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Another post-lightning strike problem: we have a run of outlets that no longer make a connection when you touch black & white wires, yet get a connection when touching black to the ground wire with a multimeter. A circuit tester reads "Hot/Ground Reversed." The outlet at the end of the run is totally dead. PLUS, we just upgraded the service TODAY and we are still having the problem, so it's not at the breaker. This was not an issue before the lightning strike. Ever heard of such a thing?

The wire coming out of the panel is a 3-wire bx. The circuit that the black wire feeds is just fine, yet the circuit the red wire feeds gives us the reverse/ground reading. I know that can be an open neutral, but if both hot wires are coming from the same cable, shouldn't both show the open problem? Any idea what could be going on? We get the bad reading at the first junction box after the panel, on the red wire coming from the panel.

  • We're testing circuits because none of the outlets work anymore and when we tested the wiring, we got the Hot/Ground Reversed reading. Can a GFCI getting fried cause the polarity to change? – K.Wilk Jul 15 '16 at 21:27
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    What kind of tester are you using (including model number)? I don't see how any tester would be able to detect a reversed hot/ground when connected only to the hot and ground -- are you sure it didn't say "Hot/Neutral reversed"? In any case, unless all 3 contacts are connected (hot+neutral+ground), an outlet tester may not give reliable results. – Johnny Jul 15 '16 at 21:40
  • We're using a "SNAPIT Correct" circuit tester. Plus, we're using a Southwire 10030S multimeter which has no reading when touching black & white, but reads 120v when touching black & ground. I know, it's a really strange thing. Had an electrician here today & he's never seen anything like it. – K.Wilk Jul 15 '16 at 21:46
  • The information about the multimeter test would be good to put into your original question, sounds like you have an open neutral. If the strike was bad enough to sever a neutral connection, I think this is the point where you call in a professional electrician to evaluate the entire house. – Johnny Jul 15 '16 at 21:48
  • Took your advice. Edited the original question. – K.Wilk Jul 15 '16 at 21:52
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Somewhere in your house wiring a neutral line is disconnected / broken / melted. You will need to open every electrical box and check the connections and splices. If you don't find anything there, do continuity tests between junction boxes. If the fault is between boxes you may need to open the walls up.

Your GFCI outlets are almost certainly dead. Any overcurrent big enough to sever a wire will fry a GFCI. Just replace the lot.

"Hot/Ground Reversed" isn't testable without a third connection. There should be full voltage between hot and ground - if not then you have an open ground. If you put a meter between ground and a known-good ground (like a metal water pipe) and see full voltage then you really do have hot and ground reversed (and a major problem - call an electrician).

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  • Most 3-lamp testers will show "Hot/Ground reversed" if the neutral's open. – ThreePhaseEel Jul 16 '16 at 0:00
  • Yes. Because any load on the circuit will pull neutral toward 120V, so it looks to the tester like there's 120V between neutral and ground. – Harper - Reinstate Monica Jul 18 '16 at 0:53
  • ANOTHER QUESTION: We've been trying to trace this crazy maze of wires, but still haven't been able to sort it out. In the trace, I found a bx cable that seems to be caved in. The cable is at an end of the run & that outlet was the only one that was totally dead (the others all showed reversed ground.) Can a squished bx go bad out of nowhere, when it's been there since, probably, the 60s or 70s? And could it cause the reversed ground on the rest, even tho it's the end of the line? – K.Wilk Jul 21 '16 at 0:34
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    UPDATE: Looks like the squished cable was the culprit. We took it out of the circuit & everything works again. – K.Wilk Aug 8 '16 at 1:15

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