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GFCI Breaker Ghost Tripping - Next Steps?

1872 Views 9 Replies 4 Participants Last post by  Crashcup
Hi, I have a similar issue to another post I found on here, although mine is not a 27-year-old breaker.

20A GFCI breaker that serves 11 receptacles in a garage. This circuit was installed about 2 1/2 years ago, and I have it mapped from before I installed it, so I know there are no other outlets on the circuit. Garage lighting is on a separate 15A circuit.

The breaker started tripping a few months ago, around Nov or Dec 2019. At the time of the first trip I could find no moisture issues in the garage. At that time I had an air compressor and two door openers plugged in to this circuit. I unplugged the air compressor and reset the breaker.

Maybe a month went by before it tripped again. Again nothing obvious causing a ground fault. Two door openers plugged in to ceiling receptacles, nothing else.

So I procrastinated on this a while. The breaker continued to trip every few weeks and I just kept resetting it. Continued like this until we went on a long trip leaving Feb 21. We got home March 25th, and now it's tripping every few days.

Before I install a $53 replacement breaker, I'm thinking I should check more carefully for a problem that would cause enough leakage current to trip the breaker. I don't really want to slap that $53 breaker in and find the new one still trips.

First, what are your thoughts on the likelihood that the breaker itself could be bad?

Second, what would you add to this list:

1) Check wiring of breaker

2) Check integrity of wires - any rodent damage?

3) Pull receptacle from each box
a) Check for moisture
b) Check for solid connections
c) Check for hots or neutrals pressed tight against the sides of steel box?

4) If nothing from above, disconnect downstream outlets from the first outlet in the circuit. Wait to see if breaker trips. If not, systematically re-connect outlets until breaker trips, to identify one receptacle. (This sounds excruciating).

5) If nothing from (4), replace breaker.

Not even sure if (3)(c) is a possibility. Could the insulation on a conductor be slightly damaged, a small nick, so that it might pass enough current to be detected as a ground fault?

My wife seems anxious for me to replace the breaker because she gets annoyed when she has to wait 2 minutes for me to go downstairs and reset it :laugh: But I'm going to feel like an idiot if I spend $53 and that is not the problem.
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Yeah breakers and GFCI receptacles go bad. But first, a few basics. Is it a GFCI or AFCI/GFCI combo breaker? Do you have any other GFCI receptacles on this circuit? They can cause nuisance trips. Is there any exterior receptacles being protected by this breaker? Lighting, receptacle on outside wall, or on an outside pod?

Keep in mind GFCI's don't trip on overload, as they only trip on....well....Ground fault, or a minor difference in the current between the hot and neutral.
Yeah breakers and GFCI receptacles go bad. But first, a few basics. Is it a GFCI or AFCI/GFCI combo breaker? Do you have any other GFCI receptacles on this circuit? They can cause nuisance trips. Is there any exterior receptacles being protected by this breaker? Lighting, receptacle on outside wall, or on an outside pod?

Keep in mind GFCI's don't trip on overload, as they only trip on....well....Ground fault, or a minor difference in the current between the hot and neutral.
Hi Larry,
Yeah, it's a GFCI and not a combo. AFCI wasn't required in a garage at the time I finished it anyway. And no separate GFCI receps on the circuit; only the breaker. Nothing exterior. Circuit serves the garage receptacles only.
Don't be upset at my questions, but have you looked behind stacked boxes, etc. for possible hidden GFCI receptacles? Often garages are the place where they are overlooked. If you have none, and there are no compromised receptacles (broken, wet, etc), then you may have to bite the bullet and pop for a new breaker. As I said, the older they get, they can become weak. Wifey will be proud.
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c) Check for hots or neutrals pressed tight against the sides of steel box?
I would include (or add as d) screw down all unused screws on the devices.

The other thing I would consider is moving the GDOs off of that breaker. If you bring a circuit to a blank face GFCI at switch height, then run it up to the GDO receptacles, that gets them off of your receptacle circuit.

If the blank face gfci starts tripping, you will know that one of the GDOs is your problem.
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Don't be upset at my questions, but have you looked behind stacked boxes, etc. for possible hidden GFCI receptacles? Often garages are the place where they are overlooked. If you have none, and there are no compromised receptacles (broken, wet, etc), then you may have to bite the bullet and pop for a new breaker. As I said, the older they get, they can become weak. Wifey will be proud.
No problem with the questions, that's what I need. Might be something I didn't think of. But, fortunately we haven't yet stacked up a bunch of stuff in this garage. (We do have a bunch of siding store there on shelf brackets, but that's above the receptacles). All the receptacles are visible. And never would have had GFCI receptacles because I planned from the start to include the GFCI requirement at the breaker rather than at a receptacle in the garage. (Although... in a situation like this it would be a lot more convenient to reset a GFCI that's right there in the garage).

