January 23, 2007We bought this house last summer. The detached garage has a 100 amp breaker subpanel that runs through the main panel in the house. When we had the home inspection done, the inspector noted that the neutrals and grounds needed to be segregated at the subpanel. This was supposedly done by the previous owner. The home inspector did not note that problem during the reinspection, but he did note that one of the GFCIs did not work properly. I finally got around to buying a GFCI outlet tester yesterday and none of the GFCI outlets in the garage work properly. I've dinked around with them enough that I think there is something wrong with the wiring at the panel still, but I don't know what it's supposed to look like, so I'm hoping someone can give me some insight as to what to look for.
Here's what I've got
1. When I plug the GFCI tester into the outlet, it shows that it's OK, but when I push the button on the tester to trip the outlet, it doesn't trip and the lights on the tester change to indicate that the hot and neutral are reversed. When I use an analog meter, I show 120V between the left and right slots and between the right and bottom slot, but nothing between the left and bottom. Compared to a known good GFCI in the house, that seems to be the way it should be.
2. I tried reversing the hot and neutral wires on the outlets, but that only served to give me the hot/neutral reverse indication when I plug the tester in. Pushing the button on the tester does not interrupt the power flow.
3. I've tried replacing the outlet with a brand new one that I bought today and it behaves the same way.
4. I have been careful to pay attention to the line vs load terminals on the outlet when I wired it and I verified I had it correct with the multimeter. I even tried plugging the tester into a conventional outlet that is downstream of the GFCI outlet and pushed the tester button. I thought that should trip the GFCI, but it does not. This is starting to make me a little nervous.
My questions are:
1. If I take the panel cover off, what should I see as far as hot, neutral, and grounds? Where should each of them go and not go?
2. Maybe I'm already in over my head. How much can a competent homeowner do versus when do I need to call an electrician? Most of my experience lies with DC, but I can do basic AC work, such as wiring in a switch or outlet.