GFCI keeps popping

[CAMAN]

My moms house (18 years old and basement finished 8 years ago) has a GFCI outlet in the basement bathroom that keeps popping randomly for no obvious reason. It started doing it over the summer. It only does it when the lights and fan is off and there is nothing else connected to the circuit that I can find. I replaced both the circuit breaker(was too big) and GFCI outlet with brand new ones. It kept happening so I checked the fixtures and found the lights above the sink weren't grounding right, so I replaced that and it still happens. I have checked and replaced all the outlets and switches to make sure nothing is touching or bare and its all good. It still happens and I am stumped.

Anybody have any ideas or ways to diagnose this better? I'm hoping there isn't a bare or chewed up wire in the wall somewhere.

Thanks!

[catchphoto_filet]

ultimately if there is a bad ground you will have a tripping issue. make sure your line and load are connected correctly. IF nothing else take the GFCI out and put in a regular outlet. And if your really concerned about potential shock buy a 20A gfci circuit breaker or 30 for that matter and put in a regular outlet in the bathroom. That way it is still gfci protected...

[spearchucker]

I wouldn't put a 30A in place of a 20A circuit unless you want to burn the house down.

Could you check for a continuity between hot/neutral and ground to see if you have a small short somewhere. Could be the cable itself.

[BobT]

A GFCI measures for a difference in current between the ungrounded conductors. I don't believe a bad ground will be detected at all because the GFCI isn't measuring ground current. There shouldn't be any to measure.

If the current flowing on the ungrounded conductor (hot) is not the same as the current flowing on the grounded conductor (neutral) then it trips. The only way this can happen is if some or all of the current is flowing by some other unintentional path, which would most likely be through a grounded point such as the grounding conductor (bare or green) or the chassis of the appliance, etc.

If you've replaced the GFCI and it still trips, I'd start looking at the circuit for a grounded path. It may not be the ground wire that is providing this path. You mentioned it is in the basement so there are plenty of grounding paths to be had and add the moisture typical of basements and you increase this possibility.

Almost forgot. Absolutely DO NOT replace the circuit breaker with a 30A. DO NOT replace the circuit breaker with anything rated higher than the one already being used.

[CAMAN]

Yeah, I won't be putting a 30amp in, that is what was in there before and don't want to over-do it. The 20 will be staying in.

This issue is very intermittent, sometimes it will be good for a week or two, then it will trip 2 or 3 days in a row and a lot of times at night or when nobody is home. And its never tripped when the lights or fan is on or any known load is present.

In regards to the moisture thing, this basement is actually very dry and drained well, the shower rarely gets used and being none of the outlets or switches are below waist level and near no exterior walls I can't really say that is the problem.

I've checked all continuity between everything and best I can tell its all good, and being its an intermittent problem, I would need to get very lucky to have it pop up when checking it.

So short of replacing all of the wiring on this circuit, (which I would need to rip all the drywall out to do) I don't think I have a good way of diagnosing the problem unless somebody knows of something that can track it.

Is this a potentially dangerous situation? Or is it more of a hastle than anything?

[BobT]

The fact that a GFCI is tripping and assuming you are confident it is a functioning GFCI (I think since you replaced it, you almost have to assume this) then you are basically being told that you have a ground fault condition. In other words, the hot is making contact to ground somewhere but not enough to trip the circuit breaker because the GFCI catches it first.

I had a problem like this once and discovered that I had some weak neutral wirenut connections in light fixtures. I suspect that there was some small arcing going on. Reinstalled the wirenuts and the problems went away.

[SkunkedAgain]

It could also be an animal chewing on the wire somewhere. That could explain it tripping while no appliances are being used.

[BobT]

Quote:

It kept happening so I checked the fixtures and found the lights above the sink weren't grounding right, so I replaced that and it still happens.

This statement has been bugging me. They aren't suppose to be grounding at all so what do you mean by this.

[JohnMickish]

I agree with Bob Ts statements but it sure sounds like there is another load on the circuit somewhere, maybe a motor load like a fan?? Sometimes houses get wired in a non logical manner, and some remodels make it even worse.

I'm going to go with another load on the circuit or else there is a moisture/corrosion problem in a box somewhere, but if there are no other outlets on this circuit I have a had time believing there would be a j-box somewhere.

[dillrodd]

Caman, You sound pretty confident that there are no ther loads on this circuit. I would double check and my guess is there might be an outside outlet on this cicuit. I've seen many times when cheap electricians will put outside outlets on with bath outlets to keep from buying more gfci's. I suppose at one time that would have been legal but now it would not be.

[Scott K]

Caman, You sound pretty confident that there are no ther loads on this circuit. I would double check and my guess is there might be an outside outlet on this cicuit. I've seen many times when cheap electricians will put outside outlets on with bath outlets to keep from buying more gfci's. I suppose at one time that would have been legal but now it would not be.

I have that in my house

[CAMAN]

Quote:

It kept happening so I checked the fixtures and found the lights above the sink weren't grounding right, so I replaced that and it still happens.

This statement has been bugging me. They aren't suppose to be grounding at all so what do you mean by this.

Maybe I mispoke, the isolating washers between the socket and fixture on one of the sockets had degraded and there was current going from it into the fixture base and through the ground wire. It was unlike the other 3 sockets on the fixture. So to be safe I replaced it.

