GFCI tripping with breaker ‘off’

[12VoltInstalls]

I have a weird thing with a long explanation post. If you don’t want the challenge in this problem just skip the post and move along. Solution is done but my posting here is for entertainment.

Because technically this is a camper trailer (RV). 99.44% stationary, offgrid solar, “improved” for winter use I posted here.

I’ve lived in this RV like five summers but 2021/22 was the very first winter. Working great. No really, I’m pleased.

I have a 20A GFCI outlet between a 1012LV-MK and the OEM breaker panel. Originally inverter was a Giandel 1200W PSW, and I’ve also used with a 2000W QZRELB PSW and a 2500W Giandel.
Over the years the GFCI has tripped maybe 5 or 6 times for unexplained reasons. No biggie- it’s working, right?

The other day I was just installing an outlet, nothing unusual, and had disconnected 120VAC. When I plugged the 1012LV back in the fans roared a moment which I thought was the fridge surge, but they kept running for 10 seconds until suddenly the GFCI tripped. I reset and the 1012 error-coded “Output Shorted”

I diagnosed by shutting off breakers etc but couldn’t stop the GFCI tripping and the 1012 reporting shorted output.
Eventually I discovered (I thought) the fridge was causing the tripping on Circuit2 so I plugged it into the pre-breaker-panel GFCI. No problems. But also discovered Circuit2 tripped the GFCI with -nothing- plugged in.

Turned off Circuit2 breaker. Reset GFCI. Discovered the GFCI would still trip with the breaker off if I plugged anything in that drew power. I could plug coffeemaker in but the GFCI instantly tripped if I switched it on.

Hmmm

So I went to tuck the wires into the JB on Circuit3 and the GFCI tripped. Uggh. Got out the meter again and discovered- after restoring GFCI- that the circuit only had power to the first outlet; the other outlets were fed by that first outlet. Turning power off I discovered that H was grounded, had no continuity between the source outlet and itself, and neutral was open.
? hmmm. ?

I determined that I should just cut the feeder wire at the source outlet and in the JB because I cannot replace that without major destruction but I do have access to feed from the end outlet… the wire was already disconnected at the feeder outlet except the bare Ground which I left for safety cuz I didn’t think it would matter, but when I pulled the wires to separate out the H and N to be sure I would cut the correct white and black the GFCI tripped with both black and white disconnected. No power there. What?!!!

HOW IS THAT POSSIBLE?!
​

I also discovered if I check Circuit2 - with the breaker off mind you- for continuity the GFCI trips.

I can only think a mouse or maybe something legacy like a nick in a wire installed at the factory in 1978?! or a staple somewhere finally shorted and ?somehow? shorted out and burnt a wire or wires in the other circuit, too? Dunno. Very weird.

The inverter is 1000W- that’s why my 15A breakers didn’t trip fyi- the MPP shuts itself down at 8.3A.

But how does a disconnected circuit trip a GFCI? And with no continuity to anything else except its own ground. A confusing thing to me. Or hidden/illegal/buried junction box?

What do you think? I don’t need a solution (I’m rewiring the two faulty circuits) but my head wants to know what the heck is going on.

​

 

[Checkthisout]

I have a weird thing with a long explanation post. If you don’t want the challenge in this problem just skip the post and move along. Solution is done but my posting here is for entertainment.

Because technically this is a camper trailer (RV). 99.44% stationary, offgrid solar, “improved” for winter use I posted here.

I’ve lived in this RV like five summers but 2021/22 was the very first winter. Working great. No really, I’m pleased.

I have a 20A GFCI outlet between a 1012LV-MK and the OEM breaker panel. Originally inverter was a Giandel 1200W PSW, and I’ve also used with a 2000W QZRELB PSW and a 2500W Giandel.
Over the years the GFCI has tripped maybe 5 or 6 times for unexplained reasons. No biggie- it’s working, right?

