[ICOM] Grounding

[Stewart Thompson]

Hi Bill:

	Both my latest NEC (1999) and Canadian Electrical Code (2002)
require a minimum #6 awg between the stations grounding electrodes,
and the service grounding electrode. NEC 810-21(j). Both codes say
pretty much all the same things, as the US and Canada have been trying
to harmonize the codes. I would use a minimum of two electrodes for
your protection system, and connect them all together with at least
#6 multi-multi strand cable. Standard electrical wire is designed for
acceptable impedance at 60 HZ. Not at RF Frequencies, or for the fast
impulse of a lightning strike. It does refer to a minimum #10 copper
wire for the station grounding wire, but I would use the heaviest most
multistrand wire you can conveniently get out of the shack.
Many other things are mentioned, like running the wire as straight as
possible with no sudden bends to discourage the lightning from jumping
out of the wire etc.

	I would say all of Chapter 8 of the NEC would be good reading,
as well as the other sections that apply to grounding and bonding.


	So, I guess that is a long winded way of saying no, #10 would
easily burn off during a lightning event, or even if there is something
nasty happening with high RF Voltages and Currents. I would talk to
someone in your area that does the grounding for a radio or tv transmitter
installation. They should be familiar with all the NEC and any local codes.

Hope that helps.

73

Stewart Thompson
VE7BQY


-----Original Message-----
From: icom-bounces at mailman.qth.net
[mailto:icom-bounces at mailman.qth.net]On Behalf Of William Diamond
Sent: Monday, May 17, 2004 11:26 PM
To: Icom at Mailman. Qth. Net
Subject: [ICOM] Grounding


Hi folks,

I spent a few hours today with an engineer from the power company as I had a
whole house surge device put on my main electrical service.

He said that my present grounding setup is a problem, i.e.., separate ground
rods for the tower as well as the radio room.  He said that I needed "single
point" grounding system with the tower and radio room tied into the main
power company ground so there will not be a difference of potential.

He said that a small wire such as #10 will be fine.

Has anyone else heard of this?


      William J. Diamond
       Rogers, Arkansas

    Ham Radio Operator WR0T

   Please Visit My Radio Site
        wjdiamond.com



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