>
> I'm not a student of Ufer grounds. However, I HAVE engineered some
> large towers...including a 500' self supporter. Everyting I've
> read says...provide a low impedance path AROUND the foundation,
> not through it.
>
> Think about it...1 million amperes is going to vaporize just about
> anything you put down there. I've seen 8" copper strap, 1/16" thick
> simply dissapear. If it's inside the concrete, the expanding vapor
> will cause cracking and structural failure.
>
> My sense of the Ufer ground was that it was intended to reduce
> corrosive currents, and improve conductivity, not to handle peak
> lightning strikes. Perhaps I'm wrong. I'm sure the assembled
> expertise here can correct me.
>
I'm certainly no expert either. That's why I'm asking the questions. My
research pointed to Ufer grounds for towers as a good solution. Ufer
proponets claim that exploding concrete is a myth. I got the impression
that most modern communication facilities use Ufer grounds for lightning
protection.
I am curious about something. If lightning will vaporize an 8" x 1/16"
strap, why even bother? That tells me that #2 solid copper wire should
vaporize in direct strike also, yet direct hits happen all the time and the
wire and equipment survive.
Regardless of which grounding system I use, I am thinking that deeper is
better, especially since my soil is very dry for the first 7-8 feet. Here's
an interesting link that I found last night on the subject of ground rod
depth:
http://www.cpccorp.com/deep.htm
73,
Clay W7CE
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