J2 SYNCHRONOUS ALTERNATORS. [Exp. 



giving the friction and core loss of the alternator any changes in 

 motor losses being corrected for, if necessary. 



The copper losses of field and armature are calculated from resist- 

 ance measurements, and the efficiency so determined. 



If the armature has large, solid conductors, the loss in them will be 

 greater with alternating than with direct current, this additional loss 

 being a load loss. Load losses are losses which occur under load in 

 addition to the losses already accounted for, i. e., in addition to core 

 loss, RF, friction and windage. There is no simple and accurate 

 method for determining load losses in alternators. The A. I. E. E. 

 Standardization Rules (116-7) gi ye a method for estimating these 

 losses by assuming them to be in the absence of more accurate infor- 

 mation equal to one third of the short-circuit core loss. 



