"Minnie Bannister" wrote in message
...
I understand that the NEC requires that all grounds (e.g., lightning
protection grounds and grounds for radio transmitting equipment) must be
bonded to each other and to the utility company's ground. The books I
have read say this is accomplished by connecting everything to the
ground "at the service entrance panel." But how is this to be
accomplished? By clamping the ground conductors to the conduit (after
cleaning it down to bare metal) that comes out of the ground and up to
the meter on the wall of the building? By bringing the ground conductors
through the wall of the building and into the panel and there connecting
them to the existing ground bus? Or . . . ?

MB

I suggest you locate a Soars book on grounding. Probably the best
explanation to the industry. I also suggest that you start talking to the
local folks that do this sort of thing. Check around for the local
Independent Electrical Inspectors Association chapter or a Power Quality
Association in you area. Both are great people and are willing to help. I
belong to both, they have been a great source of increasing my intelligence.

Most folks take all of the grounds and tie the ground leads together on the
main grounding bus at the service entrance. Which can prove to be a problem
depending on the size of the ground bus. I have actually had to modify the
ground bus to allow for the size of wires that were needed.

I submit to you that you DO NOT want to tie an lightning protection to your
electrical service. Lightning protection is a sacrificial system. It dies
for the life of the building. All of the lightning systems (UL96A) I have
installed were grounded separately from the electrical service by at least
10 feet. I did a hospital that wanted the connections as you describe. When
I checked with the gas company they FREAKED. Letters came fast and furious.
No lightning protection connection to the gas line or no gas period.
The last computer building I did had 2 ground rings one for electrical stuff
and one for the lightning protection system, separated by 20 feet of earth.
The amount of energy that a single lightning bolt CAN deliver is sometimes
close to infinity for a fraction of a second.


I am a wizard, what I deal with is invisible. If you try to touch it; it
will kill you.