Hello All, Does anyone know the history behind lighting panels that were ground fault protected? These are mid 1970 panels. I have always assumed it was due to magnetic balasts tending to leak current. I do not think it was ever a code but not sure. With everything going to electronic I plan on defeating or replacing the shunt trip on the main breaker.
Greco: Welcome back; long time with no posts here.
Are you sure it's GF and not an 'old' system for lighting controls?
I've been 'around' since before '70s and have not encountered any GF on a lighting panel. I've seen a bad ballast trip a GF on main CB's with GF protection (NEC Mandatory), but not any dedicated lighting panels with GF.
I have been checking the board from the days of Bennie and SDS's. I don't like to use work time to post and I have dial up at home but this is work related. Yes it is GF, 400 amp. It may have been custom made we had deep pockets back then. Over the years we would have an occasional main trip due to a faulted balast, we would repair it and move on. This last one created paper work for me so it is time lose the GF. I just wanted to see if anyone knew anything about them. Thanks,
That is why when I do my inspections, I ask the EC to make sure that the GFPE is set properly. They usually give me a letter stating that they or the manufacture's company rep. has the proper setting on the breaker.
Greco: I have to go with it being a design issue. You mentioned that "deep pockets" were available.
On a 400 amp panel, it is not now, nor was in the past a NEC requirement. As to the purpose it may have served, additional safety for the installation? I've seen a lot of 'fried' old ballasts over my years, but can't remember any additional damages