Towertalk
[Top] [All Lists]

[TowerTalk] BASE REBAR and Lightning

To: <towertalk@contesting.com>
Subject: [TowerTalk] BASE REBAR and Lightning
From: <mecker@peoplepc.com>
Date: Thu, 4 Oct 2007 21:33:50 -0400
List-post: <mailto:towertalk@contesting.com>
Read that base rebar (which must be electrically tied together)
should be internal min of 4 inches from edge of concrete base.

Here's my question. (Im learning disabled...etc..etc.)

What about guys that use a piece of rohn 25 as the base, stick
the end in the 6 inches of gravel, and then fill up the rest
with concrete. There is no 4 inches of insulation with the earth
there, because the gravel has gaps  and moisture in it
which connect with the earth anyway. (a chemical fact)

How important is it to separate the bottom of your base section
and sides of base section rebar in the concrete 4 inches.... or should I put 
the base section
on bricks and not stick it in the gravel and keep the rebar the heck away from 
the sides?
Im using a chipboard concrete box form (have no choice there cause of concrete 
costs..etc...)

The concrete form will rest on the six inches of gravel, but will eventually
dissappear (be eaten by bugs..etc..), and whatever touches(or dosent touch) the 
bottom of the form will eventually
touch the gravel, hence the earth.

Am also using grade 8  7/8 size  allthread rods on another base, and
was just going to let these rods rest on the bottom of the concrete
form rather than on bricks. (the rods are electrically connected by 1/8 inch
steel 3 inches width)  Should I use the bricks here again, insulate from the 
earth
again here?

So I to summarize, should everything be on bricks, and how important
is this rule with reguards to lightning when my tower will surely be
grounded anyway to six rods in a ring, possibly also to a no longer operational 
(disconnected)well pump casing down 200 feet.
into water.

Is this because we want the electricity to go through the wires and not
the base? Have heard about exploding bases. boom! 

(the allthread tiltover rod base was custom made at the Dayton hamfest
and the other base is just a piece of rohn 25G being used as a base.)

Feedback is welcome. Thanks. KE2BP 
MEcker@peoplepc.com
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>