I will go through the entire circuit again and check all wire nuts and connections and make sure nothing was stripped too far or whatever.

Do you think I need to check the part of the circuit between the breaker and GFCI, or does a GFCI only measure the output side? I would think the breaker would trip if it were in between but maybe I'm wrong?

[dillrodd]

Are there wires on the load side of the gfci

[BobT]

A GFCI receptacle only protects the circuit connected to the "load" terminals.

When it trips, does everything go dead or only the GFCI receptacle? If only the receptacle then it is not protecting the entire circuit and the rest of the circuit is not going to be your problem. If the whole circuit goes dead then the ground fault could be anywhere from the GFCI receptacle to the last device.

[CAMAN]

Yes there are wires on both the line and load sides. As far as I can tell it is wired correctly.

And yes, everything in the bathroom goes dead, outlet, lights and fan.

I will check everything out in the next few days and see what I can find. But I'm thinking its somewhere between the outlet and one of the switches because its only tripped when the switches are in the off position.

Thanks for all the help!

[dillrodd]

It would be interesting to hook this circuit up to an arc fault breaker and see if it would trip it. One reason I say this is because with a GFCI that only trips ocassionally it is almost impossible to trouble shoot. If it would trip the arc fault it would most likely do it instantly, and you would be able eliminate loads until it holds.

[eurolarva]

Had a similar problem and it was the face plate on the GFI was metal and it was creating a problem. When the face plate was off it worked fine. When I put the face plate on it would keep popping.

[jeffreyd]

one question you mentioned that the light fixture had current going through it. how much current are we talking? I think that i would trip the GfI and see if anyother circuits are dead from it. If not trip the breaker and see what is tied to that breaker. I could be a problem with a couple outlets tied on the line and a loose connection or when it is colder out looses connectivity or causes a higher resistance. man got to love these type of things

[JohnMickish]

Caman, You sound pretty confident that there are no ther loads on this circuit. I would double check and my guess is there might be an outside outlet on this cicuit. I've seen many times when cheap electricians will put outside outlets on with bath outlets to keep from buying more gfci's. I suppose at one time that would have been legal but now it would not be.

It's not cheap electricians, it's cheap homeowners. The electrician only does what the homeowner is paying him to do.

[JohnMickish]

OK, it you have wires on both the line and load side of the GFCI other things are being protected. The lights and fan do not have to be GFCI protected unless they are above the tub. What is the light/fan placement in the bathroom? Does it trip when you turn the lights on or does it do it when nobody is using the bathroom?

[dillrodd]

It's not cheap electricians, it's cheap homeowners. The electrician only does what the homeowner is paying him to do.

If elcectricians only did things the way the homeowner wanted them done I think we would have quite a mess on our hands. Are you saying you have had homeowners tell you to put their outside outlets on with their bathroom to save $12? I think most homeowners would not even know that that would have bee posssible. Thinking like that is the reason we now have a code section that states that the bath room circuit shall have no other outlets. (NEC 210.11 c (3).

[BobT]

You're citing current codes. Don't recall what was allowed in 1992 but maybe this was? Based on the description of what outlets are going dead when this GFCI is tripping, the circuit does not meat today's code as it is. Regardless, he's left working with what it is and it doesn't help him to read a lot of arguing about what the code allows today vs. what it did 20 years ago or whether it was a lazy electrician, efficient electrician, homeowner with a low budget, or whatever because non of that matters now.

[CAMAN]

How would this not meet code? Its got the main GFCI outlet that is also feeding the power to the light over the shower, the fan over the shower, and the light over the sink. Nothing else. If anything, it is overprotected with the light over the sink being protected, which from what you guys are saying it doesn't need to be, but I would rather have it protected than not, it just seems safer to me.

But anyways, the basement was finished before the house was purchased by my mom 5 years ago, so I have no idea if a professional did it or not, but judging from the work that was done in the rest of the house it was most likely done by a profesional or very experienced DIY'er.

To answer Mnfishinguys question, the GFCI has only tripped when all of the switches to fan and lights are in the 'OFF' position. The GFCI outlet has an LED light saying that power is being fed through it and it always stays on whenever the switches are flipped on and off. It is intermitent and very random when it trips, I have tried flipping all the switches on and off at the same time to see if it trips but doesn't happen. I have never been able to get it to happen while present.

I will try going through the circuit again this weekend to see if I can find anything that may be shorting out.

[JohnMickish]

Is the fan hooked up to a separate switch or does it come on with the lights? CFL or incandescent lighting?

[JohnMickish]

Originally Posted By: mnfishinguy

It's not cheap electricians, it's cheap homeowners. The electrician only does what the homeowner is paying him to do.

If elcectricians only did things the way the homeowner wanted them done I think we would have quite a mess on our hands. Are you saying you have had homeowners tell you to put their outside outlets on with their bathroom to save $12? I think most homeowners would not even know that that would have bee posssible. Thinking like that is the reason we now have a code section that states that the bath room circuit shall have no other outlets. (NEC 210.11 c (3).

The way it generally works is the homeowner contacts a builder to build a house, they argee on price/package. Builder has his electrician wire the house. Cheap package gets X, upgraded package gets Y.

I'm not saying it's not a cheap way to do it, and I believe it is, but it's legal and like most things in life, you get what you pay for and if you don't know what you are paying for then how can you blame someone else?