ROTARY CONVERTERS 



113 



This method of supplying the C 2 R losses from a 

 booster requires such a large low voltage booster that 

 it is not often used, except for small rotaries. 



With a Booster in the A-C. Side 



A second method of pumping back rotaries on full 

 load heat runs is to use an induction voltage regulator 

 in the alternating current side of the machines as shown 

 in Figs. 33 and 34. The regulator is connected with 



Fig. 34. Table Connections for Rotary Converter Pump Back 



its secondaries in series with the alternating current 

 lines and its primaries across the alternating current 

 terminals of the inverted machine. It is always pref- 

 erable to connect the regulator between the inverted 

 rotary and the dynamometer board. The regulator 

 takes the place of the booster used in the previous 

 method, and is very satisfactory for supplying the 

 C 2 R losses. 



Starting the machines, checking the phase rotation, 

 phasing in, and other operations already described, 

 are repeated with this method. Always see that the 

 regulator is set at the no boost point before phasing in, 

 otherwise load will be thrown on when the switches 

 are closed. 



