2 9 6 



INDUCTION MACHINES. 



[Exp. 



to E; for a definite load and slip it has a definite power com- 

 ponent OC in phase with E and a definite wattless component 

 CP M lagging 90 behind E. The power factor, for a given load 

 and slip, is likewise definite. 



As a generator, the primary current is I 1 = OP Q , consisting of 



FIG. i. Circle diagram showing the operation of an induction machine as a 

 motor and as a generator. (In the range Aa the machine gives out no power.) 



the same exciting current as before, I =OA, and the added cur- 

 rent I(Z) == ^PQ,> The primary current is always leading with 

 respect to E' \ for a definite load and slip it has a definite power 

 component OC' in phase with E' and a definite wattless component 

 C'P G , which is 90 ahead of E'. The power factor for a given 

 load and slip is definite. 



4. It is seen that in an induction generator, as well as in an 

 induction motor, all the current can not be power current. There 



