I have one circuit in my home that I am getting 28 vols through the bare copper ground wire. This circuit has severallights on it. Any ideas what the problem could be? Even with the breaker off I am getting voltage. The electrical panel looks ok. Ed
First exactly how are you measuring this voltage? Between the ground wire and what?? What are you using to measure it? Why did you measure it? I am suspecting no real problems, but there is one thing that I can think of that could be a problem depending on the answers to my questions.
You probably have a (potentially dangerous) "floating (safety) ground."
If you're a novice, this would be a good time to call an electrician.
It sounds like the ground is open somewhere between where you are checking and the panel and you also have something leaking back intro that ground from another outlet. You have to isolate every box on that circuit and check them all. It may actually be coming down from a ceiling box and they are notorious for being overcrowded and having bad connections.
One way to prove phantom voltage would be to turn on one of the light switches on the ckt. If it goes completely away, it's just a phantom voltage. If there is still any voltage left, then it's time to call a repairman or at least a friend who knows how to tell when he's found a phantom voltage: It's very, very common, especially when high impedance meters are used for the measurement. Someone asked a bunch of questions that I don't yet see answered; that would help a lot.
Pop
Perhaps but is not an induced "phantom voltage" not enough to give one the "tickle"
IMO anytime you get a stray voltage reading AND the "tickle / tingle" feeeling, the problem is real.
cheers Bob
: > One way to prove phantom voltage would be to turn on one of the : > light switches on the ckt. If it goes completely away, it's just : > a phantom voltage. If there is still any voltage left, then it's : > time to call a repairman or at least a friend who knows how to : > tell when he's found a phantom voltage: It's very, very common, : > especially when high impedance meters are used for the : > measurement. : > Someone asked a bunch of questions that I don't yet see : > answered; that would help a lot. : >
: > Pop : : Perhaps but is not an induced "phantom voltage" not enough to give one : the "tickle" : : IMO anytime you get a stray voltage reading AND the "tickle / tingle" : feeeling, the problem is real. : : cheers : Bob :
True enough, but ... 28Vac shouldn't be anything most people would feel, but ... that would be a good indication of another problem. I don't recall anything about it "tickling" the OP, so I must ahve missed that part. Putting a load on the ckt, eg turning on one of the lights should show whether it's got any power behind it though. A solid
28Vac wouldn't light it up, but it would/should draw the voltage down to nothing if it's phantom; if not, then it's a very real problem, for sure. IMO, there's too little info to make any good analysis.Pop
On the safety ground? That seems pretty unlikely to me. The safety ground should have a low impedance path to earth.
I disagree. You can get quite a jolt from even a 12 volt source.
Yes, phantom voltage can be puzzling to some. I can remember my first high impedence VTVM, I found that it could read voltage between my left and and my right hand. I guess this is one of the principals of a lie detector.
I don't like that tingle. It is a sign that you could be in for a real shock, maybe the shock of your life. There are several possibilities and two of them can be dangerous and one is safe. I wanted to know exactly what kind of meter you used. The older multi meters would not have picked up on the third type of voltage but most of the new digital meters will. This one can give you a tingle but is very unlikely to do any damage.
I will have to go on with the other two. One is a floating neutral that is transferring over to the ground some how. How I don't know but it would tend to indicate a second fault as well. This one is serious and is often accompanied by lights that seem to brighten and dim for no reason. The other is a failed ground and that could kill if you get between it and a proper ground.
Finding these faults is not all that difficult if you have a good idea of wiring, but if you don't it is best left to the professional. Remember that it is an indication of something that is not right in two out of three cases. That means you can't count on things that might usually be safe being safe. I suggest you call in the pro.
Glad you have the second sentence, because this one had too many "not"s for me to understand it. :)
So all I would have to do in this situation would be to connect a 110V lightbulb from the ground wire to {another actual ground / the white wire / the black wire / ??} and keep the meter at the same points?
If the voltage drops to zero, no problem. If it stay about 10v real problem. ??
I've never noticed this problem so I don't want to buy a wiggy (willy?) for only one use.
Could I just use a low impedance meter, like one with a needle that is
20,000 or 50,000 ohms per volt. Would that load make the phantom voltage disappear?Remove NOPSAM to email me. Please let me know if you have posted also.
First, excercise caution. Avoid touching wires, ensure your circuits are properly disconnected. Sounds like common sense, but a lot of people (especially the experienced ones) ignore it.
I'm not certain what the required methods of running multi-phased circuits using single neutrals are. Perhaps someone can let us know if this is/was common practice for house hold wiring. I have gotten the general impression its not. Just so your informed, it is possible to run multiple hots on various phases using 1 neutral. If you open 1 hot this will not cut the power on the neutral completly.
At this point I'll assume your taking an interest in how to solve the dilemma, or find out exactly what is wrong. So I won't pester you with the "shouldn't do it" concerns others may have.
A suggestion which no one seems to have offered is to compare the resistance of 1 ground with another seperate ground run. It would seem to me that if I had an open on a ground wire then I wouldn't see a low impedance if I checked against another ground wire.
Seeing how I can't stand dealing with stray voltages at the best of timies, I'll simply stay away from this item. (I generally deal with low voltage signalling wire, and find that using a drain wire helps reduce stray voltages for my applications.)
JW
Under what conditions?
moist skin (e.g. sweat)
It all depends on where you get it and the frequency. AC will jolt you more than DC and if you are well grounded taking the shot on soft tissue like yje inside of your arm it will bite you. I damn near got thrown off the fire control deck of a ship getting 36v @ 400 hz in the soft part of my wrist on a sweaty day. It knocked the pee out of me.
A few things I would do: Check the voltage between that suspect ground wire and the nearest water pipe. Also check the voltage between the other wires in the switch box and the water pipe. Next I would shut each circuit breaker off in the panel one at a time and check to see if the voltage reading changes.
I would also go to a different part of the house on a different circuit and check the voltage in the same manner with the circuit off.
Let us know what you find.
How many wires are in the switch box?
I'm thinking that this particular circuit may be part of a three wire circuit. The voltage that you are reading is actually coming from the neutral because there is a load on the other leg. By shutting off the other circuit breaker the voltage should almost disappear. If this is the case I recommend that you tighten all of the neutral and ground connections in the electrical panel. There could also be a neutral connection somewhere on the circuit that needs tightening such as a receptacle.
John Grabowski
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