10 Sep
2014
10 Sep
'14
6:48 a.m.
On Sep 10, 2014, at 4:01 AM, Tothwolf <tothwolf at concentric.net> wrote:
...
One of the most interesting, and straightforward, high performance grounds is the Ufer
ground. It?s nothing more than a wire embedded in a couple of inches of concrete, fairly
long (20 or 30 feet?) and buried in the soil. Apparently this works very well even in
lousy soil. As I understand it, the fact that concrete absorbs water and is alkaline is
part of the reason. I learned about this from some professional lightning protection
literature. The technology goes back to 1940 or so.
paul
It just seemed a bit odd to me that code
didn't require more than just the two attempts to get a good earth ground.
Likely due to diminishing return. Adding yet another electrode isn't going to help
very much. In specialty applications where a low resistance ground is required (radio
communications for example), they make special chemical type ground rods. It is also
common to install large ground rings in these sorts of applications.