What makes a GFCI "compromised"?

L

Lindberg

Final Approach
Joined
Sep 25, 2013
Messages
7,658
Location
North Texas
Display Name
Display name:
Lindberg
We have a few electrical outlets on the exterior of our house, all fed through one GFCI. It used to trip whenever it rained. I crawled around under the house and checked for any loose or exposed wires and found nothing unusual.

So I replaced the GFCI. It was fine for awhile and then tripped and wouldn't reset the red light was blinking, which, according to Eaton, means the self test failed, and if it won't reset, means the GFCI has been "compromised."

So I replaced that one yesterday with a new one rated as "Weather Resistant." It rained last night. Today the new GFCI is dead. The original GFCI, without "self test" would reset after it tripped. These new ones seem to be one-time use.

The GFCI is mounted in a box on the outside of the house an has a cover rated for wet locations. There was condensation inside the cover this morning, but neither the other nor the box were went when I pulled it out.

What gives?

Is it possible to get GFCIs without self-test? Would it make a difference if I replaced the outlet with a normal outlet and just put a GFCI breaker in the panel?
 
Last edited:
Might be that the old GFI was fine, and that there's a moisture or humidity dependent fault on the load after the GFI. That fault could still be there, which won't allow the new GFI to reset. Troubleshooting step would be to unplug everything downstream, and have someone do a high-pot test on that line, specifically from hot to ground. Could be bad cable, damage from metal staple or clamp, or a bad outlet. High-pot puts 500 or 1000V DC on the line and measures resistance. It's usually enough to identify something as bad that's marginal or intermittent at 120V. If the cable looks ok, no chew marks or anything, and it's UF or Romex, my bet is over driven metal staple, or sharp edge on a clamp.
 
Lindberg said:
We have a few electrical outlets on the exterior of our house, all fed through one GFCI. It used to trip whenever it rained. I crawled around under the house and checked for any loose or exposed wires and found nothing unusual.

So I replaced the GFCI. It was fine for awhile and then tripped and wouldn't reset the red light was blinking, which, according to Eaton, means the self test failed, and if it won't reset, means the GFCI has been "compromised."

So I replaced that one yesterday with a new one rated as "Weather Resistant." It rained last night. Today the new GFCI is dead. The original GFCI, without "self test" would reset after it tripped. These new ones seem to be one-time use.

The GFCI is mounted in a box on the outside of the house an has a cover rated for wet locations. There was condensation inside the cover this morning, but neither the other nor the box were went when I pulled it out.

What gives?

Is it possible to get GFCIs without self-test? Would it make a difference if I replaced the outlet with a normal outlet and just put a GFCI breaker in the panel?
Click to expand...
Maybe it is an AFCI. Those things can be pretty tweaky. Some codes require them now instead of GFCI. They're expensive.
 
Any underground cables downstream of the GFCI (say, to a garage?). When I bought the current house, the garage circuit used to trip the actual 15 amp breaker (not some wimpy GFCI) when we had enough rain.

I would start by disconnecting the "load" wire from the GFCI and see if it will then reset. But I ain't no electrician.
 
Sometimes it's best to hire a professional. A visit from your favorite electrician may be the way to go. Just ask Clark Griswold.
 
Half Fast said:
Have you examined the downstream outlets? Maybe something the GFCI is protecting is taking it out.
Click to expand...
They've all been replaced, but I will definitely check them again.

Albany Tom said:
Might be that the old GFI was fine, and that there's a moisture or humidity dependent fault on the load after the GFI. That fault could still be there, which won't allow the new GFI to reset.
Click to expand...
I disconnected the load side and it still wouldn't reset. The red light keeps blinking, which Eaton says means the GFCI failed the self test and is "compromised." So whatever the issue is, it's not just tripping the GFCI, it's rendering it inoperable.

Capt. Geoffrey Thorpe said:
Any underground cables downstream of the GFCI (say, to a garage?).
Click to expand...
Nope. The garage has its own subpanel.
 
@Lindberg

A GFCI measures the current going out the hot, and coming back on the neutral.

If they aren’t the same, it means that current from the hot is leaking somewhere and isn’t registering back on the neutral, so it trips. Arc detectors are different, and look for the high frequency RF generated by an arcing short somewhere.

Fluke has a nice guide here: https://www.fluke.com/en-us/learn/blog/grounding/chasing-ghost-trips-in-gfci-protected-circuits

The staple, nail, or drywall screw mentioned before can be one cause. Doesn’t need to short, just needs to be touching the hot and draining away a few milliamps.

Degraded insulation can be another.

The article suggests how to measure for leakage.

If you can’t find it that way, I’d break the circuit near the first junction and see if it still trips. If it doesn’t, keep moving downstream until you find the suspect section.

I forgot about capacitors in the circuit Fluke mentions as well. As the capacitor is charging, there may not be an equivalent flow on the neutral that can trip it.
 
Lindberg said:
They've all been replaced, but I will definitely check them again.
Click to expand...
They're not necessarily faulty. Maybe one's getting soaked when it rains, which results in the GFCI tripping.

When I first moved into my house, I was perplexed by the GFCI in the bathroom tripping for seemingly no reason. Turns out there's an outside outlet nearby that's protected by that GFCI, and its box was leaking and letting that outlet get wet.
 
The most common GFCI failure is when people install then and put the incoming power on the LOAD terminals instead of the line. With the old dumb GFCIs, that put unprotected voltage on the plug (though you'd have realized that the test/reset didn't work). The newer ones detect stupid installations like that.
 
flyingron said:
The most common GFCI failure is when people install then and put the incoming power on the LOAD terminals instead of the line. With the old dumb GFCIs, that put unprotected voltage on the plug (though you'd have realized that the test/reset didn't work). The newer ones detect stupid installations like that.
Click to expand...
It's a good thought, but this one was wired correctly. And it worked when first installed.
 
luvflyin said:
Maybe it is an AFCI. Those things can be pretty tweaky. Some codes require them now instead of GFCI. They're expensive.
Click to expand...
That's all you can get around here. Very finicky; if they stay closed, your circuit is certainly good!
 
My experience has been that GFCIs sometimes simply fail for no apparent reason.

But they definitely don't like water.
 
Lindberg said:
Is it possible to get GFCIs without self-test? Would it make a difference if I replaced the outlet with a normal outlet and just put a GFCI breaker in the panel?
Click to expand...

I had a similar problem and I went through and added an extender ring with a gasket (and some silicone) to each outlet. Turns out some moisture was seeping in and somehow tripping things. Haven't had a problem since.
 
Ventucky Red said:
I had a similar problem and I went through and added an extender ring with a gasket (and some silicone) to each outlet. Turns out some moisture was seeping in and somehow tripping things. Haven't had a problem since.
Click to expand...

I had a similar situation. A slight bead of clear silicon around plate worked. As others have said, several possibilities but that worked for my situation. The gasket that came with outdoor box just didn’t do it. Could have been a slight kink in gasket that i didn’t catch.
 
You must log in or register to reply here.
Back
Top