Came home to no power in the garage (partially).
We have a GFI on 1 wall that runs the water heater (tankless), 3 garage openers & the outlet where my workbench/toolbox is. It's always been sensitive, little power blips would trip the GFI.

Got home from work yesterday & the garage wouldn't open. with all the weather we've had, I assumed [correctly] that the GFI was tripped.

Should be simple, go in garage, reset GFI, and be done with it.....3 hours later, it still wouldn't reset.

Pulled every outlet in the series & have it narrowed down to what I believe to be the first outlet after the GFI. Replaced the outlet with a spare, same result. Also tried swapping the GFI with another. Same result.
Turn off breaker & I'm still getting ~56v on the multimeter at the GFI.

Have some help coming over this afternoon to see if we can resolve it before calling in an electrician. Shame my stepdad [electrician] lives in Vegas, or I'd have him come by.

Luckily, I still have 2 active plugs on a separate GFI circuit & was able to run an ext cord to the water heater as a temp solution.

This message has been edited. Last edited by: P250UA5,

If you disconnect all the circuits after the GFCI outlet, can you get it to reset?

If yes, unplug EVERYTHING on all of the outlets, reattach the circuit and see if it will reset.

If yes, start plugging items in, one at a time and see if/when it trips.

My folks just had a GFCI outlet short out, and that circuit feeds the radon pump. We finally figured out the the shorting of the outlet (wire came loose and arced the outlet to the box) likely fried the motor of the radon pump as whenever the pump is turned on it instantly trips the GFCI.

Pump off, no issues with the lines, pump on, instant trip.

As I currently have it. I have removed all of the outlets in the GFI circuit.

It'll reset that way. Reconnect what I believe to be the first outlet, and it will no longer reset, with nothing plugged in anywhere..

If you're only getting 56V at the first stop (gfci) you have a power issue between the GFCI and the breaker box.

To clarify, I get 110v at the GFI with the breaker on.
I'm seeing ~55-56v at the GFI, with the breaker turned off.

This happened to me recently. If you are replacing an old Leviton with a new Leviton, be advised, they changed their polarity on the diagram a few years ago. You'll only notice it if you put both boxes side by side on their faces and compare with the diagram in the instructions. So you can't just slap in a new box and put the wires onto the same terminals.

However, that wasn't my issue. I had to call a pro and he found a dead neutral in the panel on the side of the house.

quote:

I'm seeing ~55-56v at the GFI, with the breaker turned off.

Your breaker's broken.

quote:

Originally posted by Shaql:

quote:

I'm seeing ~55-56v at the GFI, with the breaker turned off.

Your breaker's broken.

That would make for an easy fix.

quote:

Originally posted by Shaql:

quote:

I'm seeing ~55-56v at the GFI, with the breaker turned off.

Your breaker's broken.

Check for voltage at the breaker,
if you have voltage with it off, unhook the wire from the breaker and re-test for voltage with no wiring connected.

What's the results?

quote:

Originally posted by P250UA5:
It's always been sensitive, little power blips would trip the GFI.

GFCI's can false, but, unless you know the circuit and all that's attached to it is solid, this kind of thing should be regarded as a warning.

We have five GFCI breakers (two of which are also AFCI) and five GFCI outlets. Not a one of them has ever tripped due to power glitches. (We did have one, in the kitchen, that, if the range hood fan was turned on and back off quickly, would trigger. I understood why that happened. [Impulse noise.])

quote:

Originally posted by P250UA5:
Pulled every outlet in the series & have it narrowed down to what I believe to be the first outlet after the GFI.

"Believe to be?" This is electricity that can kill you or burn down your home. Don't "believe," know.

quote:

Originally posted by P250UA5:
Replaced the outlet with a spare, same result.

No surprise there. Plain old outlets are mechanically and electrically pretty damn simple. Short of obvious damage: Unless it was somehow water-soaked internally there's nothing that could have been wrong with the first one.

quote:

Originally posted by P250UA5:
Turn off breaker & I'm still getting ~56v on the multimeter at the GFI.

That is very wrong. The absolute most you'll ususally see on a deactivated circuit is a few volts resulting from noise. (E.g.: Coupling from adjacent cables. Aka: "Phantom voltage.")

Plug an incandescent lamp into the outlet and measure again. If there's still voltage there, then you know it's not that.

quote:

Originally posted by P250UA5:
Have some help coming over this afternoon to see if we can resolve it before calling in an electrician.

Unless this help knows a lot more than you about electrical wiring, please call an electrician.

quote:

Originally posted by Rick Lee:
If you are replacing an old Leviton with a new Leviton, be advised, they changed their polarity on the diagram a few years ago. ... So you can't just slap in a new box and put the wires onto the same terminals.

