There are only a few possibilities here. One in the power distribution One with the appliances. Or no problem at all and misinterpretation of the data. WHen i get a chance, i will fluke some pieces i have laying around and see what the results are. If any reads high, i will put a leakage tester on them and recheck. Personally, i doubt that its in the wiring unless it has been tampered with.
Bob
That is the problem, you are an electrician and not into the electronics. Many devices will have some leakage to them . A digital voltmeter will show high voltages but do not take into account the current. To see if the device is really leaking enough current to be a hazzard to the user you need to use a special meter or load the meter you have with a resistor of a known value.
Some times the capacitors and surge supressors will become damaged due to old age or voltage surges. This can then become a big issue.
electronics.
Ok, master electrician. The GFCI compairs the current going into the device on the hot wire and comming out of the device on the nutral. As the mixer probably does not have a ground wire the GFIC will not detect any leakage to ground as there is no ground involved. If it did have a ground wire the gfic would be tripping if there was a leakage of a big enough current. A device can have a small ammount of leakage and not be detected by the GFIC . A very high impedance voltmeter will show some voltage. A good old Simpson
260 will show a much lower voltage than a digital meter if this is the case.Hate to tell you but the analog voltmeters are actually current meters and are calibrated in voltage. If you take care to look at the Simpson 260 you will see it is a basic 50 microamp meter and resistors are put in series with it to give a voltage reading. There is also a diode to convert the AC to DC for the basic meter movement. As analog meters usually have a much lower impedance they will read a lower voltage than the the digital meters if the voltage source can not supply enough current due to the impedance of the circuit.
I work in a large factory and deal with everything from low miliamp circuits to 480 3 phase circuits at 600 amps. In the last couple of months I have started some training on the 4160 volt and 13 K volt main feeders in the plant.
Aside from all the other suggestions, don't forget that the cable system gets its power from the cable itself. That's on the order of 75 volts send down the large center conductor of the cable. You might need a visit from the Cable Guy to check it out.
Sounds like induced voltage. Put a resistor, say 47k up to 470k, across those points and measure again. You can use a night light if you don't have any resistors. If the voltage goes away, it's induced voltage, which is harmless. If it looks gone, take the meter down to a lower scale, say 10Vac, and see if it still reads zero. If the voltage doesn't go away, and especially if it stays at the previous voltages, it's dangerous. Start disconnecting things one at a time until it goes away. I suspect it will go away. Hope you'll post back with the solution; interesting problem.
Better to measure voltage cross the bulb. Incandescents won't glow until they get to around 85-90V. If it's zero with the bulb, then it's just induced voltages. He said they were 2 prong outlets and thus no earth ground is present.
You must be a plumber, eh? Kinda smelly where you keep that head of yours?
BTW, I'm an electical engineer; so what? He DOES have the tools, he used them in order to post here, and he also has the advice to work that out without bringing in a hi-priced electrician (yet) to tell him it's induced voltages or worse yet a few thousand in repairs, most of which he probably doesn't need. IFF the equipment came as two-wire, he's fine. If he's fiddled with removing ground pins for two prong outlets eg plugged 3-wires into unearthed outlets, he's not likely to call in an electrician, is he? Thimk man, thimk! Yes, I said thimk! Pop
Good advice. But, whenever a person wishes to call in a contractor, I would never recommend against it. The only real problem here is the buffoon with his egocentric mouth-hole in gear without a running motor to drive it. Concensus usually wins out with most posters, so one of that ilk only causes a little momentary stress. It's also possible he's right but he's bypassing the simple things that might easily determine that an electrician isn't needed, and that it won't take digging into anything more than a light bulb or resistor to measure across in order to see what kind of current might be there. Besides that, he probably enjoys flames because he gets to show off the vocabulary his father taught him. Pop
I do suggest rechecking it with an older analog meter or add a 120V lamp across the circuit before testing. See what you get.
I agree with those who pointed out a number of issues like floating neutral that might be involved. You don't want to mess with this kind of problem, you want to fix it and now.
Luke :
Sorry to say that we are having a little problem with one or more local trolls. It should be easy for you to ID them and ignore them.
