I have a GFCI outlet and when the GFCI tester is plugged in, that shows this error code when it is tripped: greater than 30VAC, and open ground, open neutral.

I’ve replaced the GFCI, but I still get the error, so it looks like there is an issue with the wiring. The outlet works with no problems and when I trip the circuit, the power does goes off. I only get the error code. Any recommendations????

  • What tester are you using? – manassehkatz-Moving 2 Codidact Jan 21 at 23:53
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    I suspect you are using an "intelligent" tester, combined with a hot/neutral reverse (or some other strange problem). Get a simple Magic 8-Ball + GFCI tester and see what that shows. Need to know the lights before & after the GFCI test. – manassehkatz-Moving 2 Codidact Jan 22 at 0:15
  • I used the Klein GFCI Receptacle Tester with LCD homedepot.com/p/…. Before test lights were green. After test it showed red with the error: open ground neutral with >30vac. Ok thanks, I’ll have to get the Magic 8 ball. Also hot/neutral is not reversed and line load wiring is correct. – Sammy Jan 22 at 0:45
  • The tester you used is a microprocessor controlled simulation of the magic 8 ball. No matter how well designed, it is more susceptible to phantom voltage and various other problems – manassehkatz-Moving 2 Codidact Jan 22 at 0:50
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    There's a HUGE difference between "everything is working" and "everything is safe". Many combinations of electrical wire hooks will work and will kill you. That's why people (who don't know what they're doing) experimenting by trying different combinations of wires is a bad idea. They are more likely to stumble onto a "works, but lethal" combo than a "works+safe" combo. – Harper - Reinstate Monica Jan 22 at 0:50

That tester.

Don't read too much into it. It's a hokey-dokey tester. They work in new construction with all new products and open walls, because that work only tends to see a few types of problems. The product is tuned for that. When troubleshooting old work, they are wrong far more than they're right. That's bad because it send you on wild goose chases to hunt down a problem that isn't really there.

The original 3-light (red yellow yellow) testers were useful, simply because they were 3 neon lights each connected to 2 of the 3 pins. So just like that it would do 3 neon-light tests. They had a sticker that interpreted the 3 lights, and the sticker was pretty useless (all the problems I mentioned earlier).

This particular one eliminates the (rather useful) 3 lights and gives you a computer that gives you only the (rather misleading) interpretation. Send it back.

Your problem.

Honestly, the most likely problem with a "working, but tests badly" GFCI recep is a lack of a ground wire. On a proper 3-light "Magic 8-ball" tester that would test as "middle yellow only" (the hot-neutral neon).

It's perfectly legal to fit 3-prong receptacles that are ungrounded as long as

  • a) the receptacle is GFCI-protected somewhere, AND
  • b) the receptacle is labeled to indicate "GFCI Protected" and "No Equipment Ground".

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Therefore it's quite possible that the real defect here is the lack of that sticker, the one that says "No Equipment Ground". That is mandatory. It doesn't have to be the hokey blue stickers you get in GFCI packages.

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