On Sat, 11 Oct 2014 10:00:19 -0400, "Robert Green"
wrote:

wrote in message
wrote:

In that case the ground wire did NOT go back to the panel, but to a
clamp on a cold water pipe.

Until the 70s that was legal.

But stupid. And that's why they outlawed the practice. The wire went off
to parts unknown (in my case) and some small amount of current leakage
apparently caused galvanic corrosion to occur where it was clamped to the
waterpipe. It caused a pinhole leaked to develop. All tucked away behind a
stapled ceiling and hard to find without making a hell of a mess. I would
not even had known about it until I took the ceiling down (revealing all
sorts of other nasty surprises). I am sure the previous owner installed
that stapled up ceiling to keep those sorts of issues from the eyes of a
good home inspector.
My bet is the ceiling was installed LONG before home inspectors became
in vogue.

It was also far enough away from the service entrance that a replacement of
a section of copper with plastic where it entered the house would have
broken the connection to ground.
Ant it was likely done long before plastic pipe was an approved
option.

In my mind, those are two good reasons why they changed the code and why
such connections should be removed and done according to modern rules
whenever they are discovered even if they are still grandfathered.

As for the OP, what was legal in the 70's is moot.
Except the upgrade was likely done either during or before the
seventies. - so not ENTIRELY a moot point. It was "standard practice"
and "approved" when it was done.
Not to say it should not be redone today.