Turtle somehow get tied up in this. He has been long known for great advice and his gentleman manor. I suggest you ignore his responses to the troll(s) but do listen to his advice.
Note to Turtle.
The less attention given to those who have social problems, the better. Don't let them get you down.
If your antenna/cable is ungrounded, perhaps the shock was static from dry wind on the antenna and not related to your reading.
Are all these readings AC? Digital meters have such high impedence that they can show the voltage metal picks up from radiated electromagnetic energy. I'd get a resistor of 20,000 ohms or so and clip it between my test leads to see if the reading dropped a lot. I'd be concerned if it didn't drop much. If it dropped a lot I'd measure current.
Either way, I'd see if I got readings with all the circuit breakers turned off. Then I'd check the effect of turning on each breaker.
Choreboy
Sorry, but this is over my head to diagnose without seeing it. It can't be induced voltage because you don't get a shock off induced voltage. It can't be a floating neutral because you would be having other serious effects (lights way too bright, lights way too dim) from a floating neutral. And it can't be from your cable system because you don't have a cable system. And that exhausts this group's suggestions.
Obviously you have test more systematically to isolate the problem, but you already know that. Good luck.
Luke,
AC or DC voltage?
Doesn't sound like a problem with the TV antenna. To check, disconnect the antenna cable and measure for voltage between the center conductor and the screw-on F-connector. You shouldn't see any voltage, or maybe a volt or two at most (induction, meter inaccuracies, etc.).
If you are getting DC voltage from the coax coming from your TV antenna (not connected to anything), see if you have an antenna rotator or remote amplifier. These often get power from DC voltage sent over the coax TV cable. If that's the case, there should be an indoor transformer connected to the coax somewhere. Follow the cable back to the antenna to track it down.
That would lead me to believe the coax cable is grounded too, since the ground and coax connector are at the same voltage potential.
I wouldn't be too concerned about small voltages coming off the F- connectors, but you should not be getting any significant voltages off of the cases of your DVD player or stand mixer.
My first guess would be a faulty electrical ground.
Set your meter to AC voltage and go to a grounded electrical outlet in your house. Measure between the ground hole and each of the two "prong" holes. You should get about 100-130 volts between ground and the small "hot" slot, and you should get 0 volts between ground and the larger "neutral" slot. You should also read the same 110-120 volts between the hot and neutral slots. (You can buy inexpensive plug-in "electrical testers" at any home center to verify the wiring is connected properly).
The ground and neutral should be at the same voltage potential, as they connect to the same bus bar back at the main breaker panel. If you measure more than a few volts between the ground and neutral, you could have wiring problems, either in the house somewhere, or at the breaker panel itself. Time to call an electrician.
Even if the wiring is all connected properly, some old houses used metal water piping as their electrical grounds. It's possible that someone replaced plumbing at some point with plastic (non-conductive) piping. This could potentially leave you without a grounded electrical system. That's why it's not allowed by code anymore. You should have dedicated ground rods for your electrical system. Even if you have the ground rods, it's possible the wires running to them are broken somewhere.
If you are getting voltages outside of the numbers mentioned above, you may have a bad meter. Install a fresh battery and/or try a different meter. If you still get wild voltages, call the power company to come check the voltage to your house.
Also, be sure you are not touching the tips of the meter probes with your fingers. You can induce some wild voltage readings on sensitive meters just with your body...
Anthony
Assuming this case and the mixer works fine (and has NO internal leakage faults). Most mixers are two wire devices. That means the mixer has power. If that's the case, i see two possibilities. either the hot and ground are reversed and the mixer uses a polarized plug, or the ground on the receptacles (which is NOT used on a two wire appliance) is NOT grounded back at the service entrance. And the op is trying to use this ground which is not really hooked up to anything for his tests. Now, either of these should be an electrician issue. Maybe the house was a older house and was upgraded from two pin to three pin sockets without actually putting in and connecting the ground wire. It would not be the first time this has happened. I think you can legally do this in some retrofit cases by using a 3 pin GFI outlet with no separate ground wire back to the service panel.
Bob
Accuracy has nothing to do with it. Its the input IMPEDANCE of the volt meter. A digital fluke has a typical input z or 10M ohm or so. It can do this because it has a very high impedance OP amp buffer on the input side.
