Jimmie D wrote:
"Bud--" wrote in message
.. .
Jimmie D wrote:

Hopefully you are not really using the water pipe for a ground for your
electrical service. Hopefully your plumbing is just bonded to the
electrical ground. Dont even think about using this for lightning
protection. Nothing like having lightning run in on your plumbing while
taking a bath or have it run in on yor ground and eat about $7K worth of
test equipment(my bad).

Jimmie
Jimmie

DE KB3OPR

I am an electrician by craft. The US National Electric Code Requires
that underground metal water piping on the premise be used as a grounding
electrode for the electrical system. There is no way around it. No
matter how fast people talk you cannot avoid using an underground metal
piping system as a grounding electrode unless the electrical inspector is
incompetent.
--
Tom Horne

Tom you are confusing grounding with bonding, the plumbing should be
bonded to ground but not used for ground, at least this is getting to be
the rule in most places. I know that using the plumbing for ground is
still acceptaable in places and in a lot of places it is still acceptable
if if the local code permitted it at the time it was
installed(grandfathering)..

An electrician confusing grounding and bonding - that is pretty funny.

From the US National Electrical Code
�250.50 Grounding Electrode System
All grounding electrodes as described in 250.52(A)(1) through (A)(6) that
are present at each building or structure served shall be bonded together
to form the grounding electrode system.�

�250.52(A)(1) Metal Underground Water Pipe�
(10 feet or more metal in earth)

Using underground metal water pipe as a grounding electrode is REQUIRED.
And this has been a requirement for a very long time. Local codes may be
different from the NEC, but it is unlikely they are different on this.

And if you just "bond" metal water pipe it will work as a grounding
electrode anyway.

--
bud--


True enough but there is a difference, grounding is connecting to earth
bonding is tying conductive structures together so they are at equal
potential. Ground is a single point that everything else is bonded. Ground
should be a stucture that the qualified electrician should be familar with
not plumbing that may or may not be intact. If you dont believe me just try
to get an electrical inspection on a new home without a ground rod
installed.

BTW the NEC is a minimum standard not a guide on how to wire your house.or
perform grounding and bonding.

You wouldnt believe what electricians dont know, like checking phase
rotation before turning on a new 200KW UPS. or megging out lines before
turning on new parking lot lights or making sure a generator is not
backfeeding a line before working on it. All things I have seen electricans
screw up in the past year.

Jimmie

Jimmie
I can assure you I don't do that sort of careless nonsense. I can also
assure you that whenever I'm involved before the foundation is poured or
at least prior to it being back filled there will be no driven rods on
that job. They are the single least effective electrode you can
install. When I have to install driven rods, such as for a heavy up, I
will stack them using rod couplers until I'm under twenty five ohms and
perform a witnessed test for the inspector. I consider eight foot
driven rods a complete waste of time. Mind you I'll install them when
I'm forced to but you will usually find mine driven through the bottom
of a three foot deep trench on at least twenty feet of bare copper
number two AWG grounding electrode conductor.

As for the US NEC being a minimum standard that is not always true. In
at least ten states it is both the minimum and the maximum standard that
a public electrical inspector may apply. So called "min max" states do
not allow the local governments to amend the US NEC. Were the US NEC is
the minimum standard you have to use underground metal water piping as a
grounding electrode whether or not it jibes with your religious beliefs
about what constitutes an electrode or not. If you were bonding the
plumbing you could do that with a conductor sized for the largest branch
circuit supplying an appliance that is attached to the plumbing. When
you are using the piping as an electrode you must size the conductor to
the size of the service entry conductors. People like W Tom cannot
bring themselves to admit that underground metal water piping is an
effective grounding electrode and worse still that it more effective
then most of the other electrodes listed in the US NEC at least in
homes. I always check the impedance of my grounding electrodes and
that's what the measurements say to me.
--
Tom Horne