Masterpact breaker passes all FFTK tests except for ground fault, yet produces error codes on the trip unit; what is the problem?


28 September 2021

Masterpact NW

Find out if this breaker is used in a MDGF (Modified Differential Ground Fault) system. If so, disconnect wire going to M1 on the secondary block and retest. M1 enables MDGF and disables residual GF, and removing it puts the breaker back into residual mode where it can be tested with the FFTK.