>> 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
> 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
The advantage of the Ufer ground is that it makes your ground electrode
very large in surface area. Therefore it has low inductance (good for
impulses), large C to the surrounding earth (good for impulses), and low
R (good for everything).
Except in some weird cases, I would think that the tens of square feet
of surface area in even a small concrete encased electrode will beat a
single rod of any depth.
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