"Thomas Horne" wrote in message
k.net...
Jimmie D wrote:
"Thomas Horne" wrote in message
link.net...
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

The point I am trying to make is that the ground system must be sufficent
on its own and not need to connect to the buildings plumbing to improve
the ground. You should never depend on the plumbing especially on
residential work because you can not maintain control of modifications
to that plumbing system. Good example is my in-laws home, for years the
house connected to the well via 1 inch metal pipe and this was also the
ground for the house as it was built in 1974. When the new well was
drilled plastic pipe was installed to the new well with no groundwire
going back to the well casing. A couple of years later a new HVAC system
was installed and when there was an accidental short circuit the well
pump was fried. This would not have happened if a proper grounding system
had been installed at the house instead of relying on the plumbing.
Professionals have a responsibility to idiot -proof there work as much as
possible but you know how it is, sooner or later someone makes a better
idiot.

The fact that the water pipes may be effective or even better than the
installed ground really have nothing to do with anything. Ground sytems
are for grounding, Plumbing is for water. Electrians dont do plumbing and
plumbers dont rewire homes.

Jimmie


And my point is that your opinion does not jibe with the National Electric
Code.
--
Tom Horne

Please Tom, tell me in what way that the grounding system should be
sufficent on its own and not having to rely on the plumbing to provide
grounding for an electrical system in violation of the NEC. Also please tell
me how you intend to prevent the scenario I discribed where the ground
system was completely disconnected from the home when the well's metal
plumbing was replaced with plastic.

The Code is the min and max that an inspector can apply to an inspection
This means that the inspector cant find fault with using plumbing for
grounding if this is what the code says, it doesnt mean that the inspector
can find fault if it is built better than code requirements, so again I
say the code is written to a minimum spec. Your own definition of min max
confirms this. Traditionally the NEC has the lowest minimum standard and the
state and local codes usually have a higher standard., there may be some
exceptions to this. I will will stipulate that using plumbing for ground may
be "to code" in some places but it still is not a good way to ground your
house and definately should not be used for a lightning ground.

Jimmie