[RE-wrenches] rebar v/s fiber

[R Ray Walters]

Actually my read of 2008 code should allow the pole to qualify as the grounding electrode:
690.47 (D) allows the mounting structure to be the electrode if it meets  250.52.
250.52(A.7) plate electrode says you need at least 2 sq. ft of 1/4" steel plate. 
A 6" diam pipe 4 ft in the ground, will have 6.8 sq. ft of surface area......
A 4" diam pole will have 4.7 sq ft of surface area.....
Anybody see a flaw in this logic?

R. Walters
ray at solarray.com
Solar Engineer

On Mar 13, 2010, at 1:06 PM, Bob-O Schultze wrote:

> Agreed. I'm surprised that no one mentioned that nice 3'-5' deep hole is a hell of a nice start for your grounding electrode....
> 
> On Mar 13, 2010, at 8:30 AM, Kent Osterberg wrote:
> 
> The need for rebar or not depends on how the pole is secured and on the shape of the footing.  If you are installing a pipe in a deep narrow hole per most mount manufacturer's specifications, no rebar should be necessary.  Anything else will certainly require rebar and per manufacturers' disclaimers should be designed by an engineer.  For example, if the installation will have j-bolts in the concrete with the post welded to a plate held in place by the j-bolts, a full rebar cage will needed.
> 
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