This phantom voltage is like getting shocked off the carpet by static electricity. The voltage might be there but its not enough to cause any harm.
Bob
Might be more than one thing wrong. I'll guess a resistive short in some appliance to ground and a partial or floating ground. Do you happen to have an electric hot water heater? A punctured heating element will use the water as a resistor and make the pipes and anything connected to them hot if they are not well grounded to the main panel ground. It's easy to check; just switch off the heater at the circuit breaker panel. Try switching other large applicances too -- stove, washer, etc.
But first, why don't you pull your main breaker and then check the voltage to see if the voltage is coming from your house. It might be coming from someone else on the same cable or water line.
I agree with the others that this is a potentially dangerous situation. It's O.K. to take a voltage measurement using insulated leads and you can flip circuit breakers (some people stand on a rubber mat when they are near the circuit breaker panel), but don't touch the cable connectors and something that may be live or grounded.
Get some professional help if you can't find the source of the problem with simple testing.
TKM
You folks (almost) sound like the US Congress ;-).
I appreciate all the responses. Thanks!
We're waiting on a call back from the electrician.
Meanwhile, some more detail:
I'm using an analog multitester (Radio Shack - Micronta). [And the wet finger test, which gives a definite tingle/mild shock only between a TV connector and antenna cable end or outlet screw.] It's a roof top antenna, no cable or satellite. Results are the same with the antenna grounded or ungrounded. I see no electrical connection to the antenna or cabling, though I can't see what's in the wall.
I tested nearly all the house outlets with a GB plug-in circuit tester, and all tested correct, hot/neutral are not reversed, no other faults, all are 125V hot to ground, 0V neutral to ground. Only two-prong appliances give a voltage reading, nothing off grounded appliances. I tested the TV, VCR, DVD and mixer unconnected to each other, and each on several different circuits.
Results, at various multitester AC voltage range settings:
MIXER: range mixer off mixer on
250V ~30V 25V 250/2V* ~30V 25V+ 50V 7V 7V 10V ~1.5V ~1.5V [*250 divided by 2 = 125 range. Meter needle is in near identical position on the 250V, 50V, and 10V range readings. Readings from mixer housing, handle, other parts.]DVD:
250V 50V 250/2V 50V 50V ~18V 10V ~4V [Needle in identical position on 50V & 10V readings. Same readings with DVD on or off. Readings from housing and output jacks.]VCR:
250V 30V+ 250/2V ~32V 50V ~17V 10V 4V [Needle almost identical position on 50V & 10V readings. Same readings with VCR on or off. Readings from F-connector and output jacks.]TV: off on across night light prongs
250V 75V 100V ~45V 250/2V 75V 100V ~40V 50V ~46V pegs 35V 10V pegs pegs pegs [Readings from various TV connectors/jacks. I didn't test night light with TV on.]I'm sceptical of some of these readings because the needle is in the same position. But I also don't know what that means.
We bought this 12 year old house 5 years ago, so newish wiring and AFAIK no DIY hackers fiddling with it like in the old houses I've owned ;-). We had an addition, with subpanel, put on 4 years ago. I've done little wiring on this house myself, other than adding one outlet, replacing some switches and light fixtures, and all seem okay far as I can tell. We had DSL installed a few months ago. There's nothing else unusual electrically, that I can tell. Lights don't blink or burn out, all appliances and electronics work properly.
The main panel and subpanel look right to me. I have some idea what's what as I've done some wiring before including running new circuits, though not in this house, but since I don't understand this problem I don't know just what to look for. I can't be sure, but I think this started recently, when the antenna reception started flaking. But I can't be sure since I never thought to test voltage on appliances before :-).
I just got home from work. While we wait for the electrician I'll try testing with appliances and circuits turned off and on.
Any other thoughts, suggestions, or other questions? Thanks!
pjm@see_my_sig_for_address.com wrote in news: snipped-for-privacy@4ax.com:
I don't see YOU offering anything better.
William W. Plummer posted for all of us...
i wasn't gonna get involved butttt WTF do you mean?
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.