On 5/27/2013 4:26 PM, Doug Miller wrote:
wrote in news:afb2620e-b43c-48a2-8acf-
:

I would not an expert on the current code on this subject.
But I believe the above is incorrect. I believe in the past
an underground water service pipe was allowed to serve
as the service ground.

It used to be... but hasn't been for at least 20 years.

But as you agree later, there is not a code problem with houses built
with just a water pipe electrode when that was all that was required.


And I think even today it can serve
as part of it, but needs to be supplemented by other
grounding methods, eg ground rods.

Your understanding is incorrect. The *sole* reason that metal water pipes need to be tied to
the electrical system's grounding electrodes is to ensure that the plumbing system is at
ground potential, no matter what. The requirements for grounding the electrical system are
the same, whether the water pipes are metal or plastic.

Trader is right. You are wrong. You backpedal in later posts.

A metal water service pipe, at least 10 ft in the earth, MUST be used as
part of the earthing electrode system, just as it has been required
since time began.

A "supplemental" electrode for metal water service pipe has been
required for a long time if the metal pipe might be replaced by plastic.
With plastic becoming more common, a "supplemental" electrode is now
required. But a metal municipal water system is the best earthing
electrode that is available at a house.

If the water service pipe is plastic, interior metal water pipe systems
must be "bonded" to the ground system with rules that are not quite the
same as using the water service as an earthing electrode.

For a lot of new construction a "concrete encased electrode" (commonly
called a Ufer ground) must be created and included as part of the
earthing system. This is a good earthing electrode (and is used as the
"supplemental" electrode, where required). Ground rods are lousy.


* The electrical distribution system will work just fine without a
water-pipe ground - a water-pipe ground in NO WAY influences the electric
al
system.

It does if it's an older system and the water pipe is the
only earth ground.

That is no longer permitted in new construction.

Which is irrelevant to trader's point.



The purpose of a water-pipe ground, and its only purpose, is to
protect the water system plumber from an electrical shock.

Per above, I believe that is incorrect.

Your belief is incorrect. HeyBub has it exactly right.



HeyBub has it exactly wrong, just as he has at least 2 times previously.


============================
If I understand the OP right, there will no longer be a metal water
service pipe 10 ft metal in the ground. So it no longer needs to be
connected as an earthing electrode. The interior water pipe system needs
to be bonded, but it is by the connection at the water heater. I have
not read why the existing ground rods are not adequate, but the distance
seems long. As others suggest, I would probably install 2 new rods 8 ft
apart with a short run to the service panel.