I just got back in town and am catching up on my email.
Do not even think about pouring concrete around a ground rod or a ground
wire that can be subjected to lightning. All concrete that is in the ground
contains moisture. When electrical energy flows through a conductor, heat
is generated. Lightning can produce very high currents, even if not a
direct strike. The rapid heating of a conductor, in direct contact with
moisture carrying concrete will produce a steam explosion as the moisture
is flashed to steam. This could vaporize, or at the least crack, the
concrete. This is the same concrete taht yo are using to keep your tower
vertical. With the concrete strength compromised, the tower coulf
collapse. If you must run a ground wire or ground rod through concrete,
isolate it from the concrete with PVC pipe. This will prevent the steam
explosion from the water trapped in the concrete.
73
GLenn
WB4UIV
At 11:19 PM 8/1/02 -0400, Jerry Keller wrote:
>I'll soon be pouring a new tower base, 6 feet deep. I thought I would put an
>8-foot ground rod at each corner of the hole, drive them in the remaining 2
>feet, tie them all together with #2 solid copper, and run the copper to all
>3 of the tower mount J-bolts...then pour concrete around the whole
>business... any thoughts? Jerry K3BZ
>
>_______________________________________________
>Self Supporting Towers, Wireless Weather Stations, see web site:
>http://www.mscomputer.com
>Call 888-333-9041 to place your order, mention you saw this ad and take an
>additional 5 percent off
>any weather station price.
>_______________________________________________
>Towertalk mailing list
>Towertalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
---------------------------------------------------------------------------
Glenn Little glittle@awod.com QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@amsat.org AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) ARRL TAPR
---------------------------------------------------------------------------
|