Eh?

Outlets have wider and narrower slots. The narrow slots are hot and the wider ones neutral. The hot and neutral wire connection points will be on the same sides as their related slots. Furthermore: The screw terminals are color-coded: Brass for hot (black), silver for neutral (white), green for safety/earth ground.

quote:

Originally posted by Rick Lee:
However, that wasn't my issue. I had to call a pro and he found a dead neutral in the panel on the side of the house.

Thus my caution to @P250UA5, above. If you know how electrical wiring is supposed to be, this is easy to detect. If you don't, it's a mystery.

Mysteries and electrical wiring are a bad mix

quote:

Originally posted by Shaql:

quote:

I'm seeing ~55-56v at the GFI, with the breaker turned off.

Your breaker's broken.

I'm happy to be corrected if wrong, but, TTBOMK, breakers are simply switches. They're on or they're off. There is no "kind of on but kind of off" state.

quote:

Originally posted by Excam_Man:

quote:

Originally posted by Shaql:

quote:

I'm seeing ~55-56v at the GFI, with the breaker turned off.

Your breaker's broken.

Check for voltage at the breaker,
if you have voltage with it off, unhook the wire from the breaker and re-test for voltage with no wiring connected.

What's the results?

This. If you have voltage at the breaker with it off replace the breaker

quote:

I'm happy to be corrected if wrong, but, TTBOMK, breakers are simply switches. They're on or they're off. There is no "kind of on but kind of off" state.

This is true. But breakers can break in strange ways. Thinking more about it, the breaker would probably be hot and this doesn't appear to be the case.

If this is the only circuit in the house showing 55v then that eliminates the power company and the panel.

The other option is that it is a phantom voltage. A hot wire is near a wire not hooked to anything inducing a phantom voltage of 55v.

If the breaker is off and you get a voltage it might be as simple as a 2nd circuit (the wiring) is in close proximity to another circuit and is inducing a current in the circuit in question.

OP: Rereading the thread, you have a tankless heater WITH 3 garage door openers and your workbench???

Is it a 110v circuit? That tankless should be on a dedicated circuit, shouldn't it? Even the smallest 10Kw heater would need like a 50A dedicated circuit. I doubt your GFI is rated to carry that current.

You might want to talk to an electrician.

Could be like my old house where the garage outlets also fed an outlet in the laundry room…it made sense when I looked at where the feed came from on that wall…you would have never figured it out. But I plugged lamps into every outlet in a room and began turning off breakers.

Yes, this GFI feeds 6 outlets (including the GFI).

The GFI is on a side wall (looking from the street, left side, about 1/2 down the length of the well) where my toolbox is & has the sprinkler controller plugged into it.
Further down that wall (near the back corner) is the tankless WH (gas), power is just for the display & ignition.
3rd outlet is on the back wall (center of the middle bay) of the garage, just have a small stereo plugged in there.
The other 3 are ceiling outlets. 3 car garage with 3 doors/3 openers. The ceiling outlet furthest from the GFI has the opener & water softener plugged into it.

Everything is how it was when we moved in, except for workbench things on the GFI plug (shared with the sprinkler controller), and the stereo.

Don't we usually end up finding an unknown outlet on the outside of the house that's full of spiders and grass clippings?

Clear the breaker and test that first.

quote:

Originally posted by Some Shot:
Don't we usually end up finding an unknown outlet on the outside of the house that's full of spiders and grass clippings?

Clear the breaker and test that first.

Winner winner!
Forgot about the outside outlet on the backside of the garage.
Getting a replacement & hoping that's it.

It's nearly impossible to get voltage with the breaker off.

I'd check for two things. First open panel cover and see if it's a three wire circuit. It it is then you could get voltage if the companion circuit has a loose neutral.

Second, it could be a lose or missing power company neutral, but that usually has very visible signs like A/C not working or when the A/C turns on then some lights in the house will dim and others would brighten.

If it is a three wire circuit, you must turn off both circuits to work on either or you can get shocked on the neutral and it will hurt a lot.

Just a thought. If you are using an auto-ranging DVOM, check to make sure it is not reading 55mv instead of volts.

My Fluke meters auto-range by default.

Replacing the outdoor outlet fixed the problem.

Still need to reseal the box/cover to the wall.

Local Ace didn't have any WR outlets, so may wait to reseal until I can get a WR in there.

quote:

Originally posted by Patrick-SP2022:
Just a thought. If you are using an auto-ranging DVOM, check to make sure it is not reading 55mv instead of volts.

My Fluke meters auto-range by default.

I was thinking the same thing .