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Discussion Starter · #1 ·
So my microwave is on it's own circuit and was working fine, until I was flipping breakers off and on looking for something else. When I flipped this breaker, the microwave stopped working. I pulled it out, and now it works when I plug it into another circuit. The tester showed an open neutral on outlet it had been in. I replaced the old outlet in case, but it still reads open neutral. At the panel, I traced the wire back from the breaker and found the neutral, which goes into the neutral bus with two other neutrals on the same terminal.
With the breaker off, the non-contact tester showed current on these three white wires, and there was a bit of a spark when I went to push the neutral in, to make sure it had a good connection. Flipping the breaker back on, I no longer get a hot signal.
Does this mean one of the other two wires is somehow bringing current to that neutral? Any ideas how this can be traced?
Thanks.
 

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With the breaker off, the non-contact tester showed current on these three white wires, and there was a bit of a spark when I went to push the neutral in, to make sure it had a good connection. Flipping the breaker back on, I no longer get a hot signal.
Good explanation of why you should never attempt to use a non-contact tester as a diagnostic instrument. Get a multimeter.
 

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Naildriver
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The non contact tester is picking up induced current and is not very good when used in a panel full of hot wires. You should be using an analog multimeter for better data. There should be only two neutrals under one screw at most, so moving one of the neutrals away to another hole and tightening back up on the screws you should get a better connection. Are you using the stab back connections on the receptacle? If so, remove the wires and put them on the coordinating screws for a better connection. Be sure to turn the breaker completely off then back on. Plug something into the receptacle and let us know what happens.
 

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Naildriver
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Correct. Our inspector allows one neutral and one ground under one screw. Mis stated in post. Thanks for the catch.
 

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Discussion Starter · #6 ·
I am aware a multimeter is better, the non-contact however was just to double check when I was tracing back wires. The neutral bus is on the other side of the box from the hot side, and a signal only registered at the three white wires on this terminal. It did not signal anywhere else in the neutral bus. The neutral bus is overloaded, there are no empty spots.
So is this likely just a question of the wire not making good contact?
 

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Our inspector allows one neutral and one ground under one screw. Mis stated in post.
Not to nitpick, but I think you mean one neutral OR one ground.

The is a bit different from what I am used to. We are generally allowed one neutral OR two grounds under each screw.


Edit: speaking of #12 or #14 grounds, but it is dependent on mfg listing
 

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Naildriver
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The is a bit different from what I am used to. We are generally allowed one neutral OR two grounds under each screw.
No problem. Yes, common convention is not mixing, but he will allow it, just not more than two each hole. I usually will add buss bars to keep from having problems, and you see more and more the panels coming with more bars from the manufacturer.
 

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I am aware a multimeter is better, the non-contact however was just to double check when I was tracing back wires. The neutral bus is on the other side of the box from the hot side, and a signal only registered at the three white wires on this terminal. It did not signal anywhere else in the neutral bus. The neutral bus is overloaded, there are no empty spots.
So is this likely just a question of the wire not making good contact?
The NCVT is registering because the neutral is still open somewhere.

Either it's still open at the micro recept, or possibly a MWBC, and you'll find the neutral spliced in another box
 

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Correct. Our inspector allows one neutral and one ground under one screw. Mis stated in post. Thanks for the catch.
Your inspector is allowing a code violation. One neutral per screw. This is clearly stated in the code. Multiple grounding conductors are allowed in unused holes within certain conditions .
 
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