Todd, I think we're probably using different terminology. But yes, I'd
be willing to agree the copper pipe is energized, in the sense that the
assumed ground fault current is flowing through it.
In the eye of the NEC, there is a connection at the service entrance
between the green grounding wire and the white neutral and ground. An
appliance ground fault current SHOULD flow through the green grounding
conductor to the service entrance, and from there, take the path of
least resistance through that neutral wire back to the transformer on
the pole. Of course the higher resistance path through the ground is in
parallel with the neutral wire, so you get some current through the
ground as well. It is normally not a good thing for there to be a lot of
current through the ground, and its presence could indicate a problem
with the neutral connection, etc.
Yes, the latter is what I assumed also.
My assertion was that if there was enough
Agreed. Except that there is no voltage to speak of on the ground wire
while it is connected to the copper pipe (i.e., to ground). There is a
current through the wire. When the connection to the pipe is broken, at
that time a voltage is present between the pipe and the wire. Placing
yourself across that voltage is what could be hazardous.
If that was the case, I wouldn't handle anything
Well, touching the plumbing fixtures should be safe because they are
essentially at ground potential, again due to the copper pipe
connection. That is a benefit of the grounding system. But if currents
are detected in the grounding wire, something is amiss and maybe should
Fascinating. I'd be lost in that area.
The reason for that jumper is more likely that the meter itself does not
represent a good, low-resistance path. You see those jumpers around
plastic-bodied filters also. In the past, service entrance grounds were
often connected to metal plumbing systems. In many cases these systems
were "upgraded" to plastic, and the residence was left without any
ground connection at all!
FWIW, with so much PVC in use in new construction, the NEC now requires
a dedicated ground rod or two at the service entrance.
As long as the ground is still attached, zero risk. If you disconnect
the ground and there is something bleeding current to ground, it will be
I had a "hot" computer case once. If I touched it, while touching
something grounded I got a heck of a zap. Turned out the extension cord
I was using had the ground broken inside of the male end of the cord.
AC inducts current into nearby conductors real well, so it was loading
the ground wire, no longer connected to a ground, with lots of juice.
Since the case of the computer is directly connected to the ground
lead... Replacing the cord solved the problem.
"Life should not be a journey to the grave with the intention of
Um, no. You'd need miles of wire to induct any appreciable amount
of charge into a parallel unconnected wire at the frequencies power
lines work at.
Something else was also connected to the ground lead - quite likely
the power line neutral (the "white wire" - I'm guessing this since
you've stated the extension cord was defective). As you observed,
when the far end of the ground lead wasn't grounded, this provided
enough charge on the case to give you a tingle.
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