75 Volts off TV F-connector?

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pjm@see_my_sig_for_address.com wrote:

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.
http://www.alfaelectronics.com/FLUKE70.htm
That kind of high z input will allow a phantom voltage to read. so it has NOTHING to do with accuracy, and every thing to do with the load the meter puts on what is being measured. Older analog meter have a mid level impedance. from 1000 ohms to 50K or so. Depends on the model. Most have no input buffer amps (Older VTVM excepted), so there input impedance is a combinations of the meter movement and the voltage divider resistors used for the voltage ranges. This mid level impedance is enough of a load to make these phantom voltages disappear. Phantom voltages have voltage potential, but little current drive potential. A phantom voltage in black box form would be a voltage source with a VERY high resistor in series with the voltage source. So it cannot drive much current into a load.
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

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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
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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!
--
Luke


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pjm@see_my_sig_for_address.com wrote in

I don't see YOU offering anything better.
--
Jim Yanik
jyanik
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As I stated, that depends. Sorry, see nothing to respond to there.
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--
Let someone else do it
I\'m retired!
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pjm@see_my_sig_for_address.com wrote:

Sorry. You are wrong. Way wrong. Almost criminally wrong.
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Luke wrote:

First, the 75V on the antenna connector COULD be correct IF the antenna is a satellite TV antenna. Voltage actually travels the cable to drive the circuitry in the LMB.
Second, the voltage measured here, there, and the other place is dependent on the impedance of the meter and whether a load is active. Clamp one lead of the meter to ground and hold the other lead between dampened fingers. Bingo! Two to fifty volts on a sensitive meter.
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Where you find voltage, then switch the multimeter to current. That number is also important. For example, if the meter measures microamps, well that typically is not enough to be a danger but would also not cause 'wet finger tingle'. Milliamps or (real bad) amps of AC current tell you more. Based upon what that meter is doing, the current leakage is probably in the milliamp range.
Unfortunately, your meter sounds like something that has no current readings. Therefore put a 100 or 1000 ohm resistor between those meter probes and measure AC voltage again (do voltage for both resistors). With Ohm's law, leakage current is calculated. Resistor (and alligator test leads) also available at Radio Shack. (Good move to avoid those posting insults without including supporting numbers. Posting without numbers - junk scientist. Posting insults without numbers - junk people.)
Luke wrote:

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Snip the Bullshit
This is Turtle.
You say you give this man the correct advice already but i see no post to him at all. was you using ESP or something or dreaming again ?
TURTLE
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wrote:

This is Turtle.
Don't rattle the resident troll like that for we will hear about it for a week or two.
TURTLE
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This is Turtle.
OH My God, POP is one of those alt.hvac members out to get you. Ok Paul your right and i will send a e-mail to POP to tell him that your always right and to stop being out to get you. You know i heard that somewhere's before. '' They are all out to get me ! ''.
TURTLE
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This is Turtle.
I stand corrected for I have been a little forward the last few days. Paul must not have took his medications and i had to answer his attacks. I'll have to tone it down.
TURTLE
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wrote:

This is Turtle.
Yes Paul after 40 something years in the hvac business, I still have not learn about Lesstricity. Does owning my own business for the last 25 year count ? OK I don't know anything Paul.
TURTLE
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On Mon, 04 Apr 2005 23:07:07 GMT, pjm@see_my_sig_for_address.com wrote:

If you've had the patience to read through all the character assasination and BS on this thread, I'm going to offer that if you have enough current to feel it, you've got a real problem that should be addressed. My long distance diagnosis would be a bad ground connection at the main power supply or another circuit lower down, you do need to get this fixed, it is potentially dangerous and I think a real electrician, or the power company, should be involved, I really wish this newsgroup didn't have to absorb the overflow of the nastiness on HVAC,com, but that seems to be what's going on just now,
Dan
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when u got bs to toss, where do u throw it. at the pile of bullshit, of course.

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most of the meter readings indicate that you are measuring low level leakage current which will tickle a wet finger and is normal.
The capacitance beween the motor windings and the shell of a mixer can casue this.
The avaialble is very low and even the current needed for the meter reduces the avaiable voltage. This casues the numerical reading to change when you change scales on the meter, i.e. the pointer does not move much but the corresponding reading does change. This is a classic indication of very low current, like leakage current and is probably normal.
If you had a real problem and put wet fingers across it, you would feel it very strongly and you meter would peg on the 10V
The TV readings seem high. I don't unerstand your readings for the TV and "across night light prongs? What does that mean?
Mark
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Luke,
were you also getting a mild shock from the mixer or just from the TV connector?
Mark
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On Wed, 06 Apr 2005 02:37:46 GMT, pjm@see_my_sig_for_address.com scribbled this interesting note:

Not even static shock from the carpet on cold, dry days???
-- John Willis (Remove the Primes before e-mailing me)
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John Willis wrote:

NO! NEVER! UNSAFE! DANGEROUS! CALL THE MASTER ELECTRICIAN!
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