starting switch sticking is
eliminated.
Instructions. Apart from the special adjustments of the starting
switch, as mentioned in the description of its operation, the instruc-
tions for maintenance are the same as those for other systems. In
case this switch does not operate properly, the sequence of operations
as mentioned should be checked up, and the distances given verified.
In case these distances have become greater through wear, they
should be adjusted. To replace the brushes, remove the cover strap
over the commutator end of the unit, either generator or motor,
put the .two screws holding the rocker disc in place, disconnect the
brush leads, and withdraw the brushes from the holders. It is
important that the brushes slide freely in the holders and that the
brush-lead terminals are clean and bright before replacing the
terminal screws. See that the springs rest fairly on the ends of the
brushes and that their tension has not weakened. Follow instructions
given in connection with other systems for care of the commutator.
Failure of Engine to Start. When the starting motor cranks the
engine after the starting pedal is depressed but fails to start the engine
after a reasonable time, release the starting pedal and ascertain the
cause, which may be due to the following: Ignition off, lack of fuel,
fuel supply choked, cylinders needing priming due to weather con-
ditions, or cylinders flooded from too much priming.
Should the starting motor fail to crank the engine when the
starting pedal is fully depressed, there is a possibility that the battery
is run down (which condition will be indicated by an excessive dim-
ming of the lights), that there is a loose connection in the starting
circuit, or that the starting switch is not making proper contact.
The various tests previously given will probably take care of all
these conditions.
Oiling of Starting Motor. The starting motor should be oiled
once every 500 miles with any medium high-grade oil by applying oil
to the cups, switch rods, guide rods, and pawl; also on the compensat-
ing device. Starting motors equipped with the Bendix drive are
fitted with oil cups at each end of the unit.
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ELECTRICAL EQUIPMENT 493
U.S.L. SYSTEM
Twenty-Four— Twelve- Volt, and Twelve— Six- Volt;
Single-Unit; Two-Wire
Variations. The 24 — 12-volt signifies that the starting voltage
is 24 and the generating voltage 12, the battery of twelve cells being
divided into two groups of six each in series-parallel for charging,
while 12 — 6 signifies that the starting voltage is 12 and the generat-
ing voltage 6, the 6-cell battery being divided in the same manner.
The foregoing systems will be found on cars prior to, afld includ-
ing, 1915 models. For 1916 and 1917 models, a 12— 12-volt system
of the same single-unit two-wire type is standard. In this system the
complete battery is used for the lighting as well as the starting, so
that charging, lighting, and starting are all at the same voltage, using
the complete battery of 6 cells for both of the former.
Generator-Starting Motor. The machine is multipolar (either
six or eight poles) and is designed to take the place of the flywheel of
Fig. 329. Details of U.S.L. Flywheel Type Dynamotor with Outside Armature
Courtesy of U. S. Light and Heat Corporation, Niagara FcdU, New York
the engine. All but the 12 — 6-volt equipments are made with an
outside armature, Fig. 329, i.e., the armature revolving outside of the
field poles which it encloses; and the 12 — 6-volt with an inside arma-
ture, Fig. 330. As the armature is mounted directly on the end of the
crankshaft, the drive is direct at engine speed whether charging or
starting.
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494 ELECTRICAL EQUIPMENT
One of the advantages of this type of machine, owing to its large
size, is its ability to generate an amount of current far in excess of any
ordinary requirement. This permits the employment in the inher-
I- ieW roles Armature Brush Cover
Fig. 330. U.S.L. Inside Armature Type Dynamotor
(External Regulator)
ently regulated type of only three brushes, Fig. 331, when the unit is
running as a generator, while all the brushes are employed when it
operates as a starting motor. In the types equipped with an external
- T#p regulator, all the brushes are employed
for generating as well as for starting.
Regulation, The 24— 12-volt unit
in the U.S.L. system is made with two
types of regulation, one type using an
external regulator, which is usually
mounted on the dash, and the other
of the inherent type. The 12 — 6-volt
type has an external regulator. These
two types may be distinguished
by the presence of the regulator
3 Generating Brushes in tiie charging circuit, which, how-
Fig. 33i. Location of Generating ever, must not be confused with the
finishes in U.S.L. Dynamotor auto matic Switch, Or battery CUt-
out, which is only employed on the inherently regulated type. The
details of the regulator are shown in Fig. 332, and it will be noted that
the regulator also incorporates the battery cut-out as well as an indi-
cating pointer which shows whether the regulator is working properly
or not. In operation, the regulator cuts into the generator field
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ELECTRICAL EQUIPMENT 495
circuit a variable resistance consisting of an adjustable carbon pile.
The connections of the regulator are shown in the [wiring diagrams.
The regulation of the U.S.L. inherent type is accomplished by
the combination of a Gramme ring armature, a special arrangement
of connections and of the field windings, and the use of only a part of
the armature and fields for generating. This method is, of course,
special on this make and could not be used on other types of construc-
tion. The regulation obtained is based on armature reaction and is
similar to that resulting from the third-brush method, but the machine
Thrust Ptatd
Charging
Contacts
Switcl
Level
Magnet
Coil
Lower Adjusting Plug
Fig. 332. External Regulator of the U.S.L. System
Courtesy of U. S. Light and Heat Corporation, Niagara Falls, New York
reaches its maximum output at a lower speed than would be possible
with the third-brush method and without the employment of a
special brush for the purpose.
Instruments and Protective Devices. In addition to the indi-
cator, which is combined with the external regulator in the U.S.L. type,
an ammeter is also employed to show the rate of charge and discharge.
Two fuses, mounted in clips on the base which holds the bat-
tery cut-out, or automatic switch, protect all the circuits. The
smaller of these is a 6-ampere fuse and is in the field circuit of
the generator, while the larger is a 30-ampere switch and is in the.
generator charging circuit. This applies only to those inherently;
regulated equipments fitted with a special type of automatic switch."
97
496 ELECTRICAL EQUIPMENT
Wiring Diagrams. Figs. 333, 334,' and 335 show the standard
wiring diagrams of the three types mentioned, being, respectively,
the 24 — 12-volt externally regulated type, the 12 — 6-volt external
regulator and internal-armature type, and the 24 — 12-volt inher-
ently regulated type. In the diagram proper of each of the 24 —
12-volt types is indicated the layout for using 7-volt lamps, while the
extra diagram at the side shows the method of connecting for 14-volt
lamps. The "touring switch" shown on the first two diagrams
is a hand-operated switch in the charging circuit and is designed to
prevent overcharging of the battery when on long day runs. The
inherently regulated type requires very little field current, and on
most of these the touring switch is of the miniature push-button type,
like a lighting switch.
Instructions. Touring Switch. On the types equipped with
the touring switch, this enables the driver to control the charge.
Pulling out the button closes the switch and permits the generator
to charge the battery when the engine reaches the proper speed;
pushing it in opens the circuit. This switch must always be closed
before starting the engine, and it must be kept closed whenever
the lights are on and also under average city driving conditions
where stops are frequent and but little driving is done at speed.
When touring, the switch should be closed for an hour or two and
then allowed to remain open during the remainder of the day, as
this is sufficient to keep the battery charged, and there is no need
for further charging until the lamps are lighted. The best indication
of the necessity for opening the touring switch is the state of charge
as shown by the hydrometer. The driver should not start on a long
day's run with the battery almost fully charged, without first opening
the touring switch, as the unnecessary charging will overheat the
battery. This switch should be inspected at least once a season.
Push in the button to open the circuits, remove the screw at the back
and take off the cover. The switch fingers should be bright and
make good contact with the contact block; if they do not do so,
remove and clean them, as well as the contact pieces on the block.
Do not allow tools or other metal to come in contact with the
switch parts during the operation, for even though the switch is
t 6pfen, a short-circuit may result; then one of the fuses will blow.
rln replacing the fingers, bend sufficiently to make good firm contact.
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ELECTRICAL EQUIPMENT 497
rvOLTlAMPS
14-VOLt UMPS
Fig. 333. Wiring Diagram for 24— 12- Volt External Regulator Type, U.S.L. System
99
Fig. 334. Wiring Diagram for 12 — 6-Volt External Regulator Type, U.S.L. System
100 Digitized by G00gk
ELECTRICAL EQUIPMENT 499
14- Volt Lamps /-Volt Lamps
Pig. 335. Wiring Diagram for 24— 12-Volt Inherently Regulated Type, U.S.L. System i
101
500 ELECTRICAL EQUIPMENT
Starting Switch. The starting switch is filled with oil, and this
should be renewed once a year. To do this, the switch must be
disconnected, and the screws A, Fig. 336, removed; in case the box
sticks, insert a screwdriver point between the top of the box and the
bottom of the frame and pry loose. To guard against the switch
dropping when these screws are removed, hold the hand beneath it
while taking them out. Before attempting to remove the switch,
disconnect the positive battery connections B1+ and BS+ at the
battery as shown in Fig. 335. These are the two main terminals in
the center. It is unnecessary to tape them, as a short-circuit cannot
occur. Pour out the old oil, clean out thoroughly with gasoline,
allow to dry, and refill with transformer oil or light motor oil to the
proper lqvel with the switch box standing plumb. The proper height
on the Type E-2 or E-3 box is If inches, on E-4 box 2f inches. Before
putting in the new oil, however, the
^ drum and finger contacts should be
examined, and, if pitted or dirty,
should be cleaned with a fine file.
Make sure that all fingers bear
firmly against the drum so as to%
Fig. 336. u.s.l. oil-Fiiied starting make good contact; if they do not,
Switch
remove and bend them slightly to
insure this. If the starting switch is abused in operation, or if improper
oil containing water or other impurities be used, the contacts will
burn and fail to make good electrical connection. The switch, box
is the only place in the system requiring oil.
Brush Pressures. There is only one adjustment on the gener-
ator, viz, the tension of the brush fingers. The brushes should fit
freely in their holders so as to transmit the full pressure of the
spring against the commutator. The adjustment as made at the
factory should not need correction under one or two years of
service. Pressures required on the various machines are as fol-
lows: for Type E-12 external regulator, If pounds on each brush;
If pounds on brushes of all other external-regulator machines; If
pounds on each of the three lowest brushes on the inherently regulated
type, these being the only brushes used in generating the charging
•current; If pounds on each of the remaining brushes of the inherently
regulated generator. Keep commutator clean, as the chief cause of
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ELECTRICAL EQUIPMENT
501
Angular Brush
failure of the inherently regulated type is an excess of oil or dirt or
both accumulating on it.
Radial and Angular Brushes. The brushes employed are of two
types — radial and angular. Radial brushes are used on external-
regulator type generators other than those having "Type E-49" on
the name plate; angular brushes are used on Type E-49 and all inher-
ently regulated generators. Each radial brush should bear squarely
against that side of its holder toward which the commutator rotates.
Each angular brush should
bear squarely against that
side of its pocket away from
which the commutator
rotates. [To sand-in old
brushes or fit new brushes
properly, insert a strip of
No. 00 sandpaper (never use
emery, paper, or cloth), be-
tween the commutator and
the brush, press down on
top of brush and draw sand-
paper under it, Fig. 337. If
the brush is radial, draw the
sandpaper in the direction
of commutator rotation; if
angular y draw the sandpaper
in the direction opposite to
that .of commutator rota-
tion. No oil is needed on
the commutator as the
brushes themselves contain
all the lubricant necessary.
Fine sandpaper, as mentioned above, may be used for cleaning the
commutator when necessary, the engine being allowed to turn over
slowly during the operation.
External Regulator. Should the automatic-switch (cut-out)
member of the regulator remain closed with the engine stopped,
start the engine at once, and the switch lever should open. If it
does not, remove the regulator cover (with the engine running) and
Direction
of Sanding
In Brushes
Direction of
Rotation of
Commutator
Radial Brush
Fig. 337. Methods of Sanding-In Brushes on
Dynamotor
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502 ELECTRICAL EQUIPMENT
pull the lever open by hand. When the switch lever is correctly
set, a slight discharge will be noted on the ammeter the moment
the switch lever opens. This discharge reading should not exceed
4 amperes; if in excess of this, increase the tension of the switch-
lever spring by releasing the lock nut on the left side of the plate
and turning up on the nut at the right until the proper adjustment is
secured, then retighten the lock nut. The indicating pointer is moved
by the switch lever in closing, and when it appears in its upper position
through the sight glass on the cover, the battery is charging; when
the switch lever opens, the pointer drops against its stop by gravity.
When the battery shows a lack of capacity, the battery itself
and all connections and fuses being in good condition, note the
amount of charging current indicated by the ammeter. If the
maximum current (external-regulator type) shown by the ammeter
does not exceed 10 to 12 amperes at full engine speed after the
engine has been running for fifteen minutes, see that the brushes
and commutator are in good condition — wipe off the commutator
with a dry cloth, and, if necessary, sand-in the brushes to a good seat.
If this does not increase the generator output as shown by the
ammeter, test the latter as already noted, i.e., see whether the pointer
is binding and, if not, check with the portable testing instrument
or another ammeter of the dash type. Should none of these reme-
dies correct the fault, screw in the lower adjusting plug of the
carbon-pile lever slowly, noting the effect on the ammeter reading
as the adjustment is made.
With the external regulator, the charging current should not
exceed 18 amperes at the highest engine speed. If, at any time,
the ammeter shows a higher reading than this, screw aid the lower
adjusting plug of the carbon-pile lever slowly to decrease the cur-
rent, stopping when the indication does not go above 18 amperes
at full speed.
After making this adjustment of the lower plug, make sure that
the carbon-pile lever air gap does not exceed J inch, and is not less than
A 'inch when the engine is stopped. If the gap is too small the
switch lever will vibrate rapidly at high engine speeds. When
^ necessary to adjust this gap, screw the upper adjusting plug in or
: (jut, but, after doing so, the current output must be checked and
'"alijusted by means of the lower adjusting plug. Always tighten
104
ELECTRICAL EQUIPMENT 503
the adjustment clamping screws after setting either of the adjusting
plugs.
Testing Carbon Pile. If the automatic-switch unit of the gener-
ator does not cut in with the engine running at speed equivalent to 10
to 14 miles per hour, test the carbon pile by short-circuiting the
terminals F+ and A+ of the generator with the blade of a screw-
driver. Speed up the engine slowly and note whether the generator
cuts in much sooner than when the terminals are not short-circuited.
Do not run the engine at high speed, nor for any length of time with
the terminals short-circuited, as an excessive amount of current
would be generated. If the generator does cut in much earlier
with the terminals short-circuited than without this, the carbon pile
needs cleaning. Should the generator not cut in earlier or should
it fail to operate altogether, when the carbon pile is short-circuited
the trouble is probably in the brushes of the generator or in the
touring switch.
To clean the carbon pile, proceed as follows: Unscrew the plug
at the upper end of the glass rod and remove the rod ; if any of the discs
are pitted or burned, rub them together or against a smooth board to
make them smooth and flat. Remove the end carbons and clean the
brass plates with fine sandpaper, if necessary. In replacing end car-
bons, make sure that they fit firmly against the brass end plates and
that the screw heads do not project beyond the faces of the carbon
discs. After reassembling the carbon pile, the regulator will need
adjustment for current output, as previously noted.
If for any reason it becomes necessary to disconnect the bat-
tery, either open the touring switch and block it open so that it
cannot be closed accidentally if the car is to be run, or disconnect and
tape the right-hand regulator terminal A + . Otherwise, the machine
will be damaged by operating.
Battery Cut-Out. Should either of the fuses mounted on the
automatic switch of the inherently regulated type blow, immedi-
ately open the touring switch. A loose connection or a short-circuit
is probably the cause, and the touring switch should not be closed
again until the cause has been located.
Ammeter. The ammeter should be checked at least once a year
by comparing it with a standard instrument, such as the portable out-
fit mentioned previously, or any other suitable low-reading ammeter
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504 ELECTRICAL EQUIPMENT
of known accuracy. To do this, disconnect the positive wire from
the ammeter on the dash and connect it to the positive terminal of
the standard ammeter used for testing; then connect a wire between
bl
I
I
the negative terminal of the standard ammeter and the positive
terminal of the dash ammeter. With the engine running at various
speeds, take simultaneous readings of both instruments; any differ-
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ELECTRICAL EQUIPMENT 505
ence between the two should be taken into consideration thereafter
when reading the dash ammeter. Unless a test of this kind is carried
out, the battery may be receiving either an insufficient or an excessive
charge while the ammeter indicates the proper amount.
U.S.L. 12-Volt System. The U.S.L. 12-volt system generates
and starts at 12 volts and is
standard on the 1916 and
1917 models of the Mercer,
Fig. 338. It differs from the
other systems in having a
magnetically operated start-
ing switch and a centralized
Control Unit, Which UlCOr- *- m ^.S.L. Type E-U Starting Switch
porates all the controlling devices of the entire system, the cut-out,
the ammeter, fuse blocks for generator and lighting circuits, starting
switch, touring switch, head, side, and tail-light switches, all of
which are operated by push buttons. All of these switch buttons,
as well as the fuses, are locked in place, while the buttons may be
locked in any desired combination of positions.
Starting Switch. This is of the magnetically operated type and
is mounted on the top of the field-mounting frame. It operates by
means of a solenoid and
plunger, as illustrated in Fig.
339. Control is by means of
a spring push button on the
control unit marked" start",
Fig. 340. When this button
is pushed in, it energizes the
solenoid of the starting
switch, which causes the
plunger to close the con-
tacts. Releasing the button pjg. 340. U.S.L. Control Panel as Mounted on
, 1 .1 • , 1 1 Dash of Mercer Cars
on the control unit breaks
the circuit, and the switch itself is then opened automatically by a
self-contained spring. With this method of control, the current is
only on as long as the starting button is held in.
Fuse Blocks. There are two of these, the smaller, illustrated in
Fig. 341, being the generator fuse block. This contains only two
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ELECTRICAL EQUIPMENT
fuses, a large one 9 of 30-ampere capacity in the generator-battery
charging circuit, and a smaller one 8 of 5-ampere capacity in the
generator shunt-field circuit. Should either fuse blow, immediately
push in the touring-switch button, as a short-circuit or an open or a
loose connection is probably the cause. After
locating the trouble, remove the generator fuse
block from the instrument board. To do this,
unlock the knob, press it inward, and turn J
revolution to the right or to the left. Replace
with spare fuses carried in the light fuse block,
return the generator fuse block to its original
position, and lock.
The light fuse block, which is shown in
Fig. 342, carries a total of seven fuses, of which
four are in active use, while the remaining three
are spare fuses for use in replacing blown fuses. On the right-side
view of this fuse block there appear two large fuses 6 and 7. Fuse 7
is a protecting link in the ground-return wire of the lighting and horn
circuits. The small fuse 5 is of 10-ampere capacity and, together with
Fig. 341. U.S.L. Gener-
ator Fuse Block
Fig. 342.
U.S.L. Left-Hand Side and Right-Hand
Side Light Fuse Blocks
fuse 6 of 30-ampere capacity, is a spare fuse for emergency use. On
the left side of the block are three active fuses 1, 8, and 4 of 10-ampere
capacity; and one spare fuse 2 of 5-ampere capacity. Fuse 1 is in the
horn circuit, fuse 3 in the headlight circuit, and fuse 4 is common to the
tail-, dash-, and side-light circuits. Should any of the fuses on this
block blow, the trouble is probably a short-circuit on the frame of the
car which should be remedied before the fuse is replaced. Instructions
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ELECTRICAL EQUIPMENT 607
for the use of the touring switch in this system are the same as
previously given.
U.S. Nelson System. This type has been specially designed for
the Nelson car, which first appeared in 1917, and it differs radically
from those already described in that it is carried on the forward end
of the engine crankshaft instead of at the rear. The brushes beafr on
the inside face of the commutator and may be reached through three
openings in the armature support. To clean the commutator in this
type, it is necessary to turn the armature so that three of the six
brushes appear opposite these openings. Fold a small piece of sand-
paper into a square over one of the brushes and allow the engine to
turn over for a few minutes. Stop the engine and remove the sand-
paper through one of the openings. The engine carries a flywheel at
the rear, as usual, and this provision of flywheel weight at both ends
of the crankshaft is said to minimize vibration almost to the vanishing
point while making possible extremely high speeds.
WAGNER SYSTEM
Twelve-Volt; Single-Unit;" Two-Wire (Early Model)
Dynamotor. The bipolar-type dynamotor has both the series
and the shunt-windings, i.e., of generator and motor, connected
to the same commutator. It is driven direct as a generator, and
through a special planetary gear when operating as a starting motor.
Regulation. The regulation is of the inherent type,- utilizing
the generator winding to weaken the field with increase in speed,
i.e., a bucking coil.
Wiring Diagram. Single-Unit Type. The left side of the
lower half of the diagram, Fig. 343, illustrates the connections when
the unit is being used as a starter, as indicated by the arrow showing
the direction of rotation of the armature. Those at the right are the
running connections, the armature then rotating in the reverse
direction and generating current to charge the battery.
Control; Transmission. Switch. This is a special type of
drum switch mounted directly on the dynamotor on the same base
with the battery cut-out. As shown in Fig. 344, when the lever Q
is thrown to the left for starting, it also serves to tighten the brake
band on the planetary gear. When moved in the opposite direction,
it releases this brake, and another set of contacts on the drum of
ill
— ^
508
ELECTRICAL EQUIPMENT
the switch connect the generator for charging. Fig. 345 shows the
details of this switch: A, B, and C are the contacts on the starting
side, while H, G, and F are the running-position contacts, as shown
in Fig. 343. The segments E and L on the drum contact with
HEAD LIGHT
HEAD LIGHT
StOE LIGHT
TAIL LIGHT
no —
(1
SWITCH
o
BINOING
POST
Binding A
POST v
IMV
SIDE LIGHT
SPEEDOMETER
LIGHT
X)
°1
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^NlNQv, y
n
«[q>j
SERIES FICLO I /^^\ FIELD
fWWW
Hj p>
Fig. 343. Wiring Diagram for Wagner Twelve-Volt Single-Unit Two-Wire
System (Early Model)
the fingers mentioned when the drum is revolved part way in either
direction by the lever, shown at the right, which engages the shaft M .
Battery Cut-Out. This is of conventional design. For description
and explanation of operation, see previous systems in which a battery
cut-out, or automatic switch, is employed. Methods of locating
trouble are given in connection with instructions farther along.
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ELECTRICAL EQUIPMENT 509
Fig. 344. Wagner Control Switch of Drum Type. A — Starter Frame; B — Switch Support; C —
Outside End Plate Gear Box; D — Return Spring; F — Oil Hole Screw; G — Self-Closing Oiler;
H— Oil Plug; J— Connecting Rod; K— Brake Band; M— Battery Leads; N— End Plate Screws;
O— Back End Plate Shield; Q— Starting Switch Lever; R— Brake Band Lever; S— Front End
Plate Shield
Courtesy of Wagner Electric Manufacturing Company, St. Louis, Missouri
Fig. 345. Exploded View of Drum Switch. A, B, F, G, H, and K — Contact Screws to Contact;
C — Auxiliary Contact Finger; E — Drum Contact; J — Screw Holding C; L— Auxiliary Drum
Contact; M— Shaft
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Planetary Gear. The external form of the different gear boxes
used on the early-model single-unit Wagner starter is the same, but
Pig. 3*6. Exploded View of Planetary Gear Transmission. A — Planetary Pinion; B — Rolling
Pawl; C— Center Pinion; D— Planetary Hub; E— Pawl Seat; F— Pawl Plunger; G— Internal
Gear; H— Inside End Plate; J— Outside End Plate; K— Oil Plug; M— Sheet-Steel Diso
Fig. 347. Assembled Planetary Gear. Letters same as Fig. 346
their internal construction differs somewhat. The details of the
two types employed are shown in Figs. 346 and 347. The prin-
ciple employed is that of the planetary gear as used to obtain first,
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ELECTRICAL EQUIPMENT 511
or low, and high speeds on early-model light cars. The unit consists
of a central, or sun, gear C, Fig. 347, and three planet pinions A
meshing with the central gear and also with the internal gear ring G.
For starting, the tightening of the brake band on the outer groove
of the internal gear holds it fast, so that the drive is through the
central gear and the reducing pinions in engagement with it and
the gear ring, while, for running, the rollers B in the clutch D lock
the gears together so that when generating the gear revolves idly
as a unit.
Instructions. The instructions previously given in connection
with other systems apply here. For failure to generate, lack of
capacity, grounds, or short-circuits in windings, and for keeping the
Fig. 348. Jig for Holding Armature and Tooling Commutator
commutator and brushes in condition, see instructions already
given, as well as Summary of Instructions, Part VIII.
Method of Tooling Commutator. A different method of under-
cutting the mica of the commutator is recommended from that
already described in connection with the Delco system. This is
illustrated in Fig. 348. The armature is removed from the generator
and mounted in a simple jig, as shown. The jig is made of 1-inch oak,
while ordinary machine screws held in place by lock nuts are utilized
as the centers. The bar, or guide, on which the cutter operates, can
be made of i-inch rolled-steel rod, while the cutter itself should be
made of J-inch drill rod. The point of this cutter is ground sharp, like
the parting tool used on a lathe or planer, to the thickness of the mica
between the commutator bars. The cutter is moved backward and
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ELECTRICAL EQUIPMENT
rHoavy
Tin folded around Toot
Z^>
Section
Fig. 349. Diagram of Simple Hand Device for Tooling
Commutator
forward on its guide in the same manner as a planer or shaper tool,
and the armature is rotated one segment at a time to bring the mica
sections under the tool successively. Where there is not sufficient
work of this nature to make it worth while to build the jig, a simple
* f ' hand tool may be used,
Fig. 349. This can be
made of a discarded
hacksaw blade or a new
one, about 8 inches long.
One of the ends is
ground similarly to the cutter described for the jig, while the other
should be shaped like a hook, having the same kind of point as the
cutter end. Around the center of this tool should be folded a piece of
heavy tin (sheet iron) and the whole wrapped with electric tape. This
will prevent the brittle saw blade from breaking and make it much
easier to handle. The mica is removed by forcing the sharp end of
the tool from the outer edge of the commutator surface to the inner
edge, and the rough cut thus made is finished by drawing the hooked
end of the tool back through the groove in the opposite direction.
To do the job properly, the armature should be held in a vise, other-
wise it is liable to move, or the tool is liable to slip, and the copper
be cut away with very poor results. Fig. 350 shows the commutator
before and after under-
BEFORE ,,• ,i
cuttmg the mica.
A needle-pointed
tool should never be used,
as it will simply, make a
V-shaped cut in the mica,
removing too much in
depth and not enough in
width. The mica must
be cut out clean and
square, and a small mag-
nifying glass should be
used to see that all of the
pieces adjacent to the bars have been removed. After removing the
mica, the armature should be placed in a lathe, and a light cut taken
from the commutators, i.e., just enough to remove all roughness
Fig. 360.
AFTER
Diagram Showing Commutator Sections before
and after Tooling
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ELECTRICAL EQUIPMENT 513
and flat spots. The cutting tool employed should be very sharp, so
that the soft copper will not be dragged from one segment to another.
After turning, fine sandpaper should be used to smooth the commu-
tator. Whether the brushes are replaced with new ones or the old ones
are retained, they must be sanded-in to the commutator (see Delco
instructions). The springs also should be tested for tension; they
must never be allowed to become loose enough to permit the brushes
to chatter when the generator is running, as this would interfere
seriously with its output.
Lack of Capacity through Faulty Gear Box. Should the battery
not charge properly, note whether in starting the lights brighten
Fig. 351. Method of Pulling Wagner Gear Box with a "Come Along"
Courtesy of Wagner Electric Manufacturing Company, St. Louis, Missouri
perceptibly with the car running below 5 miles per hour, while at
high speed they remain dim. This indicates that the brake band of the
gear box does not release, owing either to improper adjustment of
the tightening screw or to something getting between the band and
drum. To remedy, the band adjusting screw should be turned until
the band feels free when the starting lever is in the running position.
If something has caught between the band and the drum, its removal
usually will be the only remedy necessary.
Should the battery show signs of exhaustion, and if there is no
noticeable increase in the brightness of the lamps when the car
reaches a speed of 10 miles per hour or its equivalent, the trouble
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514
ELECTRICAL EQUIPMENT
probably is in the gear box. Remove the front end plate and note if
the commutator is rotating. If not, and the reason therefor is not
apparent on an inspection of the gears, it may be necessary to remove
the gear box. A "come along", such as is employed for taking off
Ford wheels, is necessary for this, Fig. 351. It may be found that
some of the parts need replacement, or that an entirely new gear
box is necessary.
Failure Due to
Battery Cut-Out. If
the failure to charge
the battery be not
due to the gear box,
remove the cover of
the cut-out and see
if it is operating
properly. When the
engine is running at
a speed equivalent
to 15 miles per
hour, the contact
should spring away
from the adjusting
screw. If it does
not, connect a volt-
meter across the
terminals B and H
of the switch, Fig.
352. Should the
voltmeter needle
not move, examine
the contact fingers connected to the studs C and F and see that they
make firm contact with the drum of the switch. Place the end of a
pencil on the contact finger D and bear down lightly; if the main
contact maker then springs away from the adjusting screw, the cause
of the trouble is an open circuit at this contact. Bend D so that
it bears down on the drum segments; should the contacts not close
on making this test, the trouble will be an open connection, either in
the generator itself or between the generator and the cut-out (switch).
Fig. 352. Details of Wagner Starting Switch. A and B — Large
Contact Finger; C — Auxiliary Contact Finger; D — Auxiliary
Contact; E — Drum Switch; F, G, and H — Drum Switch Studs;
J — Screw Leading to C; Q— Starting Switch Lever
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ELECTRICAL EQUIPMENT 515
Should the voltmeter give a reading of 6 volts while the contacts
do not close, it shows that the shunt coil of the cut-out is open and
indicates that its connections are broken or that the trouble is in the
coil itself. This may be confirmed by operating the contacts by
hand — pushing the contact away from the adjusting screw until it
touches the stationary contact. If it remains in that position, the
generator is charging the battery, but the shunt coil of the cut-out is
out of action and the cut-out will function automatically as it should.
If, under the conditions mentioned in the first paragraph under
this heading, the cut-out closes, connect the voltmeter as described
and accelerate the engine to a speed corresponding to 25 miles
per hour. If the reading is then 15 to 20 volts, the trouble may be
looked for in a break in the generator connection to the cut-out.
Should it not be possible to locate any break, it may be in the series
coil of the cut-out, in which case a new cut-out will be necessary.
Switch or Generator Parts to Be Adjusted. If the starting lever
of the switch is not returning to the proper position for running after
starting the engine, it will be indicated by a low battery and dim
lights. Adjust so that the lever will go to correct position for running
and *see that the contact fingers of the switch are making proper
contact with the drum.
In case the battery does not get sufficient charge, connect an
ammeter to the terminal D of the switch and to W of the cut-out.
At a speed equivalent to 15 miles per hour, the ammeter should read
7 to 9 amperes if the generator is working properly. If it does not,
examine the commutator, brushes, and wiring, as previously described.
Six-Volt; Two-Unit
General Characteristics. This type is similar in characteristics
to most of the other makes of this class already described.
Generator. The generator is the multipolar (four-pole) shunt-
wound type.
Regulation. The regulation is of the inherent or bucking-coil
type, integral with the field windings of the generator.
Starting Motor. The motor is four-pole and series-wound, driv-
ing through a reducing gear mounted on the motor housing, Fig. 353.
Control. Battery CutrOut. The complete instrument, minus
its cover, is shown in Fig. 354. It is of standard design and is intended
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516 ELECTRICAL EQUIPMENT
to be mounted in the tool box under the driver's seat. As shown in
the photograph, the upper binding post is the series-coil connection,
the central binding post just below it is the shunt-coil connection,
Big. 353. Wagner Six-Volt Two-Unit Type Starting Motor. Left — Commutator
End; Right— Gear End
Courtesy of Wagner Electric Manufacturing Company, St. Louis, Missouri
while the lowest binding post is a connection completing the circuit
through both coils to the battery.
Switch. The switch is of the circular knife-blade type, two sets
of spring contacts close together being pressed down over the sta-
tionary contact against the spring, as shown in Fig. 355 which illus-
trates the parts of the
switch.
Wiring Diagram. A
typical wiring diagram of
the Wagner two-unit sys-
tem as installed on the
Scripps-Booth four- and
eight-cylinder models is
shown in Fig. 356. The
only difference in the
wiring of the two models
Fig. 354. Wagner Cut-Out has ^ Aq ^ ^ j^
tion and merely affects the distributor connections, as illustrated by
the panel in the upper right-hand corner, which shows the distributor
and connections for the four-cylinder car. As the system is a single-
wire type, one side of every circuit is grounded, the spark plugs
themselves representing the grounded side of the high-tension ignition
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Remy Ignition and Wagner Starting and Lighting Installations on Studebaker Four and Six, Models
SF and ED. Upper Diagram Shows Junction-Block Wiring Diagram; Lower Diagram
Shows Car Wiring Diagram
Courtesy of The Studebaker Corporation of America, Detroit, Michigan
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ELECTRICAL EQUIPMENT 517
circuit. The caution on the diagram — Never run generator with battery
removed from car nor with wire disconnected from generator— applies
not only to the Wagner system but to practically every other
system as well.
Instructions. Ground in Starting or in Lighting Circuits. When
the blowing of a fuse on one of the lighting circuits is due to a ground,
or a similar fault is suspected in the starting system, it may be tested
for either with the lamp outfit already described or with the low-
reading voltmeter, as follows:
Disconnect one battery terminal, taping the bare end to prevent
contact with any metal parts of the car, and connect one side of the
voltmeter to this terminal. Attach a length of wire having a bared
end to the other terminal of the voltmeter, as shown in Fig. 357.
Fig. 355. Details of Wagner Switch
Courtesy of Wagner Electric Manufacturing Company, St. Louis, Missouri
Connect the bared end of the free wire to some part of the car frame;
making certain that good electrical contact is made. Disconnect the
generator and starting motor completely, open all lighting switches,
and be sure that ignition switch is off. If there is no ground in the
circuit, the voltmeter will give no indication. Be sure that none of
the disconnected terminals is touching the engine or frame; to insure
this, tape them.
Should the voltmeter give a reading of 4 volts or more, it indicates
that there is a ground in the wiring between the battery and the
junction box, or in the wiring between the junction box and the gen-
erator or the starting motor. If th<* yoltmeter reads less than 4
125
518 ELECTRICAL EQUIPMENT
volts but more than \ volt, all wiring and connections should be care-
fully inspected for faults. This test should be repeated by reversing
the connections, that is, by reconnecting the wires on the side of
the battery circuit that has been opened and disconnecting the
other side.
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Localizing Any Ground. To localize any fault that the reading
of the voltmeter may show, reconnect the wires to the starting motor
and close the starting switch; any reading of the voltmeter with
such connections will indicate that the ground is in this circuit.
Should no ground be indicated with these connections, disconnect
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ELECTRICAL EQUIPMENT 519
the starter again and reconnect the generator; if the voltmeter
records any voltage, the ground is in the generator circuit. With
both starter and generator disconnected, the voltmeter being con-
nected first to one side
of the battery and then
to the other, operate
the lighting switches, the
ignition switch, and the
horn, one at a time, and
note whether the volt-
meter needle moves upon
closing any of these
switches. A voltage read-
ing upon closing any of
these switches will indi-
cate a ground in that par-
ticular Circuit. p^ 357 Testing for Ground8 ^^ Voltmeter in
Short-CirCUit Tests. Two-Wire System
To test for short-circuits, substitute the ammeter for the voltmeter, but
do not connect the instrument to the battery. The shunt reading to 2(f
Fig. 358. Testing for Short-Circuits with Ammeter in Two-Wire System
amperes should be employed, one side of the ammeter being grounded
on the frame as previously described, and the other being connected
with a short wire that can be touched to the open side of the bat-
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520 ELECTRICAL EQUIPMENT
tery, Fig. 358. Disconnect the starter and the generator and open
all the switches, then touch the bare end of the wire to the battery
terminal on the open side as shown. Any reading, no matter how
small, will indicate a short-circuit (two-wire system) in the wiring
between the battery and junction box or between the latter and the
starter, or generator. If the ammeter reading shows a heavy current,
there is a severe short-circuit.
Localizing a Short-Circuit. The short-circuit may be localized
in the same manner as described for the voltmeter test, i.e., connect
the starter and test; disconnect the starter, connect the generator and
test. A reading on the generator test may be due to the contacts of
the cut-out sticking together. If the cut-out contacts are open and
the ammeter registers, there is a short-circuit in the generator
windings.
Disconnect the generator again, remove all the lamps from the
sockets, and turn on the lighting-circuit switches one at a time, touch-
ing the wire to the battery terminal after closing each switch. A
reading with any particular switch on indicates a short-circuit in the
wiring of the lamps controlled by that switch. Only one switch should
be closed at a time, all others then being open. This test should be
made also with the ignition switch on but with the engine idle. The
ammeter then should register the ignition current, which should not
exceed 4 to 5 amperes. If greater than this, the ignition. circuit should
be examined.
Cautions. Do not attempt to test the starter circuit with the ammeter
as it will damage the instrument. To test the starter circuit, reconnect
as for operating, removing the ammeter. Close the starting switch ; a
short-circuit in the wiring will result either in failure to operate or in
slow turning over of the engine. See that the switch parts are clean
and that they make good contact. If the short-circuit is in the wind-
ing of the starting motor, there will be an odor of burning insulation
or smoke.
The battery must be fully charged for making any of these
tests. While the effect either of a ground or of a short-circuit will
be substantially the same, its location and the remedy will be more
easily determined by ascertaining whether it is the one or the
other. Instructions for making these tests have already beea dis-
cussed in the Gray & Davis section.
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Westinghouae Starter Intallation on Pierce-Arrow Series Four Cam Upper Diagram for Models
and 48; Lower Diagram for Model 66
Courtesy of Pierce-Arrow Motor Cor Company, Buffalo, New Fork
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Westinghouse Starting and Lighting Installation on Locomobile Series Two Six-Cylinder
Cars, Models 38 and 48. Upper Diagram Layout of Cables on Closed Cars;
Lower Diagram Complete Wiring Circuits for Open Cars
Courtesy of The Locomobile Company of America, Bridgeport, Connecticut
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ELECTRICAL EQUIPMENT
521
WESTINQHOUSE SYSTEM
Twelve-Volt; Single-Unit; Single-Wire
Dynamotor. The single unit of the 12-volt system, or the
"motor-and-generator" as the manufacturers term it, is a bipolar
machine, both the generator and starting-motor windings of which
are connected to the same commutator. Installation is usually by
• means of a silent chain, as o^ the Hupp (1915 and earlier). The
characteristics of this type of machine are such that when running
at a speed equivalent to 9 miles per hour or less', it acts as a motor,
and when the speed increases, it automatically becomes a generator
and begins to charge the battery.
Regulation. The third-brush method of regulation is employed,
the amount of current supplied to the shunt fields by this brush
Shunt Field
U H Horn HI
>¥=► +
Lighting
Switch
Motor end Generator
'fuse Block
Fig. 359. Wiring Diagram for Westinghouse Single-Unit System on Hupmobile
decreasing as the magnetic field of the generator becomes distorted
owing to increased speed.
Control. The switch employed with this type of combined unit
is the regular single-throw single-pole switch used on lighting-
plant switchboards. This switch controls both the ignition and
the starting-motor circuits and, at starting, is thrown on and left
closed as long as the car is running.
Wiring Diagram. The connections of the Hupp installation
are shown in Fig. 359.
Instructions. Battery Charging. As the unit acts as a motor
to drive the engine when the latter is running at a speed of less
than the equivalent of 9 miles per hour on high gear, slow driving
or permitting the engine to idle at a very low speed when the car is
standing will discharge the battery. Where no fault in the wiring
or connections exists and the battery will not stay charged (the
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522 • ELECTRICAL EQUIPMENT
generator,; of course, working properly), this practice may be the
cause of the trouble. If the voltage drops to 10 or 11 volts, with
the headlights on but with the engine stopped, it indicates that the
battery is practically discharged. This voltage reading will be
somewhat higher in summer than in winter. The remedy is to
run with fewer lights at night or to run the engine for longer periods
in the daytime, or at higher speeds. Running solely at night will
not keep the battery sufficiently charged, as most of the generator
output is consumed by the lamps. Should the battery become
discharged to a point where it cannot operate the starting motor,
disconnect the wires C and S at the dynamotor, taping their ter-
minals to prevent contact with any part of the engine or chassis.
Start the engine by hand and, when running at a speed of about
500 r.p.m., reconnect these wires, being sure to connect wire S first,
when the battery will begin to charge.
Fire Prevention. Gasoline or kerosene is frequently employed
to wash automobile engines. Before doing so, be sure that the
starting switch is open, and disconnect the negative terminal of
the battery, taking care that it does not come in contact with any
metal parts of the car. To make certain of this, it is better to tape
the metal terminal. Allow the gasoline to evaporate entirely before
reconnecting the battery, as a flash or spark would be liable to ignite
the vapor. This naturally applies to all cars, although only such as
are equipped with the Westinghouse single-unit or the Dyneto single-
unit have starting switches which remain closed all the time the
engine is running.
Weak Current. If the dynamotor fails to operate when the
starting switch is closed, open the switch and test with the port-
able voltmeter. If it indicates less than 11 volts, the battery is run
down; if it indicates 12 volts or over, look for a loose connection or
an open circuit (broken wire) either in the connection from the
battery to the starting switch, from the switch to the dynamotor,
from the latter to the ground, or from the battery to the ground, in
the order named. Dim burning of the lamps when the engine is
stopped also indicates a discharged battery. When this is the case,
it is advisable to recharge at once from an outside source, if possible.
A quick method of determining whether there is a ground in the
wiring is to disconnect the battery wire and, the engine being stopped
136
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13
'"REFERENCE LETTERS APPLYING TO WIRING DIAGRAMS
A— Storage Battery
B— Starting Switch
C— Starting Motor
D— Generator
B— Voltage Regulator
P— Ammeter
G— Ignition Switch
H— Lighting Switch
J — Spark Coil
K— Atwater-Kent Igniter
L— Honf
M— Head Lamps
N— Tail Lamp
O—Inatrument tamp
P— Horn Push Button
Q— Spark Plugs
Westinghouse Ignition, Starting, and Lighting Installation on Hupmobile Series N 1916-17
~" . Upper Diagram Applies to Westinghouse Equipment for Nun ""
60000 to 76000; Lower Diagram Applies to Cars after 76000
Cars.
Applies to Westinghouse Equipment for Numbers
Lower T'
Courtesy of Hupp Mo*m Car Corporation, Detroit, Michigan
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ELECTRICAL EQUIPMENT 523
and all lights turned off, touch the disconnected wire to the terminal
lightly. A spark, when this contact is made, will indicate a ground
between the battery and the dynamotor or the switch. The testing
lamp should then be used to locate the circuit in which the ground exists.
Failure to charge properly may be due also to imperfect con-
tact at the brushes or to a break in the shunt-field circuit of the
generator, as explained in previous instructions. If the shunt-field
circuit is found open, the trouble doubtless has been caused either
by a ground between the battery and the generator or by running
the generator when it was disconnected.
To remove the brushes, lift the spring that holds the brush in the
guide and take out the screw holding the brush shunt, when the brush
Fig. 360. Westinghouse Four-Pole Generator for Six- Volt Double-Unit Single- Wire System
Courtesy of Westinghouse Electric and Manufacturing Company, East Pittsburgh, Pennsylvania
can be slipped out. Care should be taken to replace brushes in the
same position, and if they do not bear evenly over their entire surface
on the commutator, they should be sanded-in as described in the
Delco instructions. The latter suggestion also applies to new brushes.
Six-Volt; Double-Unit; Single-Wire
Generators. Four types of generators are made, as illustrated
in Fig. 116, Part III; in Fig. 157, Part IV; and in Fig. 360, shown
herewith, the fourth being similar to the unit shown on this page
except for the method of regulation employed, which is of the third-
brush type.
Regulation. The reverse series-field winding, or bucking-coil,
method is used in the first two types of generator, while a voltage
regulator combined with the battery cut-out is employed on the
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524
ELECTRICAL EQUIPMENT
To Battery. 3"
Fig. 361. Wiring Diagram for Westinghouse Generator with Self-Contained Regulator
Closed Open
Fig. .362. Closed and Open Position of Westinghouse Cut-Out Switch
140
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ELECTRICAL EQUIPMENT 526
Fig. 303, Wiring Diagram for Westinghouae System with External Regulator
141
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526 ELECTRICAL EQUIPMENT
third, and the third-brush method on the fourth. This regulator is
either self-contained, i.e., built in the generator, or is mounted inde-
pendently. The connections of the built-in regulator are shown in
Fig. 361. The open and closed positions of the contacts of the exter-
nal cut-out are shown in Fig. 362.
Wiring Diagram. Fig. 363 shows the connections of the separately
mounted regulator together with the charging and lighting circuits.
Fig. 364. Wes%ghouse Cut-Out Switch of Generator with Third-Brush Regulation
Battery Cut-Out. The type of automatic cut-out used with
the type of generator employing the third-brush method of regu-
lation is illustrated in Fig. 364. This may or may not be combined
with a starting switch mounted on the engine side of. the dash or
some similar location. Fig. 365 is a wiring diagram showing the con-
nections of the separately mounted cut-out with the third-brush
generator. The cutting-in speed varies from five to ten miles per
hour on high gear, varying with the gear ratio and wheel diameter of
the car. This speed may be determined by running the car slowly
and speeding up very gradually, meanwhile observing the increase in
speed on the speedometer. The point at which the contacts close
142
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ELECTRICAL EQUIPMENT
527
will be indicated by a slight quick movement of the ammeter needle.
The cutting-out speed is slightly below this to prevent constant
Gejterwfar"
*5ep<7s-tr/*/y moetmWC
f 1 cufouf stuffcA.
f7jj+ Soar
Ammeter
ivmmt
-o
<ye &erffirry
co/tnecffon.
3-
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Fig. 365. Diagram of Connections for Complete Westinghouse System
with Separately Mounted Regulator
vibration of the cut-out armature when the car is being driven close
to the cutting-in speed.
145
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528
ELECTRICAL EQUIPMENT
Starting Motors. Variations. Several types are built to meet
varying requirements; i.e., with self-contained reduction gearing,
with single-reduction automatic screw pinion shift (Bendix drive),
and with automatic electromagnetic pinion shift. The first two will
be familiar from the descriptions already given of other makes.
The third is similar in principle to the Bosch-Rushmore, but an
independent magnet is employed instead of utilizing the armature
of the motor itself for this purpose.
Magnetic Engaging Type. This type, as well as the other types
of starting motors mentioned, may be operated either by a foot con-
trolled switch or by a magnetically controlled switch put in action
by a push button. The wiring diagrams, Fig. 366, show the circuits
of both installations and also make clear the operation of the auto-
Shiftmg Magnet Starting Motor
^fc__^^*Dming
Electro -Magnetic
Starting Switch.
Pinion
Startin g Mag net^Stortrng Motor
^ --"""— Driving
Pinion
FlywhetJ
A^Cutot/t
generator
Fig. 366. Wiring Diagrams of Motor Connections for Automatic Electromagnetic Pinion Shift
matic engagement. The armature is mounted on a hollow shaft;
and on the end of this shaft is carried a splined pinion designed
to engage the flywheel gear. This pinion is caused to slide along
the shaft by a shifting rod which is attached to the pinion and passes
through the hollow shaft. The other end of this shifting rod acts as
the core of the shifting magnet and will be recognized as the plunger
of a solenoid. When the motor is idle, a spring holds the pinion at
the right-hand end of the shaft and clear of the flywheel gear.
As shown diagrammatically in Fig. 366, when the starting switch
is closed, the circuit is completed from the negative terminal of the
battery, through the switch, the shifting solenoid, the armature, and
the series field of the motor to the frame of the car on which the
positive side of the battery is grounded. The large amount of
current necessary for starting energizes the shifting solenoid suffi-
146
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Motor
Dimmef Bulb
Westin&house Ignition, Starting, and Lighting Installation on Marion-Handley Six, 1917
Courtesy of The Mutual Motors Company, Jackson, Michigan
150
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ELECTRICAL EQUIPMENT 529
ciently to overcome the force of the spring so that it draws the shifting
rod to the right through the hollow shaft, meshing the pinion with
the flywheel gear. When the engine speeds up to the no-load speed
of the starting motor, the current in the latter falls off so that the
pull of the solenoid is less than that of the spring, and the pinion is
automatically disengaged, though the motor will continue to revolve
until the starting switch is opened.
Electromagnetic Switch. In principle, the electromagnetic switch
is the same as that of the automatic engaging device for the pinion.
The movable double-pole contact, instead of being attached to a rod
for foot operation, is mounted on the plunger of a solenoid and nor-
mally is held open by a spring. This solenoid requires but a small
amount of current for its operation and is connected on an independent
circuit with the battery. It is controlled by a push button, and when
the circuit is closed by means of the latter, the plunger of the solenoid
is drawn into the coil against the pull of the spring, thus bringing the
contacts together and holding them there as long as the solenoid
is energized.
Instructions. Regulator. When the generator of the voltage-
regulator type fails to charge the battery properly, all parts of the
circuits and connections having been examined to determine that
they are in proper condition, the regulator may be tested for faults.
With the aid of the portable voltmeter, note at what voltage the
contacts of the cut-out close or cut in, and at what voltage they
cut out or open. See that the contact points are clean and square
so that they make good contact over their entire surfaces when
pressed together with the hand. Insufficient charging may be due
to the voltage regulator keeping the voltage of the generator below
the proper point for this purpose. A voltage adjusting screw is
provided to compensate for this. With the voltmeter in circuit
and the engine running, turn the screw very slowly and note the
effect on the reading. For proper charging the latter should be
approximately 7^ to 8 volts, and the screw should be adjusted very
gradually to bring the voltmeter reading to this value. This screw
is properly set at the factory # and is unlikely to need adjustment;
so all other possible causes should be investigated before changing
it. The instructions for the 12-volt system also apply here, except
that for voltage tests the system operates on 6 volts.
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530 ELECTRICAL EQUIPMENT
SPECIAL SYSTEMS FOR FORD CARS
FORD SYSTEM
General Instructions. On the latest model enclosed Ford cars
such as the sedan and the coup£, an electric lighting and starting
system is now being furnished as a regular part of the equipment.
As will be noted by the illustration, Fig. 367, this has been
designed especially for the Ford motor and is combined with it
in a manner that makes it practically integral. The system is a
standard two-unit six-volt single-wire type that is of conventional
design throughout so that any repairman who is familiar with the
other system previously described will at once recognize the layout
of the Ford system and have no difficulty in handling it. The
details of the generator and starting motor are shown in Fig. 368,
while the complete wiring diagram is illustrated in Fig. 369. The
battery is a 6-volt 13-plate Exide.
The precautions mentioned in connection with other systems
of this type apply to the care and handling of the Ford. If for
any reason the generator is disconnected from the battery, the
engine must not be run unless the generator is grounded as other-
wise it is apt to be burned out. A piece of wire, preferably flexible
copper cable and in no case less than t^inch in diameter, should be
run from the terminal on the generator to one of the valve cover
stud nuts, making sure that the wire is tightly held at both ends.
Removal of Starting Motor. It is necessary to remove the
starting motor to replace the transmission bands. To do this,
first remove the engine pan on the left side of the engine and then
take out the four small screws holding the shaft cover to the
transmission cover. Upon removing the cover and gasket, turn
the Bendix driveshaft around so that the set screw on the end of
the shaft is in the position shown in the illustration, Fig. 368.
Immediately under the set screw is placed a washer of the locking
type, having lips or extensions oppositely placed on its circumfer-
ence. One of these is turned against the collar and the other is
turned up against the side of the screw head. Bend back the lip
which has been forced against the screw and remove the set screw.
A new lock washer of this type must be used when replacing the
starting motor.
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ELECTRICAL EQUIPMENT 531
Pull the Bendix assembly out of the housing, taking care to
see that the small key is not lost. Remove the four screws which
1
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hold the starter housing to the transmission cover and pull out the
starting motor, taking it down through the chassis, which explains
153
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532 ELECTRICAL EQUIPMENT
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ELECTRICAL EQUIPMENT 533
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534 ELECTRICAL EQUIPMENT
the reason for removing the engine pan. In replacing the starting
motor, note that the terminal for the electric cable must be placed
on top. If the motor is. placed in any other position, the cable
will not reach to the terminal. In case it is necessary to run the
car. without the starting motor in place, transmission cover plates
supplied for the purpose should be put in place to exclude dirt and
prevent the waste of oil.
Removing Generator. To take the generator off the engine,
first take out the three cap screws holding it to the front encl
cover and by placing the point of a screw driver between the gen-
erator and the front end cover, the generator may be forced off
the engine assembly. Always start at the top of the generator
and force it backward and downward at the same time. In case
it is necessary to run the car without the generator in place, a
plate may be had to cover the opening thus left in the timing
gear case. Should the battery be removed, the engine must not
be run without grounding the generator in the manner already
explained.
The generator is driven from the large timing gear to which
the camshaft is attached and is set to cut into the battery circuit
when the speed of the motor is equivalent to 10 miles an hour on
the direct drive, while it reaches its maximum at 20 miles per
hour. Both the generator and the starting motor are lubricated
by the splash system of the engine itself, but an additional oil cup
is placed on the rear end bearing of the generator and should be
given a few drops of oil at short intervals.
