GFCI issue

secutanudu · 10-07-2009, 07:44 AM

I am trying to GFCI-protect a circuit that runs through my basement as well as some other stuff in the house. I found a section of wire in the unfinished part of my basement near the circuit breaker, so I cut it and installed a blank-front GFCI receptacle.

Problem- the GFCI trips immediately after turning on the breaker. Does this mean I have a ground fault somewhere in my house? How do I find out where?

Just downstream of the newly-installed GFCI, the circuit branches off into 2 directions. I disconnected one of the branches, and this stopped the tripping of the GFCI. So I guess this tells me that the problem lies on the branch that I disconnected, but unfortunately this is the branch that runs into the finished floor of my house.

Any advice?

Thanks.

300zx · 10-07-2009, 08:06 AM

Not everything in your house needs to be gfci protected the wire you disconected where does it go what outlets are not working with this disconected?

secutanudu · 10-07-2009, 08:44 AM

The reason I want to GFCI-protect that portion of the circuit is because it goes to an outdoor light, and I went in to replace the light switch yesterday to find that it wasn't even grounded.

I realize not everything needs to be GFCI...but if the GFCI trips as soon as power is turned on, isn't that cause for concern?

Thanks!

jbfan · 10-07-2009, 09:09 AM

Quote:

Originally Posted by secutanudu

The reason I want to GFCI-protect that portion of the circuit is because it goes to an outdoor light, and I went in to replace the light switch yesterday to find that it wasn't even grounded.

I realize not everything needs to be GFCI...but if the GFCI trips as soon as power is turned on, isn't that cause for concern?

Thanks!

That is a concern.
To troubleshoot this, try to find the middle of the circuit, disconnect down stream and turn the gfci back on.
If it trips, the problem lies bewteen that device and the gfci.
If it does not trip, the problem lies between that device and the last device.

secutanudu · 10-07-2009, 09:12 AM

Good idea.I can just keep going halfway till I find it. Problem is, I don't really know everything on the circuit, I guess it'll take some digging.

Is there some tester I can buy to plug into a standard receptacle to test whether there is a ground fault?

jbfan · 10-07-2009, 09:19 AM

One way to find everything on that circuit is disconnect the gfci and find out what is not working.

The answer to the second question is a megger, but it does not plug into a receptacle.

secutanudu · 10-07-2009, 10:58 AM

I will try this tonight, thanks for the advice. I did not think that installing a light switch was going to lead to this much work!

jbfan · 10-07-2009, 12:02 PM

If this started after you installed the switch, that is the first place to look.
Make sure that the ground and neutral are not touching anywhere.

secutanudu · 10-07-2009, 12:07 PM

There wasn't even a GFCI on that circuit before installing the switch. I noticed the no-ground situation while swapping out a standard switch with one of those fancy timer-switches with the little screen on it. Since there was no ground, i decided to GFCI-protect the circuit.

The first thing I did, which i forgot to mention, is pull out the new switch and swap back to the old one, but the GFCI still trips

secutanudu · 10-08-2009, 11:43 PM

So I have started to pinpoint the problem. The circuit in question branches off in about 5 different directions after the spot where I installed the GFCI receptacle. Two of those branches are causing the trip, so I know i have (at least) two problems.

One of them is in a bedroom, somewhere...is there any trick to finding the direction of the circuit?

The other leads to an outlet, and when i took the outlet out, there are 4 wires (2 blacks, 2 whites) so I know it isn;'t the end of the run, but I cannot figure out where it is going. There is nothing anywhere near it or on the floor above.

Any tips on figuring out where these wires are running?

Is this something that should be an easy fix if I hire an electrician?

One other question - I noticed there was a junction box in my basement that was grounded to my water pipe. This circuit is GFCI protected, so I pulled the grounding wire off the pipe. Was this the right thing to do?

Thanks.

Thurman · 10-09-2009, 01:37 AM

You stated that part of the circuit after the GFCI goes to an outside light. Would this be a "motion detector" light? I had a problem with this situation a couple of months ago when I added a new outside motion detector fixture to a customer home and tied it into the outside duplex receptacle on the porch, which was a GFCI outlet. It turned out to be the light fixture, even though brand new. A replacement fixture, of another brand, solved the prolem. Just a thought. Thanks, David

secutanudu · 10-09-2009, 07:33 AM

David - good thought, but unfortunately I found of the two branches with problems, neither one has the outdoor light on it. Thanks, though! It is a newer fixture, but not of the motion-sensor variety.

secutanudu · 10-10-2009, 12:09 AM

So I think I have found the problem. The outlets on this circuit have the ground wired with a short bare copper wire right to the neutral screw with the white. So it is some sort of jerry-rigged ground. I removed these short wires from one of the problem branches, and this no longer trips the GFCI. I also found the same setup on outlets on the other problem branch, but still haven't gotten them all.

I assume the GFCI method is better than wiring the ground screw to the neutral terminal on receptacles, right?