On Fri, 2 Apr 2010 21:42:19 -0500, "Dave" wrote:


wrote in message
.. .
On Fri, 02 Apr 2010 15:53:44 -0800, David Nebenzahl
wrote:

On 4/2/2010 2:45 PM mike spake thus:

On Apr 2, 4:37 pm, David Nebenzahl wrote:

(This isn't to say that it isn't *possible* for a DMM to misread due to
stray capacitance or induced voltages, but it is nowhere near as
terrible a problem as you hear here.)

It has happened to me on two different occasions. It's also happened
to a lot of regulars here.

Maybe you have a really advanced digital meter that isn't affected.

Nope, I've got a Harbor Freight el cheapo (think I paid $3 for it). So
how is it that I got completely accurate readings of my AC line voltage
with it?

Just because YOUR cheap meter worked right when you tested YOUR
circuit doesn't mean SOME other cheap meters won't misbehave or
misread on SOME circuits - but I'd also lean towards it being a
floating neutral (did I say floating ground in my first post??? - not
sure - but floating NEUTRAL is what I meant to say.

http://en.wikipedia.org/wiki/Phantom_voltage

Sorry, I don't do Wikipedia (the "encyclopedia" that can be edited by
any pimple-faced 7th grader).


Hmm. Floating ground I think I understand. Floating neutral? Please tell
me, what is this?

Thanks,

Dave

The neutral is supposed to be grounded at the panel That holds the
neutral to ground potential. If the neutral is not grounded it can
be either high or low from ground (the ground can be at a higher
potential than the neutral due to ground leakage) Quite common in
rural areas - where you can sometimes get a shock from a safety
grounded device to "eath ground" - and cattle will stop drinking from
their water bowls because the grounded bowl and earth ground are at
different potentials - giving them "discomfort" when drinking.