Lighting and Ignition. The lighting system consists of two
double-bulb headlights and a small taillight controlled by a com-
bination lighting and ignition switch mounted on the instrument
board and the connections of which will be noted in the wiring
diagram. All of the lamps are connected in parallel, current
being supplied for them by the battery. The lamps should never
be connected to the magneto, as the higher voltage of the latter
will burn out the bulbs and it may discharge the magnets.
Reference to the wiring diagram will show the connection
between the battery and the combination lighting and ignition
switch by means of which the battery current may be sent
through the induction coils for starting. On models equipped with
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ELECTRICAL EQUIPMENT 535
starting and lighting systems, the magneto is employed solely for
ignition. Whenever any adjustments or repairs are to be made to
the wiring, the cable leading to the positive side of the battery
should first be disconnected and protected with insulating tape.
Otherwise, the battery current is apt to be passed through the
magnet coils, and this will result in discharging the magnets.
The operation of the system is checked by means of an
ammeter mounted on the instrument board. When the lights are
burning and the engine is not running at a speed in excess of the
equivalent of 10 miles an hour, the ammeter will show discharge.
At a speed of 15 miles per hour or faster, the ammeter should
show a reading of 10 to 12 amperes, even with the lights burning.
When the ammeter fails to give a charge reading with the engine
running at a speed of 15 miles an hour or better, the generator
should be tested, if an examination fails to reveal any loose con-
nections at the ammeter or on its line. To make the generator
test, the cable is disconnected from its terminal on the generator
and the engine run at a moderate speed. With a pair of pliers,
short-circuit the generator by placing against the terminal stud
and against the housing of the generator at the same time. If the
generator is in good working condition, a bright spark will result.
The engine should at once be stopped, as the generator should not
be run in this condition a moment longer than nefeessary. An
inspection of the connections and wiring as outlined in previous
sections will be found equally effective in discovering ^hort-circuits
or grounds as in any of the other systems mentioned.
Operating Starter, The management of the starter is simple.
The spark and throttle levers should be placed in the same position
on the quadrant as when cranking by hand, and the ignition switch
turned on. Current from either battery or magneto may be used
for ignition. When starting, especially if the engine is cold, the
ignition switch should be turned to "battery." As soon as the
engine is warmed up, turn switch back to "magneto." The start-
ing motor is operated by a push button, conveniently located in
the floor of the car at the driver's feet. With the spark and throttle
levers in the proper position, and the ignition switch turned on,
press on the push button with the foot. This closes the circuit
between the battery and starting motor, causing the pinion of the
157
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536 ELECTRICAL EQUIPMENT
Bendix drive shaft to engage with the teeth on the flywheel, thus
turning over the crankshaft. When the engine is cold, it may be
necessary to prime it by pulling out the carburetor priming rod,
which is located on the instrument board. In order to avoid flood-
ing the engine with an over-rich mixture of gas, the priming rod
should only be held out for a few seconds at a time.
GRAY AND DAVIS
General Instructions. Gray and Davis and some of the other
leading manufacturers who make the starting and lighting equip-
ment for larger cars also manufacture a special type designed for
the Ford. These special Ford systems are simple and compact,
and everything necessary to install them on the machine is pro-
vided by the maker of the apparatus so that they may be installed,
either by the owner of the machine or by the local garage man
whose electrical experience is limited. - This necessitates the removal
of the radiator, radiator brace rod, hose connections, fan, fan pul-
leys and belt, cylinder head, and in some cases the tiining-gear
housing. The ground connection of the headlights, which is
soldiered to the back of the radiator on 1915 and subsequent
models provided with electric headlights supplied by the Ford
magneto, must be discarded altogether, as the lights are to be
supplied by the storage battery. In cases where it is necessary to
remove the timer (this must be done when the timing-gear housing
has to be removed), both the timer and the carburetor should be
adjusted for efpcient running before starting to dismantle the
engine, and if the latter is turned over while the timer is off, the
ignition timing must be readjusted when the timer is put back.
As the removal of all the parts mentioned is a simple matter fully
covered in the Ford instruction books and familiar to practically
every garage man in the country, they are not repeated here.
Installation. Preparing Engine. Remove the radiator, discon-
necting the ground wire from it; disconnect the wires from the head
lamps and remove the head lamps and supports. Take off the bracket
and fan, Fig. 370, and turn the engine by hand until the pin 2 in the
fan pulley is straight up and down; remove the pin from the jaw
clutch and remove the starting-crank 4, belt 5, and the cotter pin, S;
take the pin from the fan pulley and remove the pulley 6. Remove*
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ELECTRICAL EQUIPMENT 537
the second, fourth, and fifth bolts from the crankcase flange ?, the
left and front bolt from the side-water connections 8 and 9, as well
as the second cylinder-head bolt 10.
Note — The numerals refer to the parts to be removed or replaced, as well
as the sequence in which the operations are to be carried out, as shown on the
sketches. Each illustration, however, has its own series of the same numbers,
which should not be confused with those on other views.
Lay the chain 1 in the rear of the engine support around the
crank-shaft, Fig. 371, and then place the original starting-crank jaw
Fig. 370. Preparing Engine for Mounting Starting Unit
Courtesy of Gray & Davis, Boston, Massachusetts
clutch 2 inside of the crankshaft sprocket. Place the crankshaft
sprocket 3 on the crankshaft and put the new belt 4 around the pulley
on the crankshaft. Secure the sprocket with the new pin 5 (supplied)
and then connect the starting crank in its original position. Secure
the jaw clutch to the starting crank with pin 7.
Mounting Starter-Generator. In Fig. 372 is shown the starter-
generator unit, for which note the following instructions: See that
159
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538
ELECTRICAL EQUIPMENT
Fig. 371. Putting Driving Chain on Crankshaft Sprocket in
Gray & Davis Ford Installation
Slop Collar
Screw Shaft
Pinion
rFldjusling 5crevY Jr Lock Nut S
^ " iNuls-7
■Motor Terminal-!
Dynamo (jear-
6-Clamping Hu ts
fid justing Bracket
Mounting Bracket
Fig. 372. Details of Gray & Davis Generator Unit for Ford Starter
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ELECTRICAL EQUIPMENT 539
the motor terminal 1 is free from contact with any other metal; also
that the dynamo terminal 2 and insulation are n3t injured. Test the
shaft and gears 3 to see that they turn freely, a iid then fill the oil
cups 4 with oil.
Release the top adjusting screw 5, also two lower clamping lock
.nuts 6 (front), as well as the two upper clamping lock nuts 7 (rear) and
the single middle clamping lock nut 8 (front). The units must be in
the lowest position possible on the bracket before placing it on the car.
In Fig. 373 is shown the starter-generator unit in place on the engine
with the bolts and nuts all tightened. This is carried out as follows:
Fig. 373. Starter Unit Mounted on the Engine
Courtesy of Gray & Davis, Boston, Massachusetts
Place three f-inch spacers over the first, second, and third holes in
the crankcase flange 1, and then place the unit on car 2; pass three
f- by 2|-inch bolts through the lower bracket, but do not attach nuts
8. Tip the starter unit forward and pass the chain over the dynamc
sprocket 4; attach the bracket by meams of cylinder-head bolt, but
do not fasten.
Place a M-inch spacer between the bracket and top water con-
nection 7 and attach the bracket with -&- by 2f-inch bolts, but do not
fasten securely; then place -^a-inch spacers 7 A under the bracket
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540 ELECTRICAL EQUIPMENT
so that the chain will be tight when the units are in the lowest possible
position. Use washers 8 as shims between the bracket and the
cylinder-head link. Secure the three lower bracket bolts 9 with
lock washers and nuts, also secure the water-connection bolts 6 and
7 and the cylinder-head bolt 5. Adjust the bracket stay bolt 10,
adjust the chain 11 to moderate the tension and lock adjustment,
securely tighten five clamping bracket nuts, and then crank the engine
slowly by h&nd to see that everything turns smoothly. If, through
some irregularity in the engine casting the bracket should not seat
properly, it may be necessary to file the bracket holes to meet this
condition. Be sure that the sprockets are in true alignment, or the
*r
Fig. 371. Installing Gray & Davis Wiring and Lighting Switch on Ford Car
uneven strain may cause injury. If necessary, elongate the holes in
the bracket or shim bracket as needed to insure perfect alignment
of chain.
When adjusting the bracket stay bolt 10, make sure that it rests
against the engine casting without strain and secure it with nuts on
each side of the bracket. Bend the ignition timing to clear the chain,
if necessary, but after bending, the distance between the ends of the
rod in a straight line must be equal to its original length. Adjust the
chain to moderate tension and secure both the adjustment lock nuts
at the top. If all five nuts holding the adjustable bracket are not
released before adjusting, uneven strain may cause injury. Securely
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ELECTRICAL EQUIPMENT 541
tighten the sliding-bracket nuts 12 — two at the bottom front side,
two at the top rear, and one at the front end. Test by turning the
engine over by hand slowly.
Remounting Engine Parts. Fit split pulley 1 to the hub of the
fan, Fig. 374, and attach split pulley 2 with four screws; slip a new
belt over the fan pulley, attach the fan, and adjust. Place the radia-
tor 4 on its support and screw the radiator rod into the radiator and
secure with check nut 3; secure the hose clamps at the top and side
water connection 6; place the radiator nuts and secure with cotter
pins. Attach the lighting switch at the cowl (left) with j^-inch screws
and attach three lighting-
cable clips on the rear of
the dash, using J-inch
wood screws; cut the
corner from the toe board
for clearance. Attach
three wire clips 10 to the
left side of the frame and
attach green wire 11 to
the dynamo terminal.
Then connect the short
black and red wire to the
left head lamp. Pass a
long black and red wire
through the radiator tube
tO the right head lamp, Fi S- 375 - Installation of Starting Switch
-• - i j Courtesy of Gray & Davis, Boston, Massachusetts
then connect the short
wire from each head lamp to the metal of the car frame H. Attach
the starting cable 15, which has a copper terminal at each end, to the
starting-motor terminal. Refill the radiator and watch carefully for
leaks in the circulation system.
Starting Switch. The location of the starting switch and the
method of installing it are shown in Fig. 375. Take the plate 1 off
the starting switch and use it to mark the holes in the floor strip two
inches in front of heel board and nine inches from the sill, as shown in
the illustration. Make three holes for the starting switch in the rear
floor strip 2 and attach the switoh with bolt 3 at the side nearest the
center of the car; then attach the other switch bolt 4, support
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542 ELECTRICAL EQUIPMENT
the cable clip holding the two wires, and secure the spring and the
knob with a pin.
Priming Device. Connect the priming device 1, Fig. 376. Drill
a -g^inch hole in the dash two inches to the right of the coil box and
six inches above the toe board and pass the upper rod through. Con-
nect the lever arm 2 vertically to the foremost exhaust manifold bolt
with stationary member in horizontal position; then connect the lower
rod 3 to the carburetor priming lever. Work it back and forth several
times to make sure that it returns to normal position when released.
Battery. Place the battery box on the right-hand running board,
Fig. 377, to permit easy opening of doors and access to .battery box;
Fig. 376. Replacement of Carburetor Timing Rod on Dash
. Courtesy of Gray <& Davis, Boston, Massachusetts
then mark four holes with the center punch. Drill four holes U inch
in diameter in the running board 2, using a jack or prop to support
the running board while drilling. Replace the battery box on the
running board in order to mark the holes in mud guard for insulating
cable bushings 3, then make two holes If inches in diameter. Insert
insulating-cable bushing 4 in left hole and secure with round wooden
nut; do the same with the right-hand bushing 5. Secure wood nuts 6
with a wire twisted around the thread. A coat of heavy paint will
also hold the nut in place and preserve the insulator. Place the two
flat wood cleats 7 with holes at each end between the battery box and
*he running board; then pass four bolts 8, f inch by 1? inches, through
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ELECTRICAL EQUIPMENT
543
the battery box, cleats, and running board, and secure them with
four nuts and lock washers. Place two special-shaped wood cleats 9
inside the battery box, one at each end for the battery to rest upon,
so that holes in the cleats will fit over the bolt heads. Raise springs
10 and hang on the side of the battery box, placing the battery in the
box and inserting two J-inch wood strips, one each side between the
battery and the battery box. Attach two springs 11 at opposite ends
Fig. 377. Installing Gray & Davis Battery and Wiring
to hold the battery down securely. Inspect the battery and if the
solution does not cover the plates at least \ inch, add pure water,
filling the cells to f inch above the tops of the plates. Water for
battery use should be free from iron or alkali.
Final Connections and Adjustments. Fig. 378 is a plan view of
the chassis, showing the entire system in place. Figs. 379 and 380
show the wiring in plan and in perspective. Drill and attach to the
woodwork on the underside of the body 1 three wire clips holding the
165
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544 ELECTRICAL EQUIPMENT
fr-\ CM ,<0/
166
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ELECTRICAL EQUIPMENT
545
tail-light wire; see that the wire does not make contact with any metal
edges. Attach the electric light 2. If the tail lamp has a one-point
wire connector, the lamp body must be metallically connected with
I— -t"'. !^' * ^ :V "" 4 *- ; '- -•-•'•"-"•-J'"-''^'''^ ^-^;'-^'.f;.^- ■V:-If,r.K-*^^,r!---.- -^rj"- ■ ' '-rT-.i '^-•n"S»-.-.-'— '•"'^' fij^
BATTERY
LIGHTING
'SWITCH
BLACK OR
BLACK AND
YELLOW
TARTING
MOTOR
Fig. 379. View of Complete Wiring System Simplified
the chassis frame. Be sure the connecting surfaces are clean, free
from paint, and securely connected. Connect the tail-light wire S
to the tail lamp. Tail lamps are usually made with a single wire
connector, but, if the lamp has two wire connectors, another wire
167
—
546 ELECTRICAL EQUIPMENT
m 4
should run from the second
terminal of the connector to the
metal framework of the car.
Connect the short starting
cable 4 (negative) and the
green and red wire to the start-
ing-switch terminal nearest the
battery. Then pass the end of
the battery cable through the
g foremost insulator [in the mud
guard. Attach the end of the
starting cable 5, leading
through the rear hole in the
mud guard, to the second bolt
in the transmission case. Use
a lock washer and a plain
washer under the head of the
bolt to insure permanent con-
tact. This is the positive cable
which connects to the + termi-
nal 9 of the battery. Then pass
the end of the cable through
the rear insulator in the mud
guard and under the exhaust
pipe, Tvhich it must not touch.
Attach to the starting-switch
terminal 6, securely, the end
of the cable which runs to the
starter. Support the starter
cable 7 by a clip to the inside
curved edge of the dash. When
connecting cables to the bat-
tery, be sure that the terminals
are securely fastened — firm
contact must be made. The
battery terminals are made of
lead and must be handled care-
fully. Battery-cable terminals
168
ELECTRICAL EQUIPMENT 547
differ slightly in size and correspond to the holes in the battery
terminal, the negative-cable terminal being the smaller. Pass the
foremost cables 8 through the battery-box insulator and connect
them firmly to the negative battery terminal. Do not . connect
the positive cable to the battery or insert the fuses until the instal-
lation has been made in accordance with the instructions and tests
show that wires are not in contact with the frame of the car. Turn
the lighting switch off and touch the positive terminal lightly to the
battery terminal. If there is a spark, it indicates a short-circuit or
a ground, caused by a wire coming in contact with the frame.
Remedy the trouble before connecting up the battery. If there is
no spark, permanent connection may be made. The lamp-test set
may be used to determine
whether there are any
'grounds or short-circuits,
before connecting up the
battery.
When all indications
show that the installation
has been made properly,
connect the positive start-
ing cable to the positive
terminal 9 of the battery.
Place and secure the
cover 10 on the battery Fig - M1 - Detail8 of Gray & ^^ Ford Um ^
box. Place fuse 11 in fuse clip of lighting switch. Fig. 381 shows
details of the different types of lamps.
Instructions. Oil the two generator bearings and the two motor
bearings every 200 miles, keeping oil-well covers closed. The chain
must be kept well adjusted. When the unit is first installed or when
a new chain has been fitted, the chain should be adjusted occasionally
during the first 500 miles of travel until all stretch has been taken
out of it. After this distance has been run, the chain stretch will
be slight. Never allow the chain to run slack.
To adjust the chain, release five clamping nuts (2 nuts in the rear
of the bracket at the top, 2 in front of the bracket at the bottom, and
1 at the right-hand side) a few turns to permit the bracket to slide.
Then adjust the chain to moderate tension by turning the adjusting
169
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548 ELECTRICAL EQUIPMENT
screw at the top of the bracket and tighten the check nut and adjust-
ing screw to lock the adjustment. Then retighten all five clamping
nuts securely. Turn the engine by hand to determine whether the
chain runs smoothly; the chain should not be too tight. After long
service, when all chain adjustment has been taken up, the chain may
be shortened by taking out a pair of links. The latest type of chain is
supplied with a removable pair of links, retained in position by two
removable pins. These pins are a trifle longer than the regular
riveted pins.
Where the chain has been shortened, it is sometimes necessary
to lower the supporting bracket slightly by removing some of the
^rs-inch washers under the bracket or by filing the spacers slightly, so
that the chain will be tight when the unit is in the lowest possible
position.
Wires are subject to dislodgement and injury, hence they should
be examined carefully to see that they are not resting on sharp edges
of metal and that the insulation is not worn or injured. See that none
of the wires are swinging or rubbing against metal, as this is likely to
injure the insulation. Also examine the cables leading through the
battery box and mud guards; the bushings must be intact and in place
to protect the cables from short-circuiting. Wherever injury to any
part of the insulation is found, wrap the spot carefully with insulating
tape and bend away from the metal to provide sufficient clearance to
prevent further damage.
If the lamps fail to light when the lighting switch is operated,
the fuse on the back of the lighting switch should be examined; it may
be burned out, broken, or not properly clamped in its fuse clips.
The wires may not be properly connected (this should be checked by
wiring diagram), the bulbs may be burned out, or the filaments may
be broken. The lamp wiring may be short-circuited or the charging
circuit may be open.
Do not run the engine with the battery disconnected or off the
car without first insulating or removing two of the generator brushes
to prevent the generator from generating a current. To determine
if generator is operating properly, turn on the head and tail lamps
while the engine is idle. Start the engine and accelerate to charging
speed or over; a perceptible brightening of the lamps will indicate
that the machine is generating sufficient current both to charge the
170
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ELECTRICAL EQUIPMENT 549
battery and to light the lamps. Do not open the charging circuit at
any time when the engine is running.
Testing Generator with Ammeter. A more accurate determina-
tion may be made by connecting an ammeter in, the circuit. Discon-
nect the red and green wire connected to the fuse terminal on the back
of the lighting switch and connect it to one terminal of the ammeter.
From the other terminal of the ammeter, connect a wire to the fuse
terminal to which the red and green wire was previously connected.
Turn the lights on with the engine idle. The ammeter should regis-
ter "discharge", the reading representing the v amount consumed by
the lamps turned on, i.e., head and tail lamps, 5 to 6 amperes; side and
tail lamps, 1$ to 2 amperes. If the ammeter indicated "charge"
instead of "discharge", with the lamps turned on and the engine idle,
reverse the wires connected to the ammeter terminals. In case the
ammeter does not register, see that the pointer is not jammed, other-
wise, the circuit is open at some point or the battery is exhausted.
Run the engine at a speed corresponding to 12 to 15 miles per
hour, the lights being turned off. If the ammeter registers "charge",
the generator is then charging the battery. Increase the engine speed
to a car speed corresponding to 13 to 18 miles per hour. The ammeter
reading should then be from 12 to 15 amperes. As the engine speed
is increased above 18 miles per hour, the charging rate will decrease
gradually to approximately 10 amperes at very high speed. With the
engine running at 12 miles an hour or faster, turn the lights on;
the charging rate should drop according to the number and size of the
lamps turned on (see current consumed by each lamp as given above).
Turn the lights off and, while permitting the engine to slow down,
observe the ammeter. It should drop to zero at approximately 0-
to 2-ampere charge.
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ELECTRICAL EQUIPMENT FOR
GASOLINE CARS
PART VII
ELECTRIC STARTING AND LIGHTING
SYSTEMS— (Continued)
STARTING AND LIGHTING STORAGE BATTERIES
Importance of the Battery in Starting and Lighting. In the
last analysis, every electric lighting and starting system on the
automobile is necessarily a battery system. An electric starter
is, first and last, a battery starter, since no system can be any more
powerful than its source of energy. In other words, the storage
battery is the business end of every electrical starting and lighting
system. Just as the most elaborate and reliable ignition apparatus
is of doubtful value with poor spark plugs, so the finest generators,
motors, and auxiliaries become useless if the battery is not in proper
working order.
Storage Battery Requires Careful Attention. A little experience
in the maintenance of electric starting and lighting systems will
demonstrate very forcibly that the relative importance of the storage
battery is totally disproportionate to that of all the remaining
elements of the system put together. The latter essentials have
been perfected to a point where they will operate efficiently without
attention for long periods. The battery, on the other hand, requires
a certain amount of attention at regular and comparatively short
intervals. Usually, this attention is not forthcoming, or it may be
applied at irregular intervals and with but scant knowledge of the
underlying reasons that make it necessary. Consequently, the battery
suffers. It is abused more than any other single part of the entire
system and, not being so constituted that it can withstand the effects
of this abuse and still operate efficiently, it suffers correspondingly.
Then the entire system is condemned.
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552 ELECTRICAL EQUIPMENT
Other things being equal, the successful operation of any starting
and lighting system centers almost wholly in the proper maintenance of
the storage battery. Not all the defections that this part of the elec-
trical equipment of the car suffers are caused by the battery, but unless
properly cared for, it will be responsible for such a large proportion
that the shortcomings of the rest of the system will be entirely for-
gotten. To make it even stronger, it may well be said that unless
the storage battery is kept in good condition, the rest of the system
will not have an opportunity to run long enough to suffer from wear.
In a great many cases that come to the repair man's attention, the
battery is ruined in the first six months' service, usually through
neglect. For this reason, considerable attention is devoted to the
battery and its care in this connection, despite the fact that it is
very fully covered in the volume on Electric Vehicles. The condi-
tions of operation, however, are totally unlike in the two cases.
In one instance, the energy of the battery is called for only at a rate
of discharge which is moderate by comparison with the ampere-hour
capacity, while the battery itself is constantly under the care of a
skilled attendant. In the other instance, the demand for current is
not alone excessive but wholly disproportionate to the total capacity
of the battery when it is used for starting, and intelligent care is
usually conspicuous by its absence.
PRINCIPLES AND CONSTRUCTION
Function of Storage Battery. In the sense in which it is commonly
understood, a battery does not actually store a charge of electricity.
The process is entirely one of chemical action and reaction. A battery
is divided into units termed cells. Each cell is complete in itself
and is uniform with every other cell in the battery, and one of the
chief objects of the care outlined subsequently is to maintain this
uniformity. Each cell consists of certain elements which, when a
current of electricity of a given value is sent through them in one
direction for a certain length of time, will produce a current of
electricity in the opposite direction if the terminals of the battery
are connected to a motor, lamps, or other resistance. The cell will,
of course, also produce a current if its terminals are simply brought
together without any outside resistance. This, however, would
represent a dead short-circuit and would permit the battery to dis-
174
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ELECTRICAL EQUIPMENT 553
charge itself so rapidly as to ruin its elements. This is one of the
things that must be carefully guarded against. When attending
a battery, see that its terminals are not left exposed where tools may
accidentally drop on them. When the current is being sent into the
battery, as mentioned above, it is said to be charging; when it is
connected to an outside resistance, it is discharging.
Parts of Cell. Elements. These are known as the positive
and negative plates and correspond to the positive and negative
electrodes of a primary battery. They consist of a foundation com-
posed of a casting of metallic
lead in the form of a grid, the
outer edges and the connecting
lug being of solid lead, while
the remainder of the grid is like
two sections of lattice work so
placed that the openings do not
correspond. Every manufacturer
has different patterns of grids,
but this description will apply
equally well to all of them. Fig.
382 illustrates the grid of the
Philadelphia battery. The ob-
ject in giving them this form is
to make the active material of ,,. nan T , « . , ~ , . A .. „ x . ,
w x±x<*M*y, miv »^w^ wv ^ wi v Fig. 382. Lead Grid Ready for Active Material
the plates mOSt accessible tO Courtesy of Phi^elphia Storage Battery
x s Company, Philadelphia, Pennsylvania
the electrolyte, or solution, of
the battery, and at the same time to insure retaining this active
material between the sides of the grid.
This active material consists of peroxide of lead (red lead) in
the positive plate and litharge, or spongy metallic lead, in the nega-
tive plate. The plates are said to be pasted, to distinguish them
from the old-style plates which w T ere "formed" by a number of charges
and discharges. The active material is forced into the interstices
of the grid under heavy pressure, so that when completed the
plate is as hard and smooth as a piece of planed oak plank. The
positive plate may be distinguished by its reddish color, while the
negative is a dark gray. Each positive plate faces a negative in
the cell, and as the capacity of the cell is determined by the area
175 Digitized by GoOgle '
554 ELECTRICAL EQUIPMENT
of the positive plates, there is always one more ^negative plate than
positive plates in a cell. The lead connectors of each of the plates
is burned to its neighbor of the same kind, thus forming the positive
and negative groups which constitute the elements of the cell.
Separators. As the elements must not be allowed to come in
contact with each other in the cell because to do so would cause an
internal short-circuit to which reference is made later, and as the
maximum capacity must be obtained in the minimum space, the
plates are placed very close together with wood and perforated
hard rubber separators between them. These are designed to fit
very snugly, so that the combined group of positive and negative
plates is a very compact unit. When reassembling a cell, it is impor-
tant that th^se separators be properly cared for in accordance with
the directions given later.
Electrolyte. To complete the cell, the grouped elements with
their separators are immersed in a jar holding the electrolyte. This
is a solution consisting of water and sulphuric acid in certain pro-
portions, both the acid and the water being, chemically pure to a
certain standard. This is the grade of acid sold by manufacturers as
battery acid and in drug stores as C.P. (chemically pure), while
the water should be either distilled, be cleanly caught rain water,
or melted artificial ice. In this connection, the expression "chemi-
cally pure" acid is sometimes erroneously used simply to indicate
acid of full strength, i.e., undiluted, or before adding water to make
the electrolyte. It will be apparent that whether at its original
• strength or diluted with distilled water, it is still chemically pure.
In mixing electrolyte, a glass, porcelain, or earthenware vessel
must be used and the acid must always be poured into the water. Never
attempt to pour the water into the acid, but always add the acid,
a little at a time, to the water. The addition of the acid to the water
does not make simply a mechanical mixture of the two but creates a
solution in the formation of which a considerable amount of heat is
liberated. Consequently, if the acid be poured into the water too
fast, the containing vessel may be broken by the heat. For the same
reason, if the water be poured into the acid, the chemical reaction
will be very violent, and the acid itself will be spattered about.
Sulphuric acid is highly corrosive; it will cause painful burns whenever
it comes in contact (even in dilute solution) with the skin and will
176
ELECTRICAL EQUIPMENT 555
quickly destroy any fabric or metal on which it falls. It will also
attack wood, for which reason nothing but glass, earthenware, or
hard rubber containers should be employed.
Specific Gravity. The weight of a liquid as compared with
distilled water is known as its specific gravity. Distilled water at
60° F. is 1, or unity. Liquids heavier than distilled water have a
specific gravity greater than unity; lighter liquids, such as gasoline,
have a specific gravity less than that of distilled water. Concentrated
sulphuric acid (battery acid, as received from the manufacturer)
is a heavy oily liquid having a specific gravity of about 1.835. A
battery will not operate properly on acid of full strength, and it is
therefore diluted with sufficient water to bring it down to 1.275.
This, however, is the specific gravity of the electrolyte only when the
battery -is fully charged. The specific gravity of the electrolyte
affords the most certain indication of the condition of the battery
at any time, and its importance in this connection is outlined at
considerable length under the head of Hydrometer Tests. The
desired specific gravity can be easily secured by adding concen-
trated sulphuric acid to the water. Never add the water to the
acid as it will cause undue heat.
Action of Cell on Charge. When the elements described are
immersed in a jar of electrolyte of the proper specific gravity, and
terminals are provided for connecting to the outside circuit, the
cell is complete. As the lead-plate storage battery produces current
at a potential of but two volts per cell, however, a single cell is
rarely used. The lowest number of cells in practical use' is the
three-cell unit of the 6-volt battery used for starting and lighting
on the automobile. The different cells of the battery are usually
permanently connected together/ by heavy lead straps, while detach-
able terminals are provided for connecting the battery to an outside
circuit. When the charging current is sent through the cell, the
action is as follows: The original storage-battery cell of Plants
consisted simply of two plates of lead; when the current was sent
through such a cell on charge, peroxide of lead was deposited on the
positive plate and spongy metallic lead on the negative. This was
termed "forming" the plate. By modern methods of manufacture,
this active material is formed into a paste with dilute sulphuric acid,
and is pressed into the grids. On being charged, this acid is forced
177 Digitized by G00gk
556 ELECTRICAL EQUIPMENT
out of the plates into the electrolyte, thus raising the specific gravity
of the electrolyte. When practically all of this acid has been trans-
ferred from the active material of the plates to the solution, or
electrolyte, the cell is said to be fully charged and should then show
a specific gravity reading of 1.275 to 1.3Q0. The foregoing refers of
course to the initial charge. After the cell has once been discharged,
the active material of both groups of plates has been converted into
lead sulphate. The action on charge then consists of driving the
acid out of the plates and at the same time reconverting the lead
sulphate into peroxide of lead in the positive plates and into spongy
metallic lead in the negative plates.
Action of Cell on Discharge. The action of the cell on discharge
consists of a reversal of the process just described. The acid which
has been forced out of the plates into the electrolyte by the charging
current again combines with the active material of the plates,
when the cell is connected for discharge to produce a current. When
the sulphuric acid in the electrolyte combines with the lead of the
active material, a new compound, lead sulphate, is formed at both
plates. This lead sulphate is formed in the same way that sulphuric
acid, dropped on the copper-wire terminals, forms copper sulphate,
or dropped on the iron work of the car, forms iron sulphate. In cases
of this kind, it will always be noted that the amount of sulphate
formed is all out of proportion to the quantity of metal eaten away.
In the same manner, when the sulphuric acid bf the electrolyte com-
bines with the lead in the plates to form lead sulphate, the volume
is such as to completely fill the pores of the active material when
the cell is entirely discharged. This makes it difficult for the charging
current to reach all parts- of the active material and accounts for the
manufacturers' instructions, never to discharge the battery below a
certain point.
As the discharge progresses, the electrolyte becomes weaker by
the amount of acid that is absorbed by the active material of the
plates in the formation of lead sulphate, which is a compound of
acid and lead. This lead sulphate continues to increase in bulk,
filling the pores of the plates, and as these pores are stopped up by
the sulphate, the free circulation of the acid is retarded. Since
the acid cannot reach the active material of the plates fast enough
to maintain the normal action, the battery becomes less active.
178
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ELECTRICAL EQUIPMENT 557
which is indicated by a rapid falling off in the voltage. Starting
at slightly over 2 volts per cell when fully charged, this voltage
will be maintained at normal discharge rates with but a slight drop,
until the lead sulphate begins to fill the plates. As this occurs,
the voltage gradually drops to 1.8 volts per cell and from that point
on will drop very rapidly. A voltage of 1.7 volts per cell indicates
practically complete discharge, or that the plates of the cell are
filled with lead sulphate and that the battery should be placed on
charge immediately.
During the normal discharge, the amount of acid used from the
electrolyte will cause the specific gravity of the solution to drop
100 to 150 points, so that if the hydrometer showed a reading of
1.280 when the cell was fully charged, it will indicate but 1.130 to
1 .180 when it is exhausted, or completely discharged. The electrolyte
is then very weak ; in fact, it is little more than pure water. Practically
all of the available acid has been combined with the active material
of the plates. While the acid and the lead combine with each other
in definite proportions in producing the current on discharge, it is
naturally not possible to provide them in such quantities that both
are wholly exhausted when the cell is fully discharged. Toward the
end of the discharge, the electrolyte becomes so weak that it is no
longer capable of producing current at a rate sufficient for any
practical purpose. For this reason, an amount of acid in excess of
that actually used in the plates during discharge is provided. This
is likewise true of the active material.
Capacity of a Battery. The amount of current that a cell will
produce on discharge is known as its capacity and is measured
in ampere hours. It is impossible to discharge from the cell as much
current as was needed to charge it, the efficiency of the average cell
of modern type when in good condition being 80 to 85 per cent,
or possibly a little higher when at its best, i.e., after five or six
discharges. In other words, if 100 ampere hours are required to
charge a battery, only 80 to 85 ampere hours can be discharged
from it. This ampere-hour capacity of the cell depends upon the
type of plate used, the area of the plate, and the number of plates
in the cell, i.e., total positive-plate area opposed to total negative-
plate area. To accomplish this, both outside plates in a cell are
made negative. The ampere-hour capacity of a battery, all the
179
558
ELECTRICAL EQUIPMENT
cells of which are connected up as a single series, is the same as that
of any single cell in the series; as in connecting up dry cells in series,
the current output is always that of a single cell, while the voltage
of the current increases 1 J volts for each cell added to the series. In
the case of the storage battery, it increases two volts for each cell.
The capacity of the cell as thus expressed in ampere hours is
based on its normal discharge rate or on a lower rate. For example,
take a 100-ampere-hour battery. Such a battery will produce current
at the rate of 1 am-
/'Unac^tw This Cap .11
*^ pere for practically 100
hours, 2 amperes for 50
hours, or 5 amperes for
20 hours; but as the dis-
charge rate is increased
beyond a certain point,
the capacity of the bat-
tery falls off. The battery
in question would not
produce 50 amperes of
current for 2 hours. This
is because of the fact that
the heavy discharge pro-
duces lead sulphate so
rapidly and in such large
quantities that it quickly
fills the pores of the
active material and pre-
vents further access of
the acid to it. Thus,
while it will not produce
50 amperes of current for 2 hours on continuous discharge, it will be
capable of a discharge as great or greater than this by considerable, if
allowed periods of rest between. When on open circuit, the storage
battery recuperates very rapidly. It is for this reason that when
trying to start the switch should never be kept closed for more than
a few seconds at a time. Ten trials of 10 seconds each with a half-
minute interval between them will exhaust the battery less than will
spinning the motor steadily for a minute and forty seconds.
Fig. 383. Section of Willard Starting Battery,
Showing Mud Space
180
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ELECTRICAL EQUIPMENT 559
Construction Details. For automobile starting and lighting
service, the elements of the cells are placed in insulating supports
in the bottom of the hard rubber jars and sealed in place. These
supports hold the plates off the bottom of the jar several inches in
the later types of starting batteries. Figs. 383 and 384 show sections
of the Willard starter battery and another standard type This is
known as the mud space and is designed to receive the accumulation
of sediment consisting of the active material which is shaken off the
plates in service. This ac-
tive material is naturally a
good electrical conductor,
and if it were allowed to
come in contact with the bot-
toms of the groups of plates,
it would short-circuit the
cell. Sufficient space is usu-
ally allowed under the plates
to accommodate practically
all of the active material that
can be shed by the plates
during the active life of the
cell. In a battery having
cells of this type, it is never
necessary to wash the cells,
as the elements themselves
would require renewal be-
fore the sediment could
reach the bottom Of the Fig. 384. Typical Starting Battery with Plates Cut
Down, Showing Assembly
plates.
In sealing the elements into the jar, a small opening is left for
the purpose of adding distilled water as well as to permit the escape
of the gas when the battery is charging. Except when being used
for refilling the jars, this opening is closed by a soft rubber stopper
which has a small perforation through which the hydrogen passes
out of the cell when the latter is gassing, as explained later. The
different cells of a battery are electrically connected by heavy lead
straps, these strips being usually burned onto the plates by the
lead-burning process.
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560
ELECTRICAL EQUIPMENT
Edison Cell Not Available. It will be noted that the foregoing
description has been confined entirely to the lead-plate type of storage
battery and that no mention has been made of the Edison cell. The
latter is not available for starting service on the automobile, because
its internal resistance is too high to permit the extremely heavy
discharge rate that is necessary. In extremely cold weather or where
the engine is unusually stiff for other reasons, this may be as high
as 300 amperes momentarily, while, under ordinary conditions, it
will reach 150 to 200 amperes at the moment of closing the switch.
The efficiency of the Edison cell also drops off very markedly in cold
weather, though this is
also true to a lesser extent
of the lead-plate type.
CARE OF THE BATTERY
The following in-
structions are given
about in the order in
which it is necessary to
apply them in the care of
a storage battery.
Adding Distilled
Water. In order to func-
tion properly, the plates
in the cells must be cov-
ered by the electrolyte at
all times to a depth of half an inch. Fig. 385 shows a handy method of
determining this definitely. A small piece of glass tube, open at both
ends, is inserted in the vent hole of the battery until it rests on the tops
of the plates. A finger is then pressed tightly on top of the upper end
of the tube, and the tube is withdrawn. It will bring with it at its
lower end an amount of acid equivalent to the depth over the plates.
This should always be returned to the same cell from which it was
taken. The electrolyte consists of sulphuric acid and water. The
acid does not evaporate, but the water does. The rapidity with
which the water evaporates will depend upon the conditions of charg-
ing. For example, if a car is constantly driven on long day runs and
gets very little night use, the storage battery is likely to be contin-
Fig. 385.
Diagram Showing Method of Measuring Height
of Electrolyte over Plates
Courtesy of U. S. Light and Heat Corporation,
Niagara Falls, New York
182
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"S
ELECTRICAL EQUIPMENT 561
ually overcharged and may need the addition of water to the elec-
trolyte as often as every three days, whereas, in ordinary service,
once a week would be sufficient. Even with intermittent use, the
battery should jiot be allowed to run more than two weeks without
an inspection of the level of the electrolyte and the addition of
distilled water, if necessary. Distilled water is always specified,
since the presence of impurities in the water would be harmful to
the battery, this being particularly the case where they take the
form of iron salts. Where it is not convenient to procure distilled
or rain water in sufficient quantities, samples of the local water sup-
ply may be submitted to any battery manufacturer for analysis.
While it is necessary to maintain the electrolyte one-half inch
over the plates, care must be taken not to exceed this, for, if filled
above this level, the battery will flood when charged, owing to the
expansion with the increasing temperature. The best time for adding
water is just before the car is to be taken out for several hours of use.
It may be done most conveniently with a glass and rubber syringe
of the type used with the hydrometer. Care should be taken when
washing the car to see that no water is allowed to enter the battery
box, as it is likely to short-circuit the cells across their lead connectors
and to carry impurities into the cells themselves.
Adding Acid. When the level of the electrolyte in the cell
becomes low, it is, under normal conditions, caused by the evaporation
of the water, and this loss should be replaced with water only. There
being no loss of add, it should never be necessary to add acid to the
electrolyte during the entire life of the battery. When a jar leaks or
is accidentally upset, and some of the solution lost, the loss should be
replaced with electrolyte of the same specific gravity as that remaining
in the cell, and not with full strength acid nor with water alone. The
former would make the solution too heavy, while the latter would
make it too weak. Consequently, unless acid is actually known to
have escaped from the cell, none should ever be added to it. Under
the sections on the Hydrometer and Specific Gravity, further reasons
are given why no acid or electrolyte should be added to the cell
under normal conditions, and the causes which would seem to make
the addition of acid necessary are explained.
Hydrometer. Next to the regular addition of distilled water
to the cells, the garage man will be called upon most frequently to
183
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562 ELECTRICAL EQUIPMENT
test the condition of the cells with the hydrometer. This is termed
taking the specific gravity and is one of the most important tests
in connection with the care of the battery. The specific gravity of
a liquid is determined by means of an instrument consisting of a
weighted glass tube having a scale marked on it. This instrument is
the hydrometer, and in distilled water at 60 degrees it should sink
until the scale comes to rest at the surface of the liquid at the division
1.000. The lighter the liquid, the further the instrument will sink
in it; the heavier the liquid, the higher the
instrument will float. For constant use in
connection with the care of lighting and
starting batteries, the hydrometer shown in
Fig. 386 will be found the most convenient.
Where the battery is located on the run-
ning board of the car, the test may be made
without removing the syringe from the cell,
but care must be taken to hold it vertical
I to prevent the hydrometer from sticking to
•! the sides of the glass barrel. Wherever pos-
sible, the reading should be made without
removing the syringe from the vent hole of
the cell, so that the electrolyte thus with-
drawn may always be returned to the same
cell. Where the battery is located in a posi-
tion difficult of access, as under the floor
boards, the syringe may be drawn full of
electrolyte and then lifted out; as the soft
rubber plug in the bottom of the glass barrel
Fig. 386. Syringe Hydrom- is in * he form ° f a tra P> when the in St™-
eter Set ment is held vertical, the solution will not
run out while the reading is being taken.
Failure to replace the electrolyte in the same cell from which
it was taken will result in destroying the uniformity of the cells.
For example, if electrolyte has been withdrawn from cell No. 1 of
the battery and, after taking the reading, it is put into cell No. 2,
the amount taken from No. 1 must later be made up by adding water,
and the solution will be that much weaker, while the electrolyte
of No. 2 will be correspondingly stronger.
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ELECTRICAL EQUIPMENT 563
Hydrometer Tests. In taking a hydrometer reading, first see
that the instrument is not held by the sides of the glass syringe
barrel; then note the level of the instrument in the liquid by looking
at it from below, i.e., hold it up above the level of the eye. Reading
the hydrometer in this way is found to give more accurate results
than looking down upon it. While the hydrometer affords the best
single indication of the condition of the battery — the cells should
test 1.250 to 1.300 when fully charged and 1.150 when fully dis-
charged, below which point they should never be allowed to go-
there are conditions under which the* instrument may be entirely
misleading. For example, when fresh distilled water is added to a
cell to bring the solution up to the proper level, the additional water
does not actually combine with the electrolyte until the cell has
been on charge for some time. Consequently, if a hydrometer
reading were taken of that particular cell just after the water had
been added, the test would be misleading, as it would apparently
show the cell to be nearer the fully discharged state than it actually
was, owing to the low specific gravity of the electrolyte. If, on the
other hand, fresh electrolyte or pure acid has been added to a cell
just prior to taking readings, and without the knowledge, of the tester
• the reading would apparently show the battery to be fully charged,
whereas the reverse might be the case. In this instance, the specific
gravity would be higher than it should be. To determine accurately
the condition of the cells in such circumstances, the hydrometer
readings would have to he checked by making tests with the volt-
meter, as described later.
Under average conditions, however, the hydrometer alone will
closely indicate the state of charge, and its use should always be
resorted to whenever there is any question as to the condition of
a battery. For instance, an irate owner will sometimes condemn the
battery for failure of the starting motor to operate and will be
absolutely positive that the battery has been fully charged, since he
has been driving in daylight for hours. The hydrometer reading will
show at once whether the battery is charged or not. If it is not, it will
indicate either that the generator, its regulator, or the battery cut-out
are not working properly, or that there is a short-circuit or a groutid
somewhere in the lighting or ignition circuits which permits the
battery to discharge itself. Another more or less common complaint,
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564 ELECTRICAL EQUIPMENT
the cause of which may be definitely assigned one way or the other
by the aid of the hydrometer is that "the battery is not holding
its charge". Except where it is allowed to stand for long periods
without use, as where a car is laid up for a month or more, there is
no substantial decrease in the capacity simply through standing,
unless the battery is allowed to stand in a discharged condition.
Consequently, the owner's impression that the charge of the
battery is mysteriously leaking away overnight through some short-
coming of the cells themselves is not correct. If there is a fault, it
is probably in the wiring; or a switch may have been left on inadvert-
ently; or, as is very often the case, the car is not driven long enough
in daylight to permit the generator to charge the battery sufficiently.
When driving at night with all lights on, as is commonly the custom,
the generator supplies very little current in excess of that required
by the lamps. As a result, the battery receives but a fraction of
its normal charge, so that one or two attempts to use the starting
motor exhaust it. A hydrometer test made just before using the
starting motor will show that there is only a small fraction of a charge
in the cells, so that they are not capable of supplying sufficient current
to turn the engine over longer than a few seconds. The hydrometer
is equally valuable in indicating when a battery is being overcharged,
though this is a condition which carries its own indication, known
as gassing, which is described in detail under that head.
Variations in Readings. Specific-gravity readings between
1.275 and 1.300 indicate that the battery is fully charged; between
1.200 and 1.225, that the battery is more than half discharged;
between 1.150 and 1.200, that the battery is quickly nearing a fully
discharged condition and must be recharged very shortly, otherwise
injury will result. Below 1.150 the battery is entirely exhausted and
must be recharged immediately to prevent the plates from becoming
sulphated, as explained in the section covering that condition.
Where the specific gravity in any cell tests more than 25 points
lower than the average of the other cells in the battery, it is an
indication that this cell is out of order. Dependence should not be
placed, however, on a single reading where there is any question as
to the specific gravity. Take several readings and average them.
Variations in cell readings may be caused by internal short-circuits
in the cell; by putting too much water in the cell and causing a loss
186
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ELECTRICAL EQUIPMENT 565
of electrolyte through flooding or overflowing; or by loss of electro-
lyte from a cracked or leaky jar. Internal short-circuits may result
from a broken separator or from an accumulation of sediment in the
mud space of the jars reaching the bottom of the plates.
Quite a substantial percentage of all the troubles experienced
with starting batteries, which are only too often neglected until
they give out, is caused by letting the electrolyte get too low in the
jars. The effect of this is to weaken the battery, causing it to dis-
charge more readily, and frequently resulting in harmful sulphating
of the plates and injury to the separators. When such sulphating
occurs, it permits the plates to come into contact with each other,
and an internal short-circuit results. The importance of always
maintaining the electrolyte one-half inch above the tops of the plates
will be apparent from this.
One of the most frequent causes of low electrolyte in a single
cell is the presence of a cracked ,or leaky jar. If one of the cells
requires more frequent addition of water than the others to maintain
the level of its electrolyte, it is an indication that it is leaking. Where
all the cells of a battery require the addition of water at unusually
short intervals, it is an indication that the battery is being constantly
overcharged. (See Gassing.) Unless a leaky jar is replaced
immediately, the cell itself will be ruined, and it may cause serious
damage to the remainder of the battery. Jars are often broken owing
to the hold-down bolts or straps becoming loose, thus allowing the
battery to jolt around on the running board, or they may be broken
by freezing. The presence of a frozen cell in a battery shows that
it has been allowed to stand in an undercharged condition in cold
weather, as a fully charged cell will not freeze except at unusually
low temperatures.
Frozen Cells. In some cases, the cells may freeze without crack-
ing the jars. This will be indicated by a great falling off in the
efficiency of the cells that have suffered this injury, or in a totally
discharged condition which cannot be remedied by continuous
charging. In other words, the battery is dead and the plates are
worthless except as scrap lead. In all cases where cells have been
frozen, whether the jar has * cracked or not, the plates must be
replaced at once. It must always be borne in mind that low tempera- '
tures seriously affect the efficiency of the storage battery and that
187
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566 ELECTRICAL EQUIPMENT
care should be taken to keep it constantly in a charged condition.
A variation in the temperature also affects the hydrometer readings
themselves. The effect of the temperature on the hydrometer tests
is explained *under Adjusting the Specific Gravity.
Low Cells. When one cell of the battery tests more than 25
points below the specific gravity of the others, as shown by > the
average of several readings taken of each, it should be placed on
charge separately from an outside source of current. This may be
done without removing it from the car or disconnecting it from the
other cells, since the charging leads may be clipped to its terminal
posts. If no other facilities are available and direct-current service
is at hand, use carbon lamps as a resistance in the manner illustrated
on another page. As the normal charging rate of the average starting
battery is 10 to 15 amperes or more, that many 32-c.p. carbon
filament lamps may be used in the circuit. Where only alternating
current is available, a small rectifier, as described under Charging
from Outside Sources, will be found most convenient in garages
not having enough of this work to warrant the installation of a
motor-generator. After the low cell has been on charge for an hour
or two, note whether or not its specific gravity is rising, by taking a
hydrometer reading. If, after several hours of charging, its specific
gravity has not risen to that of the other cells, it is an indication
that there is something wrong with the cell, and it should be cut
out. (See Replacing a Jar and Overhauling the Battery.)
Adjusting the Specific Gravity. Except in. such cases as those
mentioned under Hydrometer, where water has been added to the
electrolyte just before testing, or electrolyte has been added without
the knowledge of the tester, specific gravity of the electrolyte is the
best indication of the condition of the cell, and the treatment to be
given should always be governed by it. As explained in the section
on Action on Charge and Discharge, the acid of the electrolyte com-
bines with the active material of the plates to produce the current on
discharge. The further the cell is discharged the more acid there
will be in the plates, and the less in the solution. Consequently,
low-gravity readings practically always mean lack of acid in the
solution, and that implies lack of charge. Unless there is something
wrong with the cell, charging will restore the acid to the electrolyte
and bring the specific-gravity readings up to normal. In case a jar
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ELECTRICAL EQUIPMENT 567
is leaking or has been overturned and lost some of its electrolyte, no
amount of charging will bring its specific gravity up to the proper
point.
The gravity readings of the cells vary somewhat in summer and
winter, and they also decrease with the age of the plates, but the
battery will continue to give good service as long as its specific
gravity rises to between 1.250 and 1.300 when fully charged. In case
it rises above 1.300, there is an indication that excess acid has been
added to the electrolyte, and this must be corrected by drawing off
some of the electrolyte with the syringe and replacing it with distilled
water. A gradually decreasing specific gravity in all the cells
of a battery is an indication that sediment is accumulating in the
bottom of the jars and that the battery, if of the old type with
low mud space, requires washing; if of the later type with high
mud space, that its elements require renewal. Before accepting
this conclusion, however, make certain that the low reading is not
due to insufficient charging. In actual practice, starter batteries
seldom remain long enough in service without overhauling ever
to need washing.
Many starter batteries are kept in an undercharged condition
so constantly, owing to frequent use of the starting motor with but .
short periods of driving in between, that they should be put on
charge from an outside source at regular intervals. In fact, this
is the only method of determining definitely whether the battery
itself is really at fault or whether it is the unfavorable conditions
under which it is operating. Where the cells give a low reading,
no attempt should ever be made to raise the specific gravity of
the electrolyte by adding acid, until the battery has been subjected
to a long slow charge. The maximum specific gravity of the electro-
lyte is reached when all the acid combined in the active material
of the plates has been driven out by the charging current. Adding
acid will increase the specific gravity, but it will not increase the
condition of charge; it will simply give a false indication of a charged
condition. For example, if the electrolyte of a cell tested 1.225,
and, without giving it a long charge, acid were added to bring the
specific gravity up to 1 .275, it would then rise to 1 .325 if put on charge,
showing that 50 points df acid had remained combined in the plates
when the low readings were taken.
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568 ELECTRICAL EQUIPMENT
The necessity for adjusting the specific gravity of the electrolyte
in a cell can only be determined by first bringing it to its true maxi-
mum. To do this with a starter battery, it must be put on charge
from an outside source at a low rate, say 5 amperes, and kept on
charge continuously until tests show that the specific gravity of
the electrolyte has ceased to rise. This may take more than twenty-
four hours, and readings should be taken every hour or so, toward
the end of the charge. Should the battery begin to gas violently
while tests show that the specific gravity is still rising, the charging
current should be reduced to stop the gassing, or, if necessary,
stopped altogether for a short time and then renewed.
If after this prolonged charge, the specific gravity is not more
than 25 points below normal, some of the solution may be drawn
off with the syringe and replaced with small quantities of 1.300
electrolyte, which should be added very gradually to prevent bring-
ing about an excess. Should the specific gravity be too high at
the end of the charge, draw off some of the electrolyte and replace
it with distilled water to the usual level of one-half inch over the
plates. A charge of this kind is usually referred to as a conditioning
charge and, given once a month, will be found very greatly to
improve starter batteries that are constantly undercharged in service.
Temperature Corrections. All specific-gravity readings mentioned
are based upon a temperature of 70° F. of the electrolyte, and as
the electrolyte, like most other substances, expands with the heat
and contracts with the cold, its specific gravity is affected by variations
of temperature. This, of course, does not affect its strength, but
as its strength is judged by its specific gravity, the effect of the
temperature must be taken into consideration when making the tests.
The temperature in this connection is not that of the surrounding
air but that of the electrolyte itself, and as the plates and solution
of a battery increase in temperature under charge, the electrolyte
may be 70° F. or higher, even though the outside air is close
to zero. Consequently, the only method of checking this factor
accurately is to insert a battery thermometer in the vent hole of the
cell. If, on the other hand, the battery has been standing idle for
some time in a cold place, the electrolyte has the same temperature
as the surrounding air, and a hydrometer reading taken without
a temperature correction would be very misleading.
