134 



COMMERCIAL ELECTRICAL TESTING 

 TABLE XVI 



Excitation on a 100 H.P., 2080 Volt, 6-Pole, 60 Cycle, 3-Phase 

 Induction Motor 



on the bearing bracket, this space being divided into 

 about eight parts. A pointer should be attached to the 

 motor shaft or pulley so that its outer end will pass 

 over the division marks ; it is then set on mark 1 and the 

 rotor blocked so that it cannot move from that position. 

 The switches are next closed and the impressed voltage 

 increased gradually until about normal current is ob- 

 tained. Volts and amperes should be read and recorded 

 on all three phases to make sure that no unbalancing 

 occurs. Holding the same volts as for position 1, the 

 pointer is moved to mark 2, and the amperes read; this 

 procedure being repeated on each of the succeeding marks 



