Cacher_Chick
Test, Don't Guess!
With all the talk of how GFCI's work and where or why they should be used, I would appreciate some discussion on how to diagnose a problem. I have a good multi-meter and know how to use it. I could even dig out my labscope if I had some good ideas of what to look for.
I have 2- 20 amp branch circuits running through the same raceway (EMT).
One branch feeds a single GFCI receptacle and nothing else.
The other branch goes to a single pole switch which is mounted in the same box as the receptacle.
This switch feeds a bank of troffer lights.
Not that it should matter, but there are ground pigtails from the receptacle and switch ground terminals to the box. There are ground pigtails connected to the troffers. The EMT is the ground conductor back to the panel.
The lights work fine. If I plug something into the receptacle, it works fine.
BUT
When I turn the lights OFF - about one in ten times, the GFCI will trip.
The lights and the GFCI receptacle are fed from separate breakers. They do NOT share a neutral.
Nothing is plugged into the GFCI.
We want to test, not guess. Where do you start?
I have 2- 20 amp branch circuits running through the same raceway (EMT).
One branch feeds a single GFCI receptacle and nothing else.
The other branch goes to a single pole switch which is mounted in the same box as the receptacle.
This switch feeds a bank of troffer lights.
Not that it should matter, but there are ground pigtails from the receptacle and switch ground terminals to the box. There are ground pigtails connected to the troffers. The EMT is the ground conductor back to the panel.
The lights work fine. If I plug something into the receptacle, it works fine.
BUT
When I turn the lights OFF - about one in ten times, the GFCI will trip.
The lights and the GFCI receptacle are fed from separate breakers. They do NOT share a neutral.
Nothing is plugged into the GFCI.
We want to test, not guess. Where do you start?
Last edited: