Help! Any Ideas why 120 volts between neutral and ground?

[belfert]

I had a bit of a shocking experience this evening.  I switched off the circuit breaker to my bathroom circuit to remove the outlet and got shocked working on the outlet.  I found I have 120 volts between ground and neutral!  It matters not if I am using inverter power, shore power, or the generator.  I disconnected the shore power cord all together and ran the generator and it still happens.

I doubt this a neutral/ground isolation issue.  I suspect something is wrong in one of my power panels as the problem happens without any power to the transfer switch.

My main 220 volt 50 amp power goes from generator or shore power to an Iota 50 amp transfer switch.  From the transfer switch it goes to a 50 amp 200 volt power panel.  There is a 30 amp 110 volt breaker that feeds the inverter which then feeds a another power panel that is 30 amp 110 volt.  My Prosine 3000 has an internal transfer switch plus a neutral isolation relay.

Any ideas?  I have an electrician friend coming on Saturday to check things out.  I at least don't have 110 volt to the entire metal frame.

[Melbo]

Just a guess brian but I bet you have a dropped neutral downstream and you are getting feedback

Just a guess as I have very little to go on

Melbo

[Nick Badame Refrig/ACC]

Hi Brian,

With a 50 amp service, whenever there is an unballanced load on either 1 leg or the other, the nutral will carry the remainder of the current.

So, unless you have equal current draw on both legs, there will be current presant on the nutral.

Good Luck
Nick-

[belfert]

How does unequal load explain this happening with only the inverter supplying power and no loads turned on in the bus?  The inverter is 110 volt only.

[pvcces]

Brian, I figure your bathroom circuit is miswired. You might use one of those cubes with the lights to check. They're pretty good about pointing you in the right direction.

Some possibilities: hot and neutral reversed or ground and hot reversed. Remember, the mistake could be at either end of any wire feeding the bathroom.

For what it's worth.

Tom Caffrey

[Hartley]

Brian,

Unplug anything that you have on any outlets and check for the voltage
across the neutral and ground.

And I mean anything.. Including refrigerators, computers and anything else.

If you are sure that everything is unplugged.. especially anything that has
a 3 prong cord on it.

If that doesn't do it.

Then start turning off circuit breakers one at a time with someone with a meter watching that bathroom circuit... Or get a known good extension cord and
plug it in to the offending outlet. Take the other end to where the breaker panel is located and hook the meter up and watch as you cycle each breaker, Including the air conditioner that you said wasn't cooling properly... It's a good chance
that you have a ground/neutral bonding problem in that unit...

You may need to pull the wiring cover on the a/c unit and check for a short up there....

Dave....