GE 9T83B4001G55 AL 3P 20KVA 480-480

The use of SCR control circuitry with adjustable-speed drives has resulted in a need for a line of isolation transformers specifically designed to meet the demanding requirements of SCR drives. Symmetrically placed taps and added coil bracing minimize mechanical forces caused by the often severe SCR drive duty cycles. These features also help protect the transformer from the regenerative duty and more frequent short-circuits associated with SCR drives. Drive isolation transformers also reduce line-pollution feedback resulting from SCR firing circuits. The ABB delta-wye designs meet the NEC requirements for grounded secondary neutrals that isolate primary distribution systems. kVA ratings of the DIT line cover most dc motor requirements from 3 to 1000 hp. Enclosed drive isolation transformers are UL listed and meet NEMA TP1 efficiency standards.