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



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 re-test.  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.