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ELECTRICAL EQUIPMENT 569
For example, assume that the car is standing in a barn in which
the temperature is 20° F. and that it has not been running for some
time so that the electrolyte is as cold as the surrounding air. A
hydrometer reading shows the specific gravity of the electrolyte to
be 1.265, which would indicate that the battery was approximately
fully charged. But the correction for temperature amounts to one
point (.001) for each three degrees above or below 70° F., and in this
case a difference of 50 degrees would have to be allowed for. This
amounts to practically 18 points, and the specific gravity of the
cells is 1.265 minus 18, or 1.247. The battery is accordingly three-
quarters charged, instead of fully charged as the uncorrected reading
would appear to indicate. The electrolyte contracts with the drop
in temperature, and its specific gravity becomes correspondingly
higher without any actual increase in its strength. The opposite
condition will be found when the battery has commenced to gas
so violently that the temperature of the electrolyte is raised to
100° to 105° F. At the former figure there would be a difference
of 30 degrees, or 10 points, to allow for, in which case a specific gravity
reading of 1.265 would actually be 1.275. Hydrometer scales, with a
a temperature scale showing at a glance the corresponding correction
necessary, simplify the task of correcting the readings; but to do
this properly a battery thermometer must be employed, as the
temperature of the electrolyte itself is the only factor to be considered.
Gassing. When an electric current is sent through a storage-
battery cell, it immediately attacks the lead sulphate into which
the active material of both the positive and the negative plates
has been converted during the discharge and begins to reconvert
it into peroxide of lead at the positive plate and into spongy metallic
lead at the negative. As long as there is an ample supply of this
lead sulphate on which the current may work, as in a fully discharged
battery, the entire amperage being sent through the battery is restricted
to carrying on this process. In other words, the current will always
do the easiest thing first by following the path of least resistance. When
the cell is in a discharged state, the easiest thing to do is to decompose
the lead sulphate. As there is a comparatively large amount of
this lead sulphate in a fully discharged battery, a correspondingly
large amount of current can be used in charging at the start. But
as the amount of sulphate progressively decreases with the charge,
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570 ELECTRICAL EQUIPMENT
a point is reached at which there is no longer sufficient sulphate
remaining to utilize all the current that is passing through the cell.
The excess current will then begin to do the next easiest thing,
which is to decompose the water of the electrolyte and liberate
hydrogen gas. This gassing is not owing to any defect in the battery,
as some owners seem to think, but is simply the result of over-
charging it. In one instance, a car owner condemned the starting
battery with which his machine was equipped, for the reason that
it was "always boiling". In fact, it "boiled" itself to pieces and
had to be replaced by the manufacturer of the car after only a few
months of service; while, as a matter of fact, the conditions under
which the car was driven were wholly responsible. It was used for
long runs in the day time with infrequent stops, and was rarely run
at night; therefore, the battery was continually charging but seldom
had an opportunity to discharge.
This erroneous impression is also closely interlinked with another
that is equally common and equally harmful. This is that one of
the functions of the battery cut-out is to break the circuit and prevent
the battery from becoming overcharged. It is hardly necessary
to add that this is not one of its functions, but that as long as the gen-
erator is being driven above a certain speed, the cut-out will keep the
battery in circuit, and the generator will continue to charge it. Its
only purpose is to prevent the battery from discharging itself through
the generator when the speed of the generator falls to a point where
its voltage would be overcome by that of the battery unless the
battery were automatically disconnected. The cut-out does not
protect the battery from being overcharged; only the driver or the
garage man can do that by noting the conditions under which the
car is operated and taking precautions to prevent the battery
from overcharging.
Gassing is simply an indication that too much current is being
sent into the battery. Another indication of the same condition
is the necessity for refilling the cells with distilled water at very
short intervals, as an excess charge raises the temperature of the
electrolyte and causes rapid losses by evaporation. That is the
reason why it is likely to be so harmful to the battery unless remedied,
as if allowed to exceed 110° F., the active material is likely to be forced
out of the grids, and the cells to be ruined. While it is essential
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ELECTRICAL EQUIPMENT 571
that the battery be fully charged at intervals and that it be always
kept well charged, continuously overcharging it is likely to be as
harmful as allowing it to Stand undercharged. Where the conditions
of service cannot be altered to remedy the trouble, the regulator
of the generator should be adjusted to lower the charging rate, or,
if nothing else will suffice, additional resistance, controlled by an
independent switch, may be inserted in the charging circuit. (The
U.S.L. system has a provision to safeguard the battery against
overcharge, termed the touring switch.)
Higher Charge Needed in Cold Weather. While the regulator
of the generator is set by the manufacturer to give the best average
results, and some makers warn the user against altering its adjustment,
experience has demonstrated that a fixed adjustment of the regulation
will not suffice for cars driven under all sorts of service conditions,
nor for the same car as used at different seasons of the year. The
efficiency of the storage battery is at its lowest in cold weather,
which is the time when the demand upon it is greatest. A battery
that would be constantly overcharged during the summer may not
get more than sufficient current to keep it properly charged in
winter, though driven under similar conditions in both seasons.
On the other hand, a battery that is generally undercharged under
summer conditions of driving will be practically useless in winter,
as it will not have sufficient current to meet the demands upon it.
It may be put down as a simple and definite rule that if the
battery of a starting system never reaches the gassing stage, it
is constantly undercharged and is rapidly losing its efficiency, as
the sulphate remaining on the plates becomes harder with age
and prevents the circulation of the electrolyte. Even when in the
best condition, the electrolyte cannot reach all of the active material
in the plates, so that any reduction means a serious falling off. Like-
wise, when a battery is constantly gassing, it is in a continuous
state of overcharge and is apt to be entirely ruined in a comparatively
short time. The danger from undercharging is known as sulphat-
ing — the plates, become covered with a hard coating of lead sulphate
that the electrolyte cannot penetrate — while that from overcharging
is due to the electrolyte and the plates reaching a dangerous tempera-
ture (105° F. or over) at which the active material is apt to be stripped
from the grids. The conditions of service, on the average, are such
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572 ELECTRICAL EQUIPMENT
that a battery can seldom be kept in good condition for any length
of time on the charging current from the generator alone.
The hydrometer should be used frequently to keep track of
its condition and, at least once a month, it should be given a long
conditioning, or equalizing, charge, as it is variously termed.
This charge is required because of the fact that, under ordinary
conditions, a battery seldom receives a complete charge and that
every time it is discharged without this being followed by a charge
which is prolonged until the electrolyte has reached its maximum
specific gravity, more lead sulphate accumulates in the plates. The
object of the long charge is to convert this lead sulphate into peroxide
of lead at the positive plate and into spongy metallic lead at the
negative plate, as explained further under the head of Sulphating.
Sulphating. At the end of a discharge, both sets of plates
are covered with lead sulphate. This conversion of the active material
of the plates into lead sulphate, which takes place during the discharge,
is a normal reaction and, as such, occasions no damage. But if the
cells are allowed to stand for any length of time in a discharged
condition, the sulphate not only continues to increase in bulk, but
becomes hard. It is also likely to turn white, so that white spots
on the plates of a battery when it is dismantled are an indication that
the cells have been neglected. In this condition, the plates have
lost their porosity to a certain extent and it is correspondingly
more difficult for the charging current to penetrate the active material.
When a battery has stood in a discharged condition for any length
of time, it becomes sulphated. The less current it has in it at the
time and the longer it stands, the more likely it is to be seriously
damaged.
Where a car is used but little in the daytime, and then only
for short runs with more or less frequent stops, the battery never
has an opportunity to become fully charged. The demands of the
starting motor and the lights are such that the battery is never
more than half charged at any time. Consequently, there is always
a certain proportion of the lead sulphate that is not reconverted,
but which remains constantly in the plates. As already mentioned,
this condition does not remain stationary; the sulphate increases
in amount and the older portions of it harden. This represents
a loss of capacity which finally reaches a point where the cells are
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ELECTRICAL EQUIPMENT 573
no longer capable of supplying sufficient current (holding enough
of the charge, as the owner usually puts it) to operate the starting
motor. A battery that has been operating under conditions of this
kind is not prepared for the winter's service, which accounts for
the great number of complaints about the poor service rendered
by starting systems in the early part of every winter. As long as
the weather is warm, the battery continues to supply sufficient
current in spite of the abuse to which it is subjected, but when
cold weather further reduces its efficiency, it is no longer able to
meet the demand.
The only method of preventing this and of remedying it after
it has occurred is the equalizing charge mentioned in the previous
section. Long continued and persistent charging at a low rate
will cure practically any condition of sulphate, the time necessary
being proportionate to the degree to which it has been allowed to
extend. It is entirely a question of time, and, as a high rate would
only produce gassing, which would be a disadvantage, the rate of
charge must be low. In case the cells show any signs of gassing,
the charge must be further reduced.
Extra Time Necessary for Charging. The additional length of
time necessary for charging a battery that has been constantly
kept in an undercharged condition is strikingly illustrated by the
following test made with an electric vehicle battery: The cells
were charged to the maximum, and the specific gravity regulated
to exactly 1.275 with the electrolyte just J inch above the tops of
the plates, this height being carefully marked. The battery was
then discharged and recharged to 1.265 at the normal rate in each
case. The specific gravity rose from 1.265 to 1.275 during the last
hour and a half of the charge. During the following twelve weeks,
the battery was charged and discharged daily, each charge being
only to 1.265, thus leaving 10 points of acid still in the plates. At
the end of the twelve weeks, the charge was continued to determine
the time required to regain the 10 points and thus restore the specific
gravity to the original 1.275. Eleven hours were needed, as compared
with the hour and half needed at first. This test further illustrates
why it is necessary to give a battery an occasional overcharge or
equalizing charge to prevent it becoming sulphated. Had the battery
in question been charged daily to its maximum of 1 .275 and discharged
195
574 ELECTRICAL EQUIPMENT
to the same extent during the twelve weeks, 9£ hours of the last
charge would have been saved. These periods of time, of course,
refer to the charging of the electric-vehicle battery, but they indicate
in a corresponding manner the loss of efficiency suffered by the start-
ing battery owing to its being continually kept in an undercharged
condition.
Restoring Sulphated Battery. There are only three ways in
which a battery may become sulphated: The first and most common
of these is that it has not been properly charged; second, excess
acid has been added to the electrolyte; third, an individual cell
may become sulphated through an internal short-circuit or by drying
out, as might be caused by failure to replace evaporation with
water, or failure to replace promptly a cracked jar. The foregoing
only holds good, however, where the sediment has not been allowed
to reach the bottom of the plates, and where the level of the electrolyte
has been properly maintained by replacing evaporation with
distilled water.
To determine whether a battery is sulphated or not — it having
been previously ascertained that it does not need cleaning (washing) —
it should be removed from the car (the generator should not be run
with the .battery off the car without complying with the manufac-
turer's instructions in each case, usually to short-circuit or bridge
certain terminals on the generator itself) and given an equalizing
charge at its normal rate. The normal rate will usually be found
on the name plate of the battery. If the battery begins to gas at
this rate, the rate must be reduced to prevent gassing, and lowered
further each time the cells gas. Frequent hydrometer readings should
be taken, and the charge should be continued as long as the specific
gravity continues to increase. A battery is sulphated only when there
is acid retained in the plates. When the specific gravity reaches
its maximum, it indicates that there is no more sulphate to be acted
upon, since, during the charge, the electrolyte receives acid from
no other source. With a badly sulphated battery, the charge should
be continued until there has been no further rise in the specific
gravity of any of the cells for a period of at least twelve hours. Main-
tain the level of the electrolyte at a constant height by adding pure
water after each test with the hydrometer (if water were added just
before taking readings, the water would rise to the top of the solution
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ELECTRICAL EQUIPMENT 575
and the reading would be valueless). With a battery on a long
charge, the battery thermometer should be used at intervals to check
the temperature of the electrolyte, and the hydrometer readings
should be corrected in accordance with the temperature.
Specific Gravity too High. Should the specific gravity of any
of the cells rise above 1.300, draw off the electrolyte down to the top
of the plates and put in as much distilled water as possible without
flooding the cell. Continue the charge and, if the specific gravity
again exceeds 1.300, this indicates that acid has been added during the
previous operation of the battery. The electrolyte should then be
emptied out and replaced with distilled water and the charge con-
tinued. The battery can only be considered as restored to efficient
working condition when there has been no rise in the specific gravity
of any of the cells during a period of at least twelve hours of continu-
ous charging.
Upon completion of the treatment, the specific gravity of the
electrolyte should be adjusted to its proper value of 1.280, using
distilled water or 1.300 acid, as necessary. In cases where one cell
has become sulphated while the balance of the battery is in good
condition, it is usually an indication that there is a short-circuit or
other internal trouble in the cell, though this does not necessarily
follow. To determine whether or not it is necessary to dismantle
the cell, it may first be subjected to a prolonged charge, as above
described. If its specific gravity rises to the usual maximum, the
condition may be considered as remedied without taking the cell
apart. It is the negative plate which requires the prolonged charge
necessary to restore a sulphated battery. When sulphated, the
active material is generally of light color and either hard and dense
or granular and gritty, being easily disintegrated. Unless actually
buckled or stripped of considerable of their active material, the
positive plates are unchanged in appearance and can be restored
to operative condition, though their life will be shortened by this
abuse. Sulphated plates of either type should be handled as little
as possible. By keeping close check with the hydrometer on the
condition of the starting battery and, where it is not being kept in
an overcharged condition constantly, giving it an equalizing charge
once a month, the charge being continued until the cells no longer
increase in specific gravity after a period of several hours, and the
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576 ELECTRICAL EQUIPMENT
reading of all the cells being within at least 25 points of each other,
sulphating may be avoided entirely.
Internal Damage. This trouble is usually caused by a short-
circuit, owing either to an accumulation of sediment reaching the
plates or to the breaking of a separator, which may be caused by the
active material being forced out of the grid, usually termed buckling,
which is caused by overheating. It is important to be able to deter-
mine whether or not the low efficiency of a certain cell is caused by
internal trouble without having to dismantle the cell. The repair
man's most important aid for this class of work is the high-grade
portable voltmeter mentioned in connection with other tests of the
starting and lighting system.
Voltage Tests. Under some conditions, the voltmeter will also
•indicate whether the battery is practically discharged or not, but,
like the hydrometer, it should not be relied upon alone. To insure
accuracy, it must be used in conjunction with the hydrometer.
Since a variation as low as .1 (one-tenth) volt makes considerable
difference in what the reading indicates regarding the condition of
the battery, it will be apparent that a cheap and inaccurate voltmeter
would be a detriment rather than an aid. The instrument illustrated
in connection with tests of other parts of starting and lighting systems
(see Delco) is of the type required for this service. Complete
instructions for its use will be received with the instrument, and these
must be followed very carefully to avoid injuring it. For example,
on the three-volt scale, but one cell should be tested; attempting
to test the voltage of more than one cell on this scale is apt to burn
out the three-volt coil in the meter. The total voltage of the number
of cells to be tested must never exceed the reading of the particular
scale being used at the time; otherwise, the coil of the scale in question
will suffer, and the burning out of one coil will make it necessary
to rebuild the entire instrument.
Clean Contacts Necessary. Where the voltage to be tested is
so low, a very slight increase in the resistance will affect it considerably
and thus destroy the accuracy of the reading. Make certain that
the place on the connector selected for the contact point is clean
and bright, and press the contact down on it firmly. To insure a
clean bright contact point, use a fine file on the lead connector.
The Contact will be improved by filing the test points fairly sharp.
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ELECTRICAL EQUIPMENT 577
Even a thin film of dirt or a weak contact will increase the resistance
to a point where the test is bound to be misleading. The positive
terminal of the voltmeter must be brought into contact with the posi-
tive terminal of the battery, and the negative terminal of the volt-
meter with the negative of the battery. If the markings of the cell
terminals are indistinct, connect the voltmeter across any one cell.
In case the pointer butts up against the stop at the left instead of
giving a reading, the connections are wrong and should be reversed;
if the instrument shows a reading for one cell, the positive terminal
of the voltmeter is in contact with the positive of the battery. This
test can be made with a voltmeter without any risk of short-circuiting
the cell, as the voltmeter is wound to a high resistance and will pass
very little current. Connecting an ammeter directly across a cell, how-
ever, would short-circuit it and instantly burn out the instrument.
How to Take Readings. It is one of the peculiarities of the
storage cell that when on "open circuit", i.e., not connected in
circuit with a load of any kind, it will always show approximately
two volts, regardless of whether it is almost fully charged or almost
the reverse. Consequently, voltage readings taken when the battery
is on open circuit, i.e., neither charging nor discharging, are valueless,
except when a cell is out of order. Therefore, a load should be put
on the battery before making these tests. This can be done by
switching on all the lamps. With the lights on, connect the volt-
meter, as already directed, and test the individual cells. If the
battery is in good condition, the voltage readings, after the load
has been on for about ten minutes, will be but slightly lower than
if the battery were on open circuit. This should amount to about
.1 (one-tenth) volt. Should one or more of the cells be completely
discharged, the voltage of these cells will drop rapidly when the
lamps are first switched on and, when a cell is out of order, will
sometimes show a reverse reading. Where the battery is nearly
discharged, the voltage of each cell will be considerably lower than
if the battery were on open circuit, after the load has been on for
five minutes.
Detecting Deranged Cells. To distinguish the difference between
cells that are merely discharged and those that are out of order,
put the battery on charge, either from an outside source or
by starting the engine, which should always be cranked by hand
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578 ELECTRICAL EQUIPMENT
when any battery trouble is suspected. Then test again with the
voltmeter. If the voltage of each cell does not rise to approximately
two volts after the battery has been on charge for ten minutes or
more, it is an indication of internal trouble which can be remedied
only by dismantling the cell. (See instructions under that heading.)
Temperature Variations in Voltage Test When making voltage
tests, it must be borne in mind that the voltage of a cold battery rises
slightly above normal on charge and falls below normal on discharge.
The reverse is true of a warm battery in hot weather, i.e., the voltage
will be slightly less than normal on charge and higher than normal
on discharge. As explained in connection with hydrometer tests
of the electrolyte, the normal temperature of the electrolyte may
be regarded as 70° F., but this refers only to the temperature of
the liquid itself as shown by the battery thermometer, and not to
the temperature of the surrounding air. For the purpose of simple
tests for condition, voltage readings on discharge are preferable,
as variations in readings on charge mean little except to one expe-
rienced in the handling of storage batteries.
Joint Hydrometer and Voltmeter Tests. As already explained
above, neither the hydrometer nor the voltmeter reading alone
can always be taken as conclusive evidence of the condition of the
battery. There are conditions under which one must be supple-
mented by the other to obtain an accurate indication of the state
of the battery. In making any of the joint tests described below,
it is important to take into consideration the four points following:
(1) The effect of temperature on both voltage and hydrometer
readings.
(2) Voltage readings should be taken only with the battery
discharging, as voltage readings on an idle battery in good condition
indicate little or nothing.
(3) Never attempt to use the starting motor to supply a
discharge load for the battery, because the discharge rate of the
battery is so high while the starting motor is being used that even
in a fully charged battery it will cause the voltage to drop rapidly.
(4) The voltage of the charging current will cause the voltage
of a battery in good condition to rise to normal or above the moment
it is placed on charge, so that readings taken under such circumstances
are not a good indication of the condition of the battery.
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ELECTRICAL EQUIPMENT 579
In any battery which is in good condition, the voltage of each
cell at a normally low discharge rate, i.e., 5 to 10 amperes for a starter
battery of the 6-volt type or slightly less for a higher voltage battery,
will remain between 2.1 and 1.9 volts per cell until it begins to
approach the discharged condition. A voltage of less than 1.9 volts
per cell indicates either that the battery is nearly discharged or is
in a bad condition. The same state is also indicated when the
voltage drops rapidly after the load has been on for a few minutes.
The following joint hydrometer and voltmeter tests issued by the
Prest-O-Lite Company of Indianapolis will be found to cover
the majority of cases met with in actual practice.
(1) A voltage of 2 to 2.2 volts per cell with a hydrometer reading of 1.275
to 1.300 indicates that the battery is fully charged and in good condition.
(2) A voltage reading of less than 1.9 volts per cell, with a hydrometer
reading of 1.200 or less indicates that the battery is almost completely discharged.
(3) A voltage reading of 1.9 volts or less per cell, with a hydrometer
reading of 1.220 or more, indicates that excess acid has been added to the cell.
Under these conditions, lights will burn dimly, although the hydrometer reading
alone would appear to indicate that the battery was more than half charged.
(4) Regardless of voltage — high, low, or normal — any hydrometer reading
of over 1.300 indicates that an excessive amount of acid has been added.
(5) Where a low voltage reading is found, as mentioned in cases 2 and
3, to determine whether the battery is in bad order or merely discharged, stop
the discharge by switching off the load, and put the battery on charge, cranking
the engine by hand, and note whether the voltage of each cell rises promptly to
2 volts or more. Jf not, the cell is probably short-circuited or otherwise in bad
condition.
Cleaning a Battery. Electric vehicle batteries usually receive
such carefid and intelligent attention that the life of the battery
is measured by the maximum number of charges and discharges of
which the plates are capable under favorable conditions. To prevent
any possibility of short-circuiting, a cell is cut out and opened after
a certain number of discharges, and if the amount of sediment in
the jar is approaching the danger point, the entire battery is opened
and cleaned. With the old type starter cell, this would be necessary
if the battery received the proper attention; with the modern or
high mud-space type, cleaning is never necessary as the space is
designed to accommodate all the active material that can fall from
the plates without touching their under sides. As a matter of fact,
the batteries of starting and lighting systems never last long enough
to require cleaning out. They are either kept undercharged and
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580 ELECTRICAL EQUIPMENT
thus become badly sulphated, or they are overcharged to a point
where the temperature passes the danger mark frequently. When
hot, the acid attacks and injures the wood separators so that the
average life is about one year. Exceptions to this are found in
those cases where the battery has been given proper attention,
which results in unusually long life without the necessity of opening
the cells for either cleaning or the insertion of new separators. These
cases are so in the minority, however, that the battery manufacturers
usually recommend that the car owner have his starting battery
overhauled in the fall to put it in the best of condition for the winter
as well as for the following year. Even where a battery has been
Fig. 387. Drilling Off Connectors
Courtesy of Electric Storage Battery Company, Philadelphia, Pennsylvania
given conscientious attention, the conditions of charging on the
automobile are likely to vary so radically that it will be found almost
impossible to keep the cells in a good state. Consequently, it is
considered the best practice to give all starter batteries an over-
hauling once a year. The method of doing this is described in
succeeding sections.
Replacing a Jar. When a cell requires the addition of distilled
water more often than the other cells of the battery, or does not
test to the* same specific gravity as the others, it is usually an indica-
tion that there is a leak in the jar. Failure to give the same specific-
gravity reading is not proof of this condition, as the cell may be
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ELECTRICAL EQUIPMENT, 581
low from other causes, but the loss of electrolyte is certain evidence
of it. The only remedy is to replace the jar at fault.
After locating the cell in question, carefully mark the connectors
so as to be sure to replace them the same way. Disconnect the
cell from the others in the battery. This may be done either with
the aid of brace and bit, which is used to drill down through the
post of the connector, Fig. 387, or with a gasoline torch which should
be applied carefully to the strap at the post. When the metal has
become molten, pry the strap up on the post with a piece of wood.
Do not use a screwdriver or other metal for this purpose as it is
apt to short-circuit one or more of the cells. Care must also be
taken not to apply so much heat that the post itself will be melted as
this would make it difficult to reconnect the cell. For one not
accustomed to handling the
torch, it will be safer to drill out
the post, as illustrated. Lift the
complete cell out of the battery
box and then use the torch to
warm the jar around the top
to soften the sealing compound
that holds the cover, Fig. 388.
Grip the jar between the feet,
take hold of the two connectors
and pull the element almost out
of the jar, Fig. 389. Then grip
J ' ° ii Fig. 388. Softening Sealing Compound on Cell
the elements near the bottom
to prevent the plates flaring out while transferring them to the new
jar, taking care not to let the outside plates start down the outside
of the jar, Fig. 390. After the element is in the new jar, reseal the
cell by pressing the sealing compound into place with a hot putty
knife. Fill the cell with 1.250 electrolyte to the proper point, the
old electrolyte being discarded.
Before replacing the connectors, clean both the post and the
inside of the eye of the connector by scraping them smooth with
a knife. When the connector has been placed in position, tap it
down firmly over the post to insure good contact. To complete
the connection, melt the lead of the connector and the post at the
top so that they will run together, and while the lead is still molten,
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582 ELECTRICAL EQUIPMENT
melt in some more lead until the eye of the connector is filled level.
This is termed lead burning and is described at greater length in
a succeeding section. Where no facilities are at hand for carrying
it out, it may be done with an ordinary soldering copper. The
copper is brought to a red heat so that all the tinning is burned
off, and no flux of any kind is used. The method of handling the
soldering copper and the lead-burning strip to supply the extra
metal required to fill the eye is shown in Fig. 391.
Fig. 389. Lifting Elements out of Jar Fig. 390. Installing Elements
by Hand in Jar
Courtesy of Electric Storage Battery Company, Philadelphia, Pennsylvania
Put the battery on charge from an outside source, and when
the cells begin to gas freely, reduce the current to half the finishing
rate given on the battery name plate and charge at this rate as long
as there is any rise in the specific gravity of the electrolyte in
this or any of the other cells. The maximum gravity has been
reached when there has been no rise in the specific gravity for a
period of three hours. If the gravity of the cell having the new jar
is then over 1.280, draw off some of the electrolyte and replace it
with distilled water. If the gravity is below 1.270, draw off some of
the electrolyte and replace it with 1.300 electrolyte. If necessary
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ELECTRICAL EQUIPMENT 583
to put in 1.300 electrolyte, allow the battery to continue charging
for about one-half hour longer at a rate sufficient to cause gassing,
which will cause the stronger acid to become thoroughly mixed with
the rest of the electrolyte in the cell.
Overhauling the Battery. As already mentioned, it j will be
found desirable to overhaul the majority of starter batteries at
least once a year. The expense to the car owner will be less than
Fig. 391. Reburning Battery Connectors with Soldering Iron
Courtesy of Electric Storage Battery Company, Philadelphia, Pennsylvania
the cost of the frequent attention required by a run-down battery
with complete renewal at no distant date, and the service rendered
by the battery will be much improved. The best time of year to
do this is in the late fall, so that the battery may be at its best during
the cold weather. Before undertaking the work, have on hand a
complete renewal set of rubber and wood separators as well as suf-
ficient fresh add of 1.300 specific gravity with which to mix fresh
electrolyte. Use the good separators, particularly the rubber ones.
205
5&4 ELECTRICAL EQUIPMENT
Dismounting Cells. Remove the connectors by drilling, heating,
or pulling (in the same manner as a wheel is pulled), and loosen
the jar covers by heating or running a hot putty knife around their
edges so that they may be lifted off. The covers should be washed
in hot water and then stacked one on top of the other with heavy
weight on them to press them flat. Lift the jars out of the battery
box and note whether any of them have been leaking. A cracked
jar should of course be replaced. Treat one cell at a time, by
pulling the element out of the jar with the aid of the pliers, meanwhile
holding the jar with the feet. Lay the element on the bench and
Fig. 392. Removing Old Separators Fig. 393. Pressing Negative Group
from Elements
Courtesy of Electric Storage Battery Company, Philadeiphia, Pennsylvania
spread the plates slightly to permit removing the separators, taking
care not to injure the rubber sheets, Fig. 392. Separate the positive
group from the negative. If the active material of the negative
be swollen beyond the surface of the grid, press it back into position
before it has a chance to dry, placing boards of suitable thickness
between the plates and carefully squeezing the group between heavy
boards in a vise or press, as shown in Fig. 393. Boards of sufficient
size and thickness must be used between the plates or breakage
will result. Charged negative plates will become hot in a short
time when exposed to the air and, in this event, should be allowed
to cool before reassembling. Remove any loose particles adhering
206
ELECTRICAL EQUIPMENT 585
to the positive plates by passing a smooth wood paddle over the
surface but do not wash the positive plates. •
Treating the Plates. If the positive plates show signs of buckling
or stripping of the active matter, or if the negative plates have the
light spotted appearance indicative of sulphating, it may be necessary
to replace them altogether. In case sulphating appears to be the
only trouble, the groups should be reassembled in an open jar with
distilled water and given a long, slow charge, testing with the hydrom-
eter at frequent intervals to note whether the specific gravity is
rising or not. Twenty-four hours
or more may be necessary for
this charge, and two or three days
will be nothing unusual. This
charging, of course, is carried on
from the lighting mains through
a rectifier or a motor-generator,
unless direct-current service is
available. If it is necessary to
prolong the charge over t\yo or
three days, and the specific grav-
ity still continues to rise slowly,
it may be preferable to replace
the plates.
Reassembling Battery. Wash
all the sediment out of the jars,
also wash and. save the rubber
sheets, unless thev happen to be
. J "^ Fig. 394. Wood and Rubber Separator
broken, but throw away the old
wood separators. The rubber sheets should be placed in clean
running water for about a quarter of an hour. Reassemble the
positive and negative groups with the plates on edge in order to
insert the separators. Place a rubber separator against the grooved
side of a wood separator, Fig. 394, and insert a positive plate near
the center of the element. The rubber sheet must be against the
positive plate, and the wood separator against the negative plate.
In this manner insert separators in all the spaces, working in both
directions from the center. Care must be taken not to omit a sepa-
rator as that would short-circuit the cell.
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586 ELECTRICAL EQUIPMENT
The separators should be practically flush with the bottoms of
the plates to bring their tops against the hold-down below the strap,
and must extend to or beyond the side edge of the plates. Grip
the element near the bottom to prevent the plates flaring out while
placing the element in the jar. Fill the cell to within one-half inch
of the top of the jar, using electrolyte of 1.250 specific gravity. If
the negative plates show signs of sulphating, but not enough to call
for the special treatment mentioned above, use water instead of the
electrolyte. After all of the cells have been given the same treatment
and reassembled, return them to the battery box in their proper
positions, so that the positive of each cell will be connected to the
negative of the adjoining cell and connect temporarily by pressing
the old connecting straps in place by hand.
Checking the Connections. Put the battery on charge at its
finishing rate (usually about 5 amperes) and, after charging about
fifteen minutes, note the voltage of each cell. This is to insure
having reconnected the cells properly with regard to their polarity.
If this be the case, they should all read approximately 2 volts. Any
cell that reads less is likely to have been connected backward. When
the cells begin to gas freely and uniformly, take a hydrometer reading
of each cell and a temperature reading of one of them. Reduce the
current to one-half the finishing rate. Should the temperature of
the electrolyte reach 100° F., reduce the charge, or interrupt it
temporarily, to prevent the cells getting any hotter. Both hydrometer
and temperature readings must be taken at regular intervals, say
four to six hours apart, to determine if the specific gravity is still
rising or if it has reached its maximum. Continue the charge and
the readings until there has been no further rise for a period of at
least twelve hours. Maintain the height of the electrolyte constant
by adding water after each reading. (If water were added before
the reading, it would not have time to mix with the electrolyte,
and the reading would not be correct.)
Should the specific gravity rise to about 1.300 in any cell, draw
off the electrolyte down to the level of the tops of the plates and
refill with as much water as possible without overflowing. Continue
the charge, and if the specific gravity again exceeds 1.300, dump
out all the electrolyte in that cell, replace it with water, and continue
the charge. The charge can be considered complete only when
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ELECTRICAL EQUIPMENT
587
Fig. 395. Wiring Diagram for Discharging
Battery through Rheostat
there has been no rise in the gravity of any of the cells during a period
of at least twelve hours of continuous charging. Upon completion
of the charge, the electrolyte
should have its specific gravity
adjusted to its proper value
(1.270 to 1.280) using water
or 1.300 acid, as may be nec-
essary, and the level of the
electrolyte adjusted to a uni-
form \ inch above the plates.
Discharge the battery at
its normal discharge rate to
determine if there are any
low cells caused by defective
assembly. The normal dis-
charge rate of the battery is
usually given on its name
plate. To discharge the bat-
tery, the current may be
passed through a rheostat, as
in Fig. 395, or if no panel
board of this type be avail-
able, through a water resist-
ance, as shown in Fig. 396.
The resistance of a water rheo-
stat increases with the disr
tance between its plates and
decreases according to their
proximity and to the degree
of conductivity of the water
itself. If the resistance is
too high with the plates close
together, add a little acid to
the water. It will be neces-
sary, of course, to have an
ammeter in the circuit to show the rate at which the battery is
discharging. In case any of the cells are low, owing to being assem-
bled defectively or connected with their polarity reversed, as shown
Fig. 396. Wiring Diagram for Discharging
Battery through Water Resistance
209
?lc —
588 ELECTRICAL EQUIPMENT
by the voltmeter test (they should all register two volts or slightly
over at the beginning of the discharge and should fall off slowly) such
cells should be remedied at once. Recharge the battery and then
remove the temporary connectors, wipe the inside edges of the jars
dry, and put the rubber covers in place. Heat the sealing compound
which is supplied for this purpose and apply around the edges of the
covers, smoothing it down with a hot putty knife. Care must be
taken not to burn the sealing compound when heating it.^
Reconnecting Cells. If the old lead connecting straps have been
removed carefully, they may be used again, though in many cases
it will be found preferable to employ new straps. Before putting
the straps in place, scrape the posts clean with a knife and clean
out the eyes of the straps themselves. When the connectors have
been put in place, tap them down firmly to insure good contact.
Before reburning the connectors in place, test each cell with a low-
reading voltmeter to make certain: that the cells have been connected
in the right direction, i.e., that their polarity has not been reversed.
It is not sufficient to note that the voltage of each cell is correct,
i.e., 2 volts per cell or over, but care must be taken also to note that
it is in the right direction. With a voltmeter having a needle that
moves in both directions from zero, one polarity will be evidenced
by the needle moving over the scale to the right of the neutral line,
while if the polarity be reversed, the needle will move to the left.
One cell having the proper polarity should accordingly be tested
and then, to be correct, the remaining cells should cause the needle
to move in the same direction and to approximate the same voltage
when the instrument leads are held to the same terminals in the
same way for each. Where the voltmeter needle can move in but
one direction, i.e., to the right, a change of polarity will be indicated
by the needle of the instrument attempting to move to the left
and, in so doing, butting up against the stop provided to prevent
this. Complete the reassembly of the cells by burning the connectors
together, as detailed under the head of Lead Burning.
Renewals. In many cases it will be found necessary upon
overhauling a battery to renew the elements. These may be purchased
either as loose plates or as groups ready to assemble in the battery.
Except in garages doing a large amount of this work, it will not
be advisable to buy the loose plates and burn them into groups.
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ELECTRICAL EQUIPMENT , 589
The new groups should be assembled with rubber sheets and wood
separators, as directed in overhauling the battery, the jars filled
with fresh electrolyte of the proper specific gravity and the battery
given a test charge and discharge with temporary connections. The
electrolyte should be of 1.250 specific gravity, or seven parts of
water to two of pure sulphuric acid by volume. If the test charge
has been carried to a point where the specific gravity has ceased to
rise for several hours, and the discharge shows no defectively
assembled cells, the cells may be permanently connected.
Lead Burning. Type of Outfit. In the manufacture of storage
batteries, and in garages where a large number of batteries are
Fig. 397. Arc-Welding Outfit for Burning Connections
maintained, a hydrogen-gas apparatus is employed for this purpose.
For the electric-car owner or the garage doing a comparatively small
amount of battery repair work, the Electric Storage Battery Com-
pany has placed an arc lead-burning outfit on the market. This
is low in first cost and, with a little practice, good results can be
obtained with it. As the battery itself supplies the power neces-
sary, the only material required is the lead in the form of a flexible
strip or heavy wire. The complete outfit is illustrated in Fig. 397.
At one end is the clamp for making electrical connection, while at
the other is a clamp of different form having an insulated handle
and holding a one-fourth inch carbon rod. The two are electrically
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590 . ELECTRICAL EQUIPMENT
connected by a flexible cable. This simple outfit can be employed
in two ways, the second being preferable for the beginner, at least
until sufficient amount of skill has been acquired to use the arc
without danger of melting the straps.
First Method of Burning. In the first method, a potential of
from 28 to 30 volts (12 to 15 cells) is required.* The clamp should,
therefore, be fastened to the positive pole of the twelfth to the
fifteenth cell away from the joint to be burned, counting toward the
negative terminal of the battery. The carbon then forms the negative
terminal of the circuit. Otherwise particles of carbon will be carried
into the joint, as the carbon rod quickly disintegrates when it forms
the positive pole. The carbon should project 3 or 4 inches from the
holder. The surfaces of the parts to be burned should be scraped
clean and bright, and small pieces of clean lead about J to \ inch
square provided for filling the joint. The carbon is then touched to
the strap to be burned and immediately withdrawn, forming an
electric arc which melts the lead very rapidly. By moving the carbon
back and forth the arc is made to travel over the joint as desired, the
small pieces of lead being dropped in to fill the gap as required.
Owing to the high temperature generated, the work must be carried
out very quickly, otherwise the whole strap is liable to melt and run.
As this method is difficult and requires practice to secure good
results, the beginner should try his hand on some scrap pieces of
lead before attempting to operate on a cell. Its advantages are
that when properly carried out it takes but a short time to do the
work, and the result is a neat and workmanlike joint. It is extremely
hard on the eyes and smoked or colored glasses must be used.
Second Method of Burning. The second method, utilizing the
hot point of the carbon rod instead of the arc, is recommended for
general practice. Scrape the parts to be joined and connect the
clamp between the third and fourth cells from the joint. With this
method it is not necessary to determine the polarity of the carbon.
The latter is simply touched to the joint and held there; on account
of the heavy flow of current it rapidly becomes red and then white
hot. By moving it around and always keeping it in contact with
the metal, the joint can be puddled. To supply lead to fill the joint,
♦This voltage may be obtained from an electric vehicle battery in the garage or from the
lighting mains through a suitable resistance, first converting to direct current where the supply
is alternating.
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ELECTRICAL EQUIPMENT 591
an ordinary lead-burning strip can be used, simply introducing the
end into the puddle of molten lead, touching the hot carbon. The
carbon projecting out of the holder should be only one inch, or even
less, in length. After the joint has been made, it can be smoothed
off by running the carbon over it a second time.
Use of Forms to Cover Joint. In joining a strap which has been
cut in the center, it is best to make a form around the strap by means
of a piece of asbestos sheeting soaked in water and fastened around
the strap in the shape of a cup, which will prevent the lead from
running down. It will be found that sheet asbestos paper is thick
enough, but it should be fairly wet when applied. By this means a
neat joint can be easily made. The asbestos will adhere very tightly
to the metal owing to the heat, but can be removed by wetting it
again. When burning a pillar post to a strap, a form may be made
around the end of the strap in the same manner, though this is not
necessary if reasonable care is used. Two or three pieces of ^-inch
strap iron about one inch wide, and some iron nuts about one inch
square $re also of service in making the joint, the strap iron to
be used under the joints, and the nuts at the side or ends to confine
the molten lead. Clay can also be used in place of asbestos, wetting
it to a stiff paste. As the holder is liable to become so hot from
constant use as to damage the insulation, besides making it uncom-
fortable to hold, a pail of water should be handy, and the carbon
dipped into it from time to time. This will not affect its operation
in any way, as the carbon becomes hot again immediately the current
passes through it.
Illuminating Gas Outfit. Heretofore it has not been possible to
do good work in lead burning with illuminating gas, but a special
type of burner has recently been perfected by the Electric Storage
Battery Company, which permits the use of illuminating gas with
satisfactory results. The outfit consists of a special burning tip and
mixing valve. Sufficient A-inch rubber hose should be provided, and
the rubber should be wired firmly to the corrugated connections, Fig.
398, as the air is used at a comparatively high pressure. A supply of
compressed air is necessary, the proper pressure ranging from 5 to 10
pounds, depending upon the length of hose and the size of the parts to
be burned. When air from a compressor used for pumping tires is
utilized for this purpose, a suitable reducing valve must be introduced
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592 ELECTRICAL EQUIPMENT
in the supply line. This outfit is designed for use with ordinary
illuminating gas and cannot be employed with natural gas.
Connect the air hose to the right-hand cock and the gas hose to
the left-hand cock. The leader hose, about five or six feet long, is
connected to the lower pipe and to the upper end of the burning tip.
When the air pressure at the source is properly adjusted, close the
air cock and turn the gas cock on full. Light the gas at the tip and
turn on the air. If the flame blows out, reduce the air pressure,
preferably at the source. With the gas turned on full, the flame
Fig. 398. Lead-Burning Outfit for Use with Illuminating Gas
Courtesy of Electric Storage Battery Company,
Philadelphia, Pennsylvania
will have a ragged appearance and show a waist about \ inch from
the end of the tip, the flame converging there and spreading out
beyond. Such a flame is not good for lead burning.
Slowly turn the gas off until the outer portion at the waist
breaks and spreads with an inner tongue of flame issuing through the
outer ring. The flame will now have a greenish color and is properly
adjusted for burning. If the gas is turned off further or if too much
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ELECTRICAL EQUIPMENT 593
air is turned on, the flame assumes a blue color gradually becoming
invisible and is then deficient in heating power. When properly
adjusted, the hottest part of the flame is just past the end of the inner
point. Do not hold the flame too close to the work when burning,
as its heating effect is greatly reduced and the flame is spread so as to
make control difficult. The burning tip has at its lower end an
outer sleeve and lock nut; this sleeve can be taken off in case any
of the holes in the tip become clogged. The position of this sleeve
is adjustable, the best position varying with the pressure of the
flame, and it should be determined by experiment.
Hydrogen Gas Outfit. Hydrogen gas gives a hotter flame and
therefore permits of more rapid work, so that where burning is done
on a large scale, it is still preferred. The essentials of such an outfit
are: first, a hydrogen generator; second, a method of producing air
pressure at approximately 2 pounds to the square inch; and third,
the usual pipe and tips for burning. If hydrogen gas is purchased in a
tank and compressed air is available, only the blowpipe, tips, and a
reducing valve on the air line are necessary. This is an expensive
method to purchase hydrogen, however, so that it is usually generated,
and a water bottle is needed between the generator and the blowpipe
to wash the gas and to prevent the flame from traveling back to the
generator.
For this purpose hydrogen gas is generated by placing zinc in a
sulphuric-acid solution. The generator usually employed for vehicle-
battery burning requires 50 pounds of zinc, 2 gallons of sulphuric
acid, and 9 gallons of water for a charge. Where no compressed-air
supply is available, an air pump and an air tank for equalizing the
pressure must be used. An outfit of this kind is shown in Fig. 399.
In preparing the generator for use, connect up as shown in this cut,
taking care that the hose from the generator is connected to the
nipple of the water bottle L. Have the water bottle one-half to
two-thirds full and immerse it in a pail of cold water up to its neck.
Replace the water in the pail whenever it becomes warm. Have stop
cock N closed. Put the required amount of zinc, which has been
broken into pieces small enough to pass through the opening C,
into the lower reservoir. Put on cap X and screw down with clamp D,
being sure that the rubber drainage stopper H is well secured in
place. Pour the proper amount of water into reservoir A and then
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594 ELECTRICAL EQUIPMENT
pour in the acid, taking care to avoid splashing. Always pour the
water in first.
In running the hose from K to N, arrange it so that there will
be ho low points for the water of condensation to collect in; in other
words, this hose should drain back at every point to the water bottle.
If, however, water should collect in the hose to such an extent as to
interfere with the flame and it cannot readily be drained off, kink the
hose between T and U and detach it from K; close the stop cock at
W and pump until a strong pressure is obtained in the tank; then close
Fig. 393. Diagram of Lead-Burning Outfit, Using Hydrogen Gas
the cock at V, opening those at S and N and, finally, quickly open W;
the pressure in the air tank will then force the water out of the hose.
The length of the hose from T to U should be such that the mixing
cocks at S and N are always within easy reach of the man handling
the flame.
In preparing the flame for burning, close the air cock at S and
open N wide, hold a match to the gas until it lights, then add air
and adjust the gas cock slowly, turning toward the closed position
until the flame, when tried on a piece of lead, melts the metal and
leaves a clean surface. The tip to be uSed depends on the work, but
most vehicle-battery work is done with the medium tip. Replenish
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ELECTRICAL EQUIPMENT 595
the zinc every few days, keeping it up to the required amount. When
a charge is exhausted or the generator is to be laid up for the night,
the old solution should be drawn off before making up a new charge
and the generator thoroughly flushed out by running water through A.
The new charge should not be put in until the generator is to be used
again. To empty the generator, first pull off the hose at the nipple
K, then at E, and finally the rubber plug at H. Care shou d be
taken not to allow the solution to splash on anything and not to
dump the generator where the contents will damage cement, asphalt,
or wood walks.
Installing New Battery. In not a few instances, it will be neces-
sary to renew the entire battery. As received from the manufacturer,
the battery is in a charged condition, i.e., it was fully charged just
previous to being shipped, but it must be inspected and tested before
being installed on the car. Care must be taken in unpacking it to
avoid spilling any of the electrolyte. After cleaning off the packing
from the tops of the cells, take out the rubber plugs and see that the
electrolyte is \ inch over the plates. If it is uniformly or approxi-
mately below the proper level in all the cells, this is simply the loss
due to evaporation. But if low in only one or two cells, this is
evidently caused by loss of electrolyte. In case this loss has resulted
from the case being turned over in shipment, it will be indicated
by the presence of acid on the packing on top of the battery (the
acid does not evaporate), and some of the electrolyte will have
been lost from all the cells. Replace the amount lost by refilling the
cells with electrolyte of 1.250 specific gravity, as already directed.
In case the loss of electrolyte is caused by a cracked or broken
jar, the packing under the battery will be wet. Replace the broken
jar as instructed in the directions under that heading and add sufficient
electrolyte of 1.250 specific gravity to make up for the loss. Should
it be found, after replacing the broken jar and giving the battery
an equalizing charge, that the specific gravity does not reach approxi-
mately 1.275, it is due to not having replaced the same amount of
acid as was spilled. To adjust this, draw off the electrolyte from
the cell with the syringe and add water or 1.300 acid to bring the
specific gravity to between 1.270 and 1.280.
Storing a Battery. There is an amusingly erroneous idea
prevalent to some extent that the charge of a storage battery is
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Y
596 ELECTRICAL EQUIPMENT
represented by its electrolyte; that pouring off the electrolyte takes
the charge with it; that, in case it is desired to store a battery,
all that is necessary is to pour off the electrolyte and store the empty
battery and the solution separately; and when it is desired to put
the battery back in commission, it is then only necessary to pour
the electrolyte back into the cells and, presto! they are ready to
start the engine right away. Unfortunately for this theory, the charge
is in the active material of the plates and not in the electrolyte.
It is frequently necessary to allow the battery to remain idle
for a considerable length of time, in which case it should he put
out of commission. If the battery itself is in good condition at
the time and if it may be wanted for service again at short notice,
this need only consist of giving it a long equalizing charge until
the specific gravity has ceased to rise for several hours, then filling
the cells to the top with distilled water and puttfng the battery away
in a handy place. It should be given a freshening charge every
two weeks or, at least, as often as once a month. If it is actually
' to be stored, there are two ways of doing this.
One is known as the wet storage method, and the other as
the dry, the one to be adopted depending upon the condition of the
battery and the length of time it is to be out of commission. The
wet storage method is usually applied to any battery that is to be
out of commission less than a year, provided that it will not soon
require repairs necessitating dismantling it. The dry storage method
is used for any battery that is to be out of commission for more than
a year, regardless of its condition, and it is also applied to any battery
that will shortly require repairs necessitating its dismantling. It
will be apparent that this last-named class includes most starter
batteries after they have seen several months of service, so that the
majority can be placed in dry storage when necessary to put them
out of commission.
Examine the condition of the plates and the separators and
also the amount of sediment in the bottom of the jars. If it is found
that there is very little sediment and the plates and separators are
in sufficiently good condition to give considerable additional service,
the battery may be put into wet storage by giving it an equalizing
charge and covering it to exclude dust. Replace evaporation
periodically to maintain the level of the electrolyte \ inch above the
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ELECTRICAL EQUIPMENT 597
tops of the plates. At least once every four months, charge the
battery at one-half its normal finishing rate (see name plate on
battery box) until all the cells have gassed continuously for at least
three hours. Any cells not gassing should be examined, and the
trouble remedied.
When examination shows that the battery will soon require
dismantling, it should be put into dry storage. Dismantle the cells
in accordance with the instructions already given. If the positive
plates show much wear, they should be scrapped; if not, remove
any loose particles adhering to them by passing a smooth wood
paddle over the surface, but do not wash the positive plates. Charged
negative plates will become hot in a short time when exposed to
the air. They should be allowed to stand in the air until cooled.
Empty all the electrolyte out of the jars into a glass or glazed
earthenware jar or a lead-lined tank and save it for giving the negative
plates their final treatment before storage. Wash all the sediment
out of the jars and wash the rubber separators carefully, then dry
them and tie them in bundles. Place the positive groups together
in pair*, put them in the jars, and store them away. Then put the
negati /e groups together in the same way, place them in the remaining
jars, and cover them with the electrolyte saved for the purpose,
allowing them to stand in it for five hours, at least. Then pour off
the electrolyte, which may now be discarded, and store away the
jars containing the negatives. If the negative plates show any
bulging of the active material, they should be subjected to the pressing
treatment first, using boards and a vise, as described in a previous
section. All of the. jars should be well covered to exclude dust.
Make a memorandum of the amount of material required to
reassemble the battery, and, when ordering this, provide for extra
jars and covers, extra rubber separators, and an entire lot of wood
separators with a sufficient excess to take care of breakage in handling.
Unless the old connectors were carefully removed, order a new set.
When a battery is put in storage, it is well to advise the owner in
regard to the material necessary to reassemble, and to request at least
a month's notice to procure it.
Charging from Outside Source. Theoretically at least, the
starter battery on the automobile should be kept in an ideal condition.
It is constantly under charge while the car is running at anything
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. 598 ELECTRICAL EQUIPMENT
except the lowest starting speeds and should accordingly always
be fully charged. The generator is designed to take care. of the
storage battery and usually has sufficient capacity to light all the
lamps in addition. Practice, however, does not bear out this
theoretical view of the favorable conditions under which the starter
battery is supposed to operate. It will be apparent at the very
* outset that the method of charging and discharging is not beneficial.
To insure long life to a storage battery, it should be fully charged
and then discharged to at least seventy-five per cent of its maximum
capacity before recharging. It should never be allowed to stand
discharged for any length of time. If exhausted, it should be
recharged immediately. It should not be charged to half its capacity
and then discharged. It should not be overcharged to the point
where it continues to gas violently nor where its temperature exceeds
100° F.
All of these are things that should not be done to the storage
battery, but it will take only a little experience to enable the garage
man to recognize that all these are things which are constantly being
done to the majority of storage batteries on gasoline automobiles.
Most batteries receive treatment that reaches one extreme or the
other, though it will be apparent that the middle course is almost
as injurious to the battery. Either a battery is constantly kept
undercharged so that it has insufficient charge to spin the engine
more than once, and its operation is accordingly unsatisfactory, or
it is constantly kept overcharged with the result that the hot acid
makes comparatively short work of the plates, and they must be
renewed in considerably less than a year of service. The mean course
between these two is found in the case of the battery that is only
charged to about half its capacity before being discharged again by
the use of the starting motor. This treatment results in sulphating.
To keep the storage battery of the starting system in anything
like efficient operating condition, it cannot be left on the running
board with nothing but the generator of the starting and lighting
system to charge it. Hydrometer and voltage tests will be valueless
unless the conditions they indicate are remedied, and this cannot
be done with the car generator as the sole source of charging current.
Here is a typical instance: The battery is in good condition and it
is fully charged. On a cold morning, it is drawn on intermittently
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ELECTRICAL EQUIPMENT 599
for almost fifteen minutes by the starting motor before the engine
fires. As a result, it is practically discharged. The car is driven only
a few miles, stopped and after a rest started again. What charge
the battery received by the short run is again lost. The car is run
for a little longer time and returned to the garage. The battery
has received about one-fourth its normal charge. It stands this
way for several days.
The weather being warmer, the engine starts in a much shorter
time, but not before the starting motor has exhausted the small
amount of charge in the battery. It is not run enough that day to
charge the battery nor when taken out again that night, as all the
lights are switched on, and under such conditions the battery receives
very little current. Multiply this treatment by five or ten repre-
senting the number of days the car is driven during the month.
At the end of that time, the battery no longer has sufficient charge
to operate the starting motor at all and is condemned, as usual,
by the car owner as being worthless. This is only one instance of
many that are so similar that a few changes in detail would cover
them alL No battery ever made could possibly operate efficiently
under such conditions. After the car in question had been used a
few days, a hydrometer test of the battery would have indicated
its need of charging.
Equalizing Charges Necessary. Even where a battery receives
almost 100 per cent of its normal charge before being discharged again,
there will be numerous occasions on which the charge is not carried
to completion. As mentioned under the head of Sulphating,
that means so much acid left in the plates at the end of the charge.
That acid represents lead sulphate which continues to increase in
quantity as long as the acid remains in contact with the active
material. To drive it out of the active material into the electrolyte,
which is the function of charging, the charge must be carried to
completion. This is termed an equalizing charge, and it should be
given not oftener than once in two weeks, but at least once a month.
To do this, it is necessary to charge the battery from an outside
source, as it is seldom convenient to run the engine for the long
period of time needed to complete such a charge. Except in cases
where the battery is chronically overcharged, as indicated by its
violent and continued gassing, it will usually be found necessary
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600 ELECTRICAL EQUIPMENT
to give it an equalizing' charge once a month. The constantly over-
charged condition is quite as injurious as its opposite, and it can be
cured only by cutting down the output of the generator or increasing
the demand upon the battery for current.
Methods of Charging. The apparatus employed for charging
starter batteries will naturally vary in. accordance with the number
that are looked after in the garage. It may range from the makeshift
consisting of a bank of lamps up to an elaborate panel board designed
to provide charging connections for a dozen or more batteries at once.
