Utility Relay Company URC,Utility Relay,QUICK-TRIP,AC-PRO,ZERO-Hertz,General Electric,retrofits,trip units,conversions,thermal magnetic,series overloads,overcurrent release,overcurrent trip,electro-mechanical,Circuit Breakers,power circuit breakers,Federal Pacific,Federal Pioneer,FPE,Square D,Roller Smith,Unelec,Roller Smith,Sylvania,Siemens,Brown Boveri,Mears,Whipp & Bourne,English Electric Solid-state trip unit retrofit conversion kits for General Electric, Siemens, Allis-Chalmers,Brown Boveri, Mears, English Electric, Sylvania, Unelec, ABB, Square D, ITE, and Roller Smith low voltage power circuit breakers.