Hot/Ground reverse problem at GFCI

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Old 09-15-18, 12:37 PM
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Hot/Ground reverse problem at GFCI

So this morning, the power went out in our master bath. GFCI was dead and I couldn't reset it. Checked the panel and the circuit was not tripped.

The GFCI was old so I figured it was probably a dead GFCI. So I replaced it with a new one.

Still nothing. I plugged a GFCI tester and it showed a hot/ground reversal, which often can be just an open neutral. I checked the connections three times and everything looked good. So I started at the source.

Unless I am missing something, the GFCI is the first outlet on that line and then feeds lights in the bathroom, then three other bathroom outlets amongst three upstairs bathrooms. So I disconnected the GFCI and started at the beginning. I tested the line with a basic tester and there was current. But then once I attached the GFCI, nothing, same ground/hot reversal. I didn't attach the subsequent outlets on the line, just tried to plug the live line into the GFCI and see if I could get that to work. Triple checked the connections.

Nothing. So I am flummoxed. Could it be a bad GFCI again? Something at the panel?
 
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Old 09-15-18, 12:56 PM
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Sounds like way to many items on that GFI. I'm guessing an older house.

You need a meter or a two lead voltage checker to be testing. You need to check from the black to the white wire at the GFI receptacle. Since it sounds like you don't have power there (missing neutral) the GFI receptacle should not be setting either. A brand new receptacle comes in the tripped state and resets when the button is pushed in. No power = no reset.
 
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Old 09-15-18, 05:22 PM
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I should clarify about whatís on the circuit. There are two recessed cans on the circuit, so itís not a lot of lights on the circuit. 4 receptacles and 2 recessed cans.

I am also going to go up in attic tomorrow and follow the lines just to make sure there isnít something else on that line between the GFCI and panel. The second floor is largely wired through the attic and then dropped down the walls to feed switches, etc.

I tested the circuit using this:

https://www.homedepot.com/p/Klein-To...FQJ3wQodo8cNDw

I disconnected the GFCI and just tested the bare black to white wire and it showed a current. Should I check it with a better meter?
 
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Old 09-15-18, 07:07 PM
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A small basic analog meter is a good thing to do testing with. It supplies enough of a load to give true readings on a circuit. You can get one from the home improvement stores starting around $15.
Homedepot/Gardner-Bender-14-Range-Analog-Meter

At $21 from Klein..... this voltage tester is a good deal too.
Homedepot/Klein-Tools-Electronic-AC-DC-Voltage-Tester
 
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Old 09-16-18, 06:12 AM
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Suggestions for testing ground fault circuit interrupter receptacles:

1. Do not blame the GFCI unit first thing.

2. Connect just the line terminals to the power, leaving the load terminals empty for the time being. Verify that the test button works and plug something in, preferably something that draws at least 50 watts. Switch it on.

3. This test can also be done if the GFCI receptacle unit was already installed and does not work. plug something in and leave it switched on while you insert your voltmeter probes into the other receptacle. to check the voltage.

4. "Hot ground reversed" can mean that there is a loose connection in the neutral path upstream back to the panel. A loose neutral conneciton is suspect although not definite if you measure 120 volts hot to ground and a voltage much lower hot to neutral.
 
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Old 09-16-18, 08:48 AM
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I grabbed a cheap tester and ran what you guys suggested.

Hot to ground - got 120 volts

Hot to neutral - zero volts

As I said, I believe the GFCI is fed directly from the main panel so therefore somewhere along that line there has to be a break, correct? I am going to pull the panel cover off and see if there is a disconnection there and then climb in attic and follow the line coming out of the ceiling.

Someone suggested cutting half an inch off the neutral copper wire at the receptacle suggested that maybe the end might be worn? Does that even make sense?
 
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Old 09-16-18, 10:12 AM
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You are showing an open neutral. You'll need to check from the panel right to the first box.

If the copper wire was broken near the end..... it would pull right out of the insulation.
 
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Old 09-17-18, 06:04 AM
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Probably going to bring in an electrician at this point.

I got up in the attic and my initial impression of the GFCI being the first on the line from the panel is wrong. The circuit either splits or the GFCI is near the back end of the circuit. It appears the light above the sink or an outlet right outside the bathroom (non-GFCI) might be the first on the line.

What was odd odd was earlier in the day, I threw a tester in the outlet outside the bathroom and it showed open neutral. I went into the attic, dig around for a bit. Later, I checked the outlet outside the bathroom again and it was showing it was now wired correctly. Totally bizarre. So I threw the volt meter into the receptacle and it showed it was pulling only 75 or so volts. I may take the receptacle off and test bare wires later before bringing in electrician.

So so I have one receptacle pulling 75 volts and I checked the GFCI and it was zero volts hot to neutral and 120 volts hot to ground.
 
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Old 09-17-18, 02:34 PM
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You need to identify everything on the circuit so that you know which boxes to check in.
 
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Old 09-17-18, 04:07 PM
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I appreciate the help PJ. I think I have the circuit figured out. I started tracing the current backwards and removing receptacles and switches until I found the only box that still had power from the panel. Based on that, hereís how I think the circuit lays out:

- Non-GFCI receptacle (not in bathroom) is powered from the panel.
- From that box, circuit runs to light switch that has two switches for lights above sink and two eyeballs above tub.
- From that box, the GFCI plug (right next to light switches) is powered.
- Remaining two receptacles in bathroom run from that GFCI.

So after doing that, I tested the first box again with colt meter. I tested bare wires, directly from panel (as this was only box with power). Hot to ground was 120 volts. Hot to neutral was around 50-75 volts.

When I just nutted the hots and neutrals together at the source box (bypassing the non-GFCI plug), the light switch box and GFCI box then were powered. And like the non-GFCI box, hot to neutral was like 50-75 volts, hot to ground was 120 volts in both boxes.

So again, bad neutral line from panel? I checked the panel itself and saw no loose neutral wires, although didnít give a thorough check.
 
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