CHAPTER V 



TESTS OF SYNCHRONOUS MOTORS 



Characteristic Curves. It may be stated, in general, that the char- 

 acteristic curves of synchronous motors are the same as those of alter- 

 nators, i.e., the variation of the inducing flux is represented as a func- 



Field- Excifa tion. Amperes 



Fie. 63. Current consumed by a 15 H.P. synchronous motor, run at constant 

 potential with variable field-excitation. The ordinates represent armature 

 current (amperes) per phase. 



tion of the exciting ampere-turns by an " excitation-curve," and the 

 armature-reaction is represented by a short-circuit-curve obtained 

 according to the method of Behn-Eschenburg, by measuring the amper- 

 turns necessary to produce increasing currents, when the machine is 



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