Where direct current is available — and only a few starter batteries
need this attention — a bank of lamps in connection with a fused
double-pole switch will be found to fill all the requirements. Note
the charging rate (finishing) given on the name plate of the battery
and make the number of lamps in accordance. A 32 c.p. in the
circuit is practically the equivalent of one ampere of current entering
the battery, i.e., it requires one ampere to light a lamp of this size
and type (carbon filament) to incandescence. A number of standard
lamp sockets should be mounted on a board, connected in multiple,
and the group connected in series with the switch and the battery.
(See illustration in r6sum6 of questions and answers on the battery.)
As many lamps as necessary may then be screwed into the sockets.
The more current needed, the more lamps and the higher power
lamps will be necessary. Tungsten lamps may be employed as well
as the carbon-filament type, but as they take so much less current,
lamps of higher candle power will be needed. For example, to
replace a 32-c.pi, carbon-filament lamp, a 100-watt tungsten lamp
will be required.
Charging in Series for Economy. Where several starter batteries
are to be charged at the same time, it will be found more economical
to connect them in series and charge them all at once. The difference
between the 110-volt potential of the lighting mains and the 6 to 8
volts needed to charge a single three-cell battery represents that
much waste, as the drop in voltage has to be dissipated, through a
resistance, to no purpose. In this way, any number of 6-volt storage
batteries, up to twelve, can be charged from a 110-volt circuit (direct-
current) with the same expenditure of current as would be required
for a single battery. This is owing to the fact that, in any storage
battery, the capacity of the battery is the capacity of one cell,
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ELECTRICAL EQUIPMENT 601
where all are connected in series. Consequently, it will take 10 to
15 amperes to charge one 6-volt battery from the lighting circuit, «
and when several more units of the same size are connected in series
with it, the current consumption will still be the same, but a smaller
part of the voltage will have to be wasted through a resistance.
Motor-Generator. Direct current will be found available in
comparatively few places to-day, so that some means of rectifying
an alternating current, in order to use it for charging batteries, will
be necessary. Where quite a number of batteries are to be cared
for, the motor-generator will be found to give the highest .efficiency,
besides proving more economical in other ways. As its name indicates,
it consists of a motor wound for alternating current and fed from
the supply mains of the garage, and a direct-current generator which
is driven at its normal generating speed by the a.c. motor; There is
no electrical connection between the two units. Electrical power
in the form of an alternating current is converted into mechanical
power in the a.c. motor which drives the armature of the d.c. generator
and again converts it into electrical power in the form of a direct
current. The first cost of a motor-generator is such that its use is
usually confined to large establishments handling quite a number of
batteries, though motor generators are now made in much smaller
sizes than formerly.
A.C. Rectifiers. Where the amount of charging to be done
does not warrant the investment in a motor-generator, a rectifier
is usually employed. There are several makes of different types on
the market: the chemical type, which employs lead and aluminum
plates in an acid solution; the mercury-arc type, in which mercury
is vaporized in a vacuum by the passage of the current; and others,
in all of which the principle is the same. This consists in utilizing
the current on but one part of the wave, so that the efficiency of
these rectifiers ranges from 60 to 75 per cent. It is accordingly not
good practice to employ them except in the smaller sizes. While
the mercury-vapor rectifier is made for charging private vehicle
batteries, the other types are ordinarily confined to sizes intended
for charging small batteries.
A recent addition to the list that is available for this purpose is
the Tungar rectifier, made by the General Electric Company. The
principle on which this works is the same, but the medium is a new
223
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602 ELECTRICAL EQUIPMENT
one. This is a bulb exhausted of air and filled with a special gas in
whicfh a heavy tungsten-wire filament is brought to incandescence
by the passage of the alternating current. This filament is very
short and thick, its diameter depending upon the capacity of the
rectifier, and it is placed horizontally. It
constitutes the cathode of the couple.
Directly opposite it, but a short distance
away, is the anode of graphite in the form
of a button, the lower face of which is
presented to the tungsten wire. It is made
in three sizes, the smallest of which has a
capacity of but 2 amperes and is designed
for charging the batteries of small portable
lamps, such as are used by miners; and
for charging ignition, call bell, burglar
alarm batteries, and the like.
Fi 2 .403. E Prontview^^seSi«e I n the larger size, as shown in Fig.
400, the bulb is mounted in an iron case,
on the face of which are mounted the switch for alternating cur-
rent; an ammeter on the d.c. side, showing the charge received
by the battery; and a dial switch for adjusting the voltage to
the number of batteries to be charged. There is a compensator
with 15 taps, and the current is adjustable by steps up to 6 amperes.
Anything from a single three-cell battery up to ten of such units
Fig. 401. Interior View of Small Size G. E. Tungar Rectifier
Courtesy of General Electric Company, Schenectady, New York
(30 cells in all) may be charged at once. The batteries must be
connected in series and then it is only necessary to turn the switch
of the a.c. circuit. In case the alternating-current supply should fail,
the battery cannot discharge through the rectifier, and the latter
224
ELECTRICAL EQUIPMENT 603
will assume its task again automatically as soon as the current comes
on. This is the 6-ampere 75-volt size. It is also made in a 6-ampere
15-volt size designed for the charging of a three- or six-cell starter
battery in the home garage. Fig. 401 shows an interior view of this
size, illustrating the position of
the converting bulb, the compen-
sator, the reactance coil, and the
fuses, while Fig. 402 illustrates
the 6-ampere 75-volt size, show-
ing the panel instrument, i.e.,
switch, ammeter, and regulating
handle, as well as the bulb and
fuses. „ A closer view of the bulb
itself is shown in Fig. 403.
Care of Battery in Winter.
There is a more or less general
impression that special treatment Fig. 402. interior view of Large size g.e.
a. i_ • ±\_ j v , , Tungar Rectifier
must be given the storage battery
during cold weather. This is probably owing to the fact that lack
of attention makes itself apparent much more readily in winter than
in summer because of the lower efficiency of the battery resulting
from the lower temperature. The care necessary in winter does not
vary in any respect from
that which should be given
in warm weather, except
possibly that replacement of
the water due to evapora-
tion is not called for so
often, but unless it is con-
scientiously carried out, the
battery is apt to suffer to a
greater extent. In Speak- j^. 403 . Tungar Rectifying Bulb-the Heart of
ing of low temperatures, it the Rectifier
must be borne in mind that this always refers to the temperature
of the electrolyte of the battery, and not to that of the surrounding
atmosphere. The latter may be considerably below freezing, whereas
the liquid in the cells may be approaching 100° F. when the battery
is under charge.
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604 ELECTRICAL EQUIPMENT
Make the usual hydrometer and voltage tests, as described
under the headings in question, and see that the battery is constantly
kept more fully charged than would be necessary to render satisfactory
service in warmer weather. . This is important for two reasons:
first, because of the greatly increased draiiTon the battery owing to
the difficulty of starting the engine when cold; and second, because
of the liability of the electrolyte to freeze if the battery is allowed
to stand discharged in very cold weather. There is not the same
excess supply of current available for charging the battery in winter
as there is in summer, as the lights are in use during a much greater
part of the time and not so much driving is likely to be done during
the day. As the lamp load consumes almost the entire output of the
generator in the average starting and lighting system, there is very
little left for the battery when all the lamps are in use. The practice
of turning on all the lights on the car — headlights, side lights spot
light, and instrument lights — whether they are necessary or not,
should be discouraged in winter, as it is likely to result in exhausting
the battery. The instrument lights are usually in series with the
tail light, and so cannot be dispensed with, but it is never necessary
to have the headlights and side lights going at the same time, and
this also applies to the spot light, which consumes almost as much
current as one of the headlights and should be restricted to the use
for which it is intended, i.e., reading signs by the roadside.
Unless the lamp load is reduced, it may be necessary to increase
the charging rate of the generator during the cold months, and this
is not beneficial to the battery, as it may cause severe gassing and
injury to the plates when cohtinued too long. In case the car is
not driven enough to keep the battery properly charged, it may be
necessary to charge it from an outside source or, if the la.tter be not
available, to run the engine with the car idle just for this purpose.
Care must be taken to prevent any danger of freezing, and the best
method of doing this is to keep the battery fully charged, as when in
this condition it will freeze only at very low temperatures. The
more nearly discharged a battery is, the higher the temperature at
which it will freeze, and freezing will ruin the cells, regardless of
whether it happens to crack the jars or not.
Why Starting Is Harder in Cold Weather. The electric starting
and lighting system, or rather the storage battery, which is its main-
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ELECTRICAL EQUIPMENT 605
stay, is much more severely taxed in winter than in summer for the
following four reasons:
(1) The efficiency of the storage battery decreases with a
decrease in temperature, because the action of the storage battery is
chemical, and chemical action is dependent upon heat and, therefore,
always decreases as the temperature decreases.
(2) The lower the temperature the stiffer the lubricating oil,
which gums the moving parts together, adding a very considerable
load to the ordinary amount of inertia which the starting motor
must overcome and likewise adding to the difficulty of turning the
engine past compression.
(3) Gasoline will not vaporize readily at a low temperature, so
that it is necessary to turn the engine over a great many revolutions
before the cylinders become sufficiently warmed from the friction
and the repeated compression to create an explosive mixture. The
better the mixture the more readily it will fire, and consequently
a greater heat value is required in the spark to ignite it where the
mixture is poor or only partly vaporized. Anything that reduces
the efficiency of the storage battery likewise reduces the heat value
of the ignition spark.
(4) Low heat value of the. spark often makes it difficult to
start an engine when cold. This lack of heat in the spark is caused
by a partially discharged battery as well as the lower efficiency of
the battery caused by the cold weather; also by the necessity for
repeated operation of the starting motor, whereby the voltage of the
battery is temporarily cut down.
Intermittent use of the starting motor with a brief period between
attempts will frequently result in starting a cold engine where
continued operation of the starting motor will only result in exhausting
the battery to no purpose. The longer the starting motor is operated
continuously the lower the voltage of the battery becomes, with a
corresponding drop in the heat value of the ignition spark. Cranking
intermittently a number of times has practically as great an effect
in warming the cylinders and generating an explosive mixture as
running for the same period (actual operating time in each case),
while the brief periods of rest permit the battery to restore its normal
voltage, which increases the heat value of the spark and causes the
engine to fire. Both the storage battery and the remaining essentials
227
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606 ELECTRICAL EQUIPMENT
of the starting and lighting system are designed to give satisfactory
service in cold weather, but as a very low temperature brings about
conditions representing the maximum for which the system is designed,
more skillful handling is necessary in winter than in summer to obtain
equally good results.
To Test Rate of Discharge. If the battery terminals are
removable, take off either the positive or the negative terminal,
and connect the shunt of the ammeter to the terminal post and to
the cable which -has been removed, binding or wiring it tightly in
place to insure good contact. Where the battery terminals are
not easily removable, insert the shunt in the first joint in the line,
Fig. 404. Setup for Testing Rate of Discharge of Small Storage
Battery
Courtesy of Prest-O-Lite Company, Indianapolis, Indiana
as shown in the illustration, Fig. 404. Then connect the ammeter
terminals to the shunt. In case the instrument shows a reverse
reading, reverse the connections to the shunt. When the ammeter
is connected to test for discharge, the starter must never be used
unless the 300-ampere shunt is in circuit, as otherwise the instrument
is likely to be damaged. If a shunt of smaller capacity or a self-
contained ammeter, i.e., one designed to be connected directly in
the line is employed, and it is necessary to start the engine, either
crank by hand or disconnect the ammeter before using the starting
motor.
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ELECTRICAL EQUIPMENT 607
When the ammeter is connected to show the .discharge and no
lights are on, the engine being idle, no current is being used for any
purpose, and the pointer of the ammeter should remain at zero. If
any flow of current (discharge) is indicated, it shows that there is
a ground or a short-circuit (a leak) somewhere in the system. In
such a case, apply the usual tests described under the appropriate
headings for locating grounds and short-circuits.
With the ammeter connected up as .shown in the illustration,
the discharge rate of the battery under the various loads it is called
upon to carry may be checked up, and, if it proves to be excessive
in any case, the trouble may be remedied. For example, with the
300-ampere shunt in the line, the amount of energy consumed by
the starting motor may be checked. Without knowing how much
current a certain make of starting motor should consume in turning
over a given type of engine, it will naturally be impossible to make
any intelligent comparisons with the result of the tests. This infor-
mation, however, is readily obtainable from the manufacturer of
the starting system, and it will be found advantageous to obtain
details of this nature covering the various systems in general use in
your locality, as it will enable you to make these tests valuable in
correcting faults. While the starting loads imposed on the electric
motor by different engines will vary greatly, the general nature of
the load will be practically the same in all cases. When the starter
switch is closed, there will be an excessive discharge rate from the
battery for a few seconds, the discharge falling off very rapidly as
the inertia of the engine is overcome and it begins to turn over,
with a still greater drop to a comparatively small discharge the
moment it takes up its cycle and begins to run under its own power.
Before undertaking such tests, see that the battery is in good
condition *and fully charged. Make several tests. Note in each
case whether the maximum discharge at the moment of closing the
switch exceeds the maximum called for by the maker of the starting
system. If a great deal more current is necessary to turn the engine
over than should be the case, it is an indication either that the
starting motor is in need of attention or that the engine itself is
unusually stiff. Atmospheric conditions will naturally have a decided
effect on the result of such tests, as an engine that has stood overnight
in a cold garage will be gummed up with thick lubricating oil and
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608 ELECTRICAL EQUIPMENT
will require more power to move it at first than if it had been running
only a few minutes before. As a general rule, more power will
always be needed in winter than in summer, unless the tests are
carried out in a well-heated garage. The condition of the engine
itself will also have an important bearing on the significance of the
tests, as, if the engine has been overhauled recently, its main bearings
may have been tightened up to a point where the engine as a whole
is very stiff.
Note also whether the discharge rate falls off as quickly as it
should when the engine begins to turn over rapidly. If it does not,
this also is an indication of tight bearings, gummed lubricating oil,
or similar causes, rendering the engine harder to turn over. ' In
the case of a cold engine, stiffness due to the lubricating oil may be
remedied by running it for ten or fifteen minutes, and a subsequent
test should then agree with the manufacturer's rating. Where the
discharge rate does not drop to a nominal amperage within a few
seconds from the time of closing the switch, it is simply an indication
that the essentials of the engine are not in the best of working order.
The carburetor may not be working properly, or the ignition may
be sluggish.
In case the discharge rate is very much less than that called for
by the manufacturer for that particular engine, it is an indication
that the starting system itself is not in the best condition. Poor
connections, worn brushes, loose brush springs, a dirty switch, or
some similar cause is greatly increasing the resistance in the starting
circuit, thus cutting down materially the amount of current that the
battery can force through it. In such circumstances, the discharge
may not reach so high a rate as that called for by the manufacturer,
but to effect a start, even with the engine in normally good condition,
a high rate will have to be continued longer, to the correspondingly
greater detriment of the battery. In other words, a great deal more
current must be drawn from the battery each time the engine is
started. Thus, testing the rate of discharge may be made to serve
as an indication of the condition of both the starting system and
the engine itself. Should it be necessary to make more than eight
or ten starts to determine definitely the cause of any variation between
the discharge rates shown and those that should be indicated, with
everything in normally good condition, the battery should be fully
230
ELECTRICAL EQUIPMENT 609
recharged before proceeding &ny further, as using it for this purpose
when almost exhausted is very likely to damage it. Tests of this
kind show also whether the efficiency of the battery has fallen off
substantially or not, as indicated by its condition after making
several starts in succession. When this has been done, the battery
may be tested with the voltmeter and hydrometer to ascertain how
far it has been discharged. The fact that after having been in service
for some time a starting system will not start the engine so many
times without exhausting the battery as it would when new may
be due either to a loss of efficiency, in the battery or to the poor
condition of the other essentials of the system. In the majority of.
cases, however, it will be due to the condition of the battery.
By substituting the 30-ampere shunt for the 300-ampere, the
load put on the battery by the lights when switched on in various
combinations may be checked and compared with the manufacturer's
ratings. Where the discharge rate for the lights is less than it should
be, it may be due to the use of bulbs which have seen a great deal
of service, the resistance of the filaments increasing with age, or
other causes which place more resistance in the circuit, such as poor
connections, loose or dirty switches, and the like. Tests may also
be made of the ignition system where the battery is called upon to
supply current to a distributor and coil by putting the 3-ampere
shunt in the circuit. The amount of current required by the ignition
system is very small when everything is in normal working order,
usually not more than If to 2 amperes. This also can be obtained
definitely from the maker of the apparatus. Any great increase
in the amount of current necessary would usually indicate arcing at
the contact points, which should prove to be in poor condition; a
subnormal discharge would signify a great increase in the resistance
as in the foregoing cases, and should be evidenced by poor ignition
service.
To Test Rate of Charge. To determine the rate at which the
battery is being charged (the small dash ammeters are only approxi-
mately accurate), reverse the ammeter connections and start the
engine by hand. If the car is equipped with a straight 6- or 12-volt
system and a dash ammeter is used, see that its reading agrees
approximately with the portable ammeter. Should the variation
be small, advise the owner so that he may correct his readings
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610 ELECTRICAL EQUIPMENT
accordingly when noting the instrument on the road. In case it is
very large, the dash ammeter itself should be adjusted, which can
frequently be done merely by bending the pointer.
With the engine running fast enough to give the maximum
charging rate, which is indicated by the fact that the ammeter
needle stops rising, check the charging rate shown on the portable
ammeter, bearing the following in mind: In the majority of cars,
the generator is regulated to charge the battery at from 10 to 15
amperes. Some are designed to charge at as low a rate as 7 amperes.
Unless the proper charging rate is definitely known, whatever
maximum the portable ammeter shows may usually be assumed to
be correct. Where the rate is less than 7 amperes it may generally
be taken for granted, however, that the battery is undercharging,
and the various tests, described in detail under appropriate headings,
may be applied to locate the trouble either in the generator or in
the automatic cut-out. This applies where the charging rate is too
high as well as where it Is too low.
The charging rates mentioned above naturally apply only to a
6-volt battery, or to a battery having a greater number of cells,
which is connected in series multiple so as to charge at 6 volts.
In the case of a six-cell battery permanently connected in series so
that it both charges and discharges at 12 volts, the above figures
must be cut in half. Twelve-cell batteries are employed in some
cases, but the total voltage of the battery is used only for starting,
the cells being divided into four groups in series multiple so that
each group of three cells charges at 6 volts.
With the generator charging at 10 to 15 amperes, turn on all
the lights. . If more current is being drawn from the battery than
is being supplied by the generator, this will be indicated by the
ammeter showing a reverse reading or discharge. It signifies
that there is a short-circuit in the lighting switch or the lamps, or
in the wiring between the switch and the lamps, or that additional
lights, other than those furnished originally with the system, have
been added, or larger candle-power bulbs substituted, thus placing
too great a demand on the battery.
If the system has been out of adjustment for any length of
time, it is quite likely that the battery will shortly need repairs or
replacement, because charging at an excessive rate causes the plates
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ELECTRICAL EQUIPMENT
611
to buckle and break through the separators, forming an internal
short-circuit, while charging at too low a rate causes a constantly
discharged condition of the battery, due to more current being
normally called for than is put in. This results in injurious sulphating
of the plates.
In case additional equipment has been added, the entire
equipment should be turned on, and the total current required should
be noted when making discharge-rate tests. Where the generator
cannot supply sufficient current to permit the battery to take care
of this extra equipment, the battery should be charged from an
outside source at regular intervals. It is poor practice to increase
r~\
Connect Shunt Here For
Test On Charge —
Connect Shunt Mere For
Test On Charge -
¥
Fig. 405. Setup for Twelve-Volt Battery Wired to Charge and Discharge
* "" * " Totor at Twelve V "
nps at Six Volts
through Starting Motor at Twelve Volts and through
Lamp
the charging rate of the generator, as it is likely to injure the battery
through overheating. Where it is necessary to have a higher charging
rate than that originally called for by the system, it is preferable to
substitute a larger battery. The charging rate of the generator may
then be safely increased in accordance with the demand.
In cold weather, it may be necessary to slightly increase the
charging rate of the generator in order to compensate for the extra
current the battery is called upon to supply. This is owing, not only
to the fact that there is a much greater demand on the starting
system in cold weather, but also to the fact that the battery is less
efficient under winter conditions of operation.
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ELECTRICAL EQUIPMENT
Connections for Two-Voltage Batteries. Where the battery is of
either three or six cells, all connected permanently in series, thg
foicgoing suggestions for connecting the testing instruments apply.
They must be varied, however, where tests are to be made of batteries
connected in series multiple, which may be termed two-voltage
batteries since they supply current at one voltage for lighting and
at another for starting. In Fig. 405 is shown a battery of this type
which is connected so as to charge and discharge through the starting
motor at 12 volts, but which discharges at 6 volts to supply the
lamps through a neutral lead in the center of the battery. The
sketch indicates where to connect the ammeter shunt on charge at
vl
©=
=0
©=
=0
Fig. 406. Twelve-Volt Battery Connected Up to Make Two 6-Volt
Batteries in Parallel
12 volts and on discharge at 6 volts. When testing the starting-motor
discharge, it would be connected for 12 volts.
Test the 12-volt circuit with the engine running to get the
charging rate; stop the engine, reverse the ammeter terminals and
see whether there is any discharge indicating a short-circuit. Also
test the discharge rate on the 6-volt circuit with the lights turned off
and again with all lights on. These tests should show whether or
not there is a short-circuit in the system. Before attempting to
test the discharge rate of the starting motor, be certain that the
300-ampere shunt is in the circuit. A 12-volt battery will discharge
only about half the current necessary to start the engine with a
6-volt battery, but no shunt smaller than the 300-ampere size can
be depended upon to carry the load safely and protect the instrument.
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PLATE 1*9— OAKLAND WIRING DIAGRAM OF 1M0 MODEL 34-C. DELCO SYSTEM
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ELECTRICAL EQUIPMENT 613
Fig. 406 shows a 12-volt battery connected up in such a manner
that it is practically two 6-volt batteries in parallel. The battery
is charged at 6 volts, and both the lights and horn are supplied with
current at this voltage, but the discharge through the starting motor
is at 12 volts. Note the two positive cables leading to the center
of the battery. To test the charging rate, the ammeter shunt should
be connected first in one of these cables and then in the other, and
the two readings added together, to obtain the charging rate for the
entire battery. The same locations for the shunt, and the same
method of adding the readings also apply on discharge. Ammeter
readings in the connections shown will indicate whether or not
there are any short-circuits, except, of course, in the starting-motor
cable.
Voltage Tests. An equally important instrument for the testing
of the storage battery is the voltmeter. It is chiefly useful in showing
whether a cell is short-circuited or otherwise in bad condition. Under
some conditions, it indicates when the battery is practically
discharged, but, like the hydrometer, it must not \>e relied upon
alone. It should be used in conjunction with the hydrometer readings
to insure accuracy. Since a variation as low as .1 (one-tenth) of a
volt makes considerable difference in what the reading indicates as
to the condition of the battery, it will be apparent that a cheap
and inaccurate voltmeter is likely to be misleading rather than
helpful. For garage use, a good reliable instrument with several
connections for giving a variable range of readings should be employed.
Instructions furnished with the instrument give in detail the method
of using the various connections, and these instructions should be
followed closely, as otherwise the voltmeter is likely to be damaged.
For example, on the S-volt scale only one cell should be tested.
Attempting to test any more is likely to burn out the 3-volt coil
in the meter. The total voltage of the number of cells tested must
never exceed the reading of the particular scale being used at the
time, as otherwise the instrument will be ruined.
Always make certain that the place on the connector selected
for the contact of the testing point is clean and bright and that
the contact is firm, as otherwise the reading will be misleading,
since the increased resistance of a poor contact will cut down the
voltage. The positive terminal of the voltmeter must be brought
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614 ELECTRICAL EQUIPMENT
in contact with the positive terminal of the battery, and the negative
terminal of the voltmeter with the negative terminal of the battery.
If the markings of the cell terminals are indistinct, the proper terminals
may be determined by connecting the voltmeter across any one cell.
Should the pointer not give any voltage reading, butting up against
the stop at the left instead, the connections are wrong and should
be reversed; if the instrument shows a reading for one cell, the positive
terminal of the voltmeter is in contact with the positive of the cell.
This test can be made with a voltmeter without any risk of short-
circuiting the cell, since the voltmeter is wound to a high resistance
and will pass very little current. This is not the case with an ammeter,
Fig. 407. Proper Setup for Testing Voltage of Batteries
however, as connecting such an instrument directly across the
terminals of the battery will immediately burn out the ammeter.
Inasmuch as any cell, when idle, will show approximately 2
volts, regardless of whether it is fully charged or not, voltage readings
taken when the battery is on open circuit, i.e., neither charging
nor discharging, are practically valueless, except when a cell is out
of order. Therefore, a load, such as switching on the lamps, should
be put on the battery before making voltage tests. With the lights
on, connect the voltmeter as explained above and test the individual
cells, Fig. 407 (Prest-O-Lite). If the battery is in good condition,
the voltage readings after the load has been on for about five minutes
will be but slightly lower (about one-tenth of a volt) than if the battery
were on open circuit. If any of the cells are completely discharged,
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ELECTRICAL EQUIPMENT x 615
the voltage of these cells will drop rapidly when the load is first
put on and, sometimes when a cell is out of order, even show reverse
readings. Where the battery is nearly discharged, the voltage of
each cell will be considerably lower than if the battery were on open
circuit after the load has been on for five minutes. In the case of an
electric-vehicle battery, the lights alone would not provide sufficient
load for making an accurate test, so that one of the rear wheels may
be jacked up and the brake set lightly until the ammeter on the
dash of the car shows 50 to 70 per cent of the usual normal reading.
To do this, start the motor on first speed with the brakes loose,
and apply the brakes slowly until the desired load is shown by
the ammeter reading. Never, under any circumstances, attempt to
start with the brakes locked or on hard, as both the battery and the
motor will be damaged. In the case of a starting-system battery,
the lights alone are sufficient load, as they consume about 10 amperes.
To distinguish the difference between cells that are merely
discharged and those that are out of order, put the battery on charge
(crank the engine by hand in the case of a starter battery) and test
again with the voltmeter. If the voltage^does not rise to approxi-
mately 2 volts per cell within a short time, it is eyidence of internal
trouble which can be remedied only by dismantling the cell.
Temperature Variations in Voltage. It must be considered, in
making voltage tests, that the voltage of a cold battery rises slightly
above normal on discharge. The reverse is true of a really warm
battery in hot weather, i.e., it will be slightly less than normal on
charge and higher than normal on discharge. As explained in
connection with hydrometer tests of the electrolyte, the normal
temperature of the electrolyte may be regarded as 70° F., but this
refers only to the temperature of the liquid itself as shown by a
battery thermometer, and not to the temperature of the surrounding
air. For the purposes of simple tests for condition, voltage readings
on discharge are preferable, as variations in readings on charge mean
little except to one experienced in the handling of storage batteries.
Joint Hydrometer and Voltmeter Tests. In making any of the
joint tests described below, it is important to take into consideration
the following four points:
(1) The effect of temperature on both voltage and hydrometer
readings.
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616 ELECTRICAL EQUIPMENT
(2) Voltage readings should only be taken with the battery
discharging, the load being proportioned to the size of the battery,
as voltage readings on an idle battery in good condition indicate
little or nothing.
(3) In the case of a starter battery, never attempt to use the
starting motor to supply a discharge load for the battery, because
the discharge rate of the battery while the starter is being used is so
heavy that even in a fully charged battery in good condition it
will cause the voltage to drop rapidly.
(4) The voltage of the charging current will cause the voltage
of a battery in good condition to rise to normal or above the moment
it is placed on charge, so that readings taken under such conditions
are not a good indication of the battery's condition.
In any battery which is in good condition, the voltage of each
cell at a normally low discharge rate (20 to 30 amperes for a vehicle
battery or 5 to 10 amperes for a starting-system battery) will remain
between 2.1 and 1.9 volts per cell until it begins to approach the
discharged condition. A voltage of less than 1 .9 volts per cell indicates
either that the battery is nearly discharged or that it is in bad
condition. The same state is also indicated when the voltage drops
rapidly after the load has been on a few minutes. The joint hydrome-
ter and voltmeter tests given below will be found to cover the
majority of cases met with in actual practice.
(1) A voltage of 2 to 2.2 per cell with a hydrometer reading
of 1.275 to 1.300 indicates that the battery is fully charged and in
good condition.
(2) A voltage reading of less than 1.9 per cell with a hydrometer
reading of 1.200 or less indicates that the battery is almost completely
discharged.
(3) A voltage of 1.9 or less per cell with a hydrometer reading
or 1.220 or more indicates that excess acid has been added. Under
these conditions, lights will burn dimly, although the hydrometer
reading alone indicates the battery to be more than half charged.
(4) Regardless of voltage — high, low or normal — any hydro-
meter reading of over 1.300 indicates that an excessive amount
of acid has been added.
(5) Where a low voltage reading is found, as mentioned in
cases 2 and 3, to determine whether the battery is in bad order or
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ELECTRICAL EQUIPMENT
617
merely discharged, stop the discharge by switching off the load, and
put the battery on charge (crank the engine by hand in the case of
a starter battery) and note whether the voltage of each cell promptly
rises to 2 volts or more. If not, the cell is probably short-circuited
or otherwise in bad condition.*
Cleaning Repair Parts. The advent of electric starting and
lighting systems has added appreciably to the amount of attention
required by machines in the garage, particularly as this essential
is a part of the car about which its owner generally knows little. In
fact, it is not overstating it to say that fully 25 per cent of all the
repair work now carried on in the garage has for its object the keeping
Hot Water
Tank Ho.l
Hot Water
Tank Ho. £
"I
Cou3lvc5oo\ '
Or Potash
Solution
Hot
TonkHo.S
JarttoL JarNal
Cold Water- 4
JorM
Cold Water J
Saw Dust Sox.
Fig. 408. Layout for Battery Cleaning Outfit
of the electrical equipment of the car in good operating condition.
Where many cars are cared for and repairs to their electric systems
are made as far as possible right in the garage, it will be found
advisable td install a method for cleaning parts. Owing to the accumu-
lations of dirt and grease that parts, carry after having been in service
for a year or more, cleaning them thoroughly before making any
repairs makes it possible to detect defects which might otherwise
pass unnoticed. The following instructions are reprinted through
the courtesy of the makers of the Delco apparatus, and they strongly
recommend that the solutions mentioned be used in the exact manner
* From instructions issued by the Prest-O-Lite Company, Indianapolis, Indiana.
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618 ELECTRICAL EQUIPMENT
directed, as they are the result of several years' experience in this
work, .and considerable care has been used in checking them. The
sizes of the tanks given are merely indicative of what a very large
repair shop would require and are comparative only. They will
naturally vary with the amount of work to be done.
Cleaning Outfit. The cleaning outfit should consist of three
sheet-steel tanks, Fig. 408, of suitable size (35 gallons for a large
shop) mounted so that their contents may be kept heated to the
desired temperature, three stone jars of approximately 15 gallons
capacity, and a sawdust box. Two of the steel tanks should be
equipped with overflow pipes so that they can be kept about two-
thirds full at all times. These are tanks No. 1 and No. 2. They are
used for clear hot water for rinsing parts after they have been cleaned.
The third tank does not require a drain nor an overflow pipe and is
used for the potash or caustic soda solution. This can be used for
a long time without changing by simply adding a small amount of
soda as the solution weakens. All three tanks are maintained at a
temperature of 180° to 212° F., or approximately the boiling point.
The three jars mentioned are used for the acid solutions and are
referred to as jars No. 1, No. 2, and No. 3. A wood tank large enough
to hold the three jars and divided into two compartments, as shown
in Fig. 408, should be provided. This is important, as the parts
cannot be rinsed. in the same cold water after being immersed in the
different acid solutions. The solutions recommended are in tanks
1 and 2, clear hot water; tank 3, a solution consisting of one pound
of caustic soda per gallon of water. Jar No. 1 is filled with a solution
consisting of four gallons of nitric acid, one gallon of water, and six
gallons of sulphuric acid. The water is placed in the jar first, the
nitric acid is added slowly, and the sulphuric acid is poured in last.
This order must be strictly followed, as it is dangerous to mix a
solution of these acids in any other manner. In jar No. 2, the solution
is one gallon of hydrochloric acid to three gallons of water, while
jar No. 3 contains a solution of one-half pound of cyanide to a gallon
of water. Tank No. 2 should be used only for parts which have
been in the potash solution and for no other purpose. Tank No. 1
is for general rinsing purposes.
Method of Cleaning Parts. Various metals are cleaned as follows :
Steel is boiled in the potash solution until the dirt is removed, which
_^ 240
ELECTRICAL EQUIPMENT / 619
should require only a few minutes. The steel part is then rinsed
in tank No. 2 and dried in sawdust. Cast iron parts are boiled
in the potash solution to remove dirt, rinsed in tank No. 2, dipped
in the acid solution in jar No. 1, rinsed thoroughly in cold clear
water, dipped in the cyanide solution, rinsed again in cold
clear water, then rinsed in tank No. 1 and dried in sawdust. Copper
can be cleaned in the same manner. Polished aluminum should
first be thoroughly washed in gasoline, rinsed in. tank No. 1, dipped
in the acid solution in jar No. 1, rinsed thoroughly in cold clear
water, rinsed in tank No. 1, and dried in sawdust. . Plain aluminum,
unpolished, should be dipped in the potash solution, rinsed in tank
No. 2, dipped for a few seconds in the acid solution, rinsed in
tank No. 2, dipped for a few seconds h* thejacid solution in Jar
No. 1, rinsed in cold water, then rinsed in tank No. 1, and dried in
sawdust.
It will be noticed that when aluminum is put into the potash
solution the metal is attacked and eaten away rapidly, so that
polished parts of this metal should not be put into this solution,
and any aluminum parts should not be left in for a moment longer
than necessary. Where the parts are covered with caked deposits
of hard grease, they should first be washed in gasoline. Aluminum
parts should never be put into the potash solution unless they can
be put through the acid immediately after, as the acid dip neutralizes
the effect of tjie potash solution. Parts should only be held in the
acid for a few seeonds. Paint should first be removed with a good
paint or varnish remover unless it is present in very small quantity,
and unless the aluminum parts are to go through the potash solution.
Enameled work should be washed with soap and , water, dried
thoroughly, and then polished with a cloth dampened with a good
oil, such as Three-in-One. These cleaning methods apply only
to solid parts and should never be employed on any plated pieces,
as the caustic and acid would immediately strip off the plating.
Such parts can be cleaned only in gasoline. It will be apparent,
however, that cleaning in this manner will be found advantageous
for many parts of the car that have to be repaired other than those*
of the electric equipment, and, in view of the increasing cost of
gasoline, will be found much more economical as well as much more
thorough.
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fF^*.
&:>- •
W^"*
REMY IGNITION DISTRIBUTOR, MODEL 855-B
Courtesy of Remy Electric Comvany, Anderson, Indiana
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ELECTRICAL EQUIPMENT FOR
GASOLINE CARS
PART VIII
ELECTRIC STARTING AND LIGHTING
SYSTEMS— (Continued)
SUMMARY OF INSTRUCTIONS ON ELECTRIC
STARTING AND LIGHTING
It will be apparent from the foregoing description of the various
systems that while the majority differ more or less in detail all are
based on a comparatively small number of well-defined principles,
and that once these are mastered their application in any system
under consideration will be clear. To avoid unnecessary duplication
in the instructions covering points that are common to all, general
instructions have been given only in connection with one or two
systems, and it will be understood that descriptions of the methods
of locating short-circuits or grounds, of caring for brushes and com-
mutator, and of testing with a portable lamp or with the volt-ammeter
are equally applicable to. all. The instructions given with other
systems accordingly are limited to special references to the details
of installation that will make it easier to locate faults in that par-
ticular system.
In order to bring the two together in such form that the par-
ticular information desired may be found instantly, a summary
of aU the instructions given in the preceding sections is outlined here
in questions and answers.
GENERATORS
Types and Requirements
Q. How many types of generators are used in starting and
lighting service on the automobile?
A. Practically all are of one type, i.e., compound-wound, but
this is subdivided into other types, such as differential compound-
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622 ELECTRICAL EQUIPMENT
wound, cumulative compound-wound, and the like, that is, all
lighting generators have a shunt and a series winding on their fields,
but the relation of these windings to one another differs, depending
upon the characteristics of the remainder of the system.
Q. What is a differential compound-wound generator?
A. One in which the series winding is reversed, i.e., wound in a
direction opposite to that of the shunt winding so that its exciting
effect on the field magnets opposes that of the shunt winding. The
series winding is then termed a bucking coil because it bucks,
or opposes, the exciting effect of the shunt winding on the field mag-
nets as the speed increases. The series winding in this case is used
simply for regulating the generator output.
Q. What is a cumulative compound-wound generator?
A. One in which the exciting effect of the series coil is added to
that of the shunt coil, the series coil in this case having no connection
with the regulation of the generator output.
Q. As one of the chief requirements of an efficiently operating
system is the control of the generator output under widely varying
speeds, how is a generator of the cumulative compound-wound type
employed on the automobile?
A. The series winding is in practically an independent circuit
in connection with the lamps of the car so that its exciting effect is not
added to the field magnets except when the lights are switched on.
This automatically increases the generator output in accordance with
the number of lights turned on so that the lights have no effect on the
battery charging rate, which remains the same whether the lights are
on or off. An external regulator is employed to control the battery-
charging rate.
Q. How does the generator differ from the motor?
A. Its essentials are all the same, i.e., it has a wound armature
revolving in a magnetic field, commutator, brushes, etc., exactly the
same as the generator.
Q. This being the case, why are the two not interchangeable?
A. To a certain extent they are, that is, when a current is sent
through the generator from an outside source, it becomes motorized
and will run as a motor. But the two are far from being interchange-
able on the automobile, owing to the widely differing requirements for
which they are designed. The generator is wound to produce a cur-
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ELECTRICAL EQUIPMENT 623
rent seldom exceeding a value of 20 amperes while being driven over a
wide range of speeds, and it is in constant operation. The starting
motor, on the other hand, is designed to utilize an extremely heavy
current, ranging up to 300 amperes or more at the moment of starting
and is only used for very short periods.
Q. How are these widely varying requirements reconciled in
the single-unit type, in which both the generator and the motor are
combined in one machine?
A. The machine is practically two units in one, i.e., there are
two totally different windings on the same magnet cores, a fine wind-
ing with shunt fields for the generator, and a very heavy simple series
winding for the motor end. In sofcie cases, as in the Delco, the differ-
ent windings on the armature are brought out to independent commu-
tators. While combined on *e set of magnet cores, there is no
connection whatever between the two windings in such a machine, so
that when operating as a generator the motor windings are dead, and
the reverse is true when being used as a starting motor.
Q. What are the characteristics of the single-unit type of
machine which is simply placed in circuit with the battery by a hand-
operated switch when starting &nd left in that relation as long as the
engine is running?
A. This is a variable-potential type in which the relation that it
bears to the battery and to the engine is entirely dependent upon the
speed of the engine, that is, the speed at which the machine is driven.
When the switch is closed, current from the battery operates the
machine as a starting motor; as soon as the engine starts and attains
a certain speed, the voltage of the machine overcomes that of the
battery, the direction of current flow is reversed, and the battery begins
to charge. Whenever the driving speed falls below a certain point,
there is another reversal, and the generator once more becomes a motor
until the engine speed increases.
Loss of Capacity
Q. What are the chief causes for the falling off in output of
the generator?
A. In about the order of the frequency of their occurrence,
these are as follows : dirty or worn commutator; worn brushes making
poor contact; dirty or loose connections causing extra resistance
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624 ELECTRICAL EQUIPMENT
at generator, regulator, cut-out, ground, or battery terminals;
failure of cut-out to operate at proper voltage; worn or pitted con-
tacts in regulator or cut-out; loose connections at brush holders;
short-circuited coils in the armature; some of the armature-coil
connections broken away from the commutator; short-circuited
bars in the commutator.
Q. How can the generator output be tested?
A. The simplest method is to switch on all the lamps with
the engine idle. Start the engine and speed up to equivalent of
15 miles per hour. The lights should brighten very perceptibly,
the test being made indoors in the daytime with the lights directed
against a dark wall, or preferably at night. A more accurate test
can be made with the portable volt-ammeter, using the 30-ampere
shunt. Most generators have an aflferage current output of 10 to
12 amperes, but the normal output as given by the maker should
be checked before making the test. Generators having a constant-
voltage control will show a greatly increased output if the battery
charge is low, running up to 20 amperes or over. On such machines,
the condition of the battery should be checked either with the
hydrometer or with the voltmeter before making the test. The
charging current should be 10 to 12 amperes with a fully charged
battery, and more in proportion when only partly charged.
Q. What other simple method is there of determining quickly
whether the generator is producing its normal output or not?
A. On generators having an accessibly located field fuse (there
are several makes) lift this fuse out and, with the engine running
at a speed equivalent to 10 miles per hour or more, touch the fuse
terminals lightly to the clips. If the machine is generating properly,
there will be a bright hot spark. Should no spark appear, replace
the fuse and bridge the terminals with a pair of pliers by touching the
jaws to the fuse clips; if a spark appears, the fuse has blown. Before
replacing with a new fuse, find the short-circuit or other cause.
Q. Granting that the fuse has not blown, that the cut-out,
regulator, and wiring are all in good condition, and still the gen-
erator does not produce any current, what is likely to be the cause?
A. One of the brushes may not be touching the commutator,
a brush connection may have broken, or carbon dust may have short-
circuited the armature or field windings. Test for short-circuits.
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ELECTRICAL- EQUIPMENT 625
Q. If the machine is generating current, and the auxiliary
devices and wiring are in good condition, but the battery does not
charge, what is the cause?
A. Short-circuit in the battery due to active material having
been forced but of the plates, or accumulation of sediment touching
plates at their lower ends. (See Battery Instructions.)
Q. Is the regulator ever responsible for a falling off in the
current or for generation of excessive current?
A. Yes. Any irregularity in the operation of the regulator
will affect the output of the generator.
Q. How can this be overcome?
A. This will depend upon the type of regulation employed
(see Regulation). Where the method of regulation is inherent,
i.e., forming part of the construction* of the generator itself, such
as the third-brush method, or a bucking coil, it may be remedied
by cleaning and seating the brush properly or by testing the bucking-
coil winding to see if its connections are tight and clean, or if it is
short-circuited (see Windings). If cleaning and sanding-in the
brush do not cause the generator to produce its normal output, the
brush itself may be adjusted by shifting its location. Moving it
backward or against the direction^ of rotation of the commutator
will reduce the output; moving it forward or" in the direction of
rotation will increase the output. This refers specifically to the
Delco regulation already described. To adjust properly, the port-
able ammeter should be put in circuit, and the effect on the reading
noted as the brush is moved, clamping it back in place when the
proper point is found. The brush should then be sanded-in to the
commutator, as it will not have a good bearing if its original location
has been disturbed.
Methods of Regulation
Q. Why is it necessary to control the output of the generator?
A. As explained in the section on electric generators, the
amount of current produced depends upon the excitation of the fields,
and the faster the armature revolves before the pote faces of the field
magnets, the greater the amount of current that is sent through the
windings of the magnets. As the speed of the automobile engine
varies between such extremely wide limits, it will readily be seen that
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it may rise to a point where this increase in the field excitation will
cause so much current to be generated that the armature windings
will be literally burned up. This happened very frequently in the
early attempts to produce a lighting dynamo for automobile service.
Regardless of how fast the generator may be driven, it is essential that
its current output does not exceed a certain safe limit.
Q. What is the usual safe limit in the majority of generators?
A. Most automobile lighting-system generators are designed to
produce 10 to 15 amperes at a normal speed, i.e., sufficient to light all
the lamps and still provide a slight exgess for charging the battery.
No matter how fast its armature revolves, it must not exceed this by
more than ten to twenty-five per cent, as a rule, this being well within
its factor of safety. In some instances, where a voltage system of
regulation is employed, the output of the generator depends upon the
condition of charge of the battery. If the battery is practically
discharged, the generator will charge the battery at a rate of twenty
amperes or over. As the charge proceeds, the battery voltage
increases and the resistance is increased correspondingly, thus cutting
down the amount of current that the generator can force into the
battery.
Q. How is the current generated kept from exceeding this safe
limit?
A. Mechanical methods were employed at first, a centrifugal
governor being used to operate a slipping clutch. The generator
was driven through this clutch, and the speed at which the armature
revolved depended upon the engagement of the clutch; at low speeds
both shafts would turn at the same rate. As the driving-shaft speed
increased, the governor decreased the pressure on the clutch spring,
and the clutch faces slipped on one another, so that the driven shaft
turned proportionately slower than the driving shaft. The earliest
types of governors, employed about 1903 to 1905, were not successful,
but about 1908 a type was developed that worked effectively on
thousands of cars. It has since been superseded by electrical methods
of regulation, and practically all of those now in use are electrically
operated.
Q. How many electrical methods of regulating the amount of
current generated are in general use?
A. So far as their principle goes, practically all are the same.
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ELECTRICAL EQUIPMENT 627
They depend upon weakening the excitation of the fields of the gen-
erator to out down the output. It is in the methods of accomplishing
this that they differ. In the latter respect they may be divided into
two general classes: those that are inherent in the design of the
machine, i.e., the regulating device is actually a part of the machine
itself; and those in which an external regulator is employed. Those
most commonly employed are, in the first class, the bucking-coil
winding and the third-brush method; in the second, an external
regulator is usually combined with the battery cut-out and designed
to keep either the voltage or the current at a uiiiform value, usually
the voltage.
Q. What is a bucking-coil winding, and why is it so called?
A. We have seen that in a series-wound machine all of the
current generated in the armature passes through the field windings
and energizes the field magnets; in the shunt-wound machine the wires
carry only a part of the current which is proportional to the resistance
that the shunt winding of the fields bears to the resistance of the out-
side circuit. As this outside resistance (the load) increases, more current
will be diverted through the path of lesser resistance, or the shunt-
wound field, and the output of the machine will increase accordingly.
In the compound-wound machine, the relation of the series to the
shunt winding is such that it is called upon chiefly to help carry any
extra load. In other words, as the demands upon the machine
increase, the series winding adds its energizing effect to that
of the shunt coil. A generator with a bucking-coil winding is a com-
pound-wound machine, but the series winding is in the opposite
direction from that of the shunt winding. Consequently, instead of
adding to the field excitation caused by the latter, it opposes or bricks it,
and the more current there is produced in the shunt field by the rise
in speed, the more the series winding, or bucking coil, tends to neutral-
ize this excess, thus keeping the amount of magnetic effect produced
in the field poles practically uniform, regardless of the speed.
Q. What is the third-brush method of regulation?
A. In a conventional shunt-wound generator, the field windings
are directly in shunt with the armature through the brushes; hence, a
certain proportion of all the current induced in the armature windings
will find its way through the field magnet windings, in proportion
to their relative resistance to the outside circuit at the time. Where a
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628 ELECTRICAL EQUIPMENT
third brush is employed, the main brushes are not in shunt with the
fields, and they are not depended upon to supply the exciting current
for the latter. The third brush instead is used for this purpose. As is
well known, the output of a generator depends very largely upon the
position of its brushes. In the immediate vicinity of the proper loca-
tion for a brush, there is a short zone of maximum intensity. As we get
away from this toward the next brush, it decreases until at a point
midway between the two there is a neutral zone. The third brush is
accordingly placed between the two main brushes, and its distance
from the nearest main brush determines the amount of current that it
diverts from the armature to the field windings. See illustration
of Delco generator in section on Methods of Regulation. This
method has the advantage of supplying a strong shunt field at low
speeds. As the speed increases, the voltage applied to the shunt field
decreases, even though that between the two main brushes may have
increased.
Regulators
Q. What is a regulator, and what is its purpose?
A. It is an instrument somewhat similar to a battery cut-out,
and its purpose is to regulate the output of the generator in order that
the latter may not excee4 safe limits at high speeds. The regulator
is usually combined with the cut-out.
Q. How does the constant-voltage type of regulator operate?
A. The instrument consists of a magnet winding and a pivoted
armature, normally held open by a spring and a resistance unit.
The winding of the magnet has sufficient resistance to prevent the
core becoming energized to a degree where it will attract the armature,
unless the voltage exceeds the safe limit determined for the circuit.
The voltage increases with the speed of the generator, so that when the
latter is driven too fast the attraction of the magnet core for the arma-
ture becomes sufficient to overcome the pull of the spring which
normally holds the contacts apart. (See description of Bijjir voltage
regulator.) When the contacts come together, the field circuit of the
generator is shunted through the resistance unit; this cuts dovn the
amount of current energizing the fields, the voltage falls off, and the
contacts again separate. Unless the speed of the generator is
decreased, this action is rapidly repeated, so that the regulator arma-
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ELECTRICAL EQUIPMENT 629
ture vibrates at a high speed as long as the voltage is sufficiently high
to energize the magnet.
Q. What is the principle on which this type of regulator
operates?
A. The principle that in a circuit having considerable self-
induction the amount of current which may be sent through the
circuit will decrease if the current be pulsating instead of steady.
Every time the contacts of the regulator open, a pulsation, or surge,
of current is sent through the field windings of the generator; when
they close because of the higher voltage, the current is shunted
through the resistance unit, thus cutting it down. The decrease in
the amount of current is in proportion to the number of pulsations per
minute, i.e., the rapidity with which the vibrating contact operates.
The circuit having considerable self-induction is that of the field
winding of the generator, owing to its heavy iron core. (See Induc-
tion.)
Q. What is the constant-current type of regulator, and how does
it differ from the constant-voltage, or potential, type?
A. It consists of an electromagnet and a spring-controlled
pivoted armature, so that it is of practically the same construction as
the constant-potential type, but it is connected in circuit with the
armature of the generator and it is wound to operate under the
influence of the current rather than the voltage. Consequently,
the pivoted armature is attracted, opening the circuit when the cur-
rent exceeds a certain predetermined value, usually 10 amperes. In
operation, the armature vibrates the same as in the voltage regulator,
but the condition of the charge of the battery has no effect on it, so
that when set to limit the current to 10 amperes, it will always charge
the battery at approximately that rate regardless of the condition
of the battery. The only practical difference is that it is wound to
actuate under the influence of changes in the current flow and is
connected in the armature circuit, whereas the constant-potential
regulator is influenced by variations in the voltage and is connected in
the field circuit of the generator. The latter has the advantage of
charging the battery at a higher rate when the charge is most needed.
Q. What other forms of regulators are employed on lighting
generators?
A. The foregoing comprise practically all of the principles
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630 * ELECTRICAL EQUIPMENT
employed, but the regulators differ more or less in design and opera-
tion. For example, in the Bosch-Rushmore generator, a bucking
coil is employed in connection with what is termed a ballast
resistor, or resistance unit. This is of iron wire, and it is based on the
fact that resistance increases very rapidly with the temperature.
The size of the wire is such that it allows 10 amperes to flow without
undue heating, so that its resistance is practically unchanged; above
this point it heats rapidly and increases in resistance so greatly that all
excess current is shunted through the bucking coil. In the Splitdorf
generator, the regulator is built in, projections of the pole pieces of the
field being utilized in connection with special windings, instead of an
independent electromagnet as in the Ward-Leonard and the Bijur.
In the U.S.L. generator of the inherently regulated type, regulation is
accomplished by the combination of a Gramme ring armature, a
special arrangement of connections and of the field windings, and the
use of only a part of the fields and armature for generating current.
The regulation obtained is based on armature reaction and is similar
in effect to the third-brush method. The U.S.L. external type of
regulator cuts into the generator field circuit a variable resistance
consisting of an adjustable carbon pile. In the Adlake regulator,
which is of the constant-potential type, a solenoid operates a switch
over the contacts of a variable resistance. The plunger of the sole-
noid is counterbalanced by a weight, which must be raised to operate
the switch. It is adjustable by increasing the weight of this counter-
balance.
Q. What attention does the regulation of the generator require?
A. This will depend upon the method employed in each case.
Where an external regulator is employed, whether of the constant-
potential or the constant-current type, the attention required is
practically the same as in the case of the battery cut-out. See that
the points are not sticking, and when badly burned or pitted, smooth
and true up/taking off as little of the contact point as possible to effect
this. .When the points have become so badly pitted that this cannot
be done^mre. parts will be necessary.
>■•: rWitte^the third-brush method, the attention required by this
taush isth&sstme as that which must be given the other brushes, i.e.,
sanding-in at intervals and replacement when worn too short to
permit the spring to hold the brush firmly against the commutator.
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ELECTRICAL EQUIPMENT • 631
Where the generator fails to produce sufficient current to keep the
battery charged, all other parts of the system being in good condition
and the car driven long enough in daylight to charge the battery under
normal conditions, the position of the third brush may be shifted to
increase the output. Care must be taken not to let it come in contact
with the main brush. (See Delco instructions.) In the case of a
bucking-coil winding, no attention is necessary, as this is an integral
part of the machine itself. As the Splitdorf regulator has moving
contact points, the attention necessary is the same as that required
for an external regulator of this type. Special regulators, such as the
U.S.L. external type, require attention covered by the maker's instruc-
tions. (See U.S.L. system.)
