It looks like there has been some bad wiring done in the old house we just bought. Yesterday, I was installing a low-wattage LED nightlight in a 3-gang box on a GFCI circuit, when the whole circuit lost power. I cannot find a reason for the loss of power. I rewired the way it was when I started, but that did not fix the problem.
This circuit has a GFCI breaker. There also are (or were) three GFCI outlets on its circuit, two of which have no load. The one with a load is outside and I believe protects an additional outside outlet. I read that the circuit breaker is all that is needed and that additional GFCI outlets are not only not necessary but can be a problem, especially as they age. So, I am replacing the GFCI outlets with standard outlets. Doing so, however, has not helped.
I suspect that the GFCI breaker is faulty. When I switch it on, there is no power. When I test for power between its hot connection and neutral, there is no power. When I press the test button, nothing happens.
I can replace a breaker (I think) but I am not sure if that is what should be done.
Best Answer
I gather you have the panel cover off?
First, you cannot test any GFCI device while anything is plugged into it or on the LOAD terminals. All wires must be removed from the LOAD terminals.
Once that’s done, we can now do a clear test of the GFCI. For a breaker, turn it all the way off, then all the way on. Don’t try to go straight from “tripped” to “on”, that will not work. Once it is on, then you press the TEST button and see if you get a trip. Then to OFF then to ON, to reset.
If the GFCI breaker responds correctly when you do that, then the breaker is not faulty. It is doing its job, tripping due to a fault in wiring or devices. Now you divide and conquer.
The trick with “divide and conquer” with GFCI is that you must isolate BOTH hot AND neutral. Simply breaking hot is not enough.
You must also be very careful in boxes that have multiple circuits in them. For instance, sometimes a multi-light switch box has circuit 1’s power coming into it to run some switches, and then a switch loop for a light from circuit 2. Goober says “I want to put a smart switch on that switch-loop”, so uses the always-hot and switched-hot from the switch loop, and steals neutral from circuit 1. GFCIs won’t tolerate that.