[TowerTalk] Re: Floating Ground Steel Building?

[Keith Dutson]

Concrete is a conductor.  Unfortunately, if a large current flows through,
as from a lightning strike, the moisture in the concrete will vaporize,
usually causing the concrete to crack, and sometimes explode.  This is not a
good thing!  I would sink as many grounds around the structure as possible
and tie them to the steel frame to minimize conductivity through the slab.

Keith

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of doc
Sent: Friday, July 02, 2004 1:43 PM
To: towertalk at contesting.com
Subject: [TowerTalk] Re: Floating Ground Steel Building?

I just left a meeting with the builder of our new steel home where I
discovered something troubling -- the steel roof and wall materials appear
to be floating above ground on top of the concrete slab!

The roof and wall are 10" x 48" wide sections bonded together and along the
bottom of the wall set into a metal channel fastened to the concrete with
embedded anchor bolts -- but those bolts are buried in the slab, none of
them are grounded.

So when I bring everything to the entry panel the only point of ground is
the three planned 20' rods -- for the entire steel house shell as well as
for the power line, phone, tower-related cables, and well cables.

I have been counting on the steel shell wicking off lightning energy through
multiple grounding points minimizing the collection of energy at any single
point.

Should I place ground rods at the corners, and perhaps at additional 10 or
20 foot locations around the perimeter of the 60 x 40 structure, and tie
them to the base plate of the outer metal wall?

The lightning storm that just rolled through reminded me to take seriously!

Thanks! & 73, doc kd4e
_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.

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