Voltage on equipment ground(s)

[Smart $]

One of the very revealing numbers will be the current in the EGC. That is most easily and safely determined with a clamp-on ammeter. ...

I like the amp meter approach.

Agree problem circuit(s) better located measuring current.



@andyman

Open all branch breakers. Turn on one circuit at a time (disconnect all but one hot if MWBC). Verify current of hot to be greater than zero (higher is better) then measure current with both hot and its neutral (verify) through clamp with panel connections electrically on same side of clamp. If measure is greater than 0A, you have a ground fault on that circuit... or a faulty meter, which can be verified by clamping around an extension cord while powering a load. Measuring circuit current this way is the same principle used for GFCI protection.

 

[Cow]

I had a call like this a few years ago in a restaurant. The customer noticed a piece of aluminum flex that would spark when brushed against another metal object. It turned out to be a receptacle someone had jumped the ground-neutral because the neutral to that receptacle had been lost at some point. I took the jumper out and proceeded to track down the lost neutral connection. It was a wire that had popped out of a wirenut in a box half buried behind the countertop backsplash with a big appliance on the counter in front of it. It's no wonder they couldn't find it and just decided to jump the terminals together.:rant:

 

[don_resqcapt19]

Problem is unacceptably high voltage on equipment grounding conductor.

I would bet if you were barefoot on a concrete floor with sweaty feet and hands and you touched something like a metal toaster that you would be feeling that 80V on the equipment ground. ...

If that voltage existed while the EGC is connected to the grounding bus, I would agree you have an issue. I just don't see an issue when you are measuring voltage on a "floating" conductor.

Based on everyone's reply's it sounds like I need an analog tester to help determine problem.

I think a low impedance meter will tell you that you don't have a problem.

 

[kwired]

Based on everyone's reply's it sounds like I need an analog tester to help determine problem.

Not your only option, they make digital meters with low impedance or with a low impedance setting, you can also rig up test leads that have a resistor connected between them or somehow connect a load between the point being tested and get same results.

The "low impedance" is still a high value, probably in the lower kohm ranges, but is low compared to the impedance of a standard digital volt meter.

 

[electricalist]

Does a non contact tester pick up the voltage.

 

[don_resqcapt19]

Does a non contact tester pick up the voltage.

They, typically, will pick up that voltage.

 

[electricalist]

Mine does supposedly from 90 v up.
I was just curious if his did, if he uses one.

 

[electricalist]

I thing id lift the neutral of a light circuit at the panel and turn the circuit back on. If everything cones on then something is wrong. There is a n to ground stappled or touching. Put an afci breaker on it. See if it trips

 

[ActionDave]

Based on everyone's reply's it sounds like I need an analog tester to help determine problem.

Not necessarily, but having a low z meter is a good idea. Checking for current on the EGC is another one.

One more good troubleshooting trick is to plug an extension cord into a receptacle that you know is wired up properly, best if it can be right at the service and use it as reference inside- check hot to EGC on the cord and so on using all possible combinations.

 

[kwired]

Not necessarily, but having a low z meter is a good idea. Checking for current on the EGC is another one.

One more good troubleshooting trick is to plug an extension cord into a receptacle that you know is wired up properly, best if it can be right at the service and use it as reference inside- check hot to EGC on the cord and so on using all possible combinations.

Bad service/feeder neutral can throw you off though, I still like the probe out in the yard to determine what is truly at ground potential and what is not. But still if there is a bad service/feeder neutral we still haven't been told of any classic symptoms involving a higher then normal voltage on 120 volt circuits - just these low volts problems, otherwise everything else still seems to be pointing to possibly a bad neutral.