voltage on gnd wire.

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Re: voltage on gnd wire.

So I just took a 250' coil of 14-2 and put a plug on the end with bonding jumper across the n and G ( i a m doing this at my own house) I then applied a 500 watt load and got the same efecct as at my customers house, 50+ volts from disconnected ground to the neutral. I will assume this is the same problem at my customers house. I will t-shoot this week.

My question is I had voltage from a disconected ground to the neutral on a properly wired circuit as well, I assume this voltage is induced or phantom. How can you tell the difference between "phantom" and real volts using a digital meter. ( my wiggie does not pick up the problem voltage on the N/G bond circuit)
:confused:
 
Re: voltage on gnd wire.

jes25,
How can you tell the difference between "phantom" and real volts using a digital meter. ( my wiggie does not pick up the problem voltage on the N/G bond circuit)
Click to expand...
You can't tell the difference with a high impedance input digital meter. The answer is to use your wiggy.
Don
 
Re: voltage on gnd wire.

You can't tell the difference with a high impedance input digital meter. The answer is to use your wiggy.
Click to expand...
The wiggy didn't detect the problem when his hand could. Apparently it's enough to shock a human, but not enough to energize a solenoid tester?
 
Re: voltage on gnd wire.

Originally posted by jes25:
How can you tell the difference between "phantom" and real volts using a digital meter.
Click to expand...
A way to use your meter is to attach, say, a 60-watt bulb using a rubber socket with insulated alligator clips, and measure across (i.e., in parallel with) the bulb. A 60-watt bulb is 2 ohms (when the filament is hot; it's lower when cold).
 
Re: voltage on gnd wire.

My question would be whether the shock persisted or was it just for the moment that the separation occured. If you separate neutrals with an inductive load (ie: motors, transformers) a current will be forced thru the user for the instant of the transient. I agree that the 50 volts is probably induced from a nearby wire. I am not suggesting re-testing for shock. I probably did not explain this well - let me know if you need more.

Mark
 
Re: voltage on gnd wire.

Originally posted by georgestolz:
You can't tell the difference with a high impedance input digital meter. The answer is to use your wiggy.
Click to expand...
The wiggy didn't detect the problem when his hand could. Apparently it's enough to shock a human, but not enough to energize a solenoid tester?
Click to expand...
Yeah George that is exactly what I meant. And the shock was continous on the circuit I predict has the a N/G bond. It was a shock but not like one when you get the full 120V.
 
Re: voltage on gnd wire.

I agree with the mentioned possibity, however, prior to disconnecting the neutral, or tearing all the devices out, I would identify the effected outlets,(trace the circuit) and or equipment, and Unplug, or disconnect all devices. Then recheck at the panel. This should isolate the premis wiring, and might save time.

Also if you disconnect the neutral on a multiwire brach circuit, you could easily send over-voltage to something and damage it!

The problem could also be in utilization equipment, (common problems are reversed polarity of appliance cords, or a fault in the equipment itself, on diswashers, disposals & refrigerators etc.)

This might save damage and time also.
 
Re: voltage on gnd wire.

Going back to phantom voltages when using a digital meter.I use a fluke t3 and when testing a switched receptacle single pole I get a 25 to 27 volt reading but a wiggy doesn`t see any voltage,guess the voltage isn`t enough to register.Same sw. recep on a 3 way when wired correctly it reads 35 to 37 volts.
The reason I said wired correctly is because if the installer swapped out the travellers with the receptacle sw leg when making up a 3way sw recep the voltage will read like a sp sw recep 25 to 27 volts.Just a bit of trivia I discovered and wanted to pass it on ;)
 
Re: voltage on gnd wire.

The problem could also be in utilization equipment, (common problems are reversed polarity of appliance cords, or a fault in the equipment itself, on diswashers, disposals & refrigerators etc.)
[/QB]
Click to expand...
OK how could reverse polarity cause any of these symptoms. (assuming we are dealing with listed equipment that does not have any improper connections)?? :confused:
 
Re: voltage on gnd wire.

assuming that there are no improper connections..
I think the point was that there could be improper connections that cause the fault.If all connections were done corectly then this point would not be discussed. ????
 
