414 



THE INDUCTION MOTOR. 



a star-connected stator), the static current C a is 532 

 amperes, the no-load current C is 40 amperes and the 

 power absorbed at no-load is 1,680 watts per phase. 

 The power taken by the motor at rest with a static 

 current of 532 amperes was estimated from a measure- 

 ment at a lower pressure to be 25,100 watts per phase 

 at 202 volts. The stator resistance per phase was 

 032 ohm. 



From these figures, 



Cos (j>" = 



or <j>" = 



Cos ' = 



1,680 



40 

 77 deg. (approx.) 



25 ' 100 =0-233 



" 532 x 202 

 or <' = 77 deg. (approx.) 



The values for the static and the no-load power 

 factor happen to be practically the same in this case. 



Referring to Fig. 198 take two lines at right angles 

 OE and A. From draw a line B l making an 

 angle of 77 with the vertical line E ; this line J5 1 

 represents then the phase of the static current and of 



50 100 150 200 250 300 



Volts. 

 FIG. 197. NO-LOAD CURVES OF INDUCTION MOTOR. 



