House wiring problem

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It has happened to me on two different occasions. It's also happened to a lot of regulars here.
Maybe you have a really advanced digital meter that isn't affected.
Any time wierd voltages pop up, an analog meter should be used to double check a digital meter.
http://en.wikipedia.org/wiki/Phantom_voltage
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On 4/2/2010 2:45 PM mike spake thus:

Nope, I've got a Harbor Freight el cheapo (think I paid $3 for it). So how is it that I got completely accurate readings of my AC line voltage with it?

Sorry, I don't do Wikipedia (the "encyclopedia" that can be edited by any pimple-faced 7th grader).
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Fine, don't believe Wikipedia. Search Google for thousands of incidences of people who have experiences with ghost or phantom voltage using digital meters.
Have a good weekend, David.
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On Fri, 02 Apr 2010 15:53:44 -0800, David Nebenzahl

Just because YOUR cheap meter worked right when you tested YOUR circuit doesn't mean SOME other cheap meters won't misbehave or misread on SOME circuits - but I'd also lean towards it being a floating neutral (did I say floating ground in my first post??? - not sure - but floating NEUTRAL is what I meant to say.

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wrote:

Hmm. Floating ground I think I understand. Floating neutral? Please tell me, what is this?
Thanks,
Dave
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The neutral is supposed to be grounded at the panel That holds the neutral to ground potential. If the neutral is not grounded it can be either high or low from ground (the ground can be at a higher potential than the neutral due to ground leakage) Quite common in rural areas - where you can sometimes get a shock from a safety grounded device to "eath ground" - and cattle will stop drinking from their water bowls because the grounded bowl and earth ground are at different potentials - giving them "discomfort" when drinking.
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On Apr 2, 9:20pm, snipped-for-privacy@snyder.on.ca wrote:

If anything, a cheap digital VOM may be less likely to show a stray voltage. It isn't actually a case of misbehaving or misreading. The issue is digital VOMs have very high input impedances and hence present virually no load to the circuit being measured. In other words, they are taking a true measurement and NOT disturbing the circuit. The older analog VOMs had lower input impedances. And I wouldn't be surprised if some of the cheap $10 digital ones do too.
Still, I have to agree with David that the incidence of this occuring may be over reported. I have an excellent Fluke VOM and can't say I've seen this to be much of a problem. I would suspect that in at least some cases, something other than just having a true unconnected, floating wire picking up induced voltage is going on. Which is to say, somehow, somewhere, that wire is connected through some high resistance to some other live circuit.
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David Nebenzahl wrote:

If I have to look up something on Wikipedia, it's likely that the pimply-faced 7th grader who wrote the article knows far more about the subject than I.
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On Fri, 2 Apr 2010 15:45:53 -0700 (PDT), mike

Or simply put a half meg-ohm or higher resistance across the leads of your digital meter. It will "kill the Phantom"
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On Fri, 02 Apr 2010 21:14:33 -0400, snipped-for-privacy@snyder.on.ca wrote:
[snip]

It would be a good idea for meters to include such a feature. If the reading changes, you know you've got a problem.
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In this case, the OP got that voltage from each blade, to ground. So, it's not a ghost voltage. One of those oughta been hot, the other oughta been neutral.
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On 04/02/2010 07:37 PM, David Nebenzahl wrote:

It's not a problem, it's just the way that it works. It makes sense once it's explained.
The OP, I am 99% sure, *has* no ground, so that's why he isn't reading 0V between neutral and ground. His situation is more analogous to sticking one probe in the socket and just holding the other one in the air.
nate
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On 4/2/2010 4:00 PM Nate Nagel spake thus:

>

Agreed; the ground pin of his outlet is wired to nothing.

So why didn't that happen to me when I took my measurements? I put one probe in the socket, in the hot side, and the other in the air, and I got 0.0 volts.
Look--I understand the concept of phantom readings, and I know they're a problem under some circumstances. I just don't think they're as ever-present as some folks claim. I certainly have taken many accurate measurements using a DMM (and yes, comparing them to an analog VOM and gotten exactly the same results).
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On Fri, 02 Apr 2010 17:36:40 -0800, David Nebenzahl

The air is not capacitively coupled to the other two current carrying leads the way it is in a receptacle where they are a fraction of an inch apart. Since a floating ground would be equally coupled to each of them the reading he gets makes perfect sense. The other place you see a reading like that is when you have an RF filter and no ground connection (like an ungrounded PC) The baseplate will be at exactly half the line voltage.
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That is the difference between using a Digital Multimeter that can be safely used to determine the presence of line voltage on electrical wires namely a "low impedance" multimeter and the incorrect use of a high impedance multimeter which will incorrectly read "voltage" because of the capacitance effect being amplified by the length of the wiring in the circuit being measured...
Most cheap digital multimeters are intended to be used on small electronic circuits and circuit boards and not for use on testing long wiring runs like you would see in houses (feet compared to less than an inch/es on a circuit board)...
Since you don't do wikipedia (not even to use the referenced source materials for background verification of the articles) here is a reference: http://www.nema.org/stds/eng-bulletins/upload/Bulletin-88.pdf
~ Evan
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On 4/2/2010 10:50 PM Evan spake thus:

Then explain why my cheap DMM gave *perfectly accurate readings* on my long wiring runs. I'm listening.
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On Sat, 03 Apr 2010 00:17:08 -0800, David Nebenzahl

It all depends on how the wires are terminated. If one is solidly grounded and the other has no connection at all you have an antenna and a high impedance meter will register voltage. The amount of voltage will depend on how well the wire gets coupled to the fields around the house. Cheap really has nothing to do with it. Our $300 Fluke meters had the same problem. Guys who were used to the Tripplets we had called them "random number generators".
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On 4/3/2010 5:45 AM snipped-for-privacy@aol.com spake thus:

Well, OK, but I cannot believe that a DMM is going to pick up a false reading of *59 volts*. 59 millivolts, sure, but the OP insists that his meter is telling him there's 59 volts between each of hot & neutral and ground. This cannot be due to stray induced voltage.
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On Sat, 03 Apr 2010 09:52:55 -0800, David Nebenzahl

Yes, it can. Let's say there is a ground wire connected at the outlet but disconnected at the other end of a long piece of romex. There is a small amount of capacitance between that disconnected ground and hot as well a the same amount of capacitance between that ground and neutral. That would effectively create a voltage divider and show 50% of the voltage on the ground wire.
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snipped-for-privacy@neo.rr.com wrote:

Hi, Proving whether it is real voltage is simpe, just hook up a light bulb. If it lights up it is real voltage if not, it is nothing.
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