On Saturday, November 2, 2013 10:31:45 AM UTC-4, wrote:
On Fri, 1 Nov 2013 22:56:37 -0400, "Robert Green"

wrote:



"Nate Nagel" wrote in message



stuff snipped



Good point; I didn't think of that as it's been 30 years or more since I

lived in a house with a water meter actually indoors - but if you do

have that kind of setup definitely there should be a jumper across it.



Next thing to check for is a heavy bonding wire between the same area

and the main electrical panel. (was the main feed from the city water

line originally copper or galvanized but recently replaced with PVC?)



Hmmm. I am having a little trouble imagining what happens if there's no

good ground in a house, i.e. the cable going to a ground rod is broken and

the water pipes are not continously connected to the feeder from the street.

Is the piping now energized because it's bonded to the neutral at the panel

but it's not connected to a ground?



If there is no ground return on the house, there is still 240V across

the hot conductors but nothing holding the house "neutral" at ground.

Therefore, neutral will float somewhere in between the two hot

conductors, depending on the relative load on the two conductors (the

loads become a voltage divider between the two hots and neutral).

Since the neutral is connected to the safety ground at the entrance,

safety ground is now allowed to "move", accordingly. You now have a

potentially (boo!) dangerous situation where everything in the house

in energized. If you touch (metal) plumbing, you become part of the

load. Not good.



I woudn't say you become part of the load. The load is
still between the two hot legs or between one hot leg
and the neutral. You are not connected there.
I agree that what you will have is the neutral floating
and not being tied to earth ground potential. Hence
as you point out there can be a voltage difference between
the neutral at the house and earth at the house and you
could get a shock, depending on how large that potential
difference is. And it's not just the water pipes that
are affected. For example, an appliance with a metal
case that has a grounded cord, will have it's metal
at a potential that can be different than the wet earth
you're standing on.




Many years ago we had a neutral pull off the house. All sorts of

weird things started happening until we figured it out. Basically, we

had 75V on one side of the house and 175 on the other, but that

changed depending on what was turned on. The power company was there

in minutes after the call. They know exactly how dangerous this

situation is.

Which is very different from what Robert is talking about.
The neutral is the main path for the unbalanced portion of
the current to flow back to the transformer. Without a
neutral, you have all the unbalanced current, which
could be very large, forced into trying to use
the ground path, which has unknown resistance.
With what Robert is describing, that neutral connection
between house and transformer is intact and functioning.