Gfci circuit breakers

A GFCI 20amp circuit breaker located in a temporary supply which supplies a 115v socket outlet that I have an extension cord plug into and feeding a single phase 3 wire panel in new installation of a house, the only circuit in the panel that is on is a 15amp lighting circuit and the GFCI breaker keeps tripping.Explain The reason{s} for the tripping please.

Best guess is that the neutral is grounded somewhere on the load side of the GFCI breaker. Do you have any photo’s of this installation?

One thing with breakers is if they keep tripping they can god bad. I have seen during new construction things like skill saws and table saw tripping them.

Sounds like you need an electrician … :wink:

simple… it’s wired incorrectly or you have a ground fault somewhere.