I'm installing two new bathroom light fixtures. First one went in fine. Second one will blow the wall receptacle based circuit breaker the moment I screw in the bulb (in fact three different bulbs tried).
So for clarity both fixture circuits run through this wall receptacle based circuit breaker. It has a little green light to indicate it is "on". I measured the new fixture and found 115-120v on the light socket. So with no bulb in I can turn on the fixture and measure the voltage, but screwing in the bulb (three different bulbs, which then work fine in the first fixture) causes it to trip. This happen if the first fixture is turned off or if it is turned on. Help?
I thought if I had a short I would never be able to measure the voltage at the socket, or that it would trip when I turned on the switch without a bulb. Doesn't trip.
I thought maybe something wrong with fixture, so returned it and got another, same problem.
This one has got me.
So I opened up the box and found that the light fixture (and switch) is wired to the line connections on the GFCI, and the true "hot" wires are wired to the load connectors on the GFCI. In the following diagram just reverse the labels for Load and Line on the GFCI.
I opened up the switch and outlet under fixture number 1. Here I see the HOT lines going to a standard outlet and switch. These lines are then fed through the back of the wall over to the box under fixture number 2, where as I said earlier they go to the LOAD on the GFCI and my problem fixture (#2) is wired to the LINE terminals.
So my assumption is that due to this Fixture #1 never really had GFCI protection(?) Not sure I understand why it turned off when the GFCI tripped.
Can I fix the fixture #2 problem by just switching the incorrect(?) Load and Line terminal wires? and shouldn't this also mean my fixture #1is also now GFCI protected?