GFCI failure -- mystery...?

[djmcmath]

So I'm putting in a bathroom, and I installed a single outlet with a GFCI breaker for protection.

All is well for months. I use the outlet while I'm putting in studwalls. The drywall guys use the outlet for their tools. No problems.

A few weeks later, after we've painted the rest of the floor, done some plumbing, and a few other things, the outlet is dead. Some research shows that the breaker won't reset.

Right. First question: Where's the water? So I trace out the portion of the wire that I can still see (most of it is in the wall now), and it's all good. The outlet seems fine, but just to make sure, I pull it completely out of the circuit. So the next test is: Will the breaker reset with just the wire, no breaker. Answer: No.

So I changed out the breaker, and the new breaker worked fine. I shrugged and said, "That's $60 lesson in breaker selection. Odd, but I'm sure it's not unheard of."

That was two weeks ago. I've used the outlet half a dozen times since then. I checked it tonight and it was dead. Breaker tripped and won't reset.


My thoughts? Maybe it's bad wiring? Or maybe I've installed the breaker wrong? ... That would be strange, because they're not that hard to install. The outlet could be bad? Except that swapping in a different outlet or trying it with no outlet doesn't fix the problem. Wiring? ... Or maybe wiring?

(sigh) Never seen this before, and google turned up a lot of results that say "Check for water or something plugged in that's bad."

Any thoughts? I'm at wits end here.

Thanks,
Dan

[HardDrive]

I feel for you man. The new GFCI outlets are SO freaking sensitive. I had the same thing happen to me . Never did get to the bottom of it because I had electricians redo the whole house.

[onewhippedpuppy]

Nicked wire leading to an intermittent short? It's not uncommon to have wires hit by errant drywall screws.

[look 171]

Try a regular outlet for a few weeks and see if that trips the breaker. What did we do 20-30 years ago without them to protect us? I lived through it as a kid, and so did many of us. Yes, the GFIs do just go bad and are just too sensitive. Now they have those goddam lock out things that make it almost impossible to plug anything into it without using all my strength and scratching up all the new outlet with only using it a few times. I hate plugging a tool into a new outlet when the place is done. it always scratch the new outlets when the home owners come home. We jsut run a cord now. its better and cheaper then having to replace it with new.


Oh, you might have a cut wire on the clamp when the electrical guys pull the wire too hard. I don't think its your wires.

[djmcmath]

Nicked wire leading to an intermittent short? It's not uncommon to have wires hit by errant drywall screws.

That was my instinct as well.

I may try running a normal breaker for a while. Or maybe a normal breaker with a gfci outlet? I don't know, I just really don't feel like re-running wires from a basement breaker panel to a second floor freshly-renovated bathroom.

Any other ideas?

Thanks,
Dan

[onewhippedpuppy]

I would try the regular outlet. You still have the breaker to protect the circuit.

[GWN7]

Did you buy both breakers that went bad from the same place? If so, it could be that they got a bad batch of breakers.

Try a normal breaker with a GFI outlet at the end. The GFI outlet would be cheaper.

[wdfifteen]

I have a question, as I'm not sure what's going on.

Do you have a circuit with one plain outlet and a GFCI breaker, or a circuit with a standard breaker and a GFCI outlet?

Is this outlet the only one on the circuit?

[gr8fl4porsche]

Assuming you are referring to a GFCI outlet on a standard breaker I have had the same problem.

Installed a new GFCI outlet for my sump pump, and everytime I would check on it, it would be tripped. Eventually it would not reset just like you describe. Replaced it with another brand and all has been well for about 6 months.

Try a different brand.

Apparently some products made in China are not up to spec, or so I have heard.

[djmcmath]

Originally Posted by wdfifteen

I have a question, as I'm not sure what's going on.

Do you have a circuit with one plain outlet and a GFCI breaker, or a circuit with a standard breaker and a GFCI outlet?

Is this outlet the only one on the circuit?

It is a GFCI breaker, a single wire (no junction boxes, lights, etc.) to a single receptacle. The receptacle is a normal $2 receptacle, not a GFCI, and it is the ONLY thing on the circuit.

That's the baffling part: It's literally just breaker-wire-outlet, with nothing else there to interfere. If it isn't the outlet (I've tried other outlets already), then it's either two bad breakers (possibly the same bad batch from the same Lowe's, purchased several months apart?) or something wrong with the interconnecting wiring.

Some other ideas that I'll try tomorrow morning:
1 - Pull the receptacle out of the circuit, remove the breaker, and check for even minute grounds between branches.
2 - Swap this GFCI breaker with another one of the GFCI breakers in the same panel. See if the problem follows the breaker or the circuit.
3 - Try a normal breaker (I do have spare 20A breakers) with a GFCI outlet (I'd have to go buy one). Or just a normal breaker with a normal outlet, for temporary.

[944Larry]

If it rains hard here in Florida and the humidity goes up all our GFI's go off line. I guess they're going their job but it is inconvenient.

[wdfifteen]

Originally Posted by djmcmath

2 - Swap this GFCI breaker with another one of the GFCI breakers in the same panel. See if the problem follows the breaker or the circuit.

That would be my next step. Cheap, easy, definitive.

[gacook]

Originally Posted by onewhippedpuppy

Nicked wire leading to an intermittent short? It's not uncommon to have wires hit by errant drywall screws.

My first thought was also a short somewhere along the circuit. Or possibly interference from a more powerful circuit it's running near? Dunno what your interior wiring situation looks like...

[intakexhaust]

Never had an issue with a GFCI but wait until your local code requires AFCI (arc fault receptacles).... ridiculous. Recent basement rehab and it was required. Total waste, PITA picky little bastards.

[javadog]

Install a regular breaker and a GFCI outlet? Cheaper?

JR

[Tobra]

Those things go bad, and are sometimes bad out of the box, in my experience.

[look 171]

Originally Posted by javadog

Install a regular breaker and a GFCI outlet? Cheaper?

JR

After reading through some of the stuff here, I was going to type the same thing.

I always fail to understand why people get so up tight about GFIs, now arc fault ? They are such PITA and sometimes is completely unnecessary.

[beepbeep]

I also had those experiences, and found out that GFCI was NEVER the fault.
They fill a function and are not "overly sensitive". Here in 230V/50Hz land GFCI is required to trip at 30mA earth current in order to be classed as "personal protection". Choosing the higher current rating will certainly make it less sensitive but also worthless as protection device as more than 30mA through body will likely kill you.

It's quite easy to troubleshoot. Break the circuit, remove the breaker and measure leads going FROM GFCI with ohm-meter. Resistance between earth, phase and null should be very high, almost infinite. If resistance in-between any of those leads is less than that, you either have a short (>10 Ohm) or a sneaky-leaker (10 - 100kOhm) due to water, a nail that went through the wire or something like that. First one is easy to fix, sneaky-leaker is dangerous one.

Common fault scenario is short between earth and null (or whatever you call it in 110V-istan) in outlet itself. It will not burn the fuse (as earth and null are shorted in the fuse box anyway) but it will trip the GFCI. Next most common scenario is "in between, not-quite the short" (the dangerous one), as it might electrocute you or start to burn without burning out the fuse. And this scenario is the one GFCI is there to protect you from.

[Rusty Heap]

GFI's suck.

end of message.



But then again, seem pretty robust under testing here.




GFCI test - YouTube

[look 171]

Originally Posted by Rusty Heap

GFI's suck.

end of message.



But then again, seem pretty robust under testing here.




GFCI test - YouTube

After inspection on my own house, they are all gone from my garage and all exterior plugs. The bath GFI plugs are there but not the kitchen.