Guess I'll wait and see if other recommendations pop up tonight, and then tomorrow go up in the garage attic for a closer look at the wiring. Pop the covers off and check for moisture or questionable connections. Then maybe replace the breaker so my wife doesn't have to wait for me to conduct a full investigation! Lol. She often accuses me of analysis paralysis.
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I would include (or add as d) screw down all unused screws on the devices.

The other thing I would consider is moving the GDOs off of that breaker. If you bring a circuit to a blank face GFCI at switch height, then run it up to the GDO receptacles, that gets them off of your receptacle circuit.

If the blank face gfci starts tripping, you will know that one of the GDOs is your problem.
Thanks. The screw terminals is a good suggestion to check.

Your other suggestion... not the easiest to implement. Not impossible, but the walls between the house and garage are insulated and finished, so would take some work to poke a new circuit through. Also running short on spaces in the panel.
Good one to keep in my hip pocket, and if I can't find anything else and a new breaker also keeps tripping, I might need to look at adding that separate circuit.
I wonder if there's any way - at reasonable cost - to check if the GDOs are causing this. I have read that a clamp meter to check for leakage current should be able to measure to less than 0.1 mA, and in a quick search I didn't even find one that showed that in the specs. I'm afraid such a meter is going to be $300-400 or more.
So I procrastinated on this a while. The breaker continued to trip every few weeks and I just kept resetting it. Continued like this until we went on a long trip leaving Feb 21. We got home March 25th, and now it's tripping every few days.
The thing that's tripping it is getting worse. This sounds a lot like degradation of electronics.


Before I install a $53 replacement breaker, I'm thinking I should check more carefully for a problem that would cause enough leakage current to trip the breaker. I don't really want to slap that $53 breaker in and find the new one still trips.
Yeah, it's not the breaker. I have a saying: Ground faults only happen to other people. That's wrong, obviously :) I'm just lampshading this common viewpoint of "blaming the alarm".

If you presume that the detector is working properly, it changes the race.


Second, what would you add to this list:
My very first step would be unplugging everything from the circuit. You've still got garage door openers attached (I get it, you don't want to take em out of service). Well if you need to power those things, use an extension cord to feed them from a different circuit. (bonus points if it's a GFCI; because now you can see if the problem moves!)

My #2 is is to map the circuit more completely. Are you sure of *all* the loads on it? Any outdoor outlets? (a common place for trouble).


4) If nothing from above, disconnect downstream outlets from the first outlet in the circuit. Wait to see if breaker trips. If not, systematically re-connect outlets until breaker trips, to identify one receptacle. (This sounds excruciating).
That would be next. Divide and conquer, in a binary fashion. Break the circuit at the midpoint (remember to break BOTH hot AND neutral). See if the problem goes away. If it doesn't, the far half of the circuit is proven and can be struck off the list. Now look at the still-uncertain section and break it at its midpoint.


Not even sure if (3)(c) is a possibility. Could the insulation on a conductor be slightly damaged, a small nick, so that it might pass enough current to be detected as a ground fault?
Not likely if it's dry. That could be an issue for an outdoor outlet. Which circuit are your outdoor outlets on?
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My very first step would be unplugging everything from the circuit. You've still got garage door openers attached (I get it, you don't want to take em out of service). Well if you need to power those things, use an extension cord to feed them from a different circuit. (bonus points if it's a GFCI; because now you can see if the problem moves!)

My #2 is is to map the circuit more completely. Are you sure of *all* the loads on it? Any outdoor outlets? (a common place for trouble).
Awesome idea. There's no doubt about what outlets or loads are on this circuit. I mapped it out in the planning phase to be garage receptacles only (thinking that if I was ever running power tools out there and tripped a breaker, I don't want to interrupt anything in the house), and roughed it in per that plan.

I do have an outside recep just outside one of the garage service doors. That will be close enough to run an extension cord; 25 footer should do it, to first GDO. Then another to the second GDO.

This way I'll be able to remove ALL loads from the circuit.
Can monitor to see if the garage breaker still trips.
Can monitor the outside recep circuit to see if IT trips (this circuit also has a 20A GFCI in the panel) from the GDOs.
If the garage breaker continues to trip, and the outside circuit does not, the GDOs will still be available if I have to break down the garage circuit step by step to identify what is tripping the breaker.

I like it! :vs_closedeyes:
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Well, for all my talk about tracking down the actual cause of the issue rather than just throwing a new breaker in there... I threw a new $53 breaker in there. :plain:

I got distracted by work on my dirt bike, wife got tired of not being able to open the garage doors... finally asked me: "how long is it going to take you to connect the door openers to that outside outlet and trace down the problem?" Me: "well, hard to say...." Her: "...and how long would it take you to replace the circuit breaker?" Me: "About 15 minutes." That's all it took for her to make up my mind. :laughing:

The "bad" breaker had gotten to the point of tripping several times a day. Installed the replacement a week ago and hasn't tripped yet. Fingers crossed. :whistling2:
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