On Tue, 31 Oct 2006 23:45:05 GMT, "Ralph Mowery"
wrote:

I don't recall seeing it anywhere, but is there any problem with using some
left over guy wire (3/16 EHS) to go from the tower to a ground rod at the
base of a tower. Planning on going to about 60 feet with Rohn 25 and will
probably use a ground rod at the tower and maybe one at each of the guy
points. Just seems to me that if the correct clamps are used the wires and
tower would be the same material and not have a galvonic reaction.


Do you have codes or standards that provide guidance, or requirements?

The standard applicable here in Australia suggests that it is likely
that earthing conductors need to be 35mm^2 copper or better (~ 2AWG).

The conductor used for lightning protection should be sufficient to
carry the anticipated current without deterioration and without risk
of fire.

People often design for a scenario like 20kA for 0.1s.

I don't know how 3/16EHS performs in that scenario, but I venture that
it probably has csa of about 10mm^2, conductivity of a tenth of
copper, higher inductance than copper (which affects the voltage
rise), higher specific heat and higher melting point.

Perhaps it is safer to use copper of adequate size.

Owen
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