Masterpact ground fault breaker connected to modified differential ground fault (MDGF) system is failing secondary injection test with the full function test kit (FFTK)

Ground Fault Test is failing using FFTK

Air Circuit Breaker

The full function test kit will only test residual equipment ground fault protection. Breakers configured for modified differential ground fault (MDGF) and ground source return (GSR) cannot be secondary injection tested. The solution is to rack breaker out of cradle/cell to isolate from the MDGF system. If it is a fixed breaker, then remove MDGF wiring from terminals M1, M2, and M3 while using the FFTK.