128

ELECTRICAL APPARATUS

especially the starting torque, which, with short-circuited arma-
ture, in the case 3 drops to about one-third the value given at
constant supply voltage.

0.8

SLIP FRACTION OF SYNCHRONISM

0 7 OJ6 015 014 OJ3 0 2

TORQUE
WATTS

8YN.

8000

01

7000
6000
5000
1000
3000
2000
1000

FIG. 47.—Induction-motor speed torque characteristics with, a resistance of
0.15 ohm, in secondary circuit.

1.0 0.9 08

SLIP FRACTION OF 8Y CHRONI M
0 7 0.6 0.5 Q.4 0.3

\

TORQUE

8YN.,

WATTS

— 8000

7000
6000
5000
4000
3000
2000
1000

FIG. 48.—Induction-motor speed torque characteristics with a resistance of
0.5 ohm in secondary circuit.
It is interesting to note that in Fig. 48, with a secondary
resistance giving maximum torque in starting, at constant ter-