GENERAL THEORY OF THE INDUCTION MOTOR. 297 



Fig. 253, of the short-circuiting end-rings is \aP . Therefore, 

 knowing the size and length of each rotor rod and the size and 

 length of each portion of the short-circuiting end-rings, the rotor 

 RP loss may be easily calculated for an assumed value of 

 /'. The equivalent resistance R n of the rotor is equal to this 

 rotor RP loss divided by I 1 . Using the value of R" so de- 

 fined, the load current in the portions BB' of the rotor wind- 

 ing (see Fig. 253 ) may be thought of as equal to the load current 

 in the stator; and insofar as the induced electromotive forces in 

 the regions B and J3' t Fig. 253, are concerned, the rotor wind- 

 ing may be thought of as containing the same number of con- 

 ductors as the stator winding, all connected in series and consti- 

 tuting a single circuit. 



^ 



t 



Supply main 



Fig. 257. 



Furthermore, insofar as the induced electromotive forces A p 

 and A r in the regions A and A* ', Fig. 253, are concerned, the 

 rotor winding may be thought of as consisting of 5 conductors 

 all connected in series and distributed exactly like the stator con- 

 ductors but in the position shown in Fig. 253^, 5 being the 

 number of stator conductors. 



On the basis of the above considerations the clock diagram, 

 Fig. 254, may be understood in every detail. At synchronous 

 speed (' = ri) we have A r = A p = B r = B p = E f , and /' and 

 and I" are both zero, so that the motor takes in no power (ex- 

 cept that represented by the stator magnetizing current) and the 

 rotor develops no mechanical power. 



