whit3rd wrote:
On Nov 23, 5:38*pm, D Yuniskis wrote:

Grounding the mains to "plumbing" *was* common in the US many
years ago. *Now, I believe, you *must* ground to a metal
rod driven into the earth (8 ft?).

Just to be clear, my copy of the US National Electric Code clearly
requires (section 250-80) plumbing to be bonded to the electrical
service
ground, it just doesn't allow the buried water piping to substitute
for
a ground rod or similar to-the-soil connection.

The ground wire from the interior water pipe grounds the pipes, not
the
electric wiring.

Maybe no, but certainly not 60 years ago when my house was built.
Grounding via the water supply pipe was resonably standard then.
The problem now is that the water supply pipe is likely to be plastic,
or perhaps partly replaced by plastic. Also the water main is very
likely to be plastic if it's relatively new.

Jerry