110 



COMMERCIAL ELECTRICAL TESTING 



D-C. Circulating Current 



Fig. 32 shows the connections for two three-phase 

 converters wired for a pump back heat run without a 

 potential regulator to control the load. The core losses 

 and C Z R losses are supplied from the direct current end. 



H*- 



Fig. 32. Connections for Pumping Back Rotary Converters 

 Without the Use of a Regulator 



The diagram shows, also, the standard starting panel, 

 which should always be used when two converters are 

 tested together. 



To start the rotaries, for instance No. 1, close the shunt 

 field switch and the switch K, the latter short circuiting 

 the armature of the loss supply. Note that the shunt 

 fields are wired across the core loss supply, which in 

 turn is wired to busses B and C of the starting panel, 