The other day I was just installing an outlet, nothing unusual, and had disconnected 120VAC. When I plugged the 1012LV back in the fans roared a moment which I thought was the fridge surge, but they kept running for 10 seconds until suddenly the GFCI tripped. I reset and the 1012 error-coded “Output Shorted”

I diagnosed by shutting off breakers etc but couldn’t stop the GFCI tripping and the 1012 reporting shorted output.
Eventually I discovered (I thought) the fridge was causing the tripping on Circuit2 so I plugged it into the pre-breaker-panel GFCI. No problems. But also discovered Circuit2 tripped the GFCI with -nothing- plugged in.

Turned off Circuit2 breaker. Reset GFCI. Discovered the GFCI would still trip with the breaker off if I plugged anything in that drew power. I could plug coffeemaker in but the GFCI instantly tripped if I switched it on.

Hmmm

So I went to tuck the wires into the JB on Circuit3 and the GFCI tripped. Uggh. Got out the meter again and discovered- after restoring GFCI- that the circuit only had power to the first outlet; the other outlets were fed by that first outlet. Turning power off I discovered that H was grounded, had no continuity between the source outlet and itself, and neutral was open.
? hmmm. ?

I determined that I should just cut the feeder wire at the source outlet and in the JB because I cannot replace that without major destruction but I do have access to feed from the end outlet… the wire was already disconnected at the feeder outlet except the bare Ground which I left for safety cuz I didn’t think it would matter, but when I pulled the wires to separate out the H and N to be sure I would cut the correct white and black the GFCI tripped with both black and white disconnected. No power there. What?!!!

HOW IS THAT POSSIBLE?!
​

I also discovered if I check Circuit2 - with the breaker off mind you- for continuity the GFCI trips.

I can only think a mouse or maybe something legacy like a nick in a wire installed at the factory in 1978?! or a staple somewhere finally shorted and ?somehow? shorted out and burnt a wire or wires in the other circuit, too? Dunno. Very weird.

The inverter is 1000W- that’s why my 15A breakers didn’t trip fyi- the MPP shuts itself down at 8.3A.

But how does a disconnected circuit trip a GFCI? And with no continuity to anything else except its own ground. A confusing thing to me. Or hidden/illegal/buried junction box?

What do you think? I don’t need a solution (I’m rewiring the two faulty circuits) but my head wants to know what the heck is going on. View attachment 126327

​

Does it trip when connected to shore power?

 

[PreppenWolf]

I would first test the breaker in another system or slot. Breakers go bad.

 

[EastTexCowboy]

If it's tripping the GFCI with the breaker for that circuit off, I'm going to say PreppenWolf is on the right track with it being a bad breaker. The only other thing that comes to mind is you may have a ground loop or a short somewhere that is putting current on the ground. Either way I'd say pull the GFCI and test the wires directly with the breaker off with a multimeter. Not an electrician but I've been shocked a few times.

 

[Bud Martin]

Since the breaker only disconnect the Line, what happen if you also disconnect the Neutral to the panel too?
Also if you check the AC Voltage between Neutral and Ground on the GFCI outlet with nothing connected to the GFCI outlet, do you see about 60VAC?

 

[12VoltInstalls]

Does it trip when connected to shore power?

Yes.

I would first test the breaker in another system or slot. Breakers go bad.

The breakers are 15A and do not trip at 8.xAmps/1000W. The AIO cuts out, however.
I forgot to mention I have one GFCI on what is essentially ‘shorepower’ with a switch to kill “grid” and the other GFCI is as drawn: between AIO 120VAC out and the breaker box. Usually only the one on the incoming shorepower trios, but 1/10 the one between AIO and breaker box as lso trips.

only other thing that comes to mind is you may have a ground loop or a short somewhere that is putting current on the ground. Either way I'd say pull the GFCI and test the wires directly with the breaker off with a multimeter. Not an electrician but I've been shocked a few times.

Yes, I’m suspecting bare/green/ground is maybe suspect to be seeing current.
More likely: there’s contact somewhere with aluminum siding; it’s conceivable there’s been a fault a long time… putting a metal box in place of a crumbling plastic box I think exposed the fault.

Since the breaker only disconnect the Line, what happen if you also disconnect the Neutral to the panel too?
Also if you check the AC Voltage between Neutral and Ground on the GFCI outlet with nothing connected to the GFCI outlet, do you see about 60VAC?

