# diagnose house wiring problem



## brhodewalt (Jun 27, 2007)

All outlets on one circuit are dead. I have located the outlet closest (in the network) to the breaker box. At this outlet (two cables, each with one white, one black and a copper wire), testing with a digital multimeter shows 120V across the black line wire and the copper wire. All other combinations show 0V.

Two questions:

1) Am I correct in assuming that the voltage should be across the black and white wires (within one cable), and the lack of this probably points to the problem? (And is the voltage across black and copper normal?)

2) What problem am I likely seeing?

Notes:

I have replaced the breaker and tested for voltage there. I have tested an outlet on another circuit and found 120V across the white/black pair. Nothing obvious changed on the bad circuit before the problem appeared.

Thanks for any help.

Bruce


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## JohnWill (Oct 19, 2002)

Yep, in truth the *copper* wire is the ground wire, all the wires are copper. I'm assuming you are talking about the bare copper wire. The ground and the neutral (white) end up going to the same place in the breaker box, and your symptoms indicate the neutral wire is broken between the breaker box and the outlet in question. There should be no switching of the neutral wire on a 110V leg, it should go right to the box.


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## brhodewalt (Jun 27, 2007)

Thanks for your quick reply. Yes, I understand all the wires are copper. By "copper" I meant the bare wire.

Any idea what my options are for replacing an existing cable in a house built on a slab and with a partial attic?

Thanks.


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## Elvandil (Aug 1, 2003)

Wouldn't it be easiest to just find where the while, neutral is broken? The problem has to be betwwen the box and the first outlet. Is it even connected inside the box?


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## JohnWill (Oct 19, 2002)

Well, from the description, it sounds like the neutral (white) wire that is broken. I'd STRONGLY suspect that it might just be loose in the breaker box, or loose at the first hop. It's pretty unusual for a wire to suddenly break in a wall unless you're been drilling holes in the walls.


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## Elvandil (Aug 1, 2003)

JohnWill said:


> Well, from the description, it sounds like the neutral (white) wire that is broken. I'd STRONGLY suspect that it might just be loose in the breaker box, or loose at the first hop. It's pretty unusual for a wire to suddenly break in a wall unless you're been drilling holes in the walls.


Exactly. That's why I think a really good look around is appropriate before tearing down any walls and running new wire . If it were me, and though contrary to code, I'd short the neutral to the ground in the first box before I'd tear down any walls. It should be perfectly safe if a good connection is made. But I don't think I could sleep until I found the break, especially if any drilling was done and the other conductors may have been compromized.


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## JohnWill (Oct 19, 2002)

Yep, when I do wiring here, it is actually to code. Makes me very nervous to see what some people do with electrical wiring!


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## Skivvywaver (Mar 18, 2001)

Like JohnWill and Elvandil have pretty much said, the problem most likely is either in the box or the first outlet/switch on the run. 

Most of the time it is where the quick connect goes bad. When I wire, I use the lugs on an outlet or a switch and leave the quick connects out of the picture even if I have to pig tail to do it. Quick connects fail. Take the word of a guy that has about 28 years in homes and commercial buildings. Find the first outlet or switch on the run, test for voltage on the "hot side".


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## Elvandil (Aug 1, 2003)

JohnWill said:


> Yep, when I do wiring here, it is actually to code. Makes me very nervous to see what some people do with electrical wiring!


LOL. I got a call on a cold Winter day from a friend that couldn't get his furnace running. He had it connected by an extension cord running through the living-room, had bypassed the electric eye and all other safety devices, and had pushed the reset button so many times that oil was dripping through the floorboards. No one seemed too concerned--they just wanted it to start.

Luckily, it didn't start. I told him to call the oil company and went home.

PS. Not a *good* friend. I don't seek out idiots or anything .


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## JohnWill (Oct 19, 2002)

I could tell you some very chilling stories about my first house, involving cheap zip cord plastered into walls, and that was just the tip of the iceberg!

To get back on topic... *brhodewalt*, how did you make out checking the wiring and connections on each end?


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## Knotbored (Jun 5, 2004)

Get a cheap (a dollar or so) continuity tester (battery powered with a light bulb) and as much extra wire as you need to reach both ends of the white wire. Aligattor clip one end-touch the other. If bulb lights the wire has no breaks and problem is at the breaker panel. If the bulb does not llight then white wire is broken (or your cheap continuity tester is broken, so test it .)


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## JohnWill (Oct 19, 2002)

Like we said, it's probably at least 95% that just opening the two boxes at either end of the first run that will yield a solution. It's VERY rate for a electrical cable to fail inside the wall without some help.


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