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Author Topic: Hot and Neutral swapped.  (Read 12942 times)

Kevin Maxwell

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Re: Hot and Neutral swapped.
« Reply #40 on: September 21, 2014, 05:03:05 pm »

The breaker panel should be-but possibly may not be a better reference.

What is the wiring method to the receptacle?  Romex? Metal conduit? PVC conduit?  Non-metallic methods in general should not be used in a "place of assembly"-but hot and neutral should not be swapped, either.

Using the receptacle box for a reference assumes that it is grounded (it should be!).  Obviously,that requires a metallic path back to the breaker box-if there is no green or bare EGC (equipment grounding conductor) then that relies on metal conduit.  However, even with metal conduit we must assume that there are no breaks-loose couplings etc.  We also must assume that the breaker box itself is grounded-either through an EGC with the feeder to it, or in the case of a main service panel through a box bonding screw-and it is not too uncommon to find those missing-especially in locations wired by people/volunteers that make mistakes like reversing hot and neutrals.  These are all basic things an electrician can verify-and honestly things I usually assume to be correct-until it appears that 2+2 is not adding up to 4, so then I go back to square one and start double checking everything.  Things like a box bonding screw are a 2 second check-and if you are watching me, you may not even realize I did so, but it is all part of understanding what should be happening.

JRs method works well as does a NCVT.

It seems to be BX or MC cabling clamped to the box and I didnít see a ground wire coming into the Box. So the outlet is picking up the ground from the box itself to the little screws that hold the duplex to the box. I used a Wavetek 10XL meter set to the AC safety tester mode and all of the lights lit up to and including the 110v light. The  black wire metered 120v to the box or to the white wire and the box to white wire metered nothing.

Hopefully I will know more after tomorrow evening.
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Jonathan Johnson

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Re: Hot and Neutral swapped.
« Reply #41 on: September 21, 2014, 11:45:24 pm »

Another possibility: when the metal jacket was removed from the cable, the insulation on a conductor was nicked and it's shorting out against the jacket. Or maybe when it was installed, no bushing was inserted between the jacket and the conductors, and moving the wires around caused them to rub against the sharp or rough edge of the jacket abrading the insulation to failure.

I fought a similar problem in my own home, in a wire that I installed, but it was NM cable. It frustrated me for quite a while trying to figure out what the problem was. It turned out I had nicked the hot wire and it was shorting out against the ground wire. When I'd pull the wires out of the box, the problem went away because the wires separated. When I pushed the wires back in, they came back into contact. But it seemed to be an intermittent problem; perhaps as the ambient temperature rose and fell the wires, through expansion and contraction, came together or apart.
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Stop confusing the issue with facts and logic!

Rob Spence

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Re: Hot and Neutral swapped.
« Reply #42 on: September 22, 2014, 12:33:37 pm »

You mention jumper wires? From where to where?
Is this the only outlet on the circuit?
Perhaps other outlets are also wrong and between this and the panel?


Sent from my iPad using Tapatalk HD
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Mike Sokol

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Re: Hot and Neutral swapped.
« Reply #43 on: September 22, 2014, 12:37:51 pm »

A TLA or ETLA is handy when repeating the same thing over and over but I feel it should be spelled out at least once in the post. TLA = Three Letter Acronyms Ė ETLA = Extended Three Letter Acronyms. ;D

WTF?  ;D
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Mike Sokol
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Frank DeWitt

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Re: Hot and Neutral swapped.
« Reply #44 on: September 22, 2014, 05:15:25 pm »

A TLA or ETLA is handy when repeating the same thing over and over but I feel it should be spelled out at least once in the post. TLA = Three Letter Acronyms Ė ETLA = Extended Three Letter Acronyms. ;D

So TLA is a TLA for a TLA  Id hat right?
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Kevin Maxwell

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Re: Hot and Neutral swapped.
« Reply #45 on: September 22, 2014, 11:57:22 pm »

I canít believe how stupid it was. The black wire had a nick in it and it must have touched the grounded box. I looked carefully at the wire and saw the nick. I rewired it with new pieces of wire and it is all fine now. It also seems to have cleared up the radio reception problem. In the attached pictures it looks very obvious now, but it was dark enough in the room that I didnít see it the first time.   

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Mike Sokol

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Re: Hot and Neutral swapped.
« Reply #46 on: September 23, 2014, 07:20:04 am »

I canít believe how stupid it was. The black wire had a nick in it and it must have touched the grounded box. I looked carefully at the wire and saw the nick. I rewired it with new pieces of wire and it is all fine now. It also seems to have cleared up the radio reception problem. In the attached pictures it looks very obvious now, but it was dark enough in the room that I didnít see it the first time.   

Thanks for posting the pics. Sometimes your best tool is a good flashlight. And hindsight is 20-20, so don't beat yourself up too much.
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Mike Sokol
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Mike Sokol

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Re: Hot and Neutral swapped.
« Reply #47 on: September 23, 2014, 09:11:32 am »

It also seems to have cleared up the radio reception problem.

The radio interference was likely caused by the black wire (which was actually the neutral wire) being shorted to building steel. And shorting a neutral or ground wire to building steel can contaminate your audio ground with all sorts of garbage. The hint that something was shorted to the building steel was the fact that reversing the swapped H-N wires tripped the circuit breaker.

Never assume anything...  ;)
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Mike Sokol
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Re: Hot and Neutral swapped.
¬ę Reply #47 on: September 23, 2014, 09:11:32 am ¬Ľ


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