I just replaced my 15 amp outlet with a new decora 15 amp receptacle. I noticed even before disconnecting all of the 14 ga copper wires that when I tested each neutral wire that two neutrals were hot.

Originally they had two neutrals wired nut together with a hook to the receptacle coming from one of the conduits. The other neutral came from another location. Even after resembling it and test it with the sperry stop shock it was green or wired correctly.

Why are these neutrals hot and if so should i separated the hot and wired nut those? I didn't use a voltage meter which maybe i should had. I did us a Klein non-contact tester. Again this was the original wiring from 40 yrs ago. Suggestions would be appreciated. I also replaced all of the wire nuts and cut and stripped away copper wire as well as adding some new wiring.

UPDATE: I took it all apart the 14 ga wire from the receptacle. there are only two conduit s that feed into this box conduit 1 and conduit 2. (See all pictures below.)

I then took my voltage meter and check each white neutral wire with my klein clamp meter alligator ears which showed zero except for one voltage reading of white with a black mark on neutral wire which was only a small or negligible reading. The blue wire in the back was for a split connection and was never wired up. Put everything originally back with only one hot black wire i mark with red tape.

Saying all of this, i noticed that if i disconnect the one neutral with the black mark all of my receptacles/outlets that are controlled by that 15 amp are turned off. Why? Why not that one to be off while the other receptacles should just be turned on. Why are the rest not working? Yes the sperry stop shock test works perfectly on this receptacle. Also used a breaker finder to see which two wires are truly connected to thar one 15 amp.

If that was run in a series could that be an explanation of when i disconnect that white neutral -black mark can cause 20 receptacles/outlets to shut off? Would appreciate the help. How could this happen? Yes it works and as i mentioned earlier in another question about adding another amp to split this 20 receptacles/fixtures/switches.

On second thought, i think this also happened with any outlet that i replaced with none of then working. Would have to double check that fact. Again i didnt do anything different but to replace the receptacles and switches as they had it originally wired. Thank you again.


conduit 1


bllue wires

white wire black marking

final connections

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    If the receptacle is connected, plug in a tester and see what the test lights' tell you. To make sure those neutrals are truly hot use a voltmeter and test them to ground. Commented May 1, 2017 at 22:04
  • Isherwood is right about the picture --will correct. Jim i will test this with a voltmeter. But if does have truly voltage in one of those neutrals what do you normally do? And why did the sperry stop shocker show green (wiring is correct) or why diid the non contact tester showed neutrals hot? Regardless, Will get back to it in a few days and let you know the results with a clearer picture and the results with the voltmeter. Real Bad back and had and this receptacle is behind a huge bookcase; otherwise i would do it tomorrow. I did notice that one of the neutrals had black markings on it!! Commented May 2, 2017 at 2:52
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    Larry, I think you should trust the "Sperry Stop Shocker" especially if the wiring seems to be working correctly to the extent of not tripping breakers, and lights and other receptacles on the same circuit are apparently functioning properly. I have had trouble with a non-contact tester showing hot when a wire could not possibly be hot. Probably I was getting it too close to a truly hot wire. Commented May 2, 2017 at 11:02
  • It had worked fir 4o years before, but to play it on the safe side i will test the white neutrals for safety and learning experience? Again thanks Commented May 3, 2017 at 5:10
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    Larry, if the wiring worked for 40 years, but is not working after you changed the duplex receptacle, then, almost certainly, you did not reconnect it exactly as it had been. You thought you were connecting it the same way, but you must have missed something and it's now connected differently. Keep the old receptacles for any one that you change and identify each one as to its location. It would also be a good idea to take a picture before you disconnect. Commented May 4, 2017 at 10:41

1 Answer 1


Larry, a white wire can be used as a hot and if so is supposed to be marked with black tape or otherwise marked black. You are calling it a neutral, but, if I understand your explanation, when you connect it to true neutrals and turn on the breaker it immediately trips. This means it is a hot.

Stop connecting it to neutrals. The black marked white must be feeding something. This is what I think, but I am not an experienced electrician and have never worked on anything but my own housen and it is wired in NM. Unless someone here can help you, I fully agree that it is time for you to call an electrician.

The only thing in my limited knowledge that I can imagine is that this black marked white is or was connected to a switch. This switch controlled a receptacle or half of the duplex receptacle. If the latter, the tab would have been broken and the other half powered directly. Do you have a switch near this box which seemingly doesn't do anything? Is it on? Even if the switch is off it may have been disconnected and the two wires connected together and the switch replaced. This would be contrary to code, but could have been done.

Does everything work if you just cap this black marked white wire? If so, just leave it capped and accept that you have an abandoned wire in the wall. If my suggestion is right, then one of the black wires goes to the same switch and it could also be disconnected with no loss of function.

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    "a white wire can be used as a hot". No, not in this case (wires smaller than 4Ga in conduit). If that white wire isn't a neutral, it's a code violation and it should be replaced with a wire of a correct color. diy.stackexchange.com/a/163727
    – nobody
    Commented Jun 18, 2020 at 14:48

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