THE INDUCTION MOTOR. 



F being the friction loss in watts, Q the loss through hysteresis and 

 eddy currents. 

 The efficiency v is, 



28. The most important formulas for the design of the polyphase 

 motor have thus been determined, and it will be useful to give 

 them in the form of a table. 



Maximum Power Factor 



(3) .......... cos <t> = 



J/ 2 a -(- i 



Magnetic Field 

 (5) .............. e = 2 . 12 . ~ . z v . * . io- 8 volts. 



Magnetising Current 



($> . 1.6 A 



(6). 

 lip- 

 (7). 



2 n . V 2 

 Slip 



^- = 3 

 r 



Torque 



b 

 (8) ... .61.6 . D m kg = -^ (3 h *r 2 + P -watts) 



Impressed Energy 



(9) .............. 8 = 3*1 1\ cos? 



Output 



(10) ......... P-watts = 3*i h costyT) t\ 



Efficiency 



(11) .............. 1= 



3 'i *i cos 

 18 



