As I understand it, back on January 1, 2006, tower grounding standards in
the US were specified in ANSI/TIA-222-G-2005 to state that the connections
between the tower and grounding electrodes, or between the electrodes
themselves, shall be no smaller in surface area than 2/0 solid (way up from
#6 AWG in the previous revision of the standard). Also, the grounding
electrodes shall be a minimum of 5/8 inch diameter and 10 ft long.
I decided I'd see how "doable" this standard is on a ham budget. The first
roadblock I came across was in even finding 2/0 solid. I called one of the
largest electrical suppliers in the Houston area (think heavy industry,
refineries, etc) and got a big "huh?" when I asked their wire and cable guru
about this. He didn't have a clue where one could get such a thing. He also
offered that he sells plenty of #2 AWG solid tinned for this application,
but has never been asked about solid 2/0. So maybe it really doesn't have to
be "solid"..
Further digging resulted in a Wireless Estimator article that indicated the
"2/0 solid surface area" could be met with the use of 2/0 or 4/0 tinned
concentric strand. Yet I see respected folks on TowerTalk advise against the
use of stranded wire in ground service. I guess copper strap could also be
used if of the appropriate surface area.
Am I missing something here? Is anyone in the amateur actually using this
part of the standard? Does the standard even apply to amateur applications?
Does anyone know what prompted the huge increase from #6 AWG to 2/0? Is it
really not advisable to use stranded wire in ground service? Is there really
any value in having a 10ft ground rod vs an 8 footer?
Larry Burke WI5A
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