Q. When the generator fails to keep the battery charged prop-
erly, a normal amount of daylight driving being given the car, is the
fault most likely to be found in the regulator?
A. No. It is much more likely to be caused by a dirty commu-
tator, worn brushes, loose connections, or some similar cause which
inserts extra resistance in the charging circuit. The movement of
the regulator armature is very slight, and the current handled by the
contact points is small, so that it will seldom be the cause of the
trouble. Other causes, such as those above enumerated, should
always be sought first. (See instructions under Generator.)
Windings
Q. Are faults in the generator windings frequent?
A. They constitute one of the least frequent sources of trouble
with the machine.
Q. What is likely to cause them?
A. Dousing the machine with water is likely to be one of the
most frequent causes of short-circuits or grounds in the generator
windings. All electrical machinery is intended to be kept dry.
Except where provided with a field fuse, running the generator when
disconnected from the battery or with the battery removed from
the car is another cause. Excessive speed, in some instances, may
generate sufficient centrifugal force to lift the armature coils put
of their slots so that the insulation becomes abraded by rubbing
against the pole pieces, but this is very unusual. In rare instances,
a hard kink left in the wire when winding may crystallize the metal
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632 ELECTRICAL EQUIPMENT
and make it break at that point, due to the vibration. Unless cleaned
out at intervals, fine carbon dust from the wear of the brushes may
accumulate in the interstices of the windings, and, when aggravated
by moisture, this is apt to cause short-circuits.
Q. What are the usual indications of such faults?
A. With a short-circuited generator coil (armature), all other
parts of the apparatus and circuits being iri good condition, the
charging rate will be lower than normal. The ammeter needle will
vibrate violently when the engine is running at low speeds, and two
or more adjacent commutator bars- will burn and blacken. With
an open armature coil (broken wire), the indications will be prac-
tically the same, and there will be severe sparking at the brushes,
causing serious burning of the commutator bar corresponding to
the open coil. A grounded armature coil will give the same general
indications, and if the machine is a single-unit type, the cranking
ability of the starting motor will be seriously impaired. The
ammeter, however, will not vibrate as in the former cases. There
will be practically no charge from the generator, and the battery
will be discharged very rapidly by the starting motor.
In a single-unit machine, when the windings of the generator
and the starting motor become interconnected, the indications
will be practically the same as those of a grounded armature coil.
If the motor windings of a single-unit machine become grounded,
there will be an excessive discharge from the battery, while the
motor will develop but little power.
Q. How may such faults be located?
A. With the aid of the testing-lamp outfit. Remove the
brushes (when replacing them later, be sure to put each brush
back in the holder from which it was taken), or the brushes may
be insulated from the commutator by placing paper under them.
For a grounded coil, place one test point on the commutator and
the other on the frame; if grounded, the lamp will light. For inter-
connected motor and generator windings in a single-unit machine
having two commutators, insulate the brushes as mentioned and
place the test points one on each commutator. The light will burn
if the two windings are connected. For a grounded-motor winding,
test from the motor commutator to the frame; the light should
not burn if the insulation is all right. For a break or open circuit
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ELECTRICAL EQUIPMENT 633
in the field winding, touch the terminals of the latter with the test
points, the commutator being insulated or the armature removed.
The lamp should light. For a blown field fuse on machines so
equipped, place the points on the clips; if the fuse is intact, the
lamp will light.
Q. Are these tests conclusive?
A. No. They will indicate any of the faults mentioned,
but they will not reveal an internal short-cipcuit in the windings,
which cuts some of the armature or field turns out of action but
does not break the circuit as a whole. Such a short-circuit reduces
the output of the generator and can be determined definitely only
by measuring the resistance of the windings. This requires special and
expensive testing instruments, such as the Wheatstone bridge, so that
where all other tests fail to reveal the cause of a falling off in the out-
put of the generator, it should be* sent to the maker for inspection.
Commutator and Brushes
Q. What does a blackened and dirty commutator indicate?
A. Sparking at the brushes or an accumulation of carbon
dust due to putting lubricant on the commutator.
Q. What is the cause of sparking at the brushes?
A. Poor brush contact, due to worn brushes; brush-holder
springs too loose, so that brushes are not held firmly against the
commutator; excessive vibration, which may be due to a bent shaft,
an unbalanced gear pinion, or improper mounting; using too much
oil, or using grease in the ball bearings, which gets on the commutator
and, acting as a solvent for the binder of the carbon, forms a pasty
mass which prevents proper brush contact; worn or roughened
commutator on which the mica needs undercutting; overload due
to failure of regulator or to grounded coils in armature.
Q. What is the remedy for sparking?
A. Clean the commutator with fine sandpaper and sand-in
the brushes to a true bearing on the commutator as directed in the
Delco instructions. See that the brush springs have sufficient
tension to keep the brushes firmly pressed against the commutator
when the machine is running. If the mica protrudes above the
commutator bars, it must be undercut as directed, and the commu-
tator smoothed down again after the operation to remove any burrs.
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634 ELECTRICAL EQUIPMENT
Q. Why do some commutators need undercutting and others
not?
A. Undercutting is required only on machines equipped with
brushes that are softer than the mica. Copper-carbon brushes,
as employed on starting motors to reduce the brush resistance, are
hard enough to keep the mica worn down with the copper of the
commutator itself.
Q. If, after smoothing off and undercutting the mica, the
commutator still has an uneven and irregular surface, what is the
remedy?
A. The armature should be removed from the machine, and
the commutator trued up in the lathe, taking as light a cut as possible
consistent with obtaining a true round and smooth surface.
Q. How can excessive commutator wear be prevented?
A. Inspect at regular intervals and on the first sign of sparking
smooth up the surface and sand-in the brushes. Keep the com-
mutator clean and do not permit carbon dust or oil to accumulate
in the commutator and brush housing. Never replace brushes or
brush springs with any but those supplied by the manufacturer
for that particular model. The machine will work with any old
brush and any old spring that fits, but they will prove detrimental
to its operation in a comparatively short time, and its working under
3uch conditions will never be satisfactory.
Q. Is discoloration of the commutator ever caused by anything
else than sparking?
A. Not actual discoloration which requires cleaning, but the
normal operation of the machine produces a purplish blue tinge on
the bars, which is sometimes mistaken for discoloration by the
inexperienced. This color, in connection with a high polish of the
metal, indicates that the commutator is in the best of condition.
Once the commutator takes on this high polish, it will operate for
long periods without other attention than the removal of dirt by
wiping with a clean rag. Sanding to remove this purple tinge is a
mistake, as it only destroys the polish without having any beneficial
effect.
Q. Is it necessary to lubricate the surface of the commutator?
A. No. The brushes employed are usually of what are termed
a self-lubricating type and require no attention in this respect.
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Q. Will any harm result from putting light grease, vaseline, or
lubricating oil on the surface of the commutator?
A. As all lubricants are insulators to a greater or less extent,
the efficiency of the machine will be reduced and, as the voltage is
very low, but a slight falling off is necessary to represent a very sub-
stantial percentage of the maximum. The use of lubricant of any
nature on the commutator also has another harmful effect in that it
collects the carbon dust resulting from the wear of the brushes, caus-
ing it to lodge against them as well as between the commutator bars.
Q. Why should particular care be taken to remove all carbon
dust from the commutator housing of both the generator and the
motor (two-unit system) or the single unit where both functions are
combined in one machine?
A. Carbon dust is an excellent conductor of electric current
and, when spread over the surface of an insulator, it causes the latter
to become conducting as well. Consequently, it is likely to short-
circuit the commutator bars by lodging between them. It will cause
leakage across fiber or other insulating bushing of brush holders when
a sufficient deposit accumulates on them. It will penetrate the arma-
ture and field windings of the machine and may cause trouble by
grounding or short-circuiting them. Especial care should be taken
to remove all traces of carbon dust after sanding-in the brushes.
Q. How often should the commutator be inspected?
A. The commutator is the most vulnerable part of any direct-
current machine, whether it be a generator or motor, and it should
accordingly be inspected at more frequent intervals than any other
single part of the entire system. The efficiency of both the generator
and the motor depend upon it to a very great extent. Most of the
failures of starting and lighting systems that are not due to poor
condition of the battery may be traced directly to the commutator.
Q. What is the function of the brushes?
A. To conduct the voltage and current induced in the armature
by its revolution through the lines of force created by the magnetic
field, to the outer circuit, in the case of an electric generator; and to
conduct the operating current to the armature windings from the
battery, in the case of the starting motor.
Q. Why must the brushes bear evenly over their entire surface
on the commutator?
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A. Because their current-carrying capacity depends upon their
size, and the latter is based upon the entire surface of the end of the
brush making efficient contact. If the brush does not make uniform
contact, those parts of it that do not touch the commutator will cause
arcing or heavy sparking at the gap thus created, resulting in
damage to both the commutator and the brush.
Q. Why are springs of different strengths used on generators
and motors of different makes to hold the brushes against the commu-
tator, though the machines are of practically the same capacity,
operate at the same voltage, and are in other respects very much alike?
A. The carbon compounds of which the brushes are manufac-
tured differ greatly in their conductivity and resistance offered to the
passage of the current, and these differences call for greater or less
spring pressure to hold the brush against the commutator surface in
order to make efficient contact over the entire surface of the brush.
Every maker has his own standard in this particular respect.
Q. Why is it not advisable to use brushes other than those
supplied by the manufacturer as replacements on a machine?
A. For the reasons just given above. The manufacturer has
adopted certain standards for the operation of his machines, and the
brushes supplied have been made particularly to comply with those
standards. No other brushes will do so well, and some will result in
injury to the machine.
Q. When inspection shows that the brushes have worn down
unevenly, what should be done?
A. They should be sanded-in with a strip of fine sandpaper,
such as No. 00, preferably already worn if the brushes are very soft.
(See instructions for doing this properly in connection with machines
of different makes.) No more should be removed than is absolutely
necessary to bring the end of the brush to a firm contact all over its
bearing surface on the commutator; and the end of the brush, after
the completion of the operation, should not show any deep scratches
or pit marks. Unless the surface is smooth and true, injurious spark-
ing will result, and the efficiency of the machine will be decreased.
Q. If, with a smooth and true surface, the brush still fails to
make good contact, what is the trouble?
A. The brush has probably worn down until it is too short for
the spring to exert sufficient force against it to hold it against the
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ELECTRICAL EQUIPMENT 637
commutator properly, or the spring itself may be at fault. Wear of
the brush beyond the point where it is any longer of service will most
often be the cause.
Q. Where the brushes are true and are making good contact
against the commutator, but the machine is inoperative, all other
parts of the system being in good condition, what is likely to be the
trouble?
A. One of the pigtails, or short flexible connections, of the
brushes may have shaken out from under its spring clip. This breaks
the circuit, just as a parted wire or a ruptured connection at a terminal
in any other part of the system would.
Q. How often is it necessary to replace the brushes?
A. This differs so much with different makes of machines that it
cannot be answered definitely, even as an average. On two-unit
systems, the generator brushes will naturally require replacements
much sooner than those of the starting motor, as the starting motor i^
only in operation for very short periods, while the generator is working
constantly. On single-unit types, this naturally does not apply, as,
whether the armature has one or two sets, they are always in use.
Ordinarily, brushes should not require replacement under a year, and
frequent instances are known of their having lasted for two years or
more. It depends upon the care given the commutator and brushes
quite as much as upon the mileage covered, as, if allowed to run dirty
for any length of time, the brushes will wear away much faster than if
kept in good condition. The best rule for the replacement of the
brushes on all makes of machines is to renew them as soon as they
have worn to a point where the springs no longer hold them firm
against the commutator. When they have reached this condition, the
vibration and jolting of the car is likely to shake them out of contact,
which results in sparking.
Q. What is the "third brush", and what is its function?
A. This is an extra brush used on a generator. Its purpose is to
control the amount of current supplied by the armature to the shunt-
field winding as the speed increases. In other words, it regulates the
output of the machine and prevents it from being burned out when
the speed of the engine becomes very high.
Q. Does it differ from the other brushes in construction or in
the care required?
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638 ELECTRICAL EQUIPMENT
A. It is a carbon brush of the same nature as the others used on
the same machine, and the care required to keep it in good condition
does not differ. However, it is mounted in an independently adjust-
able holder so that it may be moved backward or forward with relation
to the main brushes in order to increase or decrease the output of
the generator. (See instructions [Delco] on this point.)
Q. Is it ever necessary to alter the location of the brushes
of a machine?
A. Except on generators fitted with the third-brush method of
regulation, on which it may be necessary to shift the main brushes
slightly to avoid having the third brush come in contact with one of
them when moved to change the output, it should never be necessary
to shift the location of the brushes. Efrush location has an important
bearing on the operation of the machine, and, in designing it, the maker
has fixed the location of the brushes to conform to its other charac-
teristics. Many nfachines have no provision for adjusting the
brushes in this respect, while some manufacturers caution the user
particularly against altering their location.
Q. How much spring pressure is usually employed to Hold the
brushes of the generator and starting motor against the commutator?
A. This varies with different makes of machines and should be
ascertained from the maker's instructions in every case in order to
check up properly. In the various models of the Gray & Davis
starting motors, this spring pressure ranges from 2\ to 3J pounds,
which is the minimum necessary. In other words, the brush must be
held against the commutator with this amount of pressure in order to
operate efficiently. While there will be a loss if the pressure drops
below the minimum, there is no advantage in greatly exceeding it, as
excess pressure simply causes greater friction loss without any com-
pensating gain in power. Generator-brush pressures are much less
than those employed on starting motors, owing to the smaller amount
of current handled.
Q. How can the proper spring pressure of the brushes be
checked?
A. With the aid of an ordinary spring scale of the direct-pull
type, in which the pull on the hook draws the pointer down over the
scale. A scale reading to five pounds is adequate for the purpose;
one intended for heavy weights is not likely to be so accurate. Attach
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the hook of the scale to the brush and pull until the brush is just clear
of the commutator. The scale will then register the pull in pounds.
Where there is nothing on the brush to which to attach the hook, such
as a screw, pl&ce a thin piece of wood on the brush face before passing
the hook of the scale around it, to prevent injuring the contact face
of the brush. In this case, the spring pressure as shown on the scale
will exceed the necessary minimum, as the spring must be compressed
further than it would be when in operation, in order to operate the
scale. This should be allowed for when taking the reading.
Q. When is it advisable to check the spring pressure of the
brushes?
A. When there is undue sparking at the commutator, while the
commutator and brushes are all in proper condition, i. e., clean, and
bearing uniformly over their entire surface so that the sparking is not
due to any fault in either of these essentials.
Q. When the brushes and commutator are in good condition
and the spring-scale test shows that the brushes are being held
against the commutator with the necessary amount of pressure, what
is likely to be the cause of the sparking?
A. There may be a short-circuited or open coil in the armature.
STARTING MOTOR
Q. In what way does the starting motor of a two-unit system
differ from the generator?
A. It is a simple series-wound machine having but one winding
of coarse wire on the fields, and all the current from the battery
passes through its armature coils and field windings.
Q. Is it subject to electrical faults other than those already
referred to in connection with the generator?
A. No. The care and the nature of the tests required to
locate faults are the same. The commutator should be kept clean,
brushes bearing firmly on commutator, and all connections kept
tight. The same instructions for sanding-in brushes and keeping
the commutator in good condition apply as in the case of the
generator.
Q. When the starting motor fails to operate, what is likely
to be the cause?
A. In the majority of instances, a low state of charge or a
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wholly discharged battery will be responsible. If the battery is
all right, a loose connection at the battery, switch, or motor, or a
short-circuit in some part of this wiring may be the cause. Should
the battery be properly charged, all wiring and connections in good
condition, switch contacts clean, etc., the starting gears may be
binding, owing to dirt or lack of alignment between the motor shaft
and the flywheel of the engine. In this case, the motor will attempt
to start when the current is first turned on, but will be held fast.
Loosen the holding bolts and line up the motor, cleaning the gear
teeth if necessary.
Q What is likely to be the cause of the starting motor running
slowly and with Very little power?
A. Exhausted battery, poor switch contacts, loose connec-
tions, partial ground or short-circuit in wiring causing leakage,
improperly meshing gears, dirty commutator, brushes making poor
contact owing to weak springs or worn brushes, or a ground hi the
motor itself. The remedies for all these faults have been given already.
Q. When the battery and all connections and wiring are in
good condition, but the motor fails to crank the engine, what is likely
to be the cause?
A. The engine may be too stiff. If it has been overhauled
just previously, the main bearings may have been set up too tight.
Test with the starting crank to see if it can be turned over easily
by hand. If unusual effort is required, easing off the bearings should
remedy the trouble. Should the engine not turn over as soon as
the switch is closed, release immediately, as otherwise the battery will
be damaged.
Q. When the engine does not start within a few seconds, why
is it better to use the starting motor intermittently than to run it con-
tinuously until the engine does fixe?
A. The intermittent use of the starting motor, say ten seconds
at a time, with a pause of half a minute or a minute between attempts
is easier on the battery. If allowed to rest for a short period, the
storage battery recuperates very rapidly. Consequently, the opera-
tion of the starting motor for two minutes, divided into twelve periods
of ten seconds each, will not run the battery down to anything like the
extent that its continuous operation for the same length of time would.
Moreover, this intermittent method of operation increases the chances
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of starting under adverse conditions, as, in very cold weather, every
time the battery is allowed to rest, it will be able to spin the engine at
its normal starting speed, whereas if the starting motor is operated
continuously, the battery will become so weak that the engine will be
turned over very slowly toward the end of the period in question..
Q. Why is it that a starting motor capable of turning an engine
over at a speed anywhere from 75 to 150 r.p.m. will sometimes fail
to start the engine, whereas hand cranking subsequently resorted
to will succeed?
A. It must be borne in mind that the operation of starting an
engine in cold weather involves several factors. (1) *The pistons,
crankpins and crankshaft (bearings) must be broken away, i.e.,
forcibly released from the hold that the gummed lubricating oil has on
them, before they can be moved. The great difference between the
power required to do this in summer and in winter is shown by the
greatly increased amount of current used by the starting motor.
(2) Gasoline and air must be drawn into the cylinders, to effect which
in sufficient quantity to start the engine requires quite a number of
revolutions. (3) The gasoline must be vaporized so that it will mix
with the air, which involves more turning of the engine to create the
necessary heat by compression in the combustion chambers and the
friction of the moving parts. In the application of energy in any
form, two factors are always involved, i.e., the unit, or quantity of
power applied, and the length of time during which it is applied. The
starting motor cranks the engine at a comparatively high speed for a
brief period. In hand cranking, a smaller unit of power is employed,
and the speed of cranking is accordingly less, but its application is
continued for a much longer time. The failure of the starting motor is
not due to its inferiority to hand cranking, but simply to the fact that
the battery has become exhausted. Success inliand cranking where
the starting motor has failed is usually due to the fact that the starting
motor has done all the preliminary work, failing in the end simply
because the storage battery did not have sufficient energy to finish
the task. No electrical starting system can ever be any stronger than
its storage battery, or source of energy.
Q. Why is it not necessary to protect the starting motor or its
circuit by fuses or other protective devices as in the case of the
generator?
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A. A simple series-wound machine (practically ali electric start-
ing motors are of this type) is capable of standing exceedingly heavy
overloads for short periods, it being nothing unusual for these small
motors to have a factor of safety of five, or even seven, for a limited
time, that is, they will take five to seven times the normal amount
of current for a brief period without injury. As a matter of fact, the
starting motor can utilize all the current the battery is capable of
supplying, provided the motor is free to move. If the engine is stuck
fast or some part of the starting system has gone wrong so that the
electric motor cannot turn over, then there is danger that the motor
may be damaged unless the switch is opened at once. This, together
with the fact that the maximum load which may be placed on the
motor at different times is such a variable quantity, would make it a
difficult matter to provide a fuse that would not blow unnecessarily.
The only object of the fuse would be to protect the motor windings,
and, as the latter can stand all the current the battery can supply, the
only source of danger is the possibility of the motor being held fast
so that its armature cannot revolve.
WIRING SYSTEMS '
Different Plans
Q. What is the difference between the single-wire and the
two-wire systems?
A. In the single-wire there is but one connection to the operat-
ing circuit by means of a wire or cable, the circuit being completed
in every instance by grounding the other side of the circuit. For
this reason the single-wire is also referred to as a grounded system.
In the two-wire system, copper wires or cables are employed to com-
plete the circuits between the generator and battery and between
the battery and the starting motor, as well as to the lamps.
Q. What forms the return circuit of a single-wire system?
A. The steel frame of the chassis.
Q. How are the various circuits grounded?
A. In the case of the battery, a special ground connection is
usually made by drilling the frame and fastening a clamp to it.
The ground cable from the battery is attached to this clamp. The
generator and starting motor are grounded internally, i.e., the end
of a winding or of a brush lead that would be taken out to form the
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return side of a two-wire system is connected to the frame of the
machine, and the latter completes the connection to the chassis
through its holding bolts or other means of attachment. ,One side
of all lamp sockets is usually grounded, so that the bulb itself com-
pletes the connection when fastened in place. Sometimes there
is a special ground connection from the battery for the return side
of the ignition or lighting circuits, and this ground wire is fused.
Q. What are the advantages and disadvantages of the single-
wire system?
A. It greatly simplifies the wiring, as but one wire connection
is necessary to the apparatus for each circuit, but this advantage
renders it more susceptible to derangement through unintentional
grounds or short-circuits, since the touching of any metal part of
the chassis by a bare wire will cause a short-circuit. This depends
to a very great extent, however, on the thoroughness with which
the wiring is protected, and, with the armored cables or loom and
the junction boxes used on modern installations, it is reduced
to a point where both systems are practically on a par in this
respect. .
Q. What are the advantages and disadvantages of the two-
wire system?
A. Each circuit is complete in itself thus rendering it easier
to locate faults, while no one connection coming in contact with
a metal part of the chassis will cause a ground. The wiring itself,
however, is much more complicated, and, with the small space
available on the bulb connections, it is more difficult to insulate
them properly.
Q. Which system of wiring is favored?
A. The single-wire system will be found on the majority of
cars, and the number of makers adopting it is steadily increasing.
Faults in Circuit
Q. What is the difference between a ground and a short-
circuit?
A. So far as the effect produced is concerned, they are the
same; the difference in the terms referring solely to the method of
producing it. For example, if the cable of the starting motor circuit
becomes abraded and the bare part touches the chassis or some
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644 ELECTRICAL EQUIPMENT
connecting part of metal, this is a ground. But it is also a short-
circuit in that the circuit to the battery is completed through a
shorter path than that intended. On the other hand, if, in a two-
wire system, the two cables of the same circuit become chafed close
together and their bared parts touch, this is a short-circuit, but
it is not a ground. For all practical purposes, however, the two
terms are really interchangeable when applied to faults in the circuit.
(See Gray & Davis instructions.)
Q. How may grounds be located in a single-wire system?
A. In any of the fused circuits, the fuse will immediately
blow out. Remove the fuse cartridge and shake it; if it rattles,
the fuse wire has melted and the fuse is blown. If it does not
rattle, short-circuit the fuse clips with the pliers or a piece of metal;
a spark will indicate the completion of the circuit and will also
indicate that the fuse has blown. If, on bridging the fuse clips,
the lamp lights, or other apparatus on the circuit operates, the
short-circuit was only temporary. This does not mean, however,
that the fault has been remedied; the vibration of the car may
have shaken whatever caused it out of contact and further vibra-
tion sooner or later will renew the contact with the same result.
Inspect the wiring of that particular circuit and note whether the
insulation is intact throughout its length. See that no frayed ends
are making contact at any of the connections and that the latter
are all tight and clean. In case the lamp does not light on bridging
the fuse clips, see if the bulb has blown out; if not, use the test
lamp by applying one point to the terminal and the other to various
points along the wiring.
Q. Does the blowing of a fuse always indicate a fault in the
wiring?
A. No. A bulb, in blowing out, frequently will cause a tem-
porary short-circuit that will blow the fuse. To determine this,
apply the points of the test-lamp outfit to the bulb contacts; if the
test lamp lights, the bulb is short-circuited, and a new fuse and bulb
may be inserted without further inspection of the circuit. In case
the test lamp does not light on this test, it does not necessarily
indicate a fault in the wiring of that circuit, though inspection is
recommended before putting in new fuse and bulb. The blowing
out of the bulb may cause a short-circuit, which is ruptured by the
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PLATE 167— SCRIPPS-BOOTH WIRING DIAGRAM OF lilt MODELS 6~St, 6-40, REMY SYSTEM
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PLATE 16»— SCRIPPS-BOOTH WIRING DIAGRAM OF 1920 SERIES B, REMY SYSTEM
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PLATE 174— STBVBNS-DURYBA WIRING DIAGRAM OF 1115 MODEL D«, DELCO
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ELECTRICAL EQUIPMENT 645
Current burning away the light metal parts that were in contact,
such as a small piece of the filament.
Q. Can a short-circuit or ground occur without blowing a fuse?
A. Yes. No fuses are employed on starting-motor circuits
owing to the very heavy current used and its great variation depend-
ing upon the conditions, such as extreme cold gumming the lubri-
cating oil, tight bearings, binding of the pinion and gear, sprung
shaft, starting motor out of alignment, or the like. On other circuits,
the amount of current leaking through the fault in the circuit may
not be sufficient to blow the fuse, as the capacity of the latter is
such that it will carry the maximum current which the apparatus in
that circuit will carry without damage — usually 5 or 10 amperes
on lighting circuits and 10 amperes on generator-field circuits.
Q. How can such faults be noted?
A. The ammeter, or indicator, will show a discharge reading
when the engine is idle and all lamps are switched off.
Q. What is the usual nature of such a fault?
A. The battery cut-out may have failed to open the circuit
completely; a frayed end of the stranded wire at one of its con-
nections may be making light contact which will permit a small
amount of current to pass; a particle of foreign matter of high
resistance may be bridging a gap either at the cut-out or some
other part of the circuit; or the ignition switch may have been
left on the battery contact so that current is flowing through the
ignition coil.
Q. How may faults be located in a two-wire system?
A. With the aid of the test lamp, placing the points along
the two wires of the circuit at fault from one set of terminal con-
nections to the other, examine all connections in the circuit in
question; note whether any wires have frayed ends and, if so, wind
them tight together and dip in molten solder. See whether any
moving part is in contact with one or both of the wires and whether
the insulation of the latter has been worn off. In some two-wire
systems there is a ground connection to the battery for the ignition
system, in which case tests for grounds in the circuit in question
must also be made. Examine the ignition switch for faults; also
the switch of the circuit under test. This applies to single-wire as
well as to two-wire systems.
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Q. What is one of the most frequent causes of short-circuits
in a two-wire system?
A. The bulbs and their sockets, owing to the very small
amount of space available for the insulation. Dirt or particles of
metal may be bridging the small gaps between their insulated con-
tacts. A blown-out bulb also may be responsible, as previously
mentioned.
Proper Conduction
Q. Why are different sizes of wire employed in the various
circuits?
A. To permit the passage of the maximum current necessary
in each circuit consistent with the m in imum drop in voltage due
to the resistance of the wire and its connections. The voltages
employed are so low that any substantial drop due to this cause
would seriously impair the efficiency of the system and particularly
of the starting motor. For the latter the cables employed are not
only large, but they are also made as short and direct as possible
to save current as well as expense in the installation.
Q. What is the smallest wire that should be employed in
automobile wiring?
A. No. 14 B. & S. gage, and this should be used only for the
tail lamp, dash, lamp, primary circuit of the ignition, or similar
purpose. No. 10 or No* 12 is usually employed for the other lighting
circuits.
Q. When, in making alterations on a car, it becomes neces-
sary to extend a circuit, what should be done?
A. The ends of the wires should be scraped clean and bright
for at least 2 inches, and a lineman's joint made with the aid of
the pliers to insure having it tight. A lineman's joint is made by
crossing the bared ends of the wires at their centers at right angles
to each other, then wrapping or coiling each extending end tight
around the opposite wire; the joint then should be soldered and
well taped. A circuit should be extended only by using wire of the
same size and character of insulation. None of the foregoing applies
to the starting-motor circuit. It is inadvisable to lengthen this
circuit if avoidable, but in the rare instances when it would be
necessary, new cable of the same size or larger and with the same
insulation should be cut to the proper length and the old cable
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discarded. All terminals should be solidly fastened to the new cable
by soldering.
Q. Why is it necessary to use such heavy cable for the connec-
tion of the starting motor to the battery?
A. It is essential that the exceedingly heavy starting current
be transmitted with the minimum of loss.
Q. What is considered the minimum permissible loss in the
starting-system wiring?
A. One maker specifies that the starting cable must be large
enough to transmit a maximum current of 400 amperes with not over
one-fourth volt total loss.
Q. Why is it important to hold the voltage drop down to a maxi-
mum so small as to be negligible in almost any other application?
A. Owing to the heavy current necessary, as a drop of but J
volt in potential with a current of 400 amperes represents a loss of 100
watts, or close to y horsepower. Of course, the current seldom
reaches such a high value as this except when a motor is exceptionally
stiff, as in severe cold weather or just after its bearings have been set
up very tight; moreover, this loss takes place at the instant of starting
only, but it is just at this time that the highest efficiency and full
battery power is needed to start without spinning the engine too much.
Q. On some of the early systems whose efficiency was not of
the best, how can the proper size of cable to use between the starting
motor and battery be determined?
A. Test the starting motor with a high-reading ammeter (scale
should read to at least 300 amperes) after having made certain by
hydrometer and voltage tests that the storage battery is fully charged.
(See instructions regarding this.) Carefully note ammeter reading
exactly at instant of closing switch, to determine maximum current
flow. Measure the length of cable between the battery and the
starting motor, i.e., both sides of starting switch. Then maximum
starting current times 10.7 times number of feet of cable used, divided
by .25 will give the cross-section of the wire in circular mills. For
example, assume that the starting motor required a maximum of 300
amperes momentarily to break away the engine, and five feet of
cable are employed for the connections. Then
300X10.7 X5 ^ 12g>400 circular miUs
25
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By referring to Table I, Part I, which gives the various size wires in
circular mills and their equivalent in gage sizes, it will be noted that
the closest approach to this is No. 00 cable, which is 133,079 circular
mills, so that the largest size cable would have to be used. If the
starting cable used on an old system which does not show particularly-
good efficiency is much smaller than this, it would probably be an
advantage to replace it with larger cable, assuming, of course, that
every other part of the system is in good condition and working
properly.
Q. Why should connections be inspected frequently?
A. The vibration and jolting to which they are subjected in
service is so severe that no mechanical joint can be depended upon
to remain tight indefinitely.
Q. What harm does a loose or dirty connection occasion?
A. A loose connection causes the formation of an arc between
its contacts whenever vibration causes the parts to separate tem-
porarily. This wastes current and burns the metal away, leaving
oxidized surfaces which are partially insulating, thus increasing
the resistance at the connection. Dirt getting between the surfaces
of the connector has the same effect; the resistance is increased and
there is a correspondingly increased drop in the voltage of the
circuit, which cuts down its efficiency.
Q. Why should all terminals be well taped when the battery,
starting motor, generator, or other apparatus is temporarily dis-
connected for purposes of inspection or test?
A. To prevent accidental short-circuits which would be caused
by these terminals coming in contact with any metal part of the
chassis on a single-wire system. Such a short-circuit would ruin
the battery and burn out any lamps that happened to be included
in the circuit. This precaution applies with equal force to the two-
wire systems, as in this case the terminals of the different wires
might come together, or there might be a ground connection in
the system.
PROTECTIVE AND OPERATIVE DEVICES
Q. What are the protective devices usually employed on
electric systems?
A. Fuses in the separate lamp circuits, in the ground con-
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nection, and in the field circuit of the generator on some machines;
battery cut-out for the charging circuit* circuit-breaker which
takes the place of the fuses.
Fuses
Q. What is a fuse and what is its function?
A. A fuse consists of a piece of wire of an alloy which melts
at a low temperature and which will only carry a certain amount of
current without melting, the latter depending upon the diameter
of the wire, i.e., cross-section and the nature of the alloy. The fuse
is usually in the form of a cartridge, the wire being encased in an
insulating tube having brass ends, to which the ends of the wire are
soldered. These brass ends are pressed into spring clips to put the
fuse in circuit. In some cases open fuse blocks are employed, the
wire itself simply being clamped under the screw connectors on the
porcelain block. The function of the fuse is to protect the battery
and the lamps when, by reason of a ground or short-circuit in the
wiring, an excessive amount of current flows.
Q. When a fuse blows out what should be done?
A. Investigate the cause before replacing it with a new one.
(See Wiring Systems.)
Q. Is it permissible to bridge the fuse gap with a piece of
copper wire when no replacements are at hand?
A. Only in cases of emergency and after the short-circuit
which has caused the fuse to blow has been remedied. The finest
size of copper wire at hand, such as a single strand from a piece of
lamp cord, should be used. If this burns out, there being no ground
or short-circuit in the wiring, use two strands. Remove the wire
as soon as a new fuse is obtainable.
Q. Why are fuses not employed in the starting-motor circuit?
A. In the starting circuit the current necessary is so heavy
and varies so widely with the conditions that it would not be
practicable to provide a protecting fuse.
Q. What does the intermittent blowing of the fuse on the same
circuit indicate?
A. A short-circuit that is caused by the vibration, or jolting, of
the car. The wire, lamp socket, or other part of the circuit that is at
fault is shaken loose at times so that the circuit is operative, and a new^
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fuse may be inserted without instantly blowing, as it would do were
the short-circuit constant. This is often the case as the car is stopped
to inspect the wiring and insert the new fuse, and standing still lets the
part drop out of contact; starting up shakes it into contact once
more and blows the new fuse. Loose connections, wires with abraded
insulation, and bulbs loosely inserted in their sockets are apt to cause
trouble of this nature.
Q. Does the blowing out of a fuse necessarily indicate a fault in
the wiring or in some other part of the system?
A. No, since a bulb in burning out will frequently cause the fuse
to blow out. This is due to the fact that in breaking, the end of the
parted filament of the bulb may fall across the other terminal where it
comes through the glass, thus causing either a short-circuit or such a
reduction in the ordinary resistance as to permit a much heavier rush
of current than normal, with the result that the fuse goes. To test,
leave burnt-out bulb in place temporarily; short-circuit fuse clips with
screw driver or pliers, just touching them momentarily; if no spark
results, replace bulb with a new one and test again; if a spark occurs,
remove old bulb and test again with no lamp in place; then if no spark
occurs in bridging the fuse terminals, the circuit is all right, and the
fuse may be replaced.
Q. When all the lighting fuses blow out at once, what does
this indicate?
A. A short-circuit across the lighting-switch terminals would
cause this. In some switches with exposed rear terminals, it is
possible to place a screwdriver or similar piece of metal in such a posi-
tion that it bridges practically all the switch terminals. If the light-
ing switches were all closed at the time, this would short-circuit them.
Circuit-Breaker
Q. What is a circuit=breaker, and what is its function?
A. The circuit-breaker is an electromagnet with a pivoted,
armature and contacts, similar in principle to the battery cut-out.
All the current used in the various circuits, except that of the start-
ing motor, passes through it, and its contacts normally remain closed.
The winding of the magnet coil is such that the normal current
used by the lamps or ignition does not affect it, but the passage
of an excessive amount of current will energize the magnet, attract
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the armature, and break the circuit. The spring holding the arma-
ture away from the magnet will again close the circuit, and the
circuit-breaker will vibrate until the cause has been removed. This
is usually a ground or short-circuit. The function of the circuit-
breaker is to protect the battery and lamps in place of the usual fuses.
Q. If the circuit-breaker operates when there are no faults
in the wiring, what is likely to be the cause?
A. Its spring may have become weakened so that the vibra-
tion of the car causes it to operate on less current. The Delco
circuit-breaker is designed to operate on 25 amperes or more, but,
once started, a current of 3 to 5 amperes will keep it vibrating.
If tests show that no faults in the wiring or connections exist,
increase the spring tension with the ammeter in circuit until the
reading of the latter indicates that the circuit-breaker is not operat-
ing on the current of less value than that intended. See that the
contacts are clean and true.
Battery Cut-Out
Q. What is a battery cut-out?
A. It is an automatic double-acting switch which is closed
by the voltage of the generator and opened by the current from
the battery.
Q. Of what does it consist?
A. It is essentially a double-wound electromagnet with a
pivoted armature and a pair of contacts. One winding, known as
the voltage coil, is of fine wire and is permanently in circuit with the
generator. The second winding of coarse wire is termed the current
coil and is put in circuit by the contacts.
Q. Why is a cut-out necessary?
A. To protect the storage battery. When the generator
speed falls below a certain point, it no longer produces sufficient
voltage to charge the battery, and the latter then would discharge
through th^ generator windings if not prevented. This discharge
would always take place when the generator was idle, except for
the ,cut-out.
Q; How does it operate?
A. When the generator voltage approaches the value nec-
essary for charging, it energizes the magnet through the voltage
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coil and closes the contacts, cutting in the current coil, which fur-
ther excites the magnet and holds the contacts firmly together.
The closing of these contacts puts the battery in circuit and it
begins to charge. As soon as the generator speed falls below the
point necessary for charging, the battery voltage overcomes that
of the generator and sends a current in the reverse direction through
the current coil, causing the contacts to separate and cutting the
battery out of the charging circuit.
Q. If the generator is run for any length of time at or near
this critical speed, what is to prevent the cut-out from vibrating
constantly instead of working positively one way or the other?
A. The resistance of the windings is so proportioned that
there is a difference of 1 to 2 volts between the cutting-in and the
cutting-out points.
Q. What is the result when the battery cut-out — which is
variously termed a cut-out, a circuit-breaker, an automatic switch,
and a reverse=current relay or an automatic relay — fails to operate?
A. If it fails to cut in, i.e., the contacts do not come together,
the battery does not charge and will quickly show a falling-off in
capacity, such as inability to operate the starting motor properly or
to light the lamps to full brilliance. If it fails to cut out, the battery
charge will be wasted through the generator windings with the same
indications of lack of capacity.
Q. What is the most frequent cause of trouble?
A. Automatic cut-outs have been perfected to a point where
but little trouble occurs. Freezing or sticking together of the
contacts due to excessive current will most often be found to be
the cause of the device failing to cut out when the generator is
stopped. The points should be cleaned and trued up as described
in previous instructions. Loose or dirty connections making poor
contact may insert sufficient extra resistance in the circuit to
prevent the device from cutting in at the proper point. Excessive
vibration, particularly when the cut-out is mounted on the dash,
may prevent the contacts from staying together as they should
when the engine is running at or above the proper speed. See that
the cut-out is solidly mounted. Temporary loss of battery capacity
may be due to slow driving over rough roads at about the speed
at which the cut-out is designed to put the battery in circuit.
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Q. None of the above causes existing, what further tests may
be made?
- A. The windings may be tested as already described for the
generator windings, but trouble from this source is equally rare.
If the contacts are clean and true and the connections are tight,
look for a loose connection elsewhere, as at the generator or battery
or the ground on the frame. A loose connection vibrates when the
car is moving, constantly opening and closing the circuit and dausing
the cut-out to do likewise, so that the battery does not charge. A wire
from which the insulation has been abraded will also vibrate, owing
to the movement, causing an intermittent short-circuit. With all con-
tacts and connections in good condition, failure to cut out indicates a
ground or short-circuit between the battery and cut-out; failure to cut
in indicates similar trouble between the generator and the cut-out.
Q. Is a battery cut-out necessary on every electrical system?
A. No. On single-unit systems of the type of the Dyneto,
in which the generator becomes motorized as soon as its speed and
consequently its .voltage drops below a certain point, the battery
is always in circuit. A plain knife-blade switch, which also controls
the ignition, is closed to start and left closed as long as the car is
running. But the engine must not be allowed to run at a speed
below which it generates sufficient voltage to charge the battery,
nor must the switch be left closed when the engine is not running;
otherwise, the battery will discharge through the generator windings.
* Q. After having trued up points of a battery cut-out, what pre-
cautions should be taken in adjusting them?
A. To insure proper operation, they must be set to the distances
given in the manufacturer's instructions. This refers not only to the
gap between the contact points themselves, but also to the distance
that the armature must be set from its backstop when the points are
open and to the air gap between the armature and the magnet.
These distances are very small in every case, and it is important that
they be adjusted accurately. They differ slightly on cut-outs of
different makes and also on different models of the same make. For
example, in the Gray & Davis cut-out, the distance between the con-
tact points should be .015, the air gap between the armature and its
backstop not less than .010, and the armature air gap, or distance
between the armature and the magnet face, .030. These dimensions
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refer to the flexible, or spring-arm type, while in the solid-arm type
of the same make, they are .010 for the distance between the contact
points and .015 for the armature air gap, it being necessary that the
armature should be set parallel with the pole face of the magnet.
Q. How can these small distances be accurately determined
with the facilities ordinarily found in a repair shop?
A. The manufacturers usually supply a small adjusting wrench,
the different edges of which have been ground to varying thicknesses
representing the proper distances for the various gaps. Lacking one
of these, small pieces of strip brass or steel may be ground or filed
down to the proper size and gauged with a micrometer, which should
be part of the equipment of every garage. The strips should be
stamped with the dimensions and name of gap for identification.
Q. How often will the point of a battery cut-out need adjust-
ment, or truing up?
A. Service conditions vary so greatly that it is impossible to give
any definite average for this, particularly as the instruments them-
selves also are a variable quantity, but, under ordinarily favorable
conditions, they should not require attention more than once a year.
Contact Points
Q. Why is it necessary to make contact points of such an expen-
sive metal as platinum, and why is the latter sometimes alloyed with
irridium?
A. There is no other metal which withstands the oxidizing
effect of the electric arc and still maintains a clean and bright con-
ducting surface as does platinum. Irridium is added to make the
platinum harder, so that it will be more durable. On cheaply made
instruments in which no platinum has been used in the contacts,
trouble will be experienced constantly with the contacts.
Q. Is there any substitute for platinum or any metal that
approaches it in adaptability for contact points?
A. There is no substitute for platinum, and the only metal that
approaches it is silver. Where contact points only separate occa-
sionally at intervals, as in the Remy thermoelectric switch, the use of
silver contacts is permissible; but in a battery cut-out, or a regulator
in which the vibration of the points is more or less constant, nothing
will serve so reliably as platinum.
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Q. What is the cause of the platinum contacts burning into such
irregular ragged forms?
A. When a current of electricity passes through a contact of this
nature, the material of the positive electrode (i.e., contact point
connected to the positive side of the circuit) is carried over by the
current in the shape of metallic vapor, or infinitely fine particles, and
deposited on the negative electrode. The positive consequently takes
on the form of a sharp point, while the negative has a depression
formed in it, usually referred to as a "peak and crater", which the two
points resemble iijL miniature after long use. This peak and crater
effect is much more noticeable in an old-style carbon arc lamp after
it has been burning only a few hours.
Q. What can be done to prevent this?
A. The passing of the metal from one electrode to the other
cannot be prevented, as it is a function of any arc or spark. It can
be minimized, however, by keeping the contacts in good condition so
that the sparking is reduced to a minimum.
Q. Can the formation of the pack and crater effect, which so
greatly reduces the efficiency of the contacts, be avoided?
Ar The use of a reversing switch in the circuit, as in the case of
the magneto or the battery-type interrupter which changes the direc-
tion in which the current flows through the points every time it is
turned on, will overcome this. Where there is no reversing switch
in the ignition circuit or where one cannot be used, attention to the
points at regular intervals will prevent this effect from reaching a
stage where most of the point has to be filed away to true it up.
Q. In the use of the file, sandpaper, or emery cloth in this con-
nection, just what is meant by truing the points up?
A. Their surfaces must be made exactly parallel to one another
so that when the points come together they touch uniformly over
their entire surfaces. In the hands of the unskilled user, there is a
tendency to bear down sidewise with the file, thus forming rounded
edges on the points. In addition to having the faces of the two points
perfectly parallel, the face of each point must be at right angles to its
sides. Otherwise, there is bound to be unnecessary sparking between
the points, and this causes them to burn away again much sooner.
It is scarcely necessary to add that as little as possible of the metal
should be removed. As long as there is enough of the platinum left
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to make true parallel surfaces, the points need not be replaced if
the means for adjustment permits utilizing them when worn far down.
Q. What is the cause of the points freezing, or sticking,
together?
A. Permitting them to wear down to a point where they are in
very poor condition and where the gap between parts of their surfaces
causes the formation of a heavy arc, or -hot flash of current, which
practically welds them together. By giving them the necessary
attention at regular intervals, this may be avoided.
Q. How often should the contact points need attention?
A. When new, they should run for a year or more without any
attention. After they have been trued up, the succeeding interval
will often depend upon the skill and care with which this has been
carried out.
Switches
Q. How do switches as employed on the automobile differ
in principle and operation?
A. StartingK^ircuit switches are either of the knife-blade or
the flat-contact type, while in the majority of cases the lighting
switches are of the push-button type, though knife-blade switches
are used for this purpose also. In some instances, one of the brushes
of the machine is made to serve as a switch, as in the Delco. Ordi-
narily, the switch is normally held open by a spring and is closed
by foot pressure, the spring returning it to the open position as
soon as released. A variation of this is the Westinghouse electro-
magnetically operated switch in which a solenoid takes the place of
foot operation. The circuit of the solenoid is controlled by a spring
push button, which is normally held out of contact. Single-unit
systems, such as the Dyneto, in which the machine automatically
becomes motorized when the speed drops below a certain point,
are controlled by a standard single-throw single-pole knife-blade
switch which is left closed as long as the machine is running.
Q. What faults may be looked for in switches?
A. Loose connections; weakening of the spring; burning of
the contact faces in the knife-blade type, due to arcing caused by
releasing too slowly; dirt or other insulating substance accumulating
on the contact faces of the flat-contact type; failure to release through
binding.
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Q. Why is it important to keep the switch contact faces clean
and bright?
A. Dirt or burned surfaces increase the resistance and cause
a drop in the voltage at the starting motor. The energy represented
by an electric current is a measure of the volume or amperes times
the voltage or pressure under which it flows, and, as such low voltages
are used, only a slight falling off represents a serious percentage
of the total potential. With a dirty switch or one that makes poor
contact, current that should be utilized in the starting motor is
* wasted in overcoming the resistance of the switch.
Q. Why is it inadvisable to insert an extra switch in the start-
ing circuit, as is done in some cases by owners to insure against
theft?
A. Because of the drop in voltage. The loss in switches as
designed for lighting circuits is about 1 per cent, or a little over 1
volt. If the same switch is used on the low voltage of the starter
system, the loss is then equivalent to about 10 per cent.
LIGHTING AND INDICATORS
Lamps
Q. How many types of bulbs are there in general use on
automobiles?
A. Four: miniature and candelabra screw base, and single-
and double-contact bayonet-lock base, both of the latter being of
the candelabra size.
Q. Are these types equally favored?
A. No. The screw-base type, particularly in the miniature
size, will be found only on old cars, and this type, generally speaking,
is practically obsolete on the automobile, as the vibration tends to
unscrew the lamp. Of the bayonet-lock type, the single-contact
style is steadily gaining favor. Ten million bulbs for automobile
lighting were produced in 1915 (S.A.E. report) and of these 67
per cent were of the single-contact type.
Q. In how many different voltages are these bulbs made?
A. Four: a 6 — 8-volt bulb for a 3-cell or 6- volt system; 12 —
16-volt bulb for 6-cell or 12-volt systems; and 18 — 24-volt bulbs for
9-cell systems; 3 — 4-volt bulbs for tail-light and dash-light use,
where these lights are binned in series on a 6-volt system.
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Q. Are these the only voltages in which the bulbs are made?
A. No. They are the types that are being standardized
to reduce the stock of replacements that it is necessary for a garage
to carry. It has been customary for the lamp manufacturer to
supply bulbs made exactly for any voltage that the maker of the
electric system ordered. Taking into consideration only the standard
sizes now listed for use on 3-, 6-, and 9-cell systems, and the different
bases regularly used, there are about twenty-four different bulbs
that should be stocked by a garage. In addition, about forty other
sizes are in general use, and if individual voltages had to be sup-
plied, considering the different standard bases, a stock of over
two-hundred different bulb sizes would be required.
Q. Why is the voltage of a bulb expressed as "6 — 8", "12 —
16", etc.?
A. Owing to the rise and fall of the battery voltage according
to its state of charge, this variation must be provided for, or the
lamps would be burned out when the battery was fully charged.
Headlight bulbs for 3-cell systems are made for 6£ volts, while the
side, rear, and speedometer lights are made for 6f volts, owing to
the lesser voltage drop in their circuits, but they will all operate
satisfactorily on a potential that does not exceed 8 volts or does not
drop below 6 volts.
Q. When all the lamps burn dimly, what is the cause?
A. The battery is nearly exhausted, in which case its voltage
will be only 5.2 to 5.5 volts for a 3-cell system. The car should be
run with as few lights as necessary to permit the generator to charge
the battery quickly.
Q. What is the cause of one light failing?
A. Bulb burned out or its fuse blown; examine the fuse before
replacing the bulb and if blown, examine the wiring before putting
in a new bulb. Poor contact; see that the lamp is put in properly
and turned to lock it in place. A double-contact bulb may have
been put in single-contact socket, or vice versa.
Q. Why will one lamp burn much brighter than the other?
A. A replacement may have been made with a bulb of higher
voltage; a 12-volt bulb will give only a dull red glow on a 3-cell
system. Where the difference is not so marked as this, but still
very perceptible, it may be due to the difference in the age of the
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lamps. A9 a bulb grows old in service, its filament resistance
increases, so that it does not take so much current and will not
burn as brightly as when new.
Q. Will the failure of a bulb cause its fuse to blow though
there is no fault in its circuit?
A. This sometimes happens owing to the breaking down of
the filament, causing a short-circuit when the lamp fails.
Q. Can the proper voltage bulbs needed for any system always
be told simply by taking the total voltage of the battery, i.e., the
number of cells times 2?
A. No. Always examine the burned out bulb and replace
with one of the same kind. Many 6-cell systems use 6-volt lamps
and are known as 12 — 6-volt systems. The battery is divided into
two groups in series parallel for lighting and sometimes for charging,
all the cells being in series for starting. Other arbitrary voltages
are also adopted; for example, 14-volt bulbs are used on 12-cell
systems, the battery being divided in the same manner, so that
this would be a 24 — 12-volt system. The only safe way to order
replacements is to give the voltage on the printed label on the old
bulb and state the make of the system on which it is to be used,
Q. What type of bulb is used where the current is taken from
the magneto, as on the Ford?
A. As supplied by the maker, only the headlights are wired,
and they are in series, and in recent models a 9-volt bulb is used,
but the above instructions for replacements will apply here also.
Ordinarily, double-contact bulbs are required, unless the fixtures
are insulated from one another, in which case the single-contact
type can be used.
Q. Why is a bulb of a voltage lower than that of the system
itself often employed on 6-, 9-, and 12=cell systems?
A. The lower the voltage, the thicker the filament can be made.
A short comparatively thick filament concentrates the light and
makes the bulb easier to focus; it is also much more durable than
the thin filament required for higher voltages.
Q. Under what conditions will the best results be obtained
from the head lamps?
A. When the bulbs are in proper focus with the lamp reflectors.
The usual focal length for headlight bulbs is £f inch, and the
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focal length of the reflector is made greater than this to permit of
adjustment. The center of the filament should be back of the focus
of the reflector to spread the beam of light. In this position a
greater number of the light rays are utilized and redirected by the
reflector, producing a higher beam candlepower. If the center of
the filament is forward of the focus, the lower part of the reflector
will produce the most glare and throw it into the eyes of pedestrians
and approaching drivers.
Q. How can the headlights be focused?
A. Place the car in position where light can be directed against
a wall about 100 feet distant. Adjust the bulbs backward or forward
until the spotlight on the wall is most brilliant and free from black
rings and streaks. When this position is found, lock the bulb securely
in place. Focus each headlight separately. See that the lamp
brackets are set so that the light is being projected directly ahead.
Q. How can metal headlight reflectors be cleaned when
discolored?
A. Wash by directing a gentle stream of cold water against
the surfaces and allow to dry without touching them. The reflectors
should never be rubbed with cloth or paper as it will scratch the
highly polished surfaces. If they become very dull, it will be neces-
sary to have them replated.
Q. What is the meaning of the identification marks usually
placed on bulbs, In addition to the voltage, such as "G=6"?
A. This refers to the size and shape of the bulb. The diameter
of the glass bulb is expressed in eighths of an inch and its shape by
a prefixed G for round (globular), T for tubular, S for straight-
side, etc. Thus, G-6 is a round bulb f inch or f inch in dfemeter.
Instruments
Q. What instruments ordinarily are employed in connection
with electric systems on the automobile?
A. Either a double-reading ammeter, a volt-ammeter, or an
indicator, the first named being employed generally. The ammeter
shows whether the battery is charging or discharging or whether no
current is passing; the indicator reads either Off or On; while the
voltammeter gives the voltage, usually upon pressing a button to
put it into operation, in addition to the readings already mentioned.
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ELECTRICAL EQUIPMENT 661
Q. On what circuits are the indicating instruments placed?
A. The charging circuit from the generator to the battery,
and the lamp and ignition circuits.
Q. Why is an ammeter not used for the starting-motor circuit?
A. The current is so heavy and varies so greatly with the
conditions that an ammeter designed to give an accurate reading
of it would not be sensitive enough to indicate the smaller amounts
of current used by the lamps, or produced by the generator for
charging. Furthermore, the starting motor is intended only to
be used for very short periods, while the other circuits are in
constant use.
