Random GFCI tripping

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jotw

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Good evening. I have a house that won't go away and hopefully someone can shed some light on what might be happening.

One of the GFI receptacles in the kitchen trips at odd times. I've replaced the GFI rec., gone through the whole circuit (taken everything apart with no continuity between grounds and neutrals). The breaker never trips, just the receptacle.

I've been over there a number of times and can't find anything wrong. The GFI resets everytime. So, the homeowners were out of town for about a week and left me a key to repull the circuit from the subpanel. Before I cut into the wall I decided to check everything one last time. I went through the whole circuit with the same result. I then went to the subpanel and took the neutral and ground from the main disconnect out. Then I tested the ground and the neutral bars and they still had continuity between them. I found the electric range to be where this continuity is coming from. So, I thought, Aha! Sure enough, the ground and neutral on the range are bonded somehow internally. That sounds like a problem to me. Correct me if I'm wrong. So, I left the range unplugged for that entire week. I went back three different times to check and that GFI was never tripped. I thought "problem solved."

The homeowner just called and told me that the GFI has tripped again. Of course, the range is plugged back in. I don't know for sure if the range is the problem or not. I just know that I don't know what it is if that isn't the culprit. Any thoughts?

Sorry for the long story. Thanks for any input/jokes/critisisms/whatever.
 
Did you happen to look at the cord in the range, make sure it wasn't tied together?
GFCI, as I have been told, will not trip from reasons on the line side only the load side
Have you asked what the HO what they were using when it tripped?
Could try putting an AFCI breaker on it just to make sure its not hot to ground, would have to be a small leak, AFCI will pick it up, if it holds, not the problem.
 
There have been numerous posts regarding this type of thing which all sorts of suggestions. One common cause is where a neutral and e=EGC ome into contact with one another somewhere in the branch circuit and then the search begins.
But I would strongly suggest that you search this forum and maybe you will get a fairly quick suggestion as to what to look for to solve this problem.
 
jotw said:
I then went to the subpanel and took the neutral and ground from the main disconnect out. Then I tested the ground and the neutral bars and they still had continuity between them. I found the electric range to be where this continuity is coming from. So, I thought, Aha! Sure enough, the ground and neutral on the range are bonded somehow internally. That sounds like a problem to me. Correct me if I'm wrong. So, I left the range unplugged for that entire week. I went back three different times to check and that GFI was never tripped. I thought "problem solved."
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I'm not sure if I understand what's going on. Is the receptacle for the range GFCI protected by the GFCI type receptacle that keeps tripping ( you know, down stream)? If it is that would be a problem.

If that is not the case I would need more information about the circuit that's tripping. If it's an old house it can be hard to tell because there can be everything in the world hooked to a kitchen circuit. I once had an outside receptacle getting spray from a sprinkler system and the darn receptacle was hidden behind some hedge bushes. You wouldn't think about an exterior receptacle on the small appliance circuit but it happens.

If the homeowners are home there is no telling what they are plugging into the circuit to trip the GFCI. People are not always honest about it either.
 
You need to find out how long this has been tripping? Always or recently? What changed? What is on the load side of the GFCI? Start of the BC. end or middle?
Did you use a megger?

If this is the last item on the circuit, odd ball things do happen. Real PIA and there have been several discussed on the forum.
 
growler said:
.....
If the homeowners are home there is no telling what they are plugging into the circuit to trip the GFCI. People are not always honest about it either.
Click to expand...

Then try to convince them that it is their appliance, blender, toaster, coffee maker, etc
 
The range is not GFI protected. I did check the cord for the range. The continuity is definitely in the range, not the cord. I wired the house late last year. The GFI is one of the two small appliance circuits in the kitchen and there are only two receptacles on that circuit (nothing plugged into either one). I just wanted to answer all of your questions/confusions at once. The range has nothing to do with the GFI circuit. The only reason I brought it up was because of the neutral and ground continuity at the sub panel when I took the neutral and ground from the main disconnect off of their bars. It was a guess that maybe it was causing the tripping somehow. Thanks
 
Do you have 1 or 2 GFI recepts?
If only one, try pigtailing everything in the first box and installing GFI recepts in each box so they each are only connected on the line side.
 
Are you sure there isn't a GFI protecting another GFI? I've done this before.

We have also seen a few bad GFI's out of the box over the last few years and had extremely poor service life out of the Cooper brand and don't use them any more.
 
Get a good credit card number from them and park 2 guys and a truck there till they find it or the card tops out.
I like the idea of individual GFCI's. That will find it.:thumbsup:
 
I assume that the whole kitchen is supplied by the sub-panel and not the range only. If the breaker for the gfi circuit is next to the range breaker, move it at least for the moment. Possibly the current in the range wiring induces current in the gfi circuit (seems unlikely). The two sabc's are not on a mwbc are they? If so, that will cause a problem. If both receptacles on the circuit are gfi receptacles, does the one closest to the sub-panel do the tripping or is it the far one?
 
IMO, replacing all receptacles with GFCI all fed on line side would eliminate the trouble not fix it, maybe I'm not thinking this all the way through,
 
jotw said:
The GFI is one of the two small appliance circuits in the kitchen and there are only two receptacles on that circuit (nothing plugged into either one).
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If there are only two receptacles on a circuit and one is a GFCI protecting the other and nothing plugged in that doesn't leave much room for doubt.

Either it's a bad GFCI or the wiring from that one to the other is bad (assuming that you checked the other receptacle connection to make sure the ground and neutral are not making contact).

To make sure use a megger and meg hot to ground and neutral to ground. Who knows maybe a staple driven to tight or a bad cable from the factory. On a kitchen counter that short piece of wire shouldn't be hard to replace.

Rather than spend much time there I would replace the GFCI, the wire and the other receptacle and that makes it completely new in about and hour.
 
So far in this thread I have seen solutions that relate to breakers and solutions that relate to receptacles.
Be careful to keep them separate.

Your range appears to be set up for a 3-wire circuit. Depending on the age of the range, it likely has a jumper installed that you can remove, if you are feeding it with a 4-wire circuit. This should be done any way, but it should have absolutely no impact on your problem, unless there are more wiring problems than you are aware of.

The only neutral to ground issues that will cause a GFCI receptacle to trip are the ones after the 'load' terminals of the receptacle (someone already mentioned a MWBC).

You do notice, that the GFCI did not trip when the homeowners were gone don't you? Are you positive it is not one the appliances they are using?
 
Gac66610 said:
IMO, replacing all receptacles with GFCI all fed on line side would eliminate the trouble not fix it, maybe I'm not thinking this all the way through,
Click to expand...

You are right and there could still be a problem with no symptoms right up to the time when the wire burns into or the house burns or whatever. That circuit won't be Arc Fault protected.

If I don't know about the problem it wouldn't matter but once you know about it then it would bother me so I would have to find and fix it.
 
Get the oven checked for screaming electron's. It's been said that two way walkie talkie's telephone's can trip a GFCI. There is a heavier amount of electronic's in today's modern oven/stoves, it's broadcasting. I don't think the average oven tech or any average electrician has the tools to measure this broadcast pulse of energy.
 
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