I’ll get back to you tomorrow - Need to hit the pillow tonight. I have seen the 60V from the Giandel; haven’t look at the MPP or reliable QZRELB

 

[12VoltInstalls]

Also if you check the AC Voltage between Neutral and Ground on the GFCI outlet with nothing connected to the GFCI outlet, do you see about 60VAC?

That’s typical of high frequency inverters but the 1012LV-MK apparently does not exhibit characteristic. 119.7VAC L1/H-N and (make believe?) 0.687VAC N-G

I’ve cut out the offending circuit that I believe is mouse chewed in some buried/unseen location, and pat-dried condensation from a junction box where a mouse tunnel pulled insulation from behind it leaving it cold. No GFCI trips since.

I also installed a non-audio electronic pest repeller. I cannot find how they were getting in- they being mice- they weren’t hitting the glue traps or victor traps or leaving evidence “inside” yet I heard them(it?) within the walls many mornings for a couple weeks. When I plugged this in I heard scrambling in a sidewall within seconds(!) but haven’t had another sound of chewing or scrambling around for the three days since. Actually a bit surprised; time will tell.
This type doesn’t emit high frequency sound but rather generates a pulsating signal over the wiring in a home that mice, arachnids, and some insects find annoying. I’ve used the audio ones in the past mostly with success so this is a new experience.

 

[Checkthisout]

That’s typical of high frequency inverters but the 1012LV-MK apparently does not exhibit characteristic. 119.7VAC L1/H-N and (make believe?) 0.687VAC N-G

I’ve cut out the offending circuit that I believe is mouse chewed in some buried/unseen location, and pat-dried condensation from a junction box where a mouse tunnel pulled insulation from behind it leaving it cold. No GFCI trips since.

I also installed a non-audio electronic pest repeller. I cannot find how they were getting in- they being mice- they weren’t hitting the glue traps or victor traps or leaving evidence “inside” yet I heard them(it?) within the walls many mornings for a couple weeks. When I plugged this in I heard scrambling in a sidewall within seconds(!) but haven’t had another sound of chewing or scrambling around for the three days since. Actually a bit surprised; time will tell.
This type doesn’t emit high frequency sound but rather generates a pulsating signal over the wiring in a home that mice, arachnids, and some insects find annoying. I’ve used the audio ones in the past mostly with success so this is a new experience.

How can a GFCI trip when it's not being powered?

 

[EastTexCowboy]

How can a GFCI trip when it's not being powered?

As far as I know it cannot. That's the logic behind there being a ground fault or some other issue which is putting current on the circuit.

 

[Danke]

I was installing a GFCI for kitchen. It immediately trips. Then I got spark from neutral when I was taking it out. Did a little investigation. I guess it isn’t uncommon in older homes to have two circuits share neutral. They call it “Multi-Wire Branch Circuit.”

 

[Checkthisout]

I was installing a GFCI for kitchen. It immediately trips. Then I got spark from neutral when I was taking it out. Did a little investigation. I guess it isn’t uncommon in older homes to have two circuits share neutral. They call it “Multi-Wire Branch Circuit.”

The circuit was powered.

 

[Danke]

The circuit was powered.

One of the two was. No volts on the hot wire going to GFCI.

 

[Checkthisout]

One of the two was.

Yes, that's how GFCI's work.

 

[12VoltInstalls]

That's the logic behind there being a ground fault or some other issue which is putting current on the circuit.

How can a GFCI trip when it's not being powered?

It can’t. The circuit behind it was what opened, not ahead of it.
The GFCI is on the feed/breaker side of the faults. One circuit was shorted H-G with no continuity between JB and outlet: burned off in a hidden location. Another circuit apparently had ‘some’ current it shouldn’t have.
Basically I put the GFCI there five years ago to protect against electrocution if Something Bad happened but it actually protected a dead short is how I’m seeing it which is just as good as far as I am concerned.

The AIO shut down on a shorted output error and the 1000W inverter in it can’t trip the 15A breaker in the box.