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Finding gfi problem

389 Views 7 Replies 5 Participants Last post by  bob22
Replaced a powder room outlet with gfci. It tripped right away. Black to ground lights and neutral to ground does not with neon test light.
I used a circuit tester on other outlets on this circuit and they all test ok.
How can I find the problem tripping the gfci outlet?

I had load and line wired correctly.
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If you are feeding down stream loads, they may be on a shared neutral with another phase. Remove the load side wires and see if the GFCI stays on.
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With gfci it is vitally important that there be no inter connecttion between nuetral and ground after the gfci.
So no shared or borrowed neutrals.
And another common is the neutral wire making contact with the metal j box.
Also try (but be careful doing this) pulling the GFCI out of the box and see if you can reset it. I would put some electrical tape over the screws first though so you don't touch the live screws. Or pull it out (power off) and tuck it back into the box being very sure no ground or neutral touch each other and then power it up and try to reset it.



If the GFCI resets then more than likely when you pushed it back into the box the neutral touched the grounded box or bare ground wire. Although attempts have been made to make the GFCI slimmer they are still far too deep for most boxes and conductors are bound to touch when you push it back into the box. Put some tape on the live and neutral screws also before pushing it back into the box just don't wrap the tape around too many times or the width increases and it is hard to get back into the box. I normally just put a strip of tape over the screws and not wrap the tape around the GFCI completely.



Also, as mentioned above in another response remove the load from the GFCI side and see if it resets.
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Well, I did have the gfci out of the box when installing and testing. Also, box is resin so no metal box to contact with anything.
This is a relative's house so I'll not get to it till the weekend. Not the end of the world but I know when we go to sell the house, an inspector's report will have no GFCI in bathroom next to sink. Now the hard part tracking this down.
I'm doubting shared or borrowed neutrals since there has been no changes to the wiring since it was built in the 70s.
I wouldn't assume no shared or bonded neutrals on the basis of nothing being changed since install. You can find some weird things in wiring, even when done by pro's and passed inspection.
Also, but should be obvious; make sure nothing is plugged into any of the protected receptacles when testing.
If you only need protection for the bathroom, take the load wires off and put them with the line feed connections where they were originally.. If the GFCI still trips with only the line wires connected, it's defective.

That's as good as it gets.
If you only need protection for the bathroom, take the load wires off and put them with the line feed connections where they were originally.. If the GFCI still trips with only the line wires connected, it's defective.

That's as good as it gets.

Thanks; I'll update once I've tried some more of these great suggestions.
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