Q. Do the small ammeters employed fail very often?
A. Considering the unusually severe treatment to which they
are subjected by the vibration and jolting of the car, their failure
is comparatively rare, but as the conditions are so severe for a
sensitive indicating instrument, too much dependence should not
be plaqed on the ammeter reading when making tests.
Q. What are the usual causes of failure?
A. Failure to indicate — the generator, wiring, and other parts
of the circuit being in good operative condition — may be caused by
the pointer becoming bent, so as to bind it; the pointer may have
been shaken off its base altogether by the jolting, or one of its connec-
tions may have sprung loose from the same cause.
Q. How can the ammeter reading be checked?
A. By inserting the portable testing voltammeter in circuit
with it, using the 30-ampere shunt and comparing the readings.
The dash ammeter must not be expected to give as accurate a
reading as the finer portable instrument. Failing the latter, a spare
dash ammeter may be employed in the same manner and the spare
may be tested beforehand by connecting to a battery of 4 dry cells
in series; if brand new, they should give a reading of 18 to 20 amperes.
Do not keep the ammeter in circuit any longer than necessary to
obtain the reading, as it only runs the cells down needlessly.
Q. Should an ammeter ever be used in testing the storage
battery?
A. No. Because it practically would short-circuit the battery,
burn out the instrument, and damage the battery itself. Nothing
but a voltmeter should be e nipl o y e ^ * or ^is purpose* as its high
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resistance coil permits only a small amount of current to pass. An
ammeter reading from a storage battery gives no indication whatever
of its condition, whereas the voltage affords a close check on the
state of charge, varying from 1.75 for a completely discharged cell
to 2.55 volts for a fully charged one, the readings always being
taken when the battery is either charging or discharging. The
voltage on discharge will v not be as high as on charge, the conditions
otherwise being the same.
Q. Why are indicators employed on some systems instead
of ammeters?
A. As the indicator is not designed to give a quantitative
reading, it need not be so sensitive as an ammeter and accordingly
can be made more durable.
Q. What are the most frequent causes of failure of an indi-
cator?
A. Usually of a mechanical nature caused by the jolting, such
as the target being shaken off its bearings, broken wire, etc. '
Q. When the engine is running slowly, and the ammeter or the
indicator flutters constantly, going from "On" to "Off" at short inter-
vals, in the case of the indicator, or from a small charging current to
zero, in the case of the ammeter, what does this signify?
A. That the setting of the battery cut-out is very sensitive
and that the engine is then running at or about the speed that the
instrument should cut-in. Since the speed of an engine varies con-
siderably when, running slowly, picking up momentarily and then
falling off for a longer period, there is a corresponding variation in the
potential, causing the cut-out to operate intermittently. This is a
condition that seldom occurs and results in no harm when it does.
Q. When the ammeter or indicator flutters in the same manner
with the engine running at medium or at high speed, what does it
indicate?
A. That there is a loose connection between the generator and
the cut-out, or an intermittent short-circuit or ground caused by a
chafed wire alternately making contact with some metal part owing
to the vibration. It is much more likely to be simply a loose connec-
tion and will be found most often on the back of the cut-out itself.
This should be remedied at once. If neglected, it will cause abnormal
wear of the platinum points in the cut-out.
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ELECTRICAL EQUIPMENT 663
Q. When the ammeter does not indicate "Charge" though the
engine is speeded up, but does register a discharge when the lights
are turned on and the engine is idle, what is the nature of the trouble?
A. Either the generator is not producing current or the regula-
tor (where an external type is employed) is not working properly.
The generator brushes may not be making proper contact with the
commutator, or there may be a loose, corroded, or broken connection
in the generator cut-out battery circuit. Where a belt drives the
generator, it may be too loose to run the machine at its proper speed.
Q. When the ammeter gives no charging indication though the
lamps are off and the engine is speeded up, and gives no discharging
indication though the engine is idle and lamps are switched on, what
is likely to be the cause?
A. There is an open or a loose connection in the battery circuit
or in the battery itself. The ammeter may be at fault. See that its
indicating pointer has not become jammed nor dropped off its bearings.
Q. In case the ammeter indicates "Discharge" though the
engine be idle and all lights turned off, what is the trouble? >
A. There is a short-circuit or a ground somewhere in the light-
ing circuits or between the battery and the ammeter, as the discharge
reading in such circumstances indicates a leakage of current; or the
cut-out has failed to operate and still has the battery in circuit with
the generator, though the engine is stopped. The ammeter pointer
may be bent.
Q. When the meter indicates a charge though the engine is at
rest, what is the nature of the fault?
A. The ammeter pointer has become bent or deranged so that
it is stuck fast in place, showing a charge.
Q. When the ammeter charge indications are below normal,
what is apt to be the cause?
A. The generator commutator or brushes may need attention,
such as cleaning or sanding-in, or new brushes may be necessary.
The generator speed may be too low; in case of belt drive, it may not
be getting the benefit of the full speed of the engine owing to a slipping
belt. The regulator (external type) may not be functioning properly,
or there may be an excessive lamp load on the generator. N
Q. When the ammeter charge reading is above normal, what
is likely to be the cause?
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664 ELECTRICAL EQUIPMENT
A. There may be a short-circuited cell in the battery, or a short
in the charging circuit, or the regulator (external type^ may not be
working properly.
Q. What will cause the discharge reading of the ammeter to
become abnormally high?
A. The lamp load may be excessive, as where higher candle-
power bulbs are used, or more lights than originally intended are put
in the circuit. There may be leakage in some part of the lighting
Circuit, or the cutout contacts may be stuck together, permitting a
discharge through it or through the generator.
ELECTRIC QEAR-SHIFT
Q. What is the operating principle upon which the electric gear-
shifting mechanism is based?
A. That of the solenoid and its attraction for its core when a
current is passed through its winding.
Q. What is the source of current supply for the electric gear-
shift?
A. The storage battery of the lighting system. The operation
of gear-shifting is carried out so quickly that only a nominal additional
demand is made on the battery.
Q. How is the electric gear-shift controlled?
A. By a series of buttons corresponding to the various speeds
and located on the steering wheel, and by a master switch..
Q. What is the object of the buttons, and what are they termed?
A. To partly close the circuit to the particular solenoid of the
speed desired. They are termed "selector switches" since they per-
mit selecting in advance the speed desired.
Q. Why is a master switch employed, and why is it so called?
A. To avoid the complication which would otherwise result
from the necessity of providing two switches for each change of speed,
i.e., a selector switch and an operating switch. It is termed a master
switch because it controls the current supply to all of the circuits.
Q. Why is a neutral button provided in addition to the but-
tons for the various speeds on the selector switch?
A. To return any of the selector buttons to neutral without
the necessity of going through that speed in case it is not desired to
engage the speed in question after the button has been pushed Also
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to open any of the selector switches that may be closed when it is
desired to stop.
Q. What is the neutralizing device?
A. It is a mechanism incorporated with the shifting mechanism
to open the master switch automatically after the gears have been
engaged.
Q. Why is the neutralizing device necessary?
A. If it were not provided, the master switch would remain
closed, causing a constant drain on the battery and rendering the
mechanism inoperative after one shift had been made.
Q. How many solenoids are provided in the standard three-
speed and reverse gear box?
A. One for every movement necessary.
Q. Is the current sent through a solenoid in one direction to
pull the shifting bar into it and then in the opposite direction to move
the bar the other way?
A. No, the current is not reversed through the same solenoid.
After the left-hand solenoid, operating the first-speed gear, for
example, has pulled the shifter bar to the left, a second solenoid,
on the opposite end of the same bar, is energized to pull it back to the
right, to shift to second or intermediate.. The current is sent through
a different solenoid by means of the selector switches for each shift
desired.
Q. When the electric gear-shift failed to operate, where would
be the most likely place to look for the cause of the trouble?
A. First see that the battery is not exhausted, then that no
connections between the battery and the terminal block have parted,
thus cutting off the current supply. The wiring is so simple and so
strongly protected that it is very unlikely to have anything happen to
it except at the connections. This is likewise true of the solenoids.
Q. In case the battery is amply charged and nothing is wrong
with the connections, what procedure should be followed?
A. Use the lamp-testing set described in connection with the
lighting and starting systems and test out the various circuits as
shown on the wiring diagram. In using this test, it must always be
borne in mind that touching the two points to the same or connecting
pieces of wire or metal will always cause the lamp to light. It is useful
in this way for indicating the continuity of a wire, i.e., that it has not
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broken under the insulation, but, until experience has been gained in
its use, it will be nothing unusual to find that the points have been
touched to connecting pieces of metal which have no relation to the
circuit. As such metal will complete the circuit through the lamp,
the latter will light, but without indicating anything of value to the
trouble hunter. Always test the lamp itself before proceeding. It
may have become partly unscrewed in its socket or its filament may
have been broken.
BATTERY
Electrolyte
Q. Why is it necessary to refill the battery jars at regular
intervals?
A. Because the heat generated in the cells evaporates the
water from the electrolyte, and, if the latter is permitted to fall
below the tops of the plates, they will dry out where they are
exposed, and the heat of charging will then cause them to disinte-
grate, ruining the battery.
Q. Why should this be done at intervals of not less than
two weeks?
A. Because the limited amount of electrolyte permitted
by the restricted size of the cells over the plates — usually one-half
inch — will be evaporated in that period by a battery that is in
more or less constant use.
Q. Why should water alone and never acid or electrolyte
be used to make up this loss?
A. Only the water evaporates, so that if either acid or fresh
electrolyte is added, it will disturb the specific gravity of the solu-
tion in the cells and totally alter their condition.
Q. What is the reason that battery manufacturers insist
that only distilled water or its nearest equivalent, rain water or
melted artificial ice, be used for this purpose?
A. Because ordinary water contains impurities that are
apt to harm the plates, such as iron salts, or alkaline salts that will
affect both the plates and the electrolyte.
Q. What should be done to a battery that has had its efficiency
impaired by being filled with impure water?
A. The cells should be taken apart, the separators discarded,
the plates thoroughly washed for hours in clean running water
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ELECTRICAL EQUIPMENT 667
without exposing them to the air where they would dry, the jars
washed out, the plates reassembled with new separators, the jars
filled with fresh electrolyte of the proper specific gravity, and the
battery put on a long slow charge from ah outside charging source,
i.e., not on the car itself. Unless there are proper facilities for
carrying this out, it will be preferable to ship the battery back to
the maker so that it can be given proper treatment, particularly
as it is necessary to reseal the cells.
Q. How is electrolyte prepared?
A. By adding pure sulphuric acid a very little at a time to
distilled water until the proper specific gravity is reached, and then
permitting the solution to cool before using. The mixture must
always be made in a porcelain, hard rubber, or glass jar; never
in a metal vessel. Commercial sulphuric acid or vitriol should
not be employed, as it is far from pure. Never add water to acid.
When the two are brought together, their chemical combination
evolves a great amount of heat, and the acid will be violently
spattered about.
Q. How often should distilled or rain water be added to the
cells?
A. This will vary not alone with different systems but with
different cars equipped with the same system, owing to the difference
in conditions of operation. The only way to determine this definitely
is to inspect the cells at short intervals and note how long they will
operate before the electrolyte gets close enough to the tops of the plates
to require additional water. This may be a week, ten days or two
weeks, or even more, if the car is not run much.
Q. When a battery requires the addition of water at very short
intervals to keep the level of the electrolyte one-half inch above the
plates, what does this indicate?
A. It shows that the battery is being constantly overcharged,
which keeps it at a high temperature, causing excessive evaporation.
This will usually occur where a car is in constant use during the day
but is driven very little at night. It may be remedied by adjustment
of the regulation so as to reduce the output of the generator. Where
this is not possible, as in the case of simple bucking-coil regulation
which is entirely self-contained and permits no variation, additional
resistance may be introduced in the generator-battery circuit. This
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may take the form of a small-resistance unit consisting of German
silver or other high-resistance wire wound on a porcelain tube
and mounted on the forward side of the dash. A single-pole knife
switch should be placed in the circuit with the resistance so that
the latter can be cut in or out of the generator circuit as circum-
stances may require.
Q. With conditions as in the preceding question, how can the
amount of resistance to be inserted in the circuit be figured?
E
A. By the use of Ohm's law. In this case, it would be R=-^ t
or resistance equals voltage divided by current. How much resist-
ance to use can only be answered by the conditions of operation.
Where a car is used steadily during the day and very seldom at night,
it may be necessary to reduce the charge by two-thirds. In the case
of a 6-volt system normally charging at 12 amperes, the generator
delivers current at 7 to 7^ volts in order to overcome the voltage
of the battery when fully charged. Selecting 7 volts, we see that
the resistance in circuit when the current is 12 amperes is 7 ■*- 12, or .6
ohm approximately. Now when the charging current is 4 amperes,
we must have 7-S-4, or 1.75 ohms in circuit; that is, to reduce the
current from 12 to 4 amperes, a resistance of 1.75— .6, or 1.15 ohms
must be inserted. The amount of resistance wire necessary to give
this resistance or any other resistance necessary may be found in
tables of wire sizes and resistances of special wire employed for this
purpose. The wire is bare and must be wound on the tube so that
adjacent coils do not touch. An extreme instance is cited here. It
may be necessary in many cases to reduce the charging rate by a
very much smaller fraction. Ordinarily the charging rate should
not be altered.
Q. When the battery is constantly gassing, or "boiling",
as the car owner usually puts it, what is the trouble?
A. It is being constantly overcharged. This will greatly reduce
the life of the battery, and the charging rate should be reduced, as
mentioned in the preceding answer. It is essential that the battery
be kept fully charged; but if it is continually overcharged, this will
keep the cells at an abnormal temperature which is injurious to the
plates. The battery treatment will vary with the season, for the
demand on it is much heavier during cold weather than in summer.
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Hydrometer Tests
Q. Why should the battery be tested with the hydrometer
at regular intervals of a week or so?
A. Because the specific gravity of the electrolyte is the most
certain indication of the battery's condition.
Q. What should the hydrometer read when the battery is
fully charged?
A. 1.280 to 1.300.
Q. What point is it dangerous to permit the specific gravity
of the electrolyte to fall below, and why?
A. 1.250; because below this point, the acid begins to attack
the plates and the battery plates sulphate. The lower the specific
gravity, the faster sulphating takes place.
Q. What should be done when the hydrometer reading is
1.250 or lower?
A. The battery should be put on charge immediately, either
by running the engine or by charging from an outside source of
current until the gravity reading becomes normal.
Q. If the hydrometer reading of one cell is lower than that
of the others, what should be done?
A. Inspect the cell to see if the jar is leaking; note whether
electrolyte is over the plates to the depth of J inch and whether
the electrolyte is dirty. If these causes are not apparent, the cell
will have to be opened and inspected for short-circuits from an accu-
mulation of sediment in the bottom of the jar or from buckling of
the plates.
Q. Are hydrometer tests alone conclusive?
A. No. To be strictly accurate, they should be checked by volt-
age tests, in addition.
Q. How should these voltage readings be taken?
A. With the aid of a portable voltmeter, using the low-reading
scale, i.e., 0-3 volts, and always with the battery discharging, the load
not exceeding its normal low discharge rate.
Q. Why should the test not be made with the starting-motor
load?
A. Because the discharge rate while the starting motor is being
used is so heavy that even in a fully charged battery in good condition
it will cause the voltage to drop rapidly.
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Q. Why should the voltage readings not be taken while the
battery is charging?
A. Because the voltage of the charging current (always in
excess of six volts) will cause the voltage of a battery in good condition
to rise to normal or above the moment it is placed on charge, such
readings are not a good indication of the battery's condition.
Q. What should the voltage of the cells be?
A. In any battery in good condition, the voltage of each cell at
the battery's normal low discharge rate (5 to 10 amperes, as in carry-
ing the lamp load) will remain between 2.1 and 1.9 volts until it begins
to approach the discharged condition. A voltage of less than 1.9 volts
per cell indicates either that the battery is nearly discharged or that
it is in bad condition. The same state is also indicated when the
voltage drops rapidly after the load has been on a few minutes.
Joint Hydrometer- Voltmeter Test
Q. What should the hydrometer and voltmeter readings be for a
fully charged battery in good condition?
A. Hydrometer 1.275 to 1.300; voltage 2 to 2.2 volts per cell.
Q. What does a hydrometer reading of 1.200 or less with a
voltage of 1.9 volts or less per cell indicate?
A. This shows that excess acid has been added to the electro-
lyte. Under these conditions, the lights will burn dimly even though
the hydrometer test alone would appear to show that the battery is
more than half charged.
Q. What does a hydrometer reading in excess of 1 .300 indicate?
A. It indicates that an excessive amount of acid has been added
to the electrolyte, regardless of whether the voltage reading is high,
low, or normal.
Q. Where a low voltage reading is found, how can it be deter-
mined whether the battery is in bad condition or merely discharged?
A. Stop the discharge by switching off the load (lamps) and put
the battery on charge, cranking the engine by hand. After a few
minutes of charging, note whether the voltage of each cell promptly
rises to 2 volts or more. Any cells that do not are probably short-
circuited or otherwise in bad condition.
Q. How can a rough test of the condition of the battery be made
without the use of any instruments?
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ELECTRICAL EQUIPMENT 671
A. On systems fitted with a battery cut-out in the generator
battery circuit, remove the cover of the cut-out (the generator being
stationary) and momentarily close the cut-out points with the finger.
The discharge shown by the ammeter the monent the points are
closed should be anywhere from 10 to 20 amperes, differing, of
course, with different systems. In any case, it should be equal to or
greater than the. maximum normal output of the generator, provided
the battery is at least three-quarters charged.
Q. What effect will allowing the electrolyte to fall too low in
the cells have, apart from the damage that it will cause to the plates?
A. It will tend to increase the voltage if the battery is otherwise
in good condition, and this may be carried to a point where it will
burn out the lamps.
Q. What is meant by "floating the battery on the line"?
A. This describes the relation of the battery to the generator
and lighting circuits in systems where the current for lighting is taken
directly from the generator when running, any excess over the require-
ments of the lamps being absorbed by the battery. The moment the
generator speed falls below the point where it supplies sufficient cur-
rent to supply all that is needed for the lamps, the battery automati-
cally supplies the balance. When the generator is idle, the battery,
of course, supplies the current for lighting as well as for starting.
Gassing
Q. Why should the cell tops be wiped dry from time to time
and the latter as well as the terminals be washed with a weak
solution of ammonia and water?
A. As the charge approaches completion, the cells gas; when
overcharged they gas very freely. This gas carries with it in the
form of a fine spray-some of the electrolyte, and the acid of the latter
will attack the terminals and corrode them. Wiping clean does
not remove this acid entirely, so the ammonia solution is necessary
to counteract its effect, the ammonia being strongly alkaline.
Q. Why should an unprotected light, i.e., any flame or spark,
not be allowed close to a storage battery?
A. Because the gas emitted by the battery on charge is hydro-
gen, which is not only highly inflammable but, when mixed in
certain proportions with air, forms a powerful explosive mixture.
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Q. What is the cause of gassing?
A. When a battery is charged, the water of the electrolyte
is decomposed by the current into gases. During the early part
of the charge these gases unite with the active material of the plates,
but as the charge proceeds, more gas is evolved than the plates
can take care of and it bubbles up through the electrolyte. This
is known as the gassing point, and the temperature of the cell also
begins to rise at that point.
Q. Is gassing harmful to the battery?
A. The greatest wear on the positive plates takes place during
the gassing period, and, if carried too far, they may be injured by
reaching a dangerous temperature (105° F., or over) which will tend
to loosen the active material.
Q. How can gassing be checked?
A. By cutting down the charge. In some systems this can
be effected by the insertion of extra resistance provided for the
purpose. Where this cannot be done and it is necessary to keep
the car running, turn on all the lamps or start the engine once or
twice to reduce the charge of the battery. As the lamps usually
consume 80 to 95 per cent of the generator output, they should be
sufficient to prevent a further overcharge.
Q. Can the generator be disconnected from the battery to
prevent overcharge?
A. Not unless it is short-circuited, as directed in the instruc-
tions covering different systems. Otherwise, it will blow its field
fuse or, where one is not provided, burn out its windings, except
in cases where special provision is made to guard against this.
Sulphating
Q. Why must a battery never be allowed to stand in a fully dis-
charged state?
A. Because the acid of the electrolyte then attacks the plates
and converts the lead into white lead sulphate which is deposited
on them in the form of a hard coating that is impenetrable to the
electrolyte, so that the plates are no longer active. The battery
then is said to be svlphated.
Q. Can a sulphated battery be put in good condition, and what
treatment must be given it to do so?
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A. If the sulphating has not gone too far, the battery may
be brought back to approximately normal condition by a long heavy
charge at a higher voltage than ordinary. Where the battery has
become badly sulphated, it is preferable to remove it from the car
and charge from an outside source of current, as it may require
several days to complete the process. (Note instructions regarding
the running of the generator when disconnected from the battery,
as otherwise it may be damaged.) If avoidable, the car should not
run with the battery removed. If the battery has not stood dis-
charged for any length of time, the charge may be given on the
car by running steadily for 8 to 10 hours with all lights off. No
lamps must be turned on, as the increased voltage is liable to burn
them out.
Voltage Tests
Q. What is the purpose of the voltmeter in connection with the
battery?
A. It is chiefly useful for showing whether a cell is short-
circuited or is otherwise in bad condition.
Q. Can the voltmeter alone be relied upon to show the condition
of the cells?
A. No; like the hydrometer, its indications are not always con-
clusive, and it must be used in conjunction with the hydrometer to
insure accuracy.
Q. What type of voltmeter should be employed for making
these tests?
A. For garage use, a reliable portable instrument with several
connections giving a variable range of readings should be employed.
For example, on the 0-3 volt scale, only one cell should ever be tested;
attempting to test any more than this is apt to burn out the 3-volt
coil in the meter. The total voltage of the number of cells tested
should never exceed the reading of the particular scale being used at
. the time, as otherwise the instrument will be ruined.
Q. Must these readings be particularly accurate?
A. Since a variation as low as .1 volt (one-tenth of a volt) makes
considerable difference in what the reading indicates as to the condi-
tion of the battery, it will be apparent that the readings must not only
be taken accurately, but that a cheap and inaccurate voltmeter is
likely to be misleading ra th 6 * ^ aan helpful.
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Q. What precautions should be taken before using the volt-
meter?
A. Always see that the place on the battery connector selected
for the contact is bright and clean and that the contact itself is firm,
otherwise the reading will be misleading since the increased resistance
of a poor contact will cut down the voltage.
Q. How is the instrument connected to the battery?
A. The positive terminal of the voltmeter must be brought in
contact with the positive terminal of the battery and the negative
terminal of the voltmeter in contact with the negative terminal of
the battery.
Q. In case the markings on the battery are indistinct, how can
the polarity be determined?
A. Connect the voltmeter across any one cell. Should the
pointer not give any voltage reading, butting against the stop at the
left instead, the connections are wrong and should be reversed; if the
instrument shows a reading for one cell, the positive terminal of the
voltmeter is in contact with the positive terminal of the battery.
This test can be made without any risk of short-circuiting the cell,
since the voltmeter is wound to a high resistance and will pass very
little current. Such is not the case with the meter, which should
never be used for this purpose.
Q. When the battery is standing idle, what is the cell voltage
and why is this not a good test?
A. Approximately two volts, regardless of whether the battery
is fully charged or not. Voltage readings taken when the battery is on
open circuit, i.e., neither charging nor discharging, are only of value
when the cell is out of order.
Q. If the battery is in good condition and has sufficient charge,
what should the voltmeter reading show?
A. Using the lamps for a load, the voltage reading after the load
has been on for five minutes or longer should be but slightly lower
(about .1 volt) than if the battery were on open circuit.
Q. When one or more cells are discharged, what will the read-
ing show?
A. The voltage of these cells will drop rapidly when the load is
first put on and sometimes even show reverse readings, as when a cell
is out of order.
296
ELECTRICAL EQUIPMENT 675
Q. What will the voltmeter indicate when the battery is nearly
discharged?
A. The voltage of each cell will be considerably lower than if on
open circuit after the load has been on for five minutes or more.
Q. How can the difference be distinguished between cells that
are merely discharged and those that are in bad condition?
A. Put the battery on charge, cranking the engine by hand to
start, and test again with the voltmeter; if the voltage does not rise to
approximately 2 volts per cell within a short time, it is evidence that
there is internal trouble which can be remedied only by dismantling
the cell.
Q. What effect has the temperature on voltage readings?
A. The voltage of a cold battery rises slightly above normal on
charge and falls below normal on discharge. This last is one of the
chief reasons for its decreased efficiency in cold weather.
Q. What is the normal temperature of the battery and to what
does this refer?
A. The normal temperature of a battery is considered at 70° F.,
but this refers to the temperature of the electrolyte in the battery as
shown by a battery thermometer and not to the temperature of the
surrounding air. If the battery has been charging at a high rate for
some time, it may.be normal even though the weather be close to zero
at the time.
Sediment
Q. What is the cause of sediment or mud accumulating
in the jars, and why must it be removed before it reaches the bottoms
of the plates?
A. This sediment consists of the active material of the plates,
which has been shaken out, due to the loosening caused by the charg-
ing and discharging, and aggravated by the constant vibration. It
must never be allowed to reach the plates, as it is a conductor and
will short-circuit them and thus ruin the battery.
Q. How long will a battery stay in service before this occurs?
A. This depends on the type of jar employed and the treat-
ment that the battery has received. Ifjt has been kept constantly
overcharged, or if discharged to exhaustion in a very short period,
as by abuse of the starrer motor when the engine is not in good
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676 ELECTRICAL EQUIPMENT
starting condition, or if it has been subjected to short-circuits by
grounding or by dropping tools on its terminals, the plates will
disintegrate much quicker than where proper treatment has been
given it. With the old-style jar, only an inch or so is allowed to
hold this accumulation of sediment below the plates, while in later
types fully 3 inches or more are allowed in the depth of the cell for
this purpose. A battery with jars of the latter type that has been
cared for properly should not require washing out under two years.
The procedure is the same as that given for removing the effects of
impure water. The plates must never be allowed to dry.
Washing the Battery
Q. What is meant by washing the battery, and why is it
necessary?
A. Washing a battery involves cutting the cells apart, wash-
ing the elements and the jars, and reassembling with new separators
and new electrolyte. It is necessary to prevent the accumulation
of sediment, consisting of active material shaken from the plates,
to a point where it will touch them and thus cause a short-circuit,
Q. How often is it necessary to wash a battery?
A. This will depend on the type of cell in the battery and the
age of the latter. If the battery has the modern-style jar with extra
deep mud space, it probably will not be necessary to wash it
until it has seen two to three seasons' use. With the older form
of cell in which the space allowed for sediment is much less, washing
doubtless will be necessary at least once a season. As the battery
ages, it will be necessary to wash it oftener.
Q. What other causes besides the type of jar and the age of
the battery influence the frequency with which it is necessary to
wash the battery?
A. The treatment the battery has received. If it has been
abused by overcharging and permitting the cells to get too hot,
the active material will be forced out of the grids much sooner.
Q. How can the necessity for washing be determined?
A. The presence of one or more short-circuited cells in a
battery that has not been washed for some time will indicate the
necessity for it. Each cell should be tested separately with the
low-reading voltmeter; a short-circuited cell will either give no
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ELECTRICAL EQUIPMENT 677
voltage reading or one much below that of the "others. Cut such
'a cell out and open it; if the short-circuit has been caused by an
accumulation of sediment, the others most likely are approaching
the same condition.
Q, How is a battery washed?
.A. By cutting the cells apart, unsealing them, and lifting out
the elements which should be immersed immediately in a wooden
tub of clean pure water. The separators then are lifted out and
the positive and negative groups of plates separated, but they must
be marked so that the same groups may go back in the right cells.
Before disposing of the old electrolyte, its specific gravity should
be noted, as new electrolyte of the same density must be used.
The plates should be washed in copious running water for several
hours, but their surfaces must never be exposed to the air. Reas-
semble with new separators, fill the jars with fresh electrolyte of
the same specific gravity as that discarded, and keep the elements
under water until ready to place in the jars, which then should be
sealed and the lead connectors burned together again.
Give a long slow charge after reassembling. The battery will
not regain its normal capacity until it has been charged and dis-
charged several times.
Connectors
Q. Why should lead connectors be employed, and why is
it necessary to burn them together?
A. Any other metal will corrode quickly. Burning is necessary
to make good electrical connection, except where bolted connectors
are employed.
Q. When connections have become badly corroded or broken,
what should be done with them?
A. They should be replaced with new lead-strap connectors
supplied by the makers. If they are i4bt obtainable andHhe battery
must be in service meanwhile, the old ones can be cleaned by cutting
away the corroded parts and burning new lead on them to bring
them to normal size. If broken, burn together with lead in the
same way. Heavy copp^ r cable can be used temporarily but must
be removed as soon as Possible, as it will corrode quickly. Never
use any other metal ex<w * lead or copper and never use light copper
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678 ELECTRICAL EQUIPMENT
wire. It will either be burned up in a flash or it will cut down the
amount of current from the battery, thus causing unsatisfactory
operation.
Buckled Plates
Q. What is the cause of badly disintegrated or buckled plates?
A. Sudden discharge due to a short-circuit or to constant
abuse of the starting motor on an insufficiently charged battery.
Q. Is there any remedy for such a condition?
A. If the plates are not badly buckled and have not lost much
of their active material, the cells may be put in service again by
washing and reassembling as described, but if there is any con-
siderable loss of active material, new plates will be necessary.
Low Battery
Q. What are the indications of a low battery?
A. The starting motor fails to turn the engine over, or does so
very slowly, or only a part of a revolution. The lights burn very dimly.
The hydrometer shows a specific-gravity reading of 1.250 or less.
Voltmeter test shows less than 5 volts for a 3-cell battery (for greater
number of cells, in proportion), or 1.75 volts or less for each cell.
Q. What are the causes of a low battery?
A. The electrolyte not covering the plates, or being too
weak or dirty. A short-circuit in the battery due to the accumulation
of sediment reaching the bottom of the plates. An excessive lamp
load, all lights being burned constantly with but little daylight
running the car. Generator not charging properly.
Specific Gravity; Voltage
Q. What are the specific gravity and voltage of fully discharged
and fully charged cells?
A. Total discharge: 1.140 to 1.170 on the hydrometer; and 1.70
to 1 .85 volts on the voltmeter. Fully charged : 1 .276 to 1 .300 specific
gravity; 2.35 to 2.55 volts.
Q. Are these readings always constant for the same conditions?
A. No. The charging voltage readings will vary" with the
temperature and the age of the cell; the higher the temperature
and the older the cell the lower the voltage will be. Hydrometer
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ELECTRICAL EQUIPMENT 679
readings also depend on the temperature to some ^extent. For
every ten degrees Fahrenheit rise in temperature, the specific gravity
reading will drop .003 or three points, and vice versa.
Q. Under what conditions should voltage tests be made?
A. Only when the battery is either charging or discharging.
Readings taken when the battery is idle are of no value.
Q. Under what conditions should hydrometer tests be made?
A. The electrolyte must be half an inch over the plates and
it must have been thoroughly mixed by being subjected to a charge.
Hydrometer readings taken just after adding water to the cells
are not dependable.
Q. When should acid be added to the electrolyte?
A. As the acid in a battery cannot evaporate, the (electrolyte
should need no addition of acid during the entire life of the battery .
under normal conditions. Therefore, if no acid has leaked or splashed
out and the specific gravity is low, the acid must be in the plates
in the form of sulphate and the proper specific gravity must be
restored by giving the battery an overcharge at a low charging rate.
Q. What does a specific gravity in some cells lower than
in others indicate?
A. Abnormal conditions, such as a leaky jar, loss of acid
through slopping, impurities in the electrolyte, or a short-circuit.
Q. How can it be remedied?
A. Correct the abnormal conditions, and then overcharge
the cells at a low rate for a long period, or until the specific gravity
has reached a maximum and shows no further increase for 8 or 10
hours. If* at the end of such an overcharge, the specific gravity is
still below 1.270, add some specially prepared electrolyte of 1.300
specific gravity. Electrolyte should not be added to the cells under
any other conditions.
Q. Is an overcharge beneficial to a battery?
A. The cells will be kept in better condition if a periodical
overcharge is given, say once a month. This overcharge should
be at a low rate and should be continued until the specific gravity
in each cell has reached its maximum and comparative readings
show that all are alike. To carry this out properly will require
at least 4 hours longer than ordinarily would be necessary for a
full charge. If the plafoo h& ve become sulphated due to insufficient
301
—
680 ELECTRICAL EQUIPMENT
charging, it may be necessary to continue the overcharge for 10 to
15 hours longer. Should the specific gravity exceed 1.300 at the
end of the charge, draw off a small amount of electrolyte with the
syringe from each cell and replace with distilled water. If below
1.270, proceed as mentioned above for addition of acid.
Charging from Outside Source
Q. What is meant by charging from an outside source?
A. A source of direct current other than the generator on
the car.
Q. Why is it necessary to charge the battery from an outside
source?
A. Wheq the battery has become sulphated, has been standing
Idle for any length of time, or has been run down from any other
cause so that it is out of condition, a long charge at a uniform rate
is necessary, and it would seldom be convenient to run the car for
8 or 10 hours steadily simply to charge the battery; frequently, a
longer charging period than this is necessary.
Q. How is charging from an outside source effected?
A. This will depend upon the equipment at hand and the nature
of the supply, i.e., whether alternating or direct current. If the
current is alternating, a means of converting it to direct current is
necessary, such as a motor-generator, a mercury-arc rectifier, chemi-
cal or vibrating type of rectifier. These are mentioned about in the
order of the investment involved. In addition, a charging panel is
needed to complete the equipment, this panel being fitted with
switches, voltmeter, and ammeter, and a variable resistance for regu-
lating the charge. Where direct-current service is obtainable at 110
or 220 volts, the rectifier is unnecessary.
Q. How can a battery be charged from direct-current service
mains without a special charging panel?
A. By inserting a double-pole single-throw switch and 10- or 15-
ampere fuses on taps from the mains and ordinary incandescent
lamps in series with the battery to reduce the voltage, Fig. 409.
Q. How many lamps will be needed?
A. This will depend upon their character and size, as well
*s upon the amount of charging current necessary. For a 10-ampere
charge for a 6-volt storage battery, seven 110-volt 100-watt (32
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ELECTRICAL EQUIPMENT
m
c.p.) carbon-filament lamps, or their equivalent, will be needed;
i.e., fourteen 110-volt 50-watt (16 c.p.) carbon-filament lamps;
eighteen 110-volt 40-watt tungsten lamps, or twenty-eight 110-volt
25-watt tungsten lamps. For a
12-volt or 24-volt battery the number
of lamps will have to be decreased
In proportion in order not to cut the
voltage of the supply current below
that of the battery. For 220-volt d.c.
supply mains, if a three- wire system is
employed, the taps should be taken
from the center wire and one outside
wire; this will give 110 volts. If the
service is 220-volt two-wire, more
lamps will be needed to reduce the
voltage, which should exceed that of
the battery by only l\ to 2 volts ex-
cept where a high voltage charge to
overcome sulphating is being given, in
which case it may be slightly higher.
Q. Where no outside source
of current is available, or where no
rectifier is at hand to convert al-
ternating current, how can the
battery be given the long charge
necessary?
A. Run the engine. Supply it
with plenty of oil and provide hose
connections from the water supply
to the filler cap on the radiator and
a drain from the lower petcock.
Open the latter and turn on just
sufficient water to keep the engine
reasonably cool; increase if necessary
as it runs hotter.
Q. What precaution must be taken always before putting the
battery on charge from an outside source?
A. The polarity of the circuit must be tested in order to
Ec^
O
O
Fig. 409
Diagram of Connections for
Charging Six-Volt Storage Battery
from Lighting Circuit
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682 ELECTRICAL EQUIPMENT
make certain that the battery will be charged in the proper
. direction.
Q. How can this be done?
A. If a suitable voltmeter is at hand, i.e., one of the proper
voltage for the 110-volt current, connect it to the mains. If the
needle does not move over the scale but shows a tendency to butt
against the stop pin at the left, reverse the connections. The needle
will then give a proper reading and the positive connection to the
meter must be used for the positive side of the battery. Should no
voltmeter of the right voltage be available, connect two short wires
with bared ends to the fused end of the switch. Dip the bared ends
of the wire in a glass of water, being careful to keep them
at least an inch part. When the switch is closed, fine bubbles
will be given off by the wire connected to the negative side. The
battery terminals are stamped Pos. and Neg., and the connec-
tions should be made accordingly.
Intermittent and Winter Use
Q. What should be done with an idle battery?
A. If it is to be idle for any length of time, as where the car
is to be stored, it should be given a long overcharge as described
above before being put out of service. Fill the cells right to the top
with distilled water to allow for evaporation and absorption of
acid by the plates. Give the battery a freshening charge at a low
rate once a month. Discharge the battery and re-charge before
putting it into service again. If it has stood out of service for a
long period, the battery will be found at a low efficiency point and
will not reach its maximum capacity again until it has had several
charges and discharges.
Q. Does cold weather have any effect on the storage
battery?
A. It causes a falling off in its efficiency. If not kept charged,
the electrolyte will freeze under the following conditions: battery
fully discharged, sp. gr. 1.120,20° Fahrenheit; battery three-quarters
discharged, sp. gr. 1.160, temperature zero; half discharged, sp. gr.
1.210, 20 degrees below zero; one quarter discharged, sp. gr. 1.260,
60 degrees below zero. When storing away for the winter, the bat-
tery must either be kept charged or put where the temperature
does not go lower than 20 degrees above zero.
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ELECTRICAL EQUIPMENT 683
Edison Battery
Q. Is it ever necessary to wash out an Edison battery?
A. No. The cells are permanently sealed, as the active
material cannot escape from its containers.
Q. Do all of the foregoing instructions apply to the Edison
as well as to the lead-plate battery?
A. No. The Edison requires very little attention, practically
the only care necessary being to keep the cars replenished with
distilled water at intervals.
Charging rates for Edison cells fire given in the article on
Electric Automobiles. S.A.E.-standard instructions for lead-plate
cells are also given in the same article.
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DELCO DISTRIBUTOR FOR PACKARD "TWELVE" ENGINE
Courtesy of Dayton Engineering Laboratories Company 9 Dayton, Ohio
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ELECTRICAL REPAIRS
FORD MAGNETO
Description. The Ford magneto consists of a stationary
spider, on which are placed sixteen coils of flat copper ribbon, each
coil wound in the opposite direction to the next and the whole
assembly connected in series, thus making the coils alternately
north and south poles. One end of this coil circuit is grounded
through a copper rivet
in the spider, and the
other end is soldered to
a terminal block at the
top of the spider. The
current is carried out
through a terminal post
on the flywheel cover by
means of a pointed spring
attached to the post and
bearing on the terminal
block.
The magnetic field
is produced by sixteen
magnets fastened to the
. Fig. 410. Copper Ribbon Coils of Ford Magneto
rim of the flywheel. The
magnets are placed with their north poles together and their south
poles together. Over each pole thus formed is placed a flat iron
pole piece. The magneto is assembled with a ^rinch clearance
between the magnets and coils, and this clearance is adjusted by
means of metal shims. Fig. 410 shows the coils.
Capacity. As this magneto has no commutator the current
produced is alternating, with sixteen reversals per revolution.
The voltage produced is from 6 to 30, depending upon the load
and the speed. The ignition requires 1 ampere and the headlights
about 3; as this magneto was designed to take care of this load
only, an increased load on the magneto is inadvisable. Numerous
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2 ELECTRICAL REPAIRS
devices have been made to charge a battery from this magneto,
but the majority of these devices are unsatisfactory owing to an
insufficient current capacity to offset the rectifying losses.
Testing. Through use, the current is decreased either by
weak magnets or by partial grounds in the coils. In making a
test with an alternating voltmeter, the voltage is taken with the
engine running at a car speed of about 25 miles per hour. With
the ignition only as a load, the voltmeter should show about 20
volts when the magneto is up to strength.
Recharging. When the magnets become weak, it is necessary
to recharge or replace them. They may be recharged without
removing them from the car,
with the flywheel off but with
the magnets still attached, or
with the magnets removed from
the flywheel; new magnets may
be used.
Recharging in Car, Recharg-
ing in the dar is done by sending
a current through the coils, caus-
ing each coil to become a sepa-
rate magnet charger, charging
each magnet which is placed
opposite to it. As it takes direct
current to charge a magnet prop-
erly, there must be a direct current supply. Two 6- volt starting bat-
teries may be satisfactory to use, the connections being made between
the batteries and the magneto with No. 6 wire. In order to. saturate
the magnets, 40 amperes should flow through the coils. Since about
1917 the resistance of the Ford magneto coils has been 0.25 ohm.
Applying 12 volts to the coil from two storage batteries connected
in series will allow 48 amperes to flow through the coils.
Before the current is applied to the magneto, the flywheel
must be set in proper relation to the coils. This is done by put-
ting a compass over the flywheel, Fig. 411. Take out the for-
ward floor boards; disconnect all wires from the terminal post;
place the compass slightly back and 1 inch to the left of the post;
raise the left-hand side of the hood so that the compass will be in
Fig. 411. Position of Compass
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ELECTRICAL REPAIRS 3
sight while cranking. Then crank the engine slowly until the
compass needle points with the north to the front of the car. It
is well to shake the compass a little after it is pointing straight to
be sure of a correct reading. Now place the positive battery wire
with the clip on the terminal post, and then touch the large nut
on the exhaust pipe several times with the lead. Do not hold the
contact more than a second as it may burn off a connection on
the inside of the magneto because of the heavy flow of current.
The first application of the current charges the magnets, but
several applications give the owner, who may be a spectator, the
assurance of a job well done. Remove the charging wires and
replace the ignition wire on the terminal post, then connect the
test instrument and note the rise in strength. In some cases it
will be found that the magneto is weaker or entirely dead; this
may be due to any one of four causes:
Poor setting of magnets with compass
Reverse setting
Polarity of charging current reversed
Magneto coil connections reversed
The first condition is caused by the needle of the compass
sticking, thus giving a false reading; therefore, reset and charge
again. If it fails to come up, reverse the setting; that is, set with the
south pole up instead of the north pole as in the original setting.
The second condition is generally caused by the compass
needle becoming reversed; therefore, recharge the compass needle
correctly on the magnet charger, and be sure that the dark end of
the needle points north. To correct this second condition, reverse
the setting of the magneto as before described and again charge.
To remedy the third condition, test the polarity of the charg-
ing wires; if it is reversed, change back and charge again, first
reversing the setting.
The fourth condition seldom arises and is generally, hard to
locate. It is caused by the coils being improperly connected at
the factory, that is, they are connected in the opposite direction.
The remedy is to reverse the setting and again charge.
In some cases the magnetism has practically disappeared; then
the only remedy is to charge in any position and continue the
cbnrging process until a polarity is found.
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4 ELECTRICAL REPAIRS
Recharging on Flywheel. In recharging without removing
from the flywheel, it is handy to use a small 6-volt charger having
Ford changing pole pieces. Find the north pole of the charger
and mark it with chalk; then find the north pole of the magnets
and mark; place the north pole of the charger to the south pole of
the first magnet and apply the current for one second. Skip the
next magnet, as that is of opposite polarity; go around the wheel
Fig. 412. Testing Coils for Grounds
and charge the seven other magnets of the same polarity as the
first magnet. Now reverse the wires on the charger, and charge
the remaining magnets in like manner.
Recharging out of Car. If the magnets are removed from the
flywheel, the first operation is to sort out the right- and left-hand
magnets and place them in separate piles. Start with one pile
and charge it to its proper polarity and again pile separately or
place on the flywheel in alternate sequence. Charge the other
pile in the reverse direction; that is, simply turn the magnet over
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ELECTRICAL REPAIRS 5
when charging, thus charging the magnet in the opposite direction;
replace on the flywheel in the remaining spaces.
Fig. 413. Winding of Old-Style Coils
Repairing Magneto Coils. The coils on the spider after a
time become grounded by fine particles of metal and carbon in the
Fig. 414. Winding of New-Style Coils
oil which work through the coil insulation and ground a portion of
the magneto. Where a magneto fails to come up on charge, it- is^
Fig. 415. Testing for Shorted Coils
generally owing to this cause, and while washing out the crankcase
rarely remedies the trouble? st ^ ^ helps, to prevent further trouble.
311
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6 ELECTRICAL REPAIRS
The spider must be removed and the grounded portion reinsulated.
The coils are tested by applying 110 volts with a lamp in series as
in Fig. 412, first unsoldering the ground connection. If the lamp
lights, a ground is present; slight grounds will cause a white smoke
at the point of trouble but heavy grounds will not. By applying
about 12 volts from a battery to the grounded coil, the ground
will generally show up. If this fails, unsolder in the middle and
test each half, when the ground may soon be found. The grounded
coil should be forced off by using two screw drivers as levers.
The old tape should be cut off and new tape put on, using cotton
tape f inch wide, wound with a lap of half the width of the tape;
more than this will be too thick.
Where the fiber end pieces are broken, be sure to cut new
ones from ^fr-inch fiber. After tapeing, shellac well. In replacing
the coils, connect each coil so that the polarity of adjoining coils
will be opposite, the old style being shown in Fig. 413 and the new
style in Fig. 414. After all the grounds are cleared and a final
test is made, the ground connection may be replaced on the spider.
A 6-volt battery current should now be applied to the whole
assembly and each coil tested with a compass for polarity, thus
proving that each pole is of opposite polarity to the poles on
either side of it. This is very important.
To be sure that there are no shorted coils, the 6-volt current
should be left on and each coil tested with the magnetmeter as in
Fig. 415. The coil is now finished and should be given one more
coat of shellac.
POLARIZATION OF HIGH-TENSION
MAGNETOS
Missing of Sparks. For several years there has been doubt
as to what causes a high-tension magneto to cut out or miss every
other spark at high speeds and, in some extreme cases, at com-
paratively low speeds. This is true of several well-known and
widely used makes, but the "miss" does not always take place
under working conditions, as the type of engine may not permit of
sufficiently high speed. In extreme cases it shows in speeding up
in lower gears, such as in truck work without a governor. This
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ELECTRICAL REPAIRS
trouble is usually laid to faulty workmanship in repairing the
ignition or to the carburetion.
In mild cases — in about fifty per cent of the magnetos now in
use — the missing shows up on the test stand and is very annoying
to the tester as he may spend many hours trying to correct the
fault. The natural tendency is to place the blame on the breaker
or cams, as the miss occurs on one side only.
Causes. This action is caused by several conditions in both
material and design. All high-tension armatures are made up of
thin steel punchings, or laminations, built up in the center, with
solid-iron end pieces, Fig. 416; these laminations and end pieces
are riveted through the edges which hold the assembly together.
Fig. 416. Construction of Armature
This provides a laminated core, on which are wound the primary
and secondary of the coil. All iron or steel has a reluctance to
change its magnetic condition, that is, its state of charge or dis-
charge; and the change which takes place from complete charge to
complete discharge, or vice versa, takes a certain definite time,
depending on the quality of the steel. The same trouble is
encountered in transformer design, although it is overcome by
using silicon-steel laminations, which have a very low time period
of change. As the magneto armature rotates between pole pieces,
Fig. 417, the magnetic lines of force are reversed once every half-
revolution, therefore the magnetization of the laminations must
rise and fall in strength likewise. This reversal takes place when
the armature has cleared the pole piece about J inch, position C,
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f
8
ELECTRICAL REPAIRS
Fig. 417; tHis is for full advance position, at which practically all
running is done.
As the maximum spark is produced when the greatest mag-
netic change takes place, it naturally occurs at the full advanced
position. The greater the current generated in the armature, the
greater the saturation of the armature core and a relatively longer
time period is then necessary for the rise and fall of the magneti-
zation. At the full advance position, the points open about \
inch after the armature leaves the pole pieces;, therefore the mag-
netic reversal must occur between the magnetic break and the
electrical break. This provides the time interval necessary for the
A B C
Fig. 417. Diagrams Showing Distribution of Magnetic Flux for Various Positions
reversal of the magnetism in the iron. This polarization is due to
three factors:
' Quality of iron used in the armature core
Speed of armature
Amount of current in the primary
Proof Si A magneto is pkfced in the test stand and the plug
wires are connected to the multiple gap, Fig. 418. Starting with a
low speed, each point will be seen to spark perfectly, and this will
continue until a higher speed is reached, when two of the points, 1
and 4 or # and S, will cut out either all the time or intermittently.
This failure closely resembles breaker trouble, but if the missing
gap be shorted with a screw driver, the missing will be transferred
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Fig. 418. High-Tension Test Points with Astatic Gap
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10 ELECTRICAL REPAIRS
to the opposite pair and may continue so, although in some cases
it will return after a few sparks to the original pair.
Short-circuiting the failing gap offers less resistance to the
secondary current, and a relatively greater amount of current is
generated in the primary, which in turn polarizes the core in the
opposite direction. The reversal may remain this way or the
original polarization may be so strong that the first polarity will
be restored. The fact* that a greater armature current is one
factor proves that the core does become polarized.
Some states of polarization are so slight that merely blowing
on the gap will cool the arc and cause a reversal. If, when miss-
ing on one pair of gaps, the timing lever is slightly retarded, the
missing will cease and all sparks will be equal. This shows that
the time allowed between the magnetic break and the electrical
break has been extended and that the iron has had time to reverse
its magnetism.
Remedies. Manufacturers have found that this difficulty can
be overcome by lengthening the magnetic break, but this gives an
undesirable correspondingly smaller range of spark advance. The
current generated in the primary during the time the points are
closed affects this condition directly; reducing the current lessens
the trouble with a certain reduction in the quality of the spark.
The use of proper iroij in the core is the real remedy — the
main factor in the design — and high-grade silicon transformer steel
would practically eliminate this trouble in new armatures. Iron,
after constant use involving continual reversals, becomes fatigued
and sluggish to reversal, which accounts for armatures developing
this trouble after several years' service.
TESTING AND CHARGING
HIGH-TENSION COIL AND ARMATURE TESTING
Methods. There are two methods of testing high-tension coil
and armatures: first, with a master vibrator; second, with a single-
break interrupter. In either case a spark gap of constant distance
and resistance should be placed in the secondary circuit; this is
done w T ith the astatic gap.
Astatic Gap. The astatic gap has three points, Fig. '418.
Point A is connected to the high-tension lead of the coil or arma-
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11
O
c
torwATER-
KENT CC
»INT5
ture, while the point B is insulated and is the static point. The
function of the static point is to maintain an even resistance between
the points A and C, thereby giving a definite resistance for a given
distance; this is of prime importance to provide a reliable test.
The action of the static point is to produce a capacity at the
points in tune with the oscillations of the high-tension discharge.
As the secondary current from any high-tension coil is of high fre-
quency, although greatly
damped because of the
amount of iron in the coil
or armature, the intro-
duction of a capacity or
condenser action into the
circuit has a direct bear-
ing on the gap.
The distance be-
tween the points A and
B should be 0.002 inch.
The two terminal posts
should be connected on
the back of the fiber base
by a small wire. The
body of the posts A, B,
C should be f inch in
diameter, especially the
static point; too small a
mass will not furnish suf-
ficient capacity to work
properly. Phonograph
points are good for this purpose and are easily mounted. Lock nuts
should be used on screws A and B and also on C if necessary.
Testing with Vibrator. A master vibrator is placed in series
with a 6-volt storage battery and the coil to be tested, the high-
tension lead being connected to the terminals on A and C and
grounded to the primary of the coil. With the spark jumping the
gap, the point C is opened until the spark will just jump it con-
tinuously. If the gap measurement is taken with a good coil a
standard is obtained.
>INWNG
HANDLE
HEXAGONAL CAM
O
BASE;
1 • ■ i "
O
Fig. 419. Breaker-Point Test Set
^v
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ELECTRICAL REPAIRS
After the vibrator is once set it should not be changed; any
change in adjustment will mean a change in the quality of the
spark. As some high-tension armatures have such a high primary
resistance that a vibrator will not operate through them, a single-
break interrupter may be used to overcome this difficulty.
Single-Break Test. A simple cheap breaker may be made as
in Fig. 419. A piece of J-mch red fibre 2§"X3§" forms the base;
Atwater-Kent type CC points are used for contacts; the hexagon
cam is made from a f-inch hexagon iron rod turned down to a
shoulder J inch in diameter and projects through the base, with a
fiber handle about an inch in diameter attached. A condenser is
connected across the points, and the whole assembly mounted on
the test board. To test with this apparatus, the coil is connected
as in Fig. 420; the battery coil primary and breaker are connected
in series; the coil second-
ary is connected to the
gap, and the spark is.
noted. As this type of
breaker has no resistance
to speak of and is oper-
ated by hand, the coil has
plenty of time to saturate
its core, the spark pro-
duced being uniform.
Special Dial Gap
dial gap, Fig. 418
BREAKER POINTSl.
3ATTERY
Fig. 420. Method of Connecting for Test
For quick results, utilize the special
This gap has a fiber base i"X3i"X5|",
on -which are mounted two stationary points marked A and B
and a grounded movable point C; below is a pointer D, which
moves on the scale E. The movable point C slides in the slot F
and is held by a plate and two rivets. The lower part of the
point body C projects through and forms one rivet, while the
other projects through the plate about" J inch, and the cam
bears on it, as well as the spring, holding the plate assembly
against the cam. Point A is connected on the back to terminal K.
