House wiring problem

Dave · 2010-04-02T18:45:20+00:00

Question for the gurus. I just tested my housewiring (at the wall outlet) and found that I have 120V AC between the hot and return, only I can't tell which of the top two "slots" is hot and which is return. They both show 59.4 VAC with referrence to the third (GND) terminal, on the bottom. Huh? Anyone have any idea what might be going on with my house wiring? It's an old house, built in '49 or '50, and has had numerous pieces added and modified. I was in the attic once, installing the wiring for a bathroom outlet, and got bit by the *white* wire, which should have been my first clue something was wrong. When I asked someone else about that though, was told that it might be normal, depending on what had been put in place. :/Any ideas or feedback are welcome. Hoping someone can explain this. Also hoping I don't have to rewire my house...Dave

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Dave 16 years ago

I didn't say it couldn't *be,* I just said it couldn't be *correct.* And it's not. That's why I suggested you have an electrician check it out. It sounds like maybe the equipment got inadvertantly connected to two different circuits somehow, which is a code violation, as there needs to be a single disconnect for each circuit. Otherwise if you kill the breaker marked "A/C" and don't subsequently test it, you could get a nasty surprise.

Since you apparently have a meter, I would do the following: turn off each breaker one at a time and see if there's voltage on the wire connected to the output of that breaker. If there is, you got a problem that ought to be fixed.

nate

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Aah. My misunderstanding. I'll check it out as you describe, with my analog meter. That will at least point me in the right direction for isolating the problem, I would think.

Many thanks.

Dave

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Tony Hwang 16 years ago

Hmmm, I just ;et my two fingers on my right hand tell. LOL!

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David Nebenzahl 16 years ago

On 4/5/2010 11:08 AM Tony Hwang spake thus:

It really doesn't matter in this caes: either type of engineer could

*easily* give the correct answer here (what size resistor to use to eliminate phantom voltage readings and not burn up or explode). In fact, it doesn't even take an engineer. Lotsa DIY types like myself know Ohm's law and the formula for power, which are the only two pieces of information necessary.

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David Nebenzahl 16 years ago

On 4/5/2010 12:33 PM Tony Hwang spake thus:

?????????

[I'd laugh if I knew what the joke was]

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Nate Nagel 16 years ago

old school electrician, licks two fingers and places them across two terminals. "yup, feels like about 120."

seriously, I've seen it.

nate

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Roy 16 years ago

Lick fingers, place them across two terminals and then touch GROUND with other hand and BINGO possible electrocution. Bad enough when it happens accidentally but to deliberately do it is dumb. I was using an old BD hand-held saw in a barn once and touched the saw frame on a stanchion accidentally and it threw me and the saw to the ground in a flash. Even 110 volts can kill.

=3D=3D

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aemeijers 16 years ago

Chuckle. Most amusing 110 bite I've had (and there have been several), didn't actually zap me directly, but I still damn near wet myself. I was about 15 (Child labor laws? Huh?) and nailing baseboard in a dishwasher cubbyhole. Swung the hammer back, and saw a flash of light and heard a big ZAP. Dumbshit electrician had heated the kitchen strings w/o capping the end of the romex that would feed the dishwasher. Had a few choice words for him, even at that young age. Figured out which breaker killed kitchen, pulled it, and then had to saw the cable off my hammer where it had neatly arc-welded itself. Good thing it was a glass handle, I guess.

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David Nebenzahl 16 years ago

On 4/5/2010 7:05 PM aemeijers spake thus:

Well, since we're talking near-electrocutions here, the last shock I got (couple years ago) was 277 volts. (Had never heard of that voltage before working on a friend's shop with commercial lighting.) I contacted hot & neutral with one hand while standing on a stepladder. Zazzed me up good, but didn't throw me off the ladder. Worst shock I've ever gotten.

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bud-- 16 years ago

If I remember right this is the thread that has "phantom voltage" and at least one person suggested a resistor between the meter leads.

I just got a Fluke toy catalog, and they have a module that plugs into the meter with the leads plugging into it that does just that: Fluke SV225 stray voltage adapter

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It maintains the Category rating of the meter - which should be of interest to anyone who is employed (under OSHA) that makes measurements on power circuits.

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House wiring problem

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