136 PROBLEMS IN ALTERNATING CURRENT MACHIM-h'Y 



unduly hot. Oscillograph records show that at this time the 

 terminal voltage of each phase of the generator practically con- 

 sists of a fundamental and a third harmonic which is 12 per 

 cent, of the fundamental. 



What is the copper loss in each transformer? If the neutral 

 point of the transformer windings is disconnected from the 

 ground bus what will be the copper loss in each transformer for 

 the same load condition? 



