On 6/4/2015 8:26 PM, Lloyd E. Sponenburgh wrote:
Ignoramus22165 fired this volley in
:

But I am still wondering how, on a disconnected busbar, I would read
that phantom voltage. Was that just electromagnetic induction?

It is still a mystery to me.

The biggest question is how come it was only on one of the two
identical boxes.

The real first question is, "what was your reference"?

Then, following that up some:
Were you measuring bar to 'local ground', bar to bar, bar to box neutral?
Was this single-phase, or three-phase?

What's the input impedance of your meter? Did you try a microscopic load
-- like (say) a couple-hundred K-ohms across the meter leads? You might
have a very high input impedance meter, and just be measuring "antenna
effect" to some nearby physically parallel live circuit.


I agree here, if you had put a lightbulb across the two points, you
would not read a voltage, or maybe millivolts.

Mikek