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Old April 8th 07, 12:50 AM posted to rec.radio.amateur.antenna
Jimmie D Jimmie D is offline
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First recorded activity by RadioBanter: Feb 2007
Posts: 287
Default Acceptable Lightning Ground?


"Thomas Horne" wrote in message
link.net...
Jimmie D wrote:
"Dave" wrote in message
. ..
wrote in message
oups.com...
I would like to propose a grounding arrangement for my [hypothetical]
antenna and get some feedback on it. I have access to the solid-copper
cold-water pipe that enters my home through the basement wall close to
the basement floor.
bad start

This pipe is used [in addition to cold water] for
the service entrance [circuit breaker box] ground.
thats bad news

I was thinking of putting an antenna outside on a pole and running the
coax into the
basement.
nope, not the way to do it right.

Then I would strip back several inches of the outer jacket
of the coax [axposing the braided shield] and connect the coax braid to
the cold water pipe using several hose clamps. This should ground the
coax directly to the service ground - the single point ground for the
house.
except the single point shouldn't be 'inside' the house.

I would add an arrester near the ground point. I would then run
the coax upstairs [about 10 feet] to the radio, where it would [via the
PL-259] connect to the transceiver chassis. The radio chassis will be
electrically bonded to peripheral equipment chassis'.
the radio chassis should be connected to the same single point ground,
and not via just the coax shield.

It seems that in the unlikely event [low altitude, semi-urban area]
that the antenna were struck by lightning, the energy [albeit
significant] would have no reason to propagate up to my station. Even
though it may elevate my house ground by thousands of volts [with
respect to some other ground point], the station should ride up with it
- and little current should flow in the coax at the station.

Am I whistling Dixie?




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)..