The dial E is cut in the fiber and white lead put in the cuts.
This dial is laid out in ten divisions, marked 1, 2, 3, 4, etc., and
moving the pointer one division. causes the gap to change & inch.
In using this apparatus, the dial makes it possible to get a quick
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13
positive reading. A table can be made up to show just what each
type of armature or coil should test, thus eliminating all guesswork.
MAGNET TESTING AND CHARGING
Magnet Materials. The permanent magnets used in magne-
tos are generally made of tungsten or chrome steel. Tungsten
magnets were in extensive use until the cost of this metal became
so great during the War that it was necessary to develop a less
expensive material. A few prominent manufacturers are having
REMOVE
REMOVE
Fig. 421. Flexible Magnet Keeper
excellent results with properly treated chrome steel, and as it is
less expensive, it is considered the ideal magnet material.
Keeper. A keeper must be used when the magnet is removed
from the magneto or when the armature is removed from the
field. A careful test has shown that a magnet will lose about
thirty per cent of its strength if a keeper is not used while remov-
ing the magnet from the charger to its proper position on the
magneto, or vice versa; the magnet was again removed and
replaced without a keeper, with an additional loss of two or three
per cent. The magnet was then allowed to stand on a shelf for
three or four days wit^ ol jt a keeper; on testing it was found to
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ELECTRICAL REPAIRS
a
have lost an additional five or ten per cent. The same magnet
was charged, a keeper being installed before removing the magnet
from the charger, and it was then tested for strength. After the
magnet had stood for six months, a test showed the strength to be
the same as on the first day.
From the foregoing it will be noted that thirty per cent — the
greatest amount of lost strength — was lost at the instant the mag-
net was removed, either from the charger or from the magneto
without a keeper. There are a number of testers on the market,
but several of them are of little use as the first loss occurs before
the tester can be placed in
operation. The aforementioned
test was made by measuring the
voltage between the brushes of
a direct-current constant-speed
generator, the magnets to be
tested forming the field of the
generator. Any loss in magnet
strength would cause a lower
voltage reading.
A prominent manufacturer
recommends that a keeper be
constructed from an old silent
chain. After annealing, the
chain is put over the magnet,
Fig. 421, in such a way that
the magnet can . be placed in position before** it is necessary to
remove the keeper.
Testing. There are several ways of testing a magnet, such as
with a compass, by the scale method, or by a voltage test as above
described. When a compass is used, it is placed on a table with the
needle at rest and pointing north; the magnet to be tested is placed
in a line at right angles to the needle and about 3 feet from it and
the deflection noted. This method is inaccurate as the deflection does
not vary much from weak to strong, and it takes too much time.
The scale method is not entirely satisfactory as there is a loss
during the test. The magnet has a keeper; this keeper is pulled
away until it leaves the magnet and the pull in pounds noted.
u
^
Fig. 422. Construction of Magnet Recharger
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ELECTRICAL REPAIRS 15
Charger. In charging a magnet it is necessary to saturate it
in order that it will retain the maximum charge. This can best be
done with a charger having a heavy field and a short magnetic
circuit with sufficient cross-section of iron to keep down the reluc-
tance. It has been found by experience that to obtain the strong-
est magnet, there must be a short magnetic circuit. Therefore, if
the magnet projects into the coils as in a solenoid, the magnetic
circuit has been reduced to the length of the magnet plus the
keeper on the bottom. If we have, in addition, a core in each
coil 3 inches long, 6 inches of length have been added to the mag-
netic circuit, and the result is poor saturation.
A satisfactory magnet charger can be obtained at a low price
in any voltage from 6 to 220 or one may be made as follows:
Two brass spools are made, Fig. 422, with a hollow center
l"Xlf"X3", to which are soldered the end pieces. To operate
on 6 volts, these spools are wound full
of No. 14 magnet wire, with the coils
wound in opposite directions, Fig. 423,
— and the two coils connected in multiple.
If 110 volts is used, wind with No. 22
wire and connect in series.
.Charging. In charging, the magnet
is held above and at right angles to the
charger and the current applied for a
second, when the magnet will swing to
Fig. 423. • Wiring Magnet Charger , . . . . , , .
the position it should occupy in the
charger to receive a proper charge. Place the magnet in the coils,
apply current for one second and the magnet is charged; any
longer application is a waste of current and time.
If a keeper be placed on a magnet and pulled toward the top
of the magnet, most of the magnetism will vanish because of the
distortion of the magnetic lines of the circuit.
IGNITION SYSTEMS
BATTERY SYSTEMS
Atwater-Kent. In setting the points of this type of ignition
system, it is necessary that the lifter throw the points far enough
together so that a long contact is made and a subsequent saturation
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16
ELECTRICAL REPAIRS
of the coil takes place. This may be determined by holding the
lifter and slowly turning the engine over. When the lifter snaps off
the notched shaft, allow it to return slowly and note how far the
Pig. 424. Diagram Showing Operation of Atwater-Kent Interrupter
points are compressed, as at C, Fig. 424. If the points do not
move far enough, the cause may be wear on the lifter, on the
notched shaft, or on the anvil,. or the anvil post may be bent.
Examine these parts for wear and if they are worn, replace them.
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ELECTRICAL REPAIRS 17
Temporary relief may be had by bending the anvil post D toward
the notched shaft, thus giving more movement. As wear of mov-
ing parts comes from lack of oil, be sure to oil all the moving
parts every 1000 miles.
In adjusting see that the lifter B clears the edge of the anvil
D about 0.005 inch on its forward movement, no more and no less,
if less, the lifter is likely to strike and break. Continual breaking
of lifters is usually due to their striking on the way forward or
from a worn roller cushion; the break generally happens at high
speed, as on an eight-cylinder engine. This roller is struck by the
lifter; and there will be difficulties ahead If the roller is worn too
much or is solid on the pin; the jar is then sufficient to break the
lifter at high speed when the blows follow one another very closely.
The spring carrying the contact point should bear against the
anvil sufficiently to give a uniform break or the contacts may
Fig. 425. Angle of Four- and Eight-Cylinder Lifters
stick. Four- and six-cylinder lifters are alike, while the eightrcyl-
inder has an angle as shown, Fig. 425. If a four-cylinder lifter
is used in an eight-cylinder head, there will be insufficient contact
and the shoulder of the lifter will strike the notched shaft too
soon.
When contact points become yellow, it is a sign that the con-
denser is weak. In the H or K-2 system the condenser is in/jthe
coil box and can be renewed by taking off the base, digging out
the wax on the narrow side of the partition, and then installing a
new condenser.
The condenser on the K-3 is on the head, the case being held
on by two screws. The condenser has two leads, one of which is
grounded while the other touches the condenser case. This case
should have a steel & D j:ing holding the condenser in place, other-
wise vibration will ^. ^ the leads.
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Fig. 426.
Atwater-Kent Closed-Circuit Type. The new type CC operates
on the closed-circuit principle and is free from some of the troubles
of the open-circuit system. The
points are opened by a steel cam,
the movable point having no piv-
oted hinge to wear but moving
on a steel spring. Bearing on the
cam is a small fiber block, and
as the pressure on the cam is
slight, the wear is negligible.
The assembly is held by one
screw, two dowels punched on
the bracket ensuring a positive
adjustment. The large tungsten
points should separate 0.006 inch,
the adjustment being made from
the stationary point fastened to
the condenser case, Fig. 426.
The circuit is shown in
Fig. 427.
The coil is of simple
construction and has a
ballast coil in the top
—j — ._.—_ __ ca p. This heats at slow
■ CONTACT MAKER l 1 ,1
jorounoeo j engine speed or when the
engine is stopped with
the switch left on and
Joro?nd primary (W) prevents the points from
■ BATTERY 9 ^^OROUND . . - .. p
burning or the coil from
burning out. A single-
pole switch is used.
Atwater-Kent Auto-
matic Type. The type
CA has a governor for
advancing the spark and
can be used with or without a manual control. Where a manual con-
trol is used, the unisparker shank is marked REST or RESTRICTED,
while the straight automatic is marked FULL.
Atwater-Kent Closed Circuit
Breaker
distributor!
RESISTANCE
Fig. 427. Wiring of Atwater-Kent Closed Circuit System
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In replacing a K-2 or K-3 with a CA, the timing is the same
except that the spark must be slightly retarded as the CA type
has no lag.
Connecticut Automatic Switch. The new Connecticut system
differs from the older types in that the head is more compact and
the advance lever is connected to a separate plate, on which are
mounted the points, while the body of the head remains station-
ary. The point plate is shown removed in Fig. 428. To replace
the points, a new plate assembly is used since the breaker arm is
riveted to this plate, as shown in the illustration.
The automatic switch used with this head, Fig. 429, operates
as follows: the current enters at post B and goes to insulated
Fig. 428. Removing Breaker-
Point Plate Fig. 429. Connecticut Automatic Switch
spring a (which makes contact with spring b) when the insulated
plunger c is pressed in and held in position by the latch d. Cur-
rent is conducted through the wire e, the bar of thermostatic
metal /, back through the heater tape g to post c and thence to
the coil. If an uninterrupted flow of current is allowed to pass
through the heater tape g, the thermostatic bar / will bend down
and make contact on the post h, setting up a vibrator action
between the coil i, hammer j, and ground post G. This will
actuate the hammer j and, striking the latch d, will dislodge it,
allowing the plunger c to return to the off position, thus breaking
the circuit between t^ e springs a and b. Pressing the plunger k by
hand will also dislocj^ fae latch d and accomplish the same result
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20 ELECTRICAL REPAIRS
In some cases this switch will throw off too soon and stop the
motor while it is running slowly. To overcome this, bend the
post h slightly away from the thermostatic arm /, adjusting it so
that the vibrator will operate one minute after the switch is
closed with the motor stopped; this will give the right setting.
The chief trouble with this switch is the burning away of the
heater tape g, opening the circuit. When this happens, a com-
plete new vibrator unit should be installed, the entire assembly
costing very little.
As the 1919 model automatic switch has no vibrator, a
double thermostat is used; it is
simpler and less likely to get out
of order. Fig. 430 shows the
arrangement of the two units.
The current enters at B and flows
to the insulated spring a, which
makes contact with' thermostatic
bar 6. When the insulated plung-
er c is pressed in and held in
position by the thermostatic latch
d, current is conducted through
the heater tape e to the post C,
thence to the coil. If an unin-
terrupted current is allowed to
flow through the heater tape e,
Fig. 430. Connecticut Thermostatic Switch the thermostatic bar b will bend
down and make contact on the
adjustment screw/, allowing the current to flow through the heater
tape g to the ground post G, thus bending up the thermostatic
latch d sufficiently to release the plunger c. Manually pulling
out the plunger c will release the latch and accomplish the same
result.
In setting the thermostat to act in the proper interval, the
adjustment / is turned in to increase the time and out to reduce
it. It will be noted that the thermostatic bar b has a coarse
winding and is in series with the coil, while the thermostatic
latch d has a fine winding and is connected across the battery
only when the series bar is in contact to cut off the ignition.
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ELECTRICAL REPAIRS 21
The coil is encased in a one-piece composition housing, closed
at the base with a sealed metal cover. Running along the side of
the coil is a brass ground strip. In the coil base is the condenser
connected across the two flexible leads that connect to the breaker
points. In time, or if it gets wet, this condenser weakens. To
replace the condenser, remove the base cap and take out the old
condenser. Use a new one if available; two thick Splitdorf TS
condensers are satisfactory if connected in multiple.
North-East Ignition. The North-East ignition head as used
on the Dodge car is a self-contained unit having the distributor,
breaker, coil, and governor all in one assembly. The breaker,
Fig. 431, has a lever on which is mounted a tungsten contact
point which makes contact with
a similar point mounted on an
adjustable screw. On this lever
is a fiber block which bears on
the steel cam; this lever and the
adjustable point are insulated
from the ground. The timing is
changed by unscrewing the lock
nut in the center of the cam and
rotating the cam to the desired
timing; the spark occurs at the
instant the points separate. The
Fig. 431. North-East Ignition Breaker
condenser is mounted in the
semicircular metal case next to the points and is connected across
the contact points. When a condenser becomes weak or is short-
circuited, it is necessary to install a new one. If the engine stalls
owing to a short-circuited condenser, the motor can be started
by disconnecting one lead and will run without the condenser; the
motor will not operate satisfactorily, but will run well enough to
save towing the car to a repair shop.
If there is a loose point on the breaker lever,' reriveting the
point will overcome the trouble, but in making the repair do not
pound too hard on the tungsten or it will crack. The points
should be set to open about 0.015 inch; if set wider, the period of
contact is so short that missing is likely to occur at high speed.
The complete head as& e tfibly is shown in Fig. 432. The vertical
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ELECTRICAL REPAIRS
camshaft carries a gear at its lower end which meshes with the
governor gear. The automatic advance governor, which is
mounted on the horizontal shaft and rotates at engine speed, con-
sists of two weights hinged on a stationary disc attached to the
shaft. As the weights move outward, owing to the centrifugal
force, they move the governor gear about 25 degrees on the hori-
zontal shaft, thereby advancing the spark. The head is also
equipped with a manual advance; the automatic takes care of a
portion of the advance.
The coil is enclosed in an iron case with the head and has a
closed magnetic circuit; it is impregnated with varnish to render
HOftiMNTM. &HATT
COlU HOUftlNO
VERTICAL ©PlRAi. 6CAA
awvamcc WEIGHT* I
^'O^ «*'«■ H<*,L>*T*. 6P.RAU OCA*
Fig. 432. Cross-Section of North-East Ignition Unit
it waterproof; and it is held in place by a stud running through
the core. A water-tight cap covers the case, and a high-tension
post makes contact with the coil secondary, this coil operating on
12 volts and requiring a small amount of current. As this current
is so slight, no ballast is used on the system and a quick satura-
tion is obtained with no burning at the points. The fact that it
will work after a fashion without a condenser is due to the small
amount of current. Very light grease is packed into the governor
case; a wick oils the vertical shaft; and a grease cup oils the hori-
zontal shaft. When replacing this unit with a magneto, the
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ELECTRICAL REPAIRS 23
entire head is taken off and a magneto base installed. Any
standard base magneto will fit without machining.
Westinghouse Horizontal Ignition. This unit is mounted on
the front of the generator and has an automatic advance which
may be used for full advance or for restricted ignition. The
governor weights are mounted on two studs screwed into the
armature shaft and are insulated from them by fiber bushings in
the weights, which also form the cam for operating the breaker
points; they are so shaped as to hold the points together as they
expand, thereby making a longer period of contact as well as
opening the points sooner and so advancing the spark. The
weights are normally held in a retarded position by the spring on
the end of the shaft which bears on
the fiber bushings. Fig. 433 shows
the weights in the position of full
advance.
The points are platinum and
should normally remain open 0.008
inch . Tungsten points last longer and
are cheaper. In ad j usting the breaker,
the contact spring, Fig. 433, should
Fig. 433. westinghouse Horizontal bear lightly on the contact screw with
rea er the breaker lever depressed. This con-
tact spring, however, must not be too strong, as it works against
the pressure of the bumper spring and if they equalize each other,
the lever will not return to the stop and the spark will be irregular.
The condenser is located in a pocket case in the end plate and is
enclosed in sealing wax. In time the condenser will become weak
— generally from dampness — and should be replaced by a new type
molded in hard damp-proof rubber. When installing the new con-
denser, be sure to fill the pocket spaces with sealing wax; this will
make the condenser rigid.
The distributor contains the high-tension coil, having a pri-
mary of flat copper ribbon which is wound on edge around a
laminated iron core and over which are placed the two secondary
bobbins connected in series. Should the primary coil burn out, it
may be rewound with 250 turns of No. 22 enameled magnet wire,
which is equivalent to u~ otig lna ^ winding.
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ELECTRICAL REPAIRS
The switch is on the dash and contains a reversing device in
the form of a square plug which reverses the direction of the cur-
rent through the points and causes them to burn evenly. The
switch also contains a ballast coil, which for a 6-volt system
should be of 0.45 ohm and for a 12-volt of 1.2 ohms resistance; the
0.45-ohm coil is painted red, while- the 1.2-ohm coil is not painted.
This ballast coil heats as the engine slows down or is stopped
with the switch on, raising the resistance of the ballast coil and
preventing the ignition coil from being burned out. A diagram of
this system is shown in Fig. 434. In testing the high-tension coil
'for strength, the spark should jump ^ inch on the astatic gap with
a 0.45-ohm ballast coil in series with the primary. Be sure to use a
ballast coil in testing — without it, the reading will be incorrect.
High Tension^
Low Te/JS/M
famm. End
\of Generator
Ignition End
{ ~ (ff 6tntritor \urocncrnur I • { • <
-j^ ^'~Qrol7nliid"Rtt!!FnOiiw7 m ~~~
]LigM$
Fig. 434. Wiring Diagram of Westinghouse Horizontal Breaker
Westinghouse Vertical Ignition. In removing the ignition
unit for repairs, disconnect the three wires; it is not necessary to
mark them. Retard the spark fully and make a light scratch on
each side of the rotor in this position, thus making the replace-
ment easy. In replacing, turn the rotor to the marks on the col-
lector ring and slip the gears into mesh. Then turn the ignition
switch on and hold the three wire terminals near the frame, con-
necting to either outside terminal post the one that sparks to the
frame. Turn the switch a half-turn to the other- bn position and
try the other wires. Next place the live wire on the other outside
post and the remaining wire on the center post. When either of
these wires shows a heavy discharge to the ground instead of
about 8 amperes, it will be known that the switch is not con-
nected properly; this applies to a single-wire system, Fig. 435.
If the connections are wrong, the coils may burn out.-
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25
When all connections are made properly and the motor is
ready to run, the ammeter should show a 5- or 6-ampere dis-
charge with the contacts together. When installing a new condenser,
be sure that the leads are in good
condition as they are very close
to the coil laminations and are
likely to be grounded on them.
A frequent cause of missing under
a load is the reversal of the dis-
tributor rotor and the subsequent
N shortening of the safety spark
gap, thus lowering the circuit's
resistance and causing a jump at
the safety gap instead of in the
cylinder. When in good condi-
tion the coil should jump | inch
on the astatic tester with a 0.45-
ohm ballast coil in series with the
primary.
Fig. 435. Weetinghouse Ignition Wiring
MAGNETO SYSTEMS
Eisemann Dual Magneto. Dual magnetos are used on large
trucks and some touring cars. The Eisemann type is waterproof
and very compact. The pole pieces, also an Eisemann feature, are
tapered, Fig. 436. This gives a
projection in the center which is
used to shorten the magnetic
break of the armature at the re-
tarded position and produces a
uniform spark throughout its range
of advance. The breaker mech-
anism is shown in Fig. 437. The
breaker arm rotates on a fiber
bushing, insulating it from the
breaker disc. The battery breaker
is mounted on the timing lever and is actuated by a steel cam
carried on the magneto breaker; the battery breaker is set to open
10 degrees later than tK magneto breaker.
Fig. 436. Eisemann Pole Pieces
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ELECTRICAL REPAIRS
The coil circuit is shown in Fig. 438. In front of the coil is a
breaker mechanism for starting on the spark, Pig. 439. The fiber
ratchet bears on the fiber roller
A, which is mounted on the lever
J?. On the end of this lever are
two points C, one on each side.
Normally the lever points rest
on the stationary point, which is
connected to the battery breaker,
and therefore these points are
in series with the battery-breaker
system. Opposite this point is
another point, D, mounted on a
movable grounded plunger. The
action of rotating the ratchet
Fig. 437. Eiaemann Breaker Mechanism Causes the lever B to move froHl
CIN0IN6
rot *ti
CICII
■ACNCTO CONUCI
StCAIEt MINTS
SFKRK PLU63
Fig. 438. Wiring Diagram of Eisemann Dual Magneto
the stationary point and, if the battery-breaker points are together,
to interrupt the circuit and cause a spark in the cylinder. If the
points are not in contact, the lever B, touching the plunger C,
332
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27
closes the circuit and, as B is in
multiple with the breaker points,
a spark results.
Some coils have the roller A
of brass and others of fiber; the .
ratchet is also of either fiber or
brass. Should a brass ratchet
be used with a brass roller, the
lever B will be grounded and
the system will not operate.
Should the fiber roller A break
while a brass ratchet is employed,
a ground will result. If the coil
ground wire M becomes loose or broken, the battery-system current
is shunted through the magneto breaker, annealing the interrupter
Fig. 439. Eisemann Coil Breaker
"^
i
K
A.
jj; u
Fig. 440. gpecial Governor Puller for Eisemann
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28
ELECTRICAL REPAIRS
LEAP BEAPEP OVER,
_ - i — i-
1*cJ
spring and putting the magneto out of commission. A reversal of
the wires R and Ma has practically the same result. Dirty-
ground brushes in the magneto will
cause the magneto to fail to shut
off and will also burn and pit the
distributor gear and bearing. In
testing the coil winding, the spark
should jump f inch on the astatic
gap test.
Eisemann Automatic Gov-
ernor. This new automatic gov-
ernor has a latch to prevent
knocking at low speeds. This
latch disengages when the speed
reaches a point where centrifugal
» force throws the latch free and the
governor opens; once open it does
not close until a very low speed is
reached. In removing the governor
from the armature shaft, a special
puller is used, Fig. 440. The small
end of this puller screw should be
hardened to prevent spreading,
press should be used, taking care
is not bent from the pressure.
A four-cylinder governor ad-
vances the spark 38 degrees while a
six advances 57 degrees, this increased
advance on a six being due to the
fact that a six-cylinder magneto oper-
ates at 1 J times engine speed. With
this arrangement the same advance
may be obtained with a six as with
a four. The old-style Franklin gov-
ernor uses lead subweights which are
held on by four screws; these screws
work out unless properly locked. A lock punch is shown in
Fig. 441 as well as the bead turned by it. In assembling, be
-CUPPEP
Double Lock Punch
Fig. 441
In replacing the governor, a
that the armature end plate
CIRCUITING IGNITION, __J
Fig. 442. Eisemann G-4
334
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ELECTRICAL REPAIRS
29
r\
sure to place the governor in the case
first, as the lead weights will not pass
by the case opening.
Eisemann G-4 1st Edition Mag-
neto. This is the weatherproof type
Eisemann. The armature differs
slightly from the general practice,
having the collector ring on the breaker
end instead of the drive end, while the
condenser is on the drive end. Two
sharp screws in line with the sharp
edge of the collector ring and project-
ing from the gear housing act as the
safety spark gap. The breaker, Fig.
442, has a different type of breaker
arm, consisting of a flat spring which
carries a platinum point re-enforced
by a pressure spring. The points are opened by
striking the fiber cams on the timing lever. A
brush is held in the breaker retaining screw and
bears on the breaker cap and is connected to
the switch for stopping the engine.
The distributor disc has an R and L timing
mark which lines up with the index screw on the
gear housing used for timing the magneto to the
engine. A fixed advance magneto should have a
distributor disc marked with an F, while the
variable has a V. Unless this setting is correct,
the timing marks are useless. The distributor
bearing is eccentric for gear-meshing adjustment
and is held in by screws and lock washers. If
short-circuited, the condenser may be "burned
out" by placing it directly across a 110- volt
line, when the short will burn off, making the
condenser as good as new. The spark should
test .up to ^ inch on the test gap. When
assembling, lock the screws as in Fig. 443, as a
tongue of metal formed in the screw slot in the
Fig. 443. Breaker Points, Single-Lock
n
L
I0LE
FDR
SHAFT-
END
TO FIT BEARING CUP -
444. Bearing Cup
Drift
335
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30
ELECTRICAL REPAIRS
old way will not hold. When bearings loosen in the end plates,
they should be reinsulated. A fish-paper gasket and strip are
used, 0.012 inch thick, and the bearing cup driven in with a cup
drift, Fig. 444. This lower offset should exactly fit a 15-millimeter
ball cup, being flush with the outside of the cup.
The points originally used were of platinum and should be set
iftr inch apart on the break. A special wrench is furnished to
adjust the points through the slot in the lower side of the timing
lever. The two breaks should be exactly alike, and in case one is
wider, the cam causing the wide gap should be filed down so that
both are even. Do not attempt to put in new fiber cam blocks as
they are put in by machine; those put in by
hand will work loose. As considerable
trouble was encountered with platinum
points, the factory supplied special points q
termed Crecium points. This is a hard
substance similar to tungsten; it lasts longer
and gives less trouble. To install Crecium
points, the contact bracket is cut away and
the lug next to the point is removed to
allow for the head of the Crecium screw.
This screw is shaped differently, to distin-
guish it from a platinum screw. The point
spring should have sufficient pressure against
the adjustable point to bear firmly without
the aid of the pressure spring. To test,
pull away the pressure spring and note
whether the point spring remains on contact. A poor spring tension
will cause missing at high speed due to the spring not returning to
contact in time for the next spark. When the timing lever becomes
loose on the triangle plate, a new lever should be installed.
Eisemann Q-4 — 2d Edition. This edition and model is an
improvement over the first edition in that the pole pieces, end
plates, and gear housing are cast in one piece. The triangular
plate at the end of the magneto is held in place by two studs and
one screw. The bearings at the drive end of this magneto are
insulated from the housing. When it becomes necessary to rein-
state this bearing, the cup should be driven in with a drift and
r"i
Fig. 445. Bushing Reamer
QAA
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ELECTRICAL REPAIRS
31
Pig. 446.
Bushing
BEAPtP OVER
the edges of the insulation trimmed with a knife or screw driver.
The breaker of this edition differs from that of the old style, or
first edition, as it consists of a pivoted breaker arm, Fig. 437.
The breaker-arm bearing is made of a special material
which wears very little. This bearing is self-lubricat-
ing, as there are fine threads of fabric in the bearing
which retain the oil and distribute it in the desired
amount. These bushings sometimes swell, causing
Breaker the bearing to grind and the breaker arm to stick in
the open position, thus causing total ignition failure.
When this occurs, the bushings should be fitted by using the reamer,
Fig. 445. This reamer should be made of tool steel tempered to
a deep blue. The center hole should be drilled and bored very accu-
rately to the size of the rocker-arm pinion and should be very smooth.
The teeth of cutters
should be straight cut; no
adjustment is needed, as the
arms are all uniform. When
bushings are worn, new ones
can be made from white
fiber, Fig. 446, the center
hole being drilled and the
fiber placed on a mandrel
and turned down to size.
When installing on the
breaker, drive the bushings
on, ream to size and to
proper height, and then cut
the top level with the cen-
ter post. Platinum points
are used and the arm point
is riveted on. In some cases
it becomes loose. In tight-
ening or when installing new
points, plain riveting Will ^ gU7 ' Mounting a Breaker Point
not hold, but the point should be beaded over, Fig. 447, using a
punch as shown. The punch is made of tool steel and tempered to
a deep blue. When riy e tii*g> ^ e polnt s ^ ^ project into a steel
fHOLE t' \ /
r SHANK J- . J
u
337
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32 ELECTRICAL REPAIRS
plate with a hole a trifle larger than the point, allowing the steel
shank of the point to take the force of the blow, as the platinum
will hammer out of shape if placed on a flat surface.
The first 2d edition magnetos put on the market had cast-
iron breaker arms which broke from the constant jar and were
replaced with an arm made of Tobin bronze. Crecium or tungsten
points cannot be used with this type of breaker, as the pounding
of the points cracks and pulverizes the hard metal. The points
should open ^t inch.
Eisemann Impulse Starter. Large engines equipped with mag-
netos, such as used on trucks and tractors, are difficult to start,
especially when cold. An impulse starter is accordingly provided
to give a maximum spark at slow cranking speeds. The impulse
Fig. 448. Impulse Starter on Eisemann Magneto
starter takes the place of the coupling and is about the same
lehgth and is easy to install. Fig. 448 shows its internal mechan-
ism to consist of but five essential members: a housing H, attached
tp the magneto shaft; a driving member C, which is itself driven by
the engine; a spiral spring S, hooked to members H and C; a float-
ing member, or trigger, T; and a fixed bar B, which is mounted
on the base of the magneto. Its operation is as follows:
Position A — when the motor is slowly cranked, the trigger T
drops by gravity, engages with the bar B, and thus temporarily
prevents the rotation of the housing H. As the cranking con-
tinues to turn the member C, the spring S is compressed until the
cam at C strikes the wedge W. This forces the trigger upward
until it slips off the lower bar, thus releasing the housing H and
338
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ELECTRICAL REPAIRS 33
allowing the heavy pressure stored in the spiral spring to give the
armature a very sharp twist forward. This action causes the mag-
neto to produce a powerful spark which should start the motor.
Position B — this shows the condition after the release and in
the normal running position. It will be seen that stops are pro-
vided on the housing and on the outer part of the member C for
preventing the armature from being thrown past the normal posi-
tion. It will also be noted that the member T is heavily over-
weighted on its upper half. The action of centrifugal force on
this counterweight draws the member still farther until a tooth on
the latter enters a notch N in the driving member C and holds it
there as long as the motor continues to operate. This notch thus
gives a positive drive for the magneto.
Fig. 449. Bosch Dual Breaker Box
These impulse starters are made for both R and L rotation,
but should one need to be reversed, a driving flange C only is
needed to make the change. In case the starter becomes broken,
a small locking device is provided to prevent the trigger T from
engaging the stop B.
Bosch DU Dual Magneto. The Bosch dual magneto has a
separate breaker and high-tension coil but uses the magneto dis-
tributor. The breaker, Fig. 449, is mounted on- the timing lever
and is actuated by a cam on the magneto-breaker disc. This cam
is steel and is set to open the battery breaker 10 degrees later
than the magneto breaker, thus making it possible to set the mag-
neto breaker 10 degrees ahead of dead center. This is desirable
with six-cylinder engines, as the six-cylinder magneto rotates Ut
339
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34
ELECTRICAL REPAIRS
Fig. 450. End of
Dash Coil
one and one-half engine speed, which reduces its actual advance
by one-third. On some models this cam is adjustable. The
breaker points should open 0.015 inch.
The coil mounted on the dash has a vibrator
for starting, Fig. 450, which is connected into the
circuit by pressing the button on the coil or by
turning the button to the starting position. In
setting this vibrator, first see that the points are
clean. This can be done by taking off the small
cross plate which carries the button and noting
how the spring assembly is placed. In adjusting
the points, loosen the small screw that holds the
button and turn the platinum point screw up or down, using a
wrench as in Fig. 451. Turn the button to the start side and
be sure that a good spark is obtained.
The four contacts at the left of the vibrator, Fig. 450, soon
become dirty and cause a poor contact on the battery-breaker line
as the lower contacts are in series with the breaker. This is
indicated by a continual vibration on the start side and a stop-
page of the engine when turned to Run. It is also likely to kick
back as the spark delivered to the cylinder is continuous. To
clean these points, remove the double contact plate and clean it
with a platinum file, taking care not to break the wire attached.
In some cases a poor ground brush
connection in the magneto, due to dirt or
a loose ground wire on the coil, will cause r
the magneto to fail to shut off when the
switch is thrown to the off position. This
will result in the high-tension spark passing
from No. 3 terminal contact to the switch
contact and then jumping the intervening
space to terminal contact No. 4, Fig. 450.
This results in the burning of the hard-
rubber terminal block and puts the mag-
neto out of commission. When the mag-
neto fails to stop on the off position, place
the switch on the magneto side and kill the engine. This will save
the coil. Sometimes wires Nos. 1 and 2 are reversed through care-
j|"p«A.-
,. LrJ
Fig. 451. Vibrator Adjusting
Wrench
)
340
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ELECTRICAL REPAIRS
35
4 3
lessness or ignorance, and the battery current is applied to the mag-
neto breaker, burning the insulation and annealing the breaker spring
Bosch Type NU Magneto. The
type NU operates on a principle
distinctly its own, having no dis-
tributor gears and attendant parts.
The primary circuit is the same
as in the DU and has a similar
breaker. The secondary winding
is entirely insulated from the pri-
mary with both ends brought out
to a slip-ring. This slip-ring is
double and has two segments oppo-
site each ether on adjacent slots.
This armature circuit is shown in
Fig. 452. One end of the primary
is grounded, and the other con-
nects to the breaker. One end of
the secondary connects to a one-
ring segment, and the other to the
CONDENSER IBREAKER POINTS
Fig. 452. Armature Circuit of
Bosch DU Type
3L jiL*.
w> w
Fig. 453. Wiring Diagram of Bosch DU Type
opposite segment. Four brushes rub on these rings and distribute
the current to the proper cylinders. The plug cables are attached
through the center of the brush holder, and this holder is attached
341
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36
ELECTRICAL REPAIRS
AAA
=L PRIMARY
to the magneto opposite the collector rings. As a four-cylinder
engine fires every other revolution, No. 1 cylinder is at the firing
point when No. 4 cylinder has just finished its exhaust stroke and
is free of gas or pressure; hence a spark may occur in this cylinder
with no effect. Therefore cylinders 4 and 1 may spark together
with an explosion in 1 only; on the next revolution a like opera-
tion fires No. 4. Cylinders 2 and 3 have a like combination. The
two spark-plug gaps are in series, and the ground completes the
circuit between them, but as one gap is only under atmospheric pres-
sure, it has practically no effect
on the spark. The plugs should
be set 0.025 inch on all cylinders.
The wiring is shown in Fig.
453. The magneto rotates at SINGLE. BREAK
engine speed and can be used on
a four-cylinder engine only. In
testing the winding, a different
procedure is necessary J;han with
the ordinary type of armature.
The armature is connected as in
Fig. 454, the primary being con-
nected to the single-break tester
and the secondary leads being
held t^t inch apart. This may be
done by driving two nails in the
bench touching the ring segments
and a gap placed between the nails; or if the slip-ring is removed,
bend the wires together for a gap. With the spark jumping this gap,
ground the lead A and note whether the spark ceases on the gap;
repeat on lead B. If either ground cuts out the spark between the
gap, the armature is broken down. This is the only reliable test for
this type of armature. In case it proves defective pull the ring off
as the ground may be in a punctured slip-ring; test again without
the ring. Where too much oil is used, the brush holders become cov-
ered with oil and carbon dust which will afford the current a path,
burning the ring and putting the magneto out of commission.
Bosch Impulse Starter. This impulse starter is built in, and
operates in oil. To start the engine, move either by hand or by a
6V
BATTERY
SWITCH
a
Fig. 454. Testing Bosch DU Type Armature
342
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ELECTRICAL REPAIRS
37
dash control the lever on the side of the case to the side marked
ENGAGED; return to neutral, as the starter is now set. Moving
to RELEASE disconnects the starter. The impulse starter will
Fig. 455. Construction of Bosch Impulse Starter
operate until the engine starts and the speed reaches about 150
r.p.m., when the starter is automatically. thrown out and remains
inoperative. Fig. 455 shows the mechanism of this starter. A
dish-shaped flange is mounted on the magneto shaft, on the edge
of which are four slots, two for right-hand rotation and two for
left-hand. The crossbar fitting into these slots is driven through
springs— two compression springs and two short bumper springs.
I
Fig. 456. Bosch Duplex Wiring Diagram
Carried on the starter drive shaft is a disc enclosing these springs
and having two cams on its rim. The small pawl at the top is
held away by a catch and released by the trigger handle on the
343
Digitized by LjOOQIC
38
ELECTRICAL REPAIRS
exterior of the case. This pawl, when released, drops onto the
driving disc and the crossbar when rotated and prevents the mag-
neto shaft ^from turning, compressing the springs. The bar is
released when the cam on the driving disc raises the pawl, and
the compressed springs rotate the magneto armature, causing a
spark in the cylinder. In changing this starter to opposite rota-
tion, place the crossbar in the other slots, change the springs,
reverse the pawl, and put in a new pawl shaft for opposite
rotation.
Bosch Vibrating Duplex System. This system can be used
with any Bosch magneto. It consists of a vibrator which is con-
nected in series with a switch and the battery as in Fig. 456.
The vibrator is of special construction to allow only enough cur-
rent to be applied to the magneto primary to produce a good spark,
without weakening the magnets, since there is
no reversal of battery current through the
armature as in a straight duplex system. The
vibrator armature and platinum points are
shown in Fig. 457. The upper bridge is of
hard rubber, while the magnet pole pieces
come very close together so as to make a
very efficient magnet. A condenser, shown
above the coil, is connected across the points.
A switch turns off and on the battery or mag-
neto ignition.
The current from a battery — which may
be 6 or 12 volts — or from 6 dry cells travels
through the vibrator to the magneto primary and the magneto
points which are together, and back to the battery through the
ground. This causes the vibrating arm to vibrate, but as the mag-
neto points are together no spark takes place as the current passes
through them. At the instant the points separate, the cur-
rent flows through the armature primary and a vibrating spark
is produced, being timed by the action of the breaker points. The
vibrator operates continuously, but louder while the magneto points
are together. As soon as the engine starts, the magneto automatic-
ally comes into operation, producing a much stronger spark than
the battery current.
Fig. 457. Duplex Vibrator
344
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ELECTRICAL REPAIRS
39
-E>
PRIMARY
iWM]
5E.C0NPARY
EXHAUST
INLET
TSTT
-CT-
o
Bosch Two-Spark Magneto.
It is well known that in gasoline
or any other explosive mixture
the spark has a certain speed of
propagation varying with the
mixture. When ignited, the aver-
age air-and- gasoline mixture
under compression requires about
shf second to reach its maximum
expansion and power, but as a
crankshaft travel of 30 degrees
takes place during this time, at
a motor speed of 1000 r.p.m.,
a considerable lag is produced in
the system. The electrical lag
has been eliminated by using a
magneto or a positive-break bat-
tery system. As the speed of
propagation represents a flame
speed of a certain number of feet
per second, by cutting down the
distance the flame must travel,
we also cut down the lag of the
explosion. This is done by using
two sparks in the cylinder at the same
instant. This system is most practical
on the T-head motor. Fig. 458 shows
how the distance of the flame travel
is reduced, each plug starting the flame
toward the center and practically
reducing the lag by half, thereby giving ^
a quicker explosion with a subsequent AAAAAAA
increase of power on the same charge
and also obtaining greater speed and
mileage.
As the two plugs ignite the charge,
the sparks must be simultaneous or the
Fig. 458. Two-Spark Magneto Circuit
EX. DISTRIBUTOR
M. DISTRIBUTOR
■&
effect is lost.
Therefo^ the source of
Fig. 459. Armature Wiring
of Two-Spark Bosch
345
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40 ELECTRICAL REPAIRS
the spark must be the same at both plugs. This is effected by using
one winding, Fig. 458; both ends of the secondary are brought out
to a slip-ring with two segments, Fig. 459. The segments are on
opposite sides of the ring
and a brush bears on
each, carrying the cur- *ams»cimtm«
rent to the distributors.
These distributors are
entirely separated from
each other and are made
in three pieces. A double
distributor brush holder Fig. 460. Wiring Diagram of Two-Spark
* J xi_ mi' i i Magneto Ignition
feeds them. The back
distributor plate is fed from the rear and is connected to the spark
gap by a wire lead to the right-hand brush holder, Fig. 460. The
front distributor is connected to the rear safety gap and the left-hand
brush holder. A switch is provided to turn the magneto off as
well as to cut out one side of the ignition. When using one side-
only, the intake side is always used, as the inrushing gases keep
the intake pocket free from burned gases, whereas the exhaust
pocket will contain a small amount of gas and will cause a poor
explosion. Fig. 460 shows the wiring for a Bosch two-spark
independent system. The off position of the switch grounds the
magneto primary, stopping the engine. No. 1 position allows the
engine to operate on the intake side only, while No. 2 position
allows it to [operate on
both sides. In starting ^*
with this system, it is ^}
best to use one side only,
as the advanced timing
obtained with the two
sparks is likely to cause
a kick back. When en- j
gineS are h,ard to Start, Fig. 461. Wiring Diagram of Two-Spark Dual
i i , • i Magneto Ignition
a dual system is used.
A regular dual coil is connected as usual, Fig. 461, but instead of a
jumper from, the front distributor to the rear of the magneto, the
coil is inserted in this line (wires 8 and 4 in diagram). A separate
346
ELECTRICAL REPAIRS 41
breaker is used for the battery, as on the regular dual system, and a
separate switch is provided to cut out one side of the ignition. It is
marked 2-1-2, the center position grounding the exhaust plugs,
while either 2 position allows the motor to run on both sets of
plugs. When starting on the battery, the intake plugs only are used.
The armature winding used on this magneto is similar to that
on the type NU, Fig. 454, and on the newer type of two-spark
magnetos, the windings are interchangeable with the NU. The
older models have a slip-ring made in two pieces screwed together
and are for R and L hand rotation. In taking apart this ring,
care must be used not to break it; heating the shaft sometimes
helps to free it.
To test the armature winding, proceed
exactly as with the NU, Fig. 454, and the
spark produced should be equal to it.
" When the winding is grounded on one side,
it causes a poor running engine but not
a regular miss, as it is firing on one side at
all times. But when the miss is present on
the intake side, the spark on the exhaust
side, although good, does not produce a
good explosion owing to burned gases, as
previously mentioned.
™ **« a ~ ™ w* u * Mea Type BK. The Mea magneto
Fig. 462. Setting Mea Distributor Jr .
armature has the condenser and the slip-
ring both placed on the same end, and the sleeve of the ring pro-
jects through the condenser. The breaker is operated by a fiber
roller which strikes a flat steel cam located back of the breaker.
The points are of platinum and should open 0.010 inch. The sta-
tionary screw should be locked in, as it sometimes works loose, cut-
ting out the magneto. The magnets should test 25 on the magnet-
meter. When charging, use the pole pieces in the charger and drill
two small holes in the center of each to allow the dowel pins of
the magnets to enter and obtain a flat contact with the magnet.
When reassembling the magneto, two methods are used for
setting the distributor gear; Fig. 462 shows one method. The
gear is turned so that No. 1 mark comes in the center of the
window when the armature leaves the pole pieces ^ inch. This
Digitized by LjOOQIC
42
ELECTRICAL REPAIRS
will give the proper setting. The other way is shown in Fig. 463.
A setting pin a is used, or a nail, which is placed in a hole b in
the gear casing, and the distributor gear c is revolved until a like
hole appears in line with the former hole. The armature d is then
Fig. 463. Another Method of Setting Mea Distributor
Fig. 464. Wiring of Mea Magneto Ignition
turned until a hole on its edge lines up with the other holes, and
the assembly is then fastened together.
The cradle, or trunnion, holding the magneto becomes worn
owing to oil and sand collecting on the exposed bearings and cut-
348
Digitized by LjOOQIC
ELECTRICAL REPAIRS 43
ting them; as a result the whole magneto becomes loose and jumps
around. When this happens, the cradle is fastened on the tool
carriage of the lathe and a boring tool used to bore out the cradle
bearings, taking care to maintain the original center line. The
magneto end plates are next turned down and a brass or bronze
bushing shrunk on and also pinned to prevent loosening.
Dual Type. When a battery is needed for starting, the dual
system is used. A high-tension coil is mounted on the dash, the
battery breaker then operating from the
distributor shaft. The wiring is shown
in Fig. 464. In the back of the coil is
placed a vibrator, which interrupts the
current. Therefore the spark is produced
when the battery-breaker points on the
magneto make contact and not when they
break as in other systems. On the edge
of the distributor gear is a mark which
is lined up with a similar mark on the
gear casing locating the firing point for
No. 1 cylinder.
Mea Type A. This is an enclosed type
and has the rocking part of the magnet
Fig. 465. Mea Breaker assembly self-contained, the timing lever
operating the advance. The timing of the distributor is done by
meshing the marked teeth on the gears; and the gear housing is
then slipped on. The breaker, Fig. 465, is of different design, the
points being actuated by the fiber breaker block striking the steel
cams and forcing open the points. When putting in new points,
be sure that they line up and have sufficient pressure to keep
them firmly together, but do not bend the spring too much as it
will break. The armature is smaller than the BK type, otherwise
it is the same. In testing, it should jump ^ inch on the test gap. .
WESTINGHOUSE VOLTAGE REGULATORS
Description. The regulator consists of an E-shaped, lam-
inated magnet, Fig. 466, which has three separate windings and is
enclosed by a case through which the pole pieces project. On
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ELECTRICAL REPAIRS
SERIES RELAY
these pole pieces are two pivoted armatures; one armature, the
cutout armature, controls the generator circuit to the battery; and
the other, or regulator armature, controls the current output of
the generator. The E-shaped magnet core provides a two-path
magnetic circuit from the center core. Both the cutout armature
and the regulator armature are pivoted over this center core, their
outer ends overhanging the other extremities of the core, one
• armature extending to the right, the other to the left, Fig. 467.
Operation. It will be seen that when the generator voltage
reaches a given value, at which the generator is intended to be
connected to the bat-
, • ., ,i COMPENSATING
tery circuit, tne mag- series r egulator
netism set up by the
shunt coil (center coil,
Fig. 466) is sufficient
to pull down the cut-
out armature, closing
the cutout contacts
and connecting the
generator to the bat-
tery. The charging
current then flows through the series coil (right-hand coil) increas-
ing the pull on the cutout armature so long as the generator is
charging and pulling the points firmer together. When the speed
of the generator falls below the generating point, the current revers-
ing in a slight discharge through the series winding neutralizes the
strength of the shunt winding and the points open.
As the generator increases in speed, the voltage increases
with it, since the shunt winding- of the regulator is connected
across the generator brushes, Fig. 467. It increases its pull on
the regulator armature, as the current delivered to the battery
passes through the series coil of the regulator (left-hand coil,
Fig. 468) and also exerts an additional pull on the armature, pull-
ing down the armature and opening the points. This cuts in the
regulator resistance coil, reducing the generator output; and as
this reduction in current allows the armature and points to return,
the operation is repeated. As the inductance of the shunt field
prevents a sudden rise or fall of the field current, an average is
Fig. 466. Wiring of Westinghouse Voltage Regulator
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45
maintained by the vibrating of the points. The resistance unit
prevents sparking at the points, which, owing to the high self-
induced current, would occur if the field were opened each time.
r~
To Battery. 3~
Regulating Contacts
O
Voltage Regulating Sere*
y oc re*
Regulating Resistor
■—WWW
Series Compensating Coil
Shunt Compen- g
sating Coil—+£
Regulator Shunt Coil
.Generator Shunt Field
KAQ.Q.0J)-Q,/
Commutator-
L
\--f
Brushes'
n
Fig. 467. Wiring Diagram for Westinghouse Generator with
Self-Contained Regulator
The cutout points are silver; the contact made is slightly lateral
owing to the offset pivoting of the armature, thereby maintaining
an even surface. The same lateral movement is applied to the
regulator points. The upper point is tungsten, and the lower, or
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46 ELECTRICAL REPAIRS
movable point, is silver. As tungsten will not transfer itself to
silver, the tungsten point should always be positive.
The adjustment of the cutout is made by bending the two
prongs of the brass support located at the end of the cutout
armature. Bending the tension-spring prong upward makes neces-
sary a greater pull against the armature to draw it in, while bend-
ing the other prong adjusts the air gap between the armature and
the pole piece. In setting the cutout, it should be adjusted close
at the point where the generator will send a charging current of
approximately 1 ampere to the battery and release at zero, or at
not more than 1 ampere discharge. The air gap determines the
SEPARATELY MOUNTED REGULATOR
Fig. 468. Internal Wiring of Pierce-Arrow Voltage Regulator
cutting-in point — the smaller the gap, the quicker the armature
will be attracted — and the spring determines the cutting-out point.
The regulator is adjusted by means of a small adjusting screw
at the top; this, when sorewed in, raises the output. The points
should be dressed smooth and perfectly flat on an oil stone, keep-
ing them flat on the stone to ensure a true surface. Be sure that
the armature is free on its pivots and that it does not come in
actual contact with the pole pieces. Run the generator at its
highest charging rate and turn down the screw adjustment until
the ammeter shows 10 amperes*
Burning of the control points generally indicates an open cir-
cuit in the resistance unit, or if slight, it may be caused by an
imperfect contact of points. When the regulator controls the out-
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ELECTRICAL REPAIRS 47
put up to a certain speed and then ceases to regulate, the current
rising above this point, it indicates a resistance unit of too low
resistance. These units are interchangeable. When the tungsten
point becomes rough and has a projection which fits into the silver
point, causing sticking of the points, it indicates the wrong polarity
of the points, the silver being positive and transferring to the
tungsten under the influence of the current flow.
Westinghouse Voltage Regulator on Pierce-Arrow. This regu-
lator is similar to the standard voltage regulator, but with a few
additional changes. The points are bridged with a condenser in
addition to the regular resistance unit, both being in multiple.
This helps to prevent sparking. The standard resistance unit
should be 30 ohms. It also contains a shunt compensating coil in
series with the generator shunt field, which increases the sensitive-
ness of the regulation. This coil is wound on the regulator pole
piece, Fig. 468, its purpose being to oppose the action of the
series compensating coil, and it also helps in demagnetizing the
regulator circuit and producing a quicker vibration with a subse-
quent even regulation. The setting is accomplished in the same
way as in the standard regulator.
EQUIPMENT
Growler Armature Tester. This type of tester is the most
efficient, and results are obtained quicker than by other methods.
Several makes may be had. In selecting one, be sure that it has
sufficient strength to do the work, as some of them are too small
or have insufficient saturation to give results.
The principle of the growler is the same as that of the trans-
former, and it operates on alternating current, generally 110 volts.
Fig. 469 shows a good design. The two coils A form the primary
of the transformer; the frame and pole pieces B, the magnetic cir-
cuit, which is open. When an armature is placed between the
pole pieces, the armature core completes this circuit. The arma-
ture conductors form the secondary winding, and if there are no
short-circuits in the coils, very little current or voltage is induced
in the windings, as in any transformer. Should there be a
shorted coil, a heavy current is induced owing to the closed circuit
of the short-circuited coiL This sets up a heavy vibration at the
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ELECTRICAL REPAIRS
slot carrying the shorted coil, which can be felt, or heard, by
placing a piece of thin steel or a hack-saw blade over the slot.
Operation. In testing, the armature is slowly revolved in the
growler, and each slot is felt with the saw blade, as it comes to
the top. If the armature is left on for a few minutes, the short-
circuited coil will become hot and will eventually burn out. Com-
mutator shorts due to small particles of copper dragged over the
insulation when turning, commonly called "bugs," will be burned
off by this heavy induced current. A poorly designed growler will
not do this. In testing for an open coil, short-circuit each com-
mutator segment in turn as the armature is revolved; each seg-
ment should give a spark
owing to the induced cur-
rent. In case of an open
coil, no spark will result.
In testing for grounds such
as between the commutator
and the armature shaft, a
grounded winding will cause
a spark.
Design. The following
is an efficient design
growler that may be readily
built in the shop, in case it
is not desired to buy one:
In Fig. 470 is shown a lamination of the proper shape and
size cut from ordinary sheet iron and with three holes drilled for
the holding bolts. There should be enough laminations to build
up to a thickness of 2J inches, and the whole assembly should
then be bolted together. Although sheet-iron laminations are the
most efficient, the lessened efficiency of cast iron makes very little
difference, as the growler is only used for a short time and the
cast iron does not have time to heat.
To make the cast laminations, a pattern should be cut from
|-inch pine to the shape of Fig. 470. The small lugs at the bot-
tom are for the feet to bolt to the bench. The holes should be
drilled after casting. The pattern should have three coats of
shellac and should be sandpapered after each coat has been
Fig. 469. Growler for Testing Armature
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49
applied. Nine castings are necessary. Smooth up the castings on
the sides and stack them together; hold them with clamps, then
drill three J-inch holes through the whole assembly, as located in
Fig. 470; and with the clamp still in place, rivet them together
with J-inch iron rod. Do not set the rivets too tightly as the
iron is likely to crack. Drill two J-inch holes in the legs, as
at C, Fig. 469; these holes can be drilled from the bottom very
easily.
The assembled frame can now be smoothed up on the emery
wheel, especially the surface of the pole pieces B. The coils A
Fig. 470. Construction of Growler Lamination
are wound up on a wooden form, and each coil consists of 175
turns of No. 14 B.&S. gage copper magnet wire, each wound in
the same direction. Leads should be brought out, using lamp cord.
The coils are taped as shown in the illustration and are well shel-
lacked. The two coils are placed on the frame, with the two
inner leads at the same side; these two leads are connected together,
and the two outside leads are brought out and connected to a
110- volt alternating-current circuit through a switch. As it is
easy to forget to turn off the growler and as it makes no noise
when there is no armature on it, it is well to connect a lamp in
the circuit, Fig. 471 , u §ing a sna P switch to turn it off and on.
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ELECTRICAL REPAIRS
Undercutting Machine. Most undercutting of commutators
is done by hand with an old hack-saw blade and is both slow and
unsatisfactory. There are several types of machines for doing
this mechanically; some do a smooth job, but others take longer
II0V0LT5 A.C.
SNAP SWITCH
6CPLAMP
GROWLER CONNECTIONS
Fig. 471. Method of Wiring Growler
and give worse results than the hack-saw blade. The revolving
needle gives excellent results and is the quickest of any type. Its
adaptability to commutators of various sizes and to different con-
ditions and its quickness in setting up make it very valuable. Its
work is clean cut as well as uniform, with no scratches left on the
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ELECTRICAL REPAIRS
51
-A*-
I " P
\
r?
1
s. &
3
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52
ELECTRICAL REPAIRS
commutator. A design for a machine of this type is given for
those wishing to make one, as there are but few on the market
at present.
