Date: Tue, 17 Oct 2017 07:29:22 -0700
From: Grant Saviers <grants2@pacbell.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Fwd: Grounding connection to tower legs
<One more alternative is to use a DX Eng saddle clamp and extend the
saddle backing plate far enough to use two hole lugs. I made the
backing plate out of 1/4 x 1-1/2" 6061 and wide enough for two lugs each
side. One clamp on each leg with 2 or 3 #6 or #2 wires to pairs of
buried 8' rods Cadwelded. I put some contact goop in the saddle area
where it contacts the tower. 2" saddles for Rohn 65 are a very close
fit. A few dollars cheaper than the Rohn similar idea, and uses two
hole lugs. Aluminum against zinc is pretty benign electrochemically.
Grant KZ1W
## Excellent idea ! DX eng makes both saddle clamps and also the
heavier assy, that is a 1 inch wide solid aluminum saddle, one solid al
saddle on each side of the tubing in question. They make em all the way from
small od up to 2 inch od. The regular saddle clamps with the single, solid al
saddle go from tiny stuff...up to 4 inch od. Then just use a wider hb al
backing plate,
and punch /drill 2 holes in it for the mating U bolt..and 2 more holes for the
mating
2 hole compression clamp assy. I would fabricate the hb backing plate so the
compression
clamp ends up in the vert plane.
## use the correct die, and compress ur 2 gauge stranded cu in the 2 hole
compression lug.
Use insulated 2 gauge cu, Then cadweld at the top of the 8ft ground rod. I
think current
eia –222 specs state that TWO legs of the tower require grounding. I do all
3 legs.
Tops of each ground rod are below ground level, so only the 2 gauge wire is
seen coming out
of the grass.
## 2 gauge, stranded cu, and insulated between tower legs and cadwelded
ground rod
is placed inside that split loom stuff u see in home depot electrical dept.
Thats easy to
install either b4..or after the fact. Then its all bomb proof.
## Only place I saw cu strap used was at the telco, if they had a rooftop
tower, like a small one,
not very tall, with 1-2 microwave dishes on it. Cu strap was 3 inch wide by
at least .125 thick.
It went over the side of the flat roof..and down to ground level. Then tied
into the ground buss
system that encircled the building..which also contained the switching
equipment, microwave gear, dsl stuff,
and everything else in a typ office. Typ 10 ft rods jack hammered in every
10 ft. around the perimeter
of the building. I dont know how the myriad of rods were connected. Winter
temps would hit –17 deg C.
They need to be below the frost line. But thats a different application, with
different specs. Had to be
2 ohms or less...even in winter. Nobody gets lightning in sub freezing wx, so
that is a moot point.
Jim VE7RF
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