Re: voltage on gnd wire.

Yeah obviously but reverse polarity alone could not cause the issue.
 
Re: voltage on gnd wire.

As a professional you do not have the luxury of saying "it is not my problem". If you suspect a potentialy dangerous problem exists you need to notify the owner IN WRITING of the problem. They can then decide whether or not to have you or someone else repair it. You need to have proof that you made the owner aware of the situation and that they opted not to have it repaired. Otherwise you are very likely to find yourself in court trying to explain that you left a dangerous situation because it "wasn't your problem".
 
Re: voltage on gnd wire.

My point exactly! I have run across many service calls, where the lady of the house was being "shocked" whenever touching a sink etc. (a grounded surface) quite often I have found either grounds, & neutrals reversed in the appliance itself, or in the receptacle. If the ground is even togather (or bonded) with the neutral, this can cause voltage in the ground (duel pathway). VERY common on older appliances, and system wiring.

My primary point was to discern between appliances, and Premis wiring PRIOR to chasing a fault that will be hidden, and probably hard to find, specially if the fault is in an appliance (which, IMO isn't an electricians job).

Also to KNOW exactly what the circuit feeds, PRIOR to disconnecting a neutral, hopefully preventing any damage caused by overvoltage of a possable multi-wire branch circuit!

Just trying to give the benefit of my experience.
 
Re: voltage on gnd wire.

Originally posted by haskindm:
As a professional you do not have the luxury of saying "it is not my problem". If you suspect a potentialy dangerous problem exists you need to notify the owner IN WRITING of the problem. They can then decide whether or not to have you or someone else repair it. You need to have proof that you made the owner aware of the situation and that they opted not to have it repaired. Otherwise you are very likely to find yourself in court trying to explain that you left a dangerous situation because it "wasn't your problem".
Click to expand...
You guys stress me out with all this talk about getting sued and it being my responsibility for something that exsists. (remember I reported it to the owner) I am a very conscience electrician. What if I did not notice the problem then is it my fault/problem? Should I run around looking for violations and "getting it in writing" every time I do a job? Just today I did a job with the Ge breakers in an ITE panel. My circuit had an ITE but I am not gonna get it in writing about the exsisting ones. ( I sure did mention it though) Give me a break

[ October 27, 2005, 09:26 PM: Message edited by: jes25 ]
 
Re: voltage on gnd wire.

Jes agreed as long as our job is code compliant pre existing violations are not our legal resposibility to remedy.Inform the owner and leave it in thier hands.You did CYOA and they know what is there done deal fade to black everyone go home.Now if our job does in fact disturb the violation then we get paid to do the job and correct the violations.If the owner says they only want this done and not that you make the call??? Me I go to the next job and not worry about a silly cheap owner.
 
Re: voltage on gnd wire.

You did he right thing to report it to the owner. I just think you would be better off if you have PROOF that you reported it to the owner. Otherwise when/if something happens you may be questioned about what you did or did not see and/or reprt when you were on the job. The homeowner will deny that you ever said anything to him in hopes that they will get a big settlement. When it comes down to a contractors word against a homeowner, the contractor will lose in court almost every time. Report any serious problems in writing to the homeowner and THEN it will be the homeowners problem.
 
Re: voltage on gnd wire.

I am very aware of Royal Oak and knowing the way houses are often rigged to work, I would venture to say it is a ground to neutral connection. I see that alot in the metro detroit area. Probably hooked together in a single gang box buried behind drywall. Is that a violation?
 
Re: voltage on gnd wire.

Originally posted by automaton:
Probably hooked together in a single gang box buried behind drywall. Is that a violation?
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A buried box and a N-G connection on the load side of the service disconnect (not meeting the excpetions) are both violations.
 
Re: voltage on gnd wire.

That sounds like a sub division that is being wired by a company that says wire it we will fix it later.Do they also make flying splices in walls but wrap them in duct tape saying duct tape has a 4 hr fire rating :eek:
 
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