THE INDUCTION MOTOR. 

 Short-circuit Currents at 50 ~ 



Resistance of primary : Each phase, 0.05 ohm. 

 Resistance of secondary : Each phase, 0.50 ohm. 



40. The data of these tables are graphically represented in Fig.i6 and 

 Fig. 17. The most remarkable fact illustrated by these curves is that 

 the short-circuit current remained almost unaltered for the two dif- 

 ferent air-gaps. We interpolate from these curves for no volts in 

 each phase the respective short-circuit and magnetizing currents, and 

 thus get the following values : 



A = 0.5 m. m. 



Magnetizing current: 3 amperes. 

 Short-circuit current: 42 amperes. 

 Watts consumed : 8550 watts. 



A = i-5 * m- 



Magnetizing current: 7 amperes. 

 Short-circuit current : 47.5 amperes. 

 Watts consumed : 9100 watts. 



41. With these data the semi-circles in Fig. 18 are drawn. We thus 

 find for the leakage factor the following values : 



A = 0.5 m. m. 

 A = 1.5 m. m. 



The leakage factor is, according to these experiments, directly pro- 

 portional to the magnetizing current, or, in other words, to the mag- 

 netic reluctance of the main field. In our case the reluctance of the 

 iron path is not negligible, as the air-gap of 0.5 mm is very small, 



a = 0.058 

 a = 0.128 



