Old panel meter, voltage to ground

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delta59

Member
Location
USA
Occupation
Engineer
I was wondering if anyone here might be able to help. I found this old panel meter and it seems to work fine but the housing has about 6V to the ground. I'm not very familiar with older meters but is it normal for the housing to have voltage referenced to ground?

 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
I see on your setup you have the black lead connected to the side of that old volt meter.
I assume the voltage is there without that voltmeter in the loop?
 

Mr. Serious

Member
Location
Oklahoma, USA
Occupation
Electrical Contractor
It definitely would help us understand if we could see the whole setup. What is that red lead connected to? What exactly are the panel meter leads connected to?
However, even without seeing everything, I would say it's likely the meter has some sort of current leakage issue. Its metal case should be electrically isolated. But, sometimes, in older equipment, they may have used a high-value resistor to the metal case, to reduce noise.
 

delta59

Member
Location
USA
Occupation
Engineer
The old panel meter leads are conneced to hot and neutral of a nearby outlet, no other devices are connected to that circuit. On the new volt meter the black lead is touching bare metal on the old meter housing and the red lead is connected to the emt of the nearby outlet. The 6V only exists when the old meter has power.

I can't feel anything when touching the meter, the reason I decided to check in the first place was I wasn't sure of the condition of the meter and didn't want the get a full shock of something had failed in the inside
 

Dsg319

Senior Member
Location
West Virginia
Occupation
(Green)Master Electrician
You could also just have "ghost" voltage.
Can you feel the 6 volt?
What made you put test leads to the case? Precaution?
He should try with a low impedance meter. Unless that old analog meter probably is, but from the picture I can tell if he has the two meters in series or what.
 

kwired

Electron manager
Location
NE Nebraska
He should try with a low impedance meter. Unless that old analog meter probably is, but from the picture I can tell if he has the two meters in series or what.
The analog meter should be low impedance, across it's input leads. But he is measuring the likely isolated case to (whatever he is calling) ground.

Case is likely capacitively coupled, bond it to "ground" and that voltage measured by the high impedance digital meter goes away.
 
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