Design. In Fig. 472 is given a side view of a motor-driven
machine. The base A is made of cast iron 24 inches long, 5|
inches wide, and 1§ inches high; sliding on this base is a carriage
^
Fig. 473. End View of Mica Undercutting Machine
B, made 3 inches wide and f inch thick, which slides on rails
cut on the base. Mounted on the carriage are two center brack-
ets C; these are bolted on with the nut D. The center screw E
is adjustable; the center F is solid. The column H holds the
motor and cutter assembly. The motor K should be about a
J-horsepower, 110- volt, high-speed universal type, using either
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ELECTRICAL REPAIRS 53
alternating-current or direct-current. The motor is mounted on
the spindle J and is held in adjustment by the set screw I on the
column. The needle N is held in the shaft L by the set screw 0*
The armature is placed between centers, the spindle J is
adjusted to the proper height, and the carriage is moved back and
forth by the handle P through the linkage R, cutting out the
mica to the required depth. Fig. 473 shows an end view. The
column H is ribbed for strength and is fastened to the baSe, 8
inches from the end, with four ^-inch standard cap screws, an
extra wide leg being cast on the base to support it. The set
screw I is ^-inch S.A.E. thread and is knurled. The handle
operating the carriage is of f-inch fiber, and the lever is hinged on
the bracket Q, which is cast on the base. The bracket Q is 1£
inches long and has a hole drilled and tapped for 10-32 screws;
this bracket should be \ inch thick and f inch wide. The base
A has two rails cut on its top, the carriage B being planed to fit.
These rails need not extend more than 6 inches on each end, as a
lessened surface will reduce friction of the carriage. A bolt, or
stud, is mounted rigid in the carriage, and a nut and washer hold
it on; the slot should be slightly larger than the stud. The thread
on this stud should be rather tight to prevent loosening, while the
washer may be a spring or cupped washer to take up any varia-
tion in the machining.
The carriage also has a groove cut % inch wide, extending
within 6 inches of each end in the center of the casting. This is
for the center standards C to slide in; by having both centers
slide, any armature may be fitted quickly. The standards have a
tongue which fits into the groove and is held by a t^-inch carriage
bolt with the head turned thin; the squared portion of the bolt
prevents turning while adjusting. The rear center is solid in the
standard, while the front center is adjustable. The knurled screw
E should be of &-inch stock with an S.A.E. thread, both centers
having a 60-degree taper.
The needle assembly, Fig. 472, consists of a spindle A f on
which is mounted the motor J screwed to the flange. The shaft
B is a piece of J-inch drill rod, which comes perfectly true and
smooth. A collar C is pinned on with a xfr-inch pin 0; the
spindle is bored out to take two bronze bushings P and Q, which
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54
ELECTRICAL REPAIRS
are pressed in and reamed to i inch. An oil hole I is drilled to
oil the upper bearing, the surplus oil running down the shaft and
oiling the lower bearing. The shaft is placed in the spindle and a
collar is pinned on at the top D. The detail sketch in Fig. 472
shows the end of the shaft, which has a tongue G fitting into a
slot M in the motor shaft H, giving a positive, though flexible,
drive.
The lower end of the shaft is drilled to take the needle E,
which is held in by the knurled screw F. The needles are made
of f-inch drill rod, turned down and having a round shoulder K
for strength, the lower shank being of various diameters, depend-
ing on the width of the slot to be undercut. It is best to make
-$|$$}$;
M-
Fig. 474. Magneto Test Stand
about three sizes of shanks. The point or cutting edge should be
pointed and ground three sided, being careful to get each side the
same and preserving a true center of the point. After the points
are shaped, they should be tempered to a dull blu§ and finished
with an oil stone. When the carriage is assembled on the base,
place a little fine valve grinding compound and oil on the rails
and grind in the surfaces to a smooth finish; this will ensure easy
operation. Holes should be drilled in the base A and the machine
fastened to the bench.
Operation. To undercut an armature, place the armature
between the centers, moving the centers so that the commutator
will come under the needle, and screw up the adjustable center so
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ELECTRICAL REPAIRS 55
that the armature will be fairly tight. Select the size of needle
suitable for the width of commutator slot, lower the needle so
that it will cut away about -gSr inch of mica, hold the armature
steady with the slot opposite the needle, and steadily draw the
needle into the slot, cutting a smooth groove the full length of the
commutator; still holding the armature steady, withdraw the needle
and cut the next slot, and so on. A little practice will make a
smooth quick job. After all the slots are cut, place the armature
in the lathe and take off the slight burrs with No. 00 sandpaper.
Fig. 475. Generator Test Stand
Magneto Test Stand. For testing magnetos, a substantial
device that may be quickly set up is necessary. Fig. 474 shows a
simple design for such an apparatus. The vise A holds the mag-
neto to be tested, clamping it tightly by the two screws B. The
magneto has a pulley provided with the standard taper, which is 5
degrees, or if a coupling is on the magneto that may be used for a
pulley, a f-inch leather belt connecting this coupling with the
motor pulley. The high-tension wires are connected to the adjust-
able spark gap, and the magneto is then tested. The motor N
should be a variable-speed, 110-volt, and, if possible, direct-
current machine. A starting box is used, taking the return
spring from the handl e and using it for a regulator. This will not
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ELECTRICAL REPAIRS
damage the resistance, as it is only on a short time and the load
is light.
The magneto vise should have a brass base A. The screws
are f-inch S.A.E. thread with a knurled handle, a flat button C
being riveted to the screw at the countersunk portion 0; this pre-
vents marring the magneto paint. The boss D on the base cast-
ing makes the threaded hole stronger. The spark gap is mounted
on a fiber base E, 4|"X6£"Xj", fastened to the bench by the
Fig. 476. Carriage of Generator Test Stand
supports MM. The binding posts G are connected to the gap
points F, which can be phonograph needles. The adjustable bar if
is i inch square, iron or brass, and swings on the links II; the
indicator hand J moves on the dial L and is connected to the bar
by the link K. These three links are made of T&"Xi" iron.
The link K is so made that when the hand rests on 7, the points
F should clear the bar tt inch, and the dial is laid off so that
each calibration represents ^ inch; this gives a quick adjustment.
The link I on the right-hand side should be connected to the sup-
port M, which, in turn, is grounded to the vise A.
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57
Generator Test Stand. To test and regulate generators
properly after repairing and before placing on the car, some
means must be provided to run the generator at various speeds.
Such a test stand must be universal and easily set up. A test
stand meeting these requirements is shown in Fig. 475. The
baseplate A is cast iron, 10"X16", surfaced on the top. Column
B is bolted to the baseplate and carries an adjustable head, which
holds the driving assembly. The location of the column should
be such that the center line of the chuck is in the center of the
base. A threaded rod bent into a crank G raises and lowers the
head; the rod should be & inch with an S.A.E. thread. The lower
end of the rod is turned with a J-inch shoulder and fits into a
^
c ;:
!!
— 1 1
?
Fig. 477. Pulley Assembly for Generator Test Stand
hole bored in the base; the upper end has a collar J pinned on,
and the plate K takes the thrust in lowering the head.
The head has a 45-degree angle groove cut in the body of the
casting, Fig. 476, which fits into a similar tongue cut on the column.
One side of the body casting A has the groove cut away slightly
more to make room for a gib H and two adjusting screws G to take
up the wear in the head. These screws G should be 12-24 iron
screws and should have lock nuts. The boss B is for the adjust-
ing rod and is threaded to receive it. The shaft runs on two
annular ball bearings, the head casting being recessed at D to
a press fit while the shoulder E prevents them from working
loose. The hole F i 3 for the shaft and is slightly larger than
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58
ELECTRICAL REPAIRS
the shaft, Fig. 477. A is the end that fits into the chuck collar;
B is turned to a good light press fit in the bearings; the collar E
is placed between the outer bearing and the pulley F and prevents
the shaft from working out; the slot G is to drive the speed
indicator; CC are the bearing seats; and D is the body casting.
Between A and C and between JE-and C are two thin brass
plates to keep the dirt out of the bearings.
The chuck F, Fig. 475, is a 4-inch, three-jawed, universal
type, fastened to a flange and pinned to the shaft D. Any chuck
will do for this, as being out of true will not make much difference.
The speedometer is made from a Corbin-Brown head, and the
scale should have an 80 m.p.h. limit. The hand is taken off and a
blank glued to the old dial. The instrument is then recalibrated
Fig. 478. Mounting Blocks for Generator in Test Stand
with a speed counter to read r.p.m. Having obtained this data on
the blank, a neat dial may be drawn and glued on. The speedom-
eter head is held on the carriage by an angle iron made of |"X3"
iron, the coupling of the head fitting into the slot G, Fig. 477.
Take care to line up the head so that the coupling will be free at
all positions of the shaft. Having the speedometer always opera-
tive saves time in testing. The pulley E, Fig. 475, should be
about 4 inches in diameter and with a 2-inch face, while the
motor pulley A should be 6 inches.
The generators are held in the stand by a motorcycle chain
attached to the screw M, Fig. 475, and hooked onto a stud.
It is tightened by the hand nut N, this screw sliding in a slanting
guide L; this guide is about 8 inches long and allows for different
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59
sizes of generators. There are three studs to which the chain
may be hooked. Holes are drilled in the base to fasten the gen-
erator to the bench. Square generators line themselves when
U= » □=□
' » »-^yJ
&
placed in the stand, while round-type generators are placed in a
V-shaped casting, Fig. 478. This is a simple casting requiring no
machine work, the bottom edges being filed so that it will set flat
on the baseplate.
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60 ELECTRICAL REPAIRS
The motor for the test stand should be a 1-h.p. variable-speed.
A 110- volt direct-current motor is the most convenient and should
have a control box of a wide variation in speeds. A 2-inch leather
belt is used, no special adjustment being necessary on the belt as
the movement of the head carriage is not sufficient to affect the
tightness of the belt. When an electric speed indicator is desired,
a small direct-current magneto generator is mounted in place of
the speedometer and driven through a similar coupling; a volt-
meter is then placed on the test board calibrated to read r.p.m.
instead of volts. A reversing switch is necessary as the voltmeter
only reads in one direction.
Generator Test Stand Switchboard. When testing a genera-
tor in the stand it is necessary to have an ammeter to show the
charge rate and a voltmeter to show the voltage. The switch-
board for this test stand is shown in Fig. 479. It is made
of slate, or marble, and has two instruments at the top of the
board; H is the voltmeter, which should be a double-scale instru-
ment with the high reading 50 volts and the low reading 10 volts,
switching from one to the other by an ordinary three-way snap
switch K . If unable to get a meter of this type, an ordinary
single-reading meter may have a tap brought out and connected
in the meter resistance so as to give the low reading. The
ammeter G should have a 50-ampere scale with a separate shunt;
the shunt wires are reversed through the four-way snap switch J
to read either charge or discharge on the meter.
As there is a great variation in the voltages of the different
systems, it is necessary to have from 6 to 24 volts available. The
double-throw switches B permit this. There are six switches and
when all of the switches are down, the batteries are connected in
parallel, giving 6 volts. When switches 1 and 6 are left open, 2
and 5 down, and 3 and 4 up, the two center batteries will be con-
nected in series and the end batteries open, giving a 12- volt cir-
cuit. When switches 1, 2, 3, and 4 are up, 5 down, and 6 open,
batteries 1, 2, and 3 are connected in series, leaving battery 4
open, giving 18 volts. When all switches are up, the four batter-
ies are connected in series, giving 24 volts. The switch H cuts off
and reverses the polarity of the battery circuit to the test clips N,
Fig. 480. Switch F is used for detecting grounds and is connected
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ELECTRICAL REPAIRS 61
to the 110-volt line through the lamp /; in the up position, one
lead is tested, and in -the down position, the other lead. The
switch C is for grounding the leads and saves time in setting up.
i
i
>
!
a
i
The motor operating the stand is controlled from the board,
the switch E being fused and controlling the main current to the
armature, while the switch D is a field switch and is reversible.
The leads N from the switch H are the test leads and should
have test clips attached; the leads from the switches B are the
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Google —
62
ELECTRICAL REPAIRS
battery connections and lead to the four 6-volt batteries, the first
terminals, —1 and +1, connect to the first battery, —2 and +2
to the second battery, and so on. The leads Q from switch D
attach to the motor field, while the leads P connect to the arma-
ture. The leads are from the 110-volt line and supply the test
lamp 7. The shunt L is used for the ammeter.
Ignition Switchboard. For quickness in operation, the single
break must be connected so that any type of coil can be tested
without using separate ballast coils or leads. This is accomplished
Fig. 481. Ignition Switchboard
by having everything on one switch, as shown in Fig. 481. The
switch A has eight combinations: 220 volts in series with two
110-volt lamps D mounted in sign receptacles so that the lamps
project through the board; 110 volts in series with one lamp; a
battery contact which gives either 6 or 12 volts, depending on the
position of the switch E. This switching of the battery current
allows either voltage to be used on any of the other switch points.
There is also a master vibrator; a single-break tester operated by
the handle C; the same single break with a 0.45-ohm ballast coil
in series; a 0.45-ohm ballast coil; and a 1.2-ohm ballast coil. An
ammeter B shows the current used.
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ELECTRICAL REPAIRS 63
In Fig. 482 is shown the wiring for the board. The switch A
is connected to the various units and has the three ballast coils
mounted directly on it. The single break C has a condenser I
QQ
I
1-1
I
OQ
connected across the points; the master vibrator G also has a con-
denser H across the points. The terminal posts J connect to the
battery and the terminals K to the 110- and 220-volt line. The
posts F are the test leads and should have test clips attached to
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ELECTRICAL REPAIRS
flexible cables. The whole board may be of wood and enclosed in
a box frame, the front swinging on hinges.
The construction of the switch is shown in Fig. 483. The
base A is made of J-inch red fiber, mounted on a mandrel and
turned in the lathe to a true circle. It is then placed in the
chuck without the mandrel and the two sides faced off; sixteen
12-24 right-hand brass screws are then screwed into the base,
Fig. 481. The base is again chucked and the heads are
'^J^rt'
JL
i i
i I
i i
J
>,ic a/ feT
U
(X "X )D
Fig. 483. Construction of Combination Switch for Ignition Test Board
turned off to ^ inch thick. These screws should be 2 inches long
so as to extend through the switchboard. Every other screw is
cut off flush on the back, as there is a dead point between each
two contacts to prevent short-circuits in switching from one point
to another.
A center sleeve is made for the switch shaft to rotate in.
This is made from a f-inch S.A.E. cap screw with the head and
nut C and D turned thin and a J-inch hole drilled in it to receive
the shaft E. The sleeve C is fastened in the base with a terminal
clip H under the nut D; this is for the center connection. The
shaft E has a blade of phosphor bronze G screwed to the flange
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.65
with two 4r-36 screws J; the shaft itself is held by the nut F,
under which is a washer M ; a pin through at L prevents the nut
from working loose. A fiber handle I, pinned on at K, completes
the switch.
Bearing Puller. There are several bearing pullers on the
market, but they are not adaptable to every kind of job and are
weak when it comes to a real hard pull. A practical puller is
shown in Fig. 484. The base A is of cast iron, having a front
vertical standard J and a boss B cast to receive the screw C.
This screw is f inch with a standard thread. A good snug fit
Fig. 484. Bearing Puller Side View
should be made, as wear will eventually cause it to become
slightly loose; the crossbar D is used in turning the screw. The
plate F on the front standard is held on by two f-inch cap screws
and carries the clamp screw G, which holds the jaws together.
The ribs are placed on each end to strengthen the base, and four
holes are drilled in the base to bolt it to the bench. Fig. 485
shows the sliding jaws H and I which fit into a slot in the end
standard J; the slot is cut from top to bottom. The top plate F
carries the clamp screw which is f inch with an S.A.E. thread;
the lower end has n groove turned in it. This plate fits on the
371
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ELECTRICAL REPAIRS
screw G and is held on the sliding block H by two 8-32 screws.
The block is counter bored to allow the end of the screw to turn
free; this device is to raise the block in changing jaws.
The sliding blocks are shown in Fig. 486; these blocks are cut
away, as shown, to receive the jaws, which are held by the two
small pins M. In recessing the blocks, place them in the lathe
im
\ o
Fig. 485. Bearing Puller End View
with a piece of f-inch metal between them at W; this will make it
possible to tighten the jaws in place. The jaws used to grip the
bearing are shown in Fig. 487 and should be made of steel, either
tool or cold rolled, and case hardened. They are made of round
stock of the proper outside size, cut off in lengths, faced off,
bored out at P, and turned round in the chuck with the shoulder
R. The jaw face at Q is bored and rounded to fit the face of the
372
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ELECTRICAL REPAIRS
67
bearing. The jaws are made for several sizes of bearings, a differ-
ent set of jaws being made for each, such as 12-millimeter,
15-millimeter, 17-millimeter, etc. The only change in any of these
jaws is the size of the face Q. Make the jaws for the largest
bearing first and then make up the rest the same, with the excep-
tion of the face Q. After the jaws are machined, the holes are
Ks ■ r H
o
^.U^-JV
..-*<"
■■*<
-w
Fig. 486. Assembly of Bearing Puller Clamps
drilled and the finished ring is cut in half as at S; this can be
done in a milling machine or with a hack saw.
As the push rods used in pulling the bearings turn and burr
the work, an end piece or point is made, Fig. 488. This end
piece E is made of tool steel and hardened. The screw C is
drilled as at T, and a ball-bearing U is placed in the hole the end
piece rests on. This ball takes the thrust, allowing the end piece
to turn. As the screw cannot be used against the work, the push
rods shown in Fig. 489 are used. These are made of f-inch cold-
rolled steel with dift e ?ent shaped ends; A is used for general work,
373
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68
ELECTRICAL REPAIRS
A
"7
1
Fig. 487. Bearing Puller Clamps
/ C /U |T
fm
Fig. 488. Free Center
X>
?•
*
3°
Q-
Fig. 489. Push Rods for Testing
Generators
Fig. 490. Handy Electrical Work Bench
374
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ELECTRICAL REPAIRS
69
B for shafts with centers, C is hollow and fits over magneto drive
shafts to protect the threads, D is for small bearings, E is for
Bosch breaker end bearings and F is for Eisemann breaker end
bearings. Various other shaped rods may be made to meet
requirements. These rods should all be case hardened. In using
the puller, the bearing is placed in the proper sized jaws and
screwed down with the clamp screw, the proper rod being used to
push off the bearing.
Work Bench. To work with neatness and precision a neat
and handy one-man bench is required. It helps create the right
atmosphere as a dirty and disorderly shop is sure to produce poor
K^
Fig. 491. Wash Rack for Cleaning Generator Parts
workmanship. Where the benches are separate, no workman is
crowded, and the tendency to keep the shop clean is greater. A
very convenient bench of this type is shown in Fig. 490. This is
made of dressed pine, the top being of 2"X12" planks two wide;
the legs B and the crosspieces G and D are 2"X4" with the top
of the bench 32 inches from the floor. A crosspiece E is placed
for a foot test, the other half of the bench being used for the
drawers J. The bench has a back F, 18 inches high with a shelf
G of 8-inch board. To the left is a tool cupboard with a locking
door 7. On the board back F are hung the tools that are used
most. The portion of the bench used for work should be covered
with 28-gage sheet steel. The gas furnace can be placed at the
extreme left. The test switches and lights can be pla.ced at H on
375
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ELECTRICAL REPAIRS
Fig. 492. Gasket Punch
the end of the cupboard, the wires
being run inside the cupboard.
These benches may be used singly
or built double with a right and
left unit to fit between a window.
Wash Rack. A serviceable
wash rack is shown in Fig. 491.
This is placed wherever conven-
ient and a pail is set under it to
catch the drip. The sides C and
the bottom are made of 1-inch
pine; the legs E are 2"X4".
The iron brackets G support the
legs, which may be any desired
height. The length A should be
3 feet, and the width B 9 18 inches;
if made too large the rack col-
lects trash. The inside is lined
with 28-gage galvanized iron with
a drain hole at F. Some shops
put casters on this rack and move
it from bench to bench.
Small Tools. As the gaskets
used in insulating magneto bear-
ings .are sometimes hard to get,
a punch to make them is shown
in Fig. 492. The handle of the
punch A may be made of tool
steel or of soft steel with a steel
cutter. A groove is cut at C to
form an edge B, while the center
is turned out at D, leaving two
cutting edges to form the gasket.
By relieving the cutting edges on
the outside, it makes a clean-cut
gasket. In order to get the fin-
ished gaskets out of the punch,
an extractor is placed in the slot.
376
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ELECTRICAL REPAIRS
71
The hole E is drilled, and a wire circle F is placed in the hole
and is held by the set screw G; this wire is bent so that it
will force the gasket out as soon as the pressure is taken from the
punch. There are several sizes of these gaskets, such as insulation
Fig. 493. Cone Bearing Drift
for 12-, 15-, and 17-millimeter bearing cups, and shims for the
same sizes, the 15-millimeter being used the most.
Cup Drift. In Fig. 493 is shown a drift for driving on cone
bearings. The body A is made of cold-rolled steel of the size
needed for the drift. It is drilled out at B to the desired size; the
dimensions C and D should be to fit 15-millimeter and 17-milli-
meter bearings. As these are very handy tools around the shop,
a variety of sizes should be made.
Bearing Cup Puller. As it is very hard to get a bearing cup
out of an end plate, such a puller as shown in Fig. 494 is quick
and efficient. The body A is made of cold-rolled steel, the lower
end being shaped to a sharp angle and slotted so that it will
r " E c
Fig. 494. Cone Puller
expand. These slots B may be milled or cut with a hack saw.
A j^-inch hole C is drilled and threaded with an S.A.E. thread,
and a taper bolt D is screwed into the hole. This screw has a
taper E which expa^Jg the body of the puller, a flattened portion
377
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72 ELECTRICAL REPAIRS
F being made for a wrench. A T handle is placed in the shank at
G, and the whole tool is case hardened. In using this puller, the
screw is backed out and the sharp angle points placed back of the
cup. The screw is then turned up tight and the whole assembly
struck sharply on the bench, striking the screw, when the cup will
be forced out without damaging the cup or the end plate.
378
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INDEX
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INDEX
The page numbers of this volume will be found at the bottom of the pages;
the numbers at the top refer only to the section.
If you do not find what you want under one heading, stop and think
what other headings it could be under.
I
Page
A
A.C. rectifiers 223
Abbott-Detroit-Remy installation 42
Acid (see Sulphuric acid)
Active material 175, 179
Allen-Westinghouse installation 148
Aluminum, cleaning 241
Ammeter 77, 85, 97, 105
Ampere-hour capacity of battery
175, 179
Angular brushes 103
Apelco-Splitdorf system 88
Apperson-Remy installation 41
Arcing 16
Armature
magneto
testing
astatic gap
breaker
growler
master vibrator
single-break interrupter
special dial gap
static point
winding
Armature core of magneto 313, 314, 316
Astatic gap 314, 316, 318
Atwater-Kent ignition system 321
Auburn-Remy installation 39, 40
Automatic Atwater-Kent ignition
system 324
Automatic governor, Eisemann 334
Automatic switch 325
313, 314, 316, 335
316, 353
316
318
353
317
318
318
317
347
B
Ballast coil
324, 330
Page
Bank of lamps for battery charg-
ing 222
Battery (see Storage batteries)
Battery breaker 331, 339
Battery cut-out (see Starting
and lighting, general
data)
Battery ignition systems, repairs 321
Atwater-Kent
321
Connecticut
325
North East
327
Westinghouse
329
Bearing cup puller
377
Bearing puller
371
Bench
375
Bendix drive 55, 60, 146
Bosch ignition
129, 339
DU dual magneto
339
impulse starter
342
NU magneto
341
two-spark magneto
345
vibrating duplex system
343, 344
Breaker
Bosch magneto
339
Eisemann magneto 331,
335, 337
Mea magneto
349
North-East system
327
testing with
318
Westinghouse system
329
Breaker box
60
Brushes (see Starting and light-
ing, general data)
Bucking coil 22,
121, 139
Buckling
198
"Bugs"
354
381
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INDEX
Page
C
Capacity of battery 175, 179
Capacity of Ford magneto 307
Cast iron, cleaning 241
Cell 174, 175, 177
dismounting 206
Chalmers-Remy installation 43, 44
Charge of magnet, loss of 319
Charger, magnet 321
Charging battery 175, 177, 188,
221, 231
Charging magnets 321
Chemical rectifiers 223
Chemically pure acid 176
Chrome-steel magnets 319
Circuit-breaker 13, 15, 16, 272
Cleaning battery 201, 239
Cleaning electrical equipment 239
Closed-circuit Atwater-Kent igni-
tion system 324
Coils, high-tension, testing 316
Coils of Ford magneto 307
repairs 311
Cold weather, effect on storage
battery 193, 195, 225, 233
Commutator
machine for undercutting 356
tooling 115
Compass method of testing mag-
nets 320
Condenser 32
Conditioning charge
190, 194-196, 207, 221
Cone-bearing drift 377
Cone puller 377
Connecticut automatic switch 325
Connecticut ignition system 134,
144, 147
Constant-voltage regulation 47, 89
Contact points 276
Copper, cleaning 241
Core of magneto armature
reversal of magnetism 313, 314, 316
silicon steel 316
Crecium points 336
Cunningham-Westinghouse instal-
lation 143
Note. — For page numbers see foot of pages.
Page
Cup drift 377
Cut-out (see Starting and light-
ing, general data — bat-
tery cut-out)
Daniels-Westinghouse installation 138
Dead short-circuit 174
Delco distributor 306
Delco ignition system 149
Differential winding 22
Discharge rate of battery 180,
228, 233
Discharged battery 60, 135
Discharging battery 175, 178
Distilled water 176
adding 182
specific gravity 177
Distributor 329, 346-348
Distributor disc 335
Dodge-North-East installation 22,
24,29
Dort-Westinghouse installation
144, 147
Double-deck Remy system 60
Dry storage of batteries 218
Dual magnetos
Bosch 339, 346
Eisemann 331
Mea 349
Duplex ignition system 344
Duplex vibrator 344
Dynamotor (see Starting and
lighting, general data)
E
Edison battery 22, 182
Efficiency of battery 179
Eight-cylinder lifters 323
Eisemann ignition 331
automatic governor 334
dual magneto 331
G-4 1st edition magneto 335
G-4 2nd edition magneto 336
impulse starter 338
Electric gear-shift 286
382
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INDEX
Page
Electric starting and lighting
(see Starting and light-
ing, general data)
Electric Storage Battery Com-
pany lead-burning out-
fits 211, 213
Electric thermostat 51
Electrical equipment
repairs (see Repairs, electrical)
starting and lighting (see Start-
ing and lighting, general
data)
storage batteries (see Storage
batteries)
Electrical lag 345
Electrolyte 175, 176
height of 182
specific gravity 177, 178, 179,
186, 188
Electromagnetic switch 151
Elements 175
Elgin-Wagner installation 117, 118
Enamel, cleaning 241
Equalizing charge 190, 194-196,
207, 221
Equipment for repairs 353
armature tester 353
bearing puller 371
generator test stand 363
growler armature tester 353
ignition switchboard 368
magneto test stand 361
small tools 376
switchboards 366, 368
undercutting machine 356
wash rack 376
work bench 375
External regulator
Splitdorf system 89
U.S.L. system 96, 98, 102, 103
Westinghouse system 141, 142, 145
Field winding 16
Fire prevention 136
Five-terminal starter-generator 31
Flame, speed of propagation 345
Note. — For page numbers see f^a of page*.
Page
Flame travel
345
Ford cars, systems for
Ford system
152
Gray and Davis system
158
Ford magneto
307
capacity
307
testing
308
recharging magnets
308
repairing coils
311
Ford-North-East installation
26
Ford system
152
generator
152
ignition
156
lighting
156
starting motor 152, 157
wiring diagram 155
Formed plates 175, 177
Four-cylinder lifters 323
Four-terminal starter-generator 28
Franklin governor 334
Frozen cells 187
Fuse (see Starting and lighting,
general data)
G
Gasket punch
376
Gassing
191
Gear-box troubles
119
Gear-shift
286
General Electric rectifier
223
Generator (see Starting and light-
ing, general data)
Generator test stand 363
switchboard 366
Governor 334
Grant-Remy installation 45
Grant- Wagner installation 124
Gray and Davis Ford system 158
ammeter 171
battery 164
generator tests 171
installation 158
instructions 169
priming device 164
starter-generator, mounting 159
starting switch 163
tests, generator 171
383
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INDEX
Page
Gray and Davis Ford system
(continued)
wiring diagrams 166-168
Grids 175
Ground 35, 85, 125, 136, 354
Growler armature tester 353, 356
H
H A L-Remy installation 49, 133
H A L-Westinghouse installation 133
Harroun-Remy installation 50
Haynes-Leece-Neville system 13,
14, 17
Haynes-Remy installation 46
High-tension armatures, testing
(see Armature, testing)
High-tension coils, testing 316
astatic gap 316
breaker 318
master vibrator 317
single-break interrupter 318
special dial gap 318
static point 317
High-tension magnetos, polariza-
tion of 312
Hollier-Atwater-Kent installation 93
Hollier-Splitdorf installation 93
Horizontal ignition, Westinghouse 329
Hupmobile-Westinghouse installa-
tion 135, 137
Hydrometer 183
Hydrometer tests 200, 237
I
Ignition, failure of 72
Ignition switchboard 368
Ignition systems (see also Start-
ing and lighting and
separate Index to Wir-
ing Diagrams, Vol. VI)
repairs 321
Atwater-Kent 321
Bosch 339
Connecticut 325
Eisemann * 331
Mea 347
North East 327
Westinghouse 329
Note. — For page numbers see foot of pages.
Page
Impulse starter
Bosch 342
Eisemann 338
Indicating battery cut-out 12
Indicator 12, 55, 77, 97
Induction coils, testing 316
Inherent regulation 96-98, 102,
103, 121
Inspection of generator 16
Installing new battery 217
Instruments 282
Internal damage 198
Internal short-circuit 176, 186,
187, 196-198
Interstate-Remy installation 53
Jumper
K
Keeper of magnet
Kissel system
Krit-North-East installation
19
319, 321
54
25,26
Lamps for battery charging 222
Lead battery, determining voltage 22
Lead burning 211
arc-welding outfit 211
hydrogen-gas outfit 215
illuminating-gas outfit 213
Lead-plate storage battery 174
Lead sulphate 178
Leaky jar of battery 187
Leece-Neville system 11
arcing 16
battery cut-out 12
brush replacements 21
circuit-breaker 13, 16
field winding, testing 16
fuse 13, 16
generator 11, 13, 16, 21
Haynes installation 13, 14, 17
indicator 12
instructions 13
instruments 12
jumper 19
384
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INDEX
Page
Leece-Neville system (continued)
loose connections 15, 16
motor failure 21
open circuits 15
regulating brush 19
regulation 11
short-circuit 16, 21
short>-circuiting generator 13
starting motor 12
third brush 11, 20
White installation 13, 15, 18
wiring diagrams . (see separate
Index of Wiring Dia-
grams, Vol. VI)
Lexington-Westinghouse installa-
tion 134
Lifter of ignition system 323
Lighting
failure of 72
summary of instructions 279
Limiting relay 22
Litharge - 175
Locomobile- Westinghouse instal-
lation 132
Loose connections 15, 16, 60
Low cells 188
M
63
McLaughlin-Remy installation
Magnet
charger for 321
charging 321
Ford magneto 307, 308
keeper 319, 321
materials 319
strength, loss in 319
testing 320
Magnetic break 314, 316
Magnetic-engaging starting motor 146
Magnetism, reversal of 313, 314, 316
Magneto
Ford (see Ford magneto)
polarization of 312
test stand for 361
Magneto breaker 331, 339
Magneto ignition systems repairs 331
Bosch
339
Note. — For page numbers «ee / n f page*'
Page
Magneto ignition systems, repairs
(continued)
Eisemann 331
Mea 347
Marion - Handley - Westinghouse
installation 150
Master relay 22, 31, 32
Master vibrator, testing with 317
MaxweU-Simms-Huff installation
80, 81, 83, 84
Mea magneto
A type 349
BK type 347
dual type 349
Mercer-U.S.L. installation 106, 107
Mercury-arc rectifiers 223
Mica undercutting machine 356
"Missing" of magnetos 312
causes 313
remedies 316
Mitchell-Splitdorf installation 94
Motor failure 21
Motor-generator 223
Mud space 181
Multiple gap 314, 318
N
National-Remy installation 60, 71
National-Westinghouse installa-
tion 149
Needle assembly of undercutting
machine 359
Negative plate 175, 177, 178
area 179
sulphated 197
Nelson-U.S. installation 111
North East System 22, 327
battery cut-out 28
chain, replacing 38
characteristics x 36
condenser 32
Dodge installation 22, 24, 29, 38
dynamotor 22
five-terminal unit 31
four-terminal unit 28
Ford installation 26
fuse 22
385
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6
INDEX
Page
North East System (continued)
instructions 26
Krit installation 26
regulation 22, 28
relays 28, 31
single-wire system 24, 29
sixteen-volt system 26
starter-generator 31, 32
starting switch 34, 35
table giving characteristics of
apparatus 36
twelve-volt system 24, 25
twenty-four-volt system 27
two-wire system 25-27, 30
wiring diagrams (see separate
Index of Wiring Dia-
grams, Vol. VI)
Oakland-Remy installation 60, 63, 65
Open circuit 15, 354
Open-circuit readings valueless
199, 236
Overcharging battery 192
Overhauling battery 205
Packard-Bijur installation 172
Packard-Delco installation 172
Paige-Remy installation 57, 58
Pasted plates 175
Peroxide of lead 175, 177, 178
Philadelphia storage-battery grid 175
Pierce- Arrow-Westinghouse instal-
lation 130, 131
Pierce-Arrow-Westinghouse volt-
age regulator 353
Planetary gear 114
Plante" storage battery 177
Plated parts, cleaning 241
Polarization of high-tension mag-
netos 312
causes 313
proofs % 314
remedies 316
Positive plate 175, 177, 178
area 179
Note. — For page numbers see foot of pages.
Page
Positive plate (continued)
sulphated 197
Push rods 373
R
Radial brushes 103
Ratchet reversing switch 56
Recharging magneto magnets 308
in car 308
out of car 310
on flywheel 310
Rectifiers 223
Red lead 175
Regulating brush (third brush) 19
Regulation (see Starting and
lighting, general data)
Remy ignition distributor 242
Remy system 47, 133
Abbott-Detroit installation 42
Apperson installation 41
Auburn installation 39, 40
battery cut-out » 47
battery discharge 60
Bendix drive 55
Chalmers installation 43, 44
double-deck system 60
electric thermostat 51
fuse 56
generator 47
Grant installation 45
grounds 60
HAL installation 49
Harroun installation 50
Haynes installation 46
ignition, failure of 72
indicator 55, 77
instructions 60
Interstate installation 53
Kissel installation 54
lighting, failure of 72
McLaughlin installation 63
National installation 60, 71
Oakland installation 60, 63-65
open circuits 60
Paige installation 57, 58
regulation 47, 56
Reo installation 60, 67-69
386
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INDEX
Page
Remy system (continued)
Scripps-Booth installation 70
single-unit system 56, 60
starting, failure of 72
starting motor 55
Stearns installation 73, 74
Studebaker installation 75, 123
Stutz installation 76
telltale (ammeter) 55
thermostatic switch 48
two-wire system 60
Velie installation 56, 59, 61, 62
voltage regulator 56
wiring diagrams (see separate
Index of Wiring dia-
grams, Vol. VI)
Renewing battery 217
Reo-Remy installation 60, 67-69
Repairs, electrical 307
equipment 353
Ford Magneto 307
ignition systems 321
polarization of high-tension
magnetos 312
testing and charging 316
Westinghouse voltage regula-
tors 349
Reversal of magnetism 313, 314, 316
Reverse series-field winding 139
S
Sanding-in brushes 103, 111
Saxon- Wagner installation 109, 110
Scale method of testing magnets 320
Scripps-Booth-Remy installation 70
Scripps-Booth- Wagner installation 126
Separators, battery 176, 205, 207
Series charging 222
Short-circuit
Leece-Neville system 16, 21
Simms-Huff system 85
storage battery 174, 176, 181, 183
tests for 312
Wagner system 127
Short-circuiting generators 13
Silent-chain installation 22, 38
Note. — For page numbers see foot of pages.
Page
Silicon steel, use in magneto
armature core 316
Simms-Hufif system * 77
ammeter 77, 85
battery cut-out 82, 85
dynamotor 77, 78
generator tests 85
instructions 82
Maxwell installation 80, 81, 83, 84
regulation 77, 82, 85
starting switch 81
voltage, change of 79
wiring diagrams 79, 82
Single-unit systems (see Starting
and lighting, general
data)
Single-wire systems (see Starting
and lighting, general
data)
Six-volt systems (see Starting
and lighting, general
data)
Sixteen-volt systems 22, 26
Spark
length of
Eisemann dual magneto 334
Eisemann G-4 1st edition
magneto 335
Westinghouse horizontal igni-
tion 330
Westinghouse vertical igni-
tion 331
speed of propagation 345
Spark gap, variable 314, 318
Sparking, excessive 16
Specific gravity 177-179
high 197
readings 186, 188
taking 184
Splitdorf system 87
Apelco system 88
battery 90
dynamotor 87
Hollier installation 93
instructions 89, 92
lighting generator 90
Mitchell installation 94
387
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INDEX
Page
Splitdorf system (continued)
regulation 88
start, failure to 92
starting motor 91, 92
starting switch 88
VR regulator 90
voltage regulator 89, 90
wiring diagrams (see also sep-
arate Index of Wiring
Diagrams, Vol. VI) 87
Spongy metallic lead 175, 177, 178
Starter-generator 28, 31, 32
Starting, failure of 72, 92
Starting in cold weather 226
Starting and lighting (see also
Index, Vol. Ill)
Ford system 152
Gray and Davis Ford system 158
Leece-Neville system 11
North East system 22
Remy system 47
Simms-Huff system 77
Splitdorf system 87
U.S.L. system 95
Wagner system 111
Westinghouse system 135
Starting and lighting, general
data (see also Index,
Vol. Ill) 11
Abbott-Detroit-Remy installa-
tion 42
Allen-Westinghouse installation 148
ammeter 77, 85, 97, 105
Apelco-Splitdorf system 88
Apperson-Remy installation 41
Auburn-Remy installation 39, 40
battery 90
battery charging 135
battery-cut-out
Leece-Neville system 12
North East system 22, 28
Remy system 47
Simms-Huff system 82, 85
Wagner system 111
Westinghouse system 135
battery discharge 60
Bendix drive 55, 60, 146
Note. — For page numbers see foot of pages.
Page
Starting and lighting, general data
(continued)
Bosch ignition system 129
brushes
pressures 102
replacements 21
sanding-in 103, 111
types 103
bucking coil 22, 121, 139
Chalmers-Remy installation 43, 44
circuit-breaker 13, 15, 16
commutator, tooling 115
condenser 32
constant-voltage regulation 47, 89
Cunningham- Westinghouse in-
stallation 143
cut-out (see battery cut-out)
Daniels-Westinghouse installa-
tion 138
differential winding 22
Dodge-North-East installa-
tion 22, 24, 29
Dort-Westinghouse installation
144, 147
double-deck Remy system 60
dynamotor (see also generator
and starting motor)
North East system 22
Simms-Huff system 77
Splitdorf system 87
U.S.L. system 95
Wagner system 111
Westinghouse system 135
electro thermostat 51
electromagnetic switch 151
Elgin-Wagner installation 117, 118
external regulator
Splitdorf system 89
U.S.L. system 96, 98, 102, 103
Westinghouse system 141,
142, 145
field winding 16
five-terminal starter generator 31
Ford cars, systems for
Ford system 152
Gray and Davis system 158
Ford-North-East installation 26
388
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INDEX
9
Page
Starting and lighting, general data
(continued)
four-terminal starter-generator 28
fuse
Leece-Neville system 13, 16
North east system 22
Remy system 56
U.S.L. system 97, 107
gear-box troubles 119
generator (see also dynamotor)
Ford system 152
Gray and Davis Ford sys-
tem • 159, 171
inspection 16
Leece-Neville system 11, 13,
15, 16, 21
Remy system 47
Simms-Huff system 85
Splitdorf system 90
tests of 85
Wagner system 121
Westinghouse system 139
Grant-Remy installation 45
Grant-Wagner installation 124
ground 35, 85, 125, 136
H A L-Remy installation 49, 133
H A L-Westinghouse installa-
tion 133
Harroun-Remy installation 50
Haynes-Leece-Neville system
13, 14, 17
Haynes-Remy installation 46
Hollier-Atwater-Kent installa-
tion 93
Hollier-Splitdorf installation 93
Hupmobile- Westinghouse instal-
lation 135, 137
indicator 12, 55, 77, 97
inherent regulation 96-98, 102,
103, 121
Interstate-Remy installation 53
jumper 19
Kissel system 54
Kirk-North-East installation 25, 26
Leece-Neville system 11
Lexington- Westinghouse instal-
lation 134
Note. — For page numbers $ ee foot of pages.
Page
Starting and lighting, general data
(continued)
lighting, failure of 72
limiting relay 22
Locomobile-Westinghouse in-
stallation 132
loose connections 15, 16, 60
McLaughlin-Remy installation 63
magnetic-engaging starting
motor 146
master relay 22, 31, 32
Marion-Handley-Westinghouse
installation 150
MaxweU-Simms-Huff installa-
tion 80, 81, 83, 84
Mercer-U.S. L. installation 106, 107
Mitchell-Splitdorf installation 94
motor failure 21
National-Remy installation 60, 71
National- Westinghouse installa-
tion 149
" Nelson-U.S.L. installation 111
North East system 22
Oakland-Remy installation
60, 63-65
open circuits 15
Paige-Remy installation 57, 58
Pierce-Arrow- Westinghouse in-
stallation 130, 131
planetary gear 114
ratchet reversing switch 56
regulating brush (third brush) 19
regulation
Leece-Neville system 11
North East system 22, 28
Remy system 47, 56
Simms-Huff system 77, 82, 85
Splitdorf system 88
U.S.L. system 96
Wagner system 111,121
Westinghouse system 135, 139
Remy ignition system 133
Reo-Remy installation 60, 67-69
reverse series-field winding 139
sanding-in brushes 103,111
Saxon- Wagner installation 109, 110
Scripps-Booth-Remy installation 70
389
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10
INDEX
Page
Starting and lighting, general data
(continued)
Scripps-Booth-Wagner installa-
tion 126
short-circuit 16, 21, 85, 127
short-circuiting generators 13
silent-chain installation 22, 38
single-unit systems
North East 22
Remy 56, 60
Simms-Huff 77
Splitdorf 87
U.S.L. 95
Wagner 111
Westinghouse 135
single-wire systems
Ford 152
North East 22, 24, 29
Remy 47
Simms-Huff 77
Wagner 122
Westinghouse 135, 139
six-volt systems
Ford 152
Leece-Neville 11
Remy 47
Splitdorf 87, 88
U.S.L. 95, 100
Wagner 121
Westinghouse 139
sixteen-volt systems 22, 26
starter-generator 28, 31, 32
starting, failure of 72, 92
starting motor (see also dyna-
motor)
Ford system 152, 157
Leece-Neville system 12
Remy system 55
Splitdorf system 91, 92
Wagner system 121
Westinghouse system 146
starting switch
North East system 34, 35
Simms-Huff system 81
Splitdorf system 88
U.S.L. system 102, 107
Stearns-Remy installation 73, 74
Note. — For page numbers see foot of pages.
Page
Starting and lighting, general data
(continued)
storage batteries (see Storage
batteries)
Studebaker-Remy installation
75, 123
Studebaker- Wagner installation 123
Stutz-Remy installation 76
summary^ of instructions 243
tables
characteristics of North East
starting and lighting ap-
paratus 36
telltale (ammeter) 55
tests
field winding 16
generator 85
grounds 35, 85, 125, 136
short-circuit 16, 21, 85, 127
switch 35
voltage-regulator 151
thermostatic switch 48
third-brush regulation
Leece-Neville system 11, 19, 20
Remy system 47, 48, 52
Westinghouse system 135, 142
touring switch 98
twelve — six-volt system 87
twelve- volt systems
Leece-Neville 12
North East 22, 24, 25
Simms-Huff 77
Splitdorf 87
U.S.L. 95, 99-101, 107
Wagner 111
Westinghouse 135
twenty-four-volt systems
Leece-Neville 12
North East 22, 27
U.S.L. 95, 99, 101
two-unit systems
Ford 152
Leece-Neville 11
Remy 47
Splitdorf 88
Wagner 121, 122
Westinghouse 139
390
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INDEX
11
Page
Starting and lighting, general data
(continued)
two-wire systems
Leece-Neville 11
North East 22, 25-27, 30
Remy 60
Splitdorf 87
U.S.L. 95, 111
Velie-Remy installation 56,
59, 61, 62
vibrating-type regulator 56, 88, 89
voltage, change of 79
voltage regulation 56
voltage regulator 89, 90, 139, .151
White-Leece-Neville system
13, 15, 18
Starting motor (see Starting and
lighting, general data)
Starting switch (see Starting and
lighting, general data)
Static point 317
Stearns-Remy installation 73, 74
Steel, cleaning 240
Storage batteries 22, 90, 173
a.c. rectifiers 223
acid (see sulphuric acid)
active material 175, 179
aluminum, cleaning 241
ampere-hour capacity 175, 179
bank of lamps for battery
charging 222
buckling 198
capacity of battery 175, 179
care of 173, 182
cell 174, 175, 177
dismounting 206
charging battery 175, 177,
188, 221, 231
chemical rectifiers 223
chemically pure acid 176
cleaning battery 201, 239
cold weather, effect on storage
battery 193, 195, 225, 233
conditioning charge 190, 194,
195, 196, 207, 221
construction details 1 ^ 1
Note.— For page number* . ^ of page*.
Page
Storage batteries (continued)
dead short-circuit 174
discharge rate of battery 180,
228, 233
discharged battery 60, 135
discharging battery 175, 178
distilled water 176
adding 182
specific gravity 177
dry storage of batteries 218
Edison cell 182
efficiency of battery 179
Electric Storage Battery
Company lead-burning out-
fits 211, 213
electrolyte 175, 176
height of 182
specific gravity 177-179, 186, 188
elements 175
enameled parts, cleaning 241
equalizing charge 190, 194r-
196, 207, 221
formed plates 175, 177
frozen cells 187
gassing 191
General Electric rectifier 223
grids 175
hydrometer 183
hydrometer tests 200, 237
installing new battery 217
internal damage 198
internal short-circuit 176,
186, 187, 196-198
jar, replacing 202
lamps for battery charging 222
lead burning 211
arc- welding outfit 211
hydrogen-gas outfit 215
illuminating-gas outfit 213
lead-plate storage battery 174
lead sulphate 178
leaky jar 187
Leece-Neville system 20
litharge 175
low cells 188
mercury-arc rectifiers 223
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12
INDEX
Page
Storage batteries (continued)
m6tor-generator 223
mud space 181
negative plate 175, 177, 178
area 179
sulphated 197
open-circuit readings valueless
199, 236
overcharging battery 192
overhauling battery 205
pasted plates * 175
peroxide of lead 175, 177, 178
Philadelphia storage-battery
grid 175
Plante* storage battery 177
plated parts, cleaning 241
positive plate 175, 177, 178
area 179
sulphated 197
rectifiers 223
red lead 175
Remy system 60
renewing battery 217
separators 176, 205, 207
series charging 222
short-circuit 174, 176, 181, 183
specific gravity 177-179
high 197
readings 186, 188
taking 184
spongy metallic lead 175, 177, 178
starting in cold weather 226
storing battery 217
sulphating 187, 193, 194
sulphuric acid 176
adding 183, 189
excess of 179
specific gravity 177
summary of instructions 288
syringe hydrometer 184
temperature
effect on battery 187, 193,
225, 226, 233, 237
effect on explosive mixture 227
effect on hydrometer tests
188, 190
effect on oil 227
Note. — For page numbers eee foot of pages.
Page
Storage batteries (continued)
temperature
effect on spark 227
effect on voltage tests 200
tests
rate of charge 2Q8, 231
rate of discharge 209, 228, 233
touring switch 193
Tungar rectifier 223
two-voltage batteries, connec-
tions for 234
undercharging 187, 193, 194
voltage of battery cell 177, 179
voltmeter tests 198, 200, 208, ,
210, 235, 237
water for electrolyte 176
wet storage of batteries 218
white spots on battery plates 194
Willard battery 180, 181
winter weather, effect on stor-
age battery 193, 195, 225, 233
Storing battery 217
Strength of magnet, loss in 319
Studebaker-Remy installation 75, 123
Studebaker- Wagner installation 123
Stutz-Remy installation 76
Sulphating 187, 193, 194
Sulphuric acid 176
adding 183, 189
excess of 179
specific gravity 177
Switch for ignition switchboard 370
Switchboards
generator test stand 366
ignition 368
Switches 278
Syringe hydrometer 184
Table
characteristics of North East
starting and lighting ap-
paratus 36
Telltale (ammeter) 55
Temperature
effect on battery 187, 193,
225, 226, 233, 237
392
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INDEX
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Page
Temperature (continued)
effect on explosive mixture 227
effect on hydrometer tests 188, 190
Page
effect on oil
227
effect on spark
227
effect on voltage tests
200
Test stands
generator
363
magneto •
361
Testers, magnet
32Q
Testing
armatures
316, 354
field winding
16
Ford magnetos
308, 312
generator
85
grounds 35,
85, 125, 136
high-tension coils
316
magnets
320
open circuits
354
rate of battery charge
208, 231
rate of battery discharge 209,
''
228, 233
short-circuit 16, 21,
85, 127, 312
switch
35
voltage regulator
151
Thermostatic automatic
switch
48, 326
Third-brush regulation
Leece-Neville system 11, 19, 20
Remy system 47, 48, 52
Westinghouse system 135, 142
Touring switch 98, 193
Troubles and remedies (see Re-
pairs, electrical)
Tungar rectifier 223
Tungsten magnets 319
Twelve — six-volt system 87
Twelve-volt systems (see Starting
and lighting, general
data)
Twenty-four-volt systems (see
Starting and lighting,
general data)
Two-spark magneto, Bosch 345
Two-unit systems (see Starting
and lighting, general
data)
Note. — For page numbers see foot of pages.
connec-
Starting
general
234
Two-voltage batteries,
tions for
Two-wire systems (see
and lighting,
data)
U
U.S.L. system 95
ammeter 97, 105
angular brushes 103
brush pressures 102
carbon pile 105
dynamotor 95
external regulator 103
fuses 79, 107
indicator 97
instructions 98
Mercer installation 106, 107
Nelson installation 111
radial brushes 103
regulation 96
starting switch 102, 107
touring switch 98
twelve — six-volt system 100
twenty-four-twelve systems 99, 101
wiring diagrams 98-101
Undercharging 187, 193, 194
Undercutting machine 356
Velie-Remy installation 56, 59, 61, 62
Vertical ignition, Westinghouse 330
Vibrating duplex system 344
Vibrating-type regulator 56, 88, 89
Vibrator
Voltage
of battery cell
change of
determining
Voltage regulation
Voltage regulator
Pierce-Arrow
Westinghouse
317, 340, 344
177, 179
79
22
56
89, 90, 139, 151
353
349
Voltage test of magnets 320
Voltmeter tests of battery 198,
200, 208, 210, 235, 237
393
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14
INDEX
W
Page
Wagner system 45, 111
battery cut-out 112, 120, 121
commutator, tooling 115
control switch 111
dynamotor 111
Elgin installation 117, 118
gear-box troubles 119
generator 121
Grant installation 124
grounds 125
instructions 115, 125
planetary gear 114,
regulation 111, 121
Saxon installation 109, 110
Scripps-Booth installation 126
short circuits 127
starting motor 121
Studebaker installation 123
tests 125, 127
twelve-volt system 112
wiring diagrams (see also separ-
ate Index of Wiring
Diagrams, Vol. VI) 111, 122
Wash rack 376
Water for electrolyte 176
Waterproof magneto, Eisemann
331, 335
Westinghouse breaker 330
Westinghouse horizontal ignition 329
Westinghouse system 135
Allen installation 148
battery charging 135
battery cut-out 142
Chalmers installation 43, 44
control 135
Note. — For page numbers see foot of pages.
Page
Westinghouse system (continued)
Cunningham installation 143
current, weak 136
Daniels installation 138
Dort installation 144, 147
dynamotor 135
external regulator 141, 145
generator 139
grounds 136
H A L installation 49, 133
HupmobUe installation 135, 137
instructions 135, 151
Lexington installation 134
Locomobile installation 132
Marion-Handley installation 150
National installation 149
Pierce- Arrow installation 130, 131
regulation 135, 139
self-contained regulator 140
starting motor 146
third-brush regulation 135, 142
wiring diagrams ((see separate
Index of Wiring Dia-
grams, Vol. VI)
Westinghouse vertical ignition 330
Westinghouse voltage regulators 349
Pierce- Arrow type 353
Wet storage of batteries 218
White-Leece-Neville system 13, 15, 18
Willard battery 180, 181
Winter weather, effect on storage
battery 193, 195, 225, 233
Wiring diagrams (see also sep-
arate Index of Wiring
Diagrams, Vol. VI) 264
Work bench 375
394
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