Roger (K8RI) wrote:
>
> Larry & Karen wrote:
>> My wife, a EE/P.E. forwarded this to me just today.
>>
>> http://www.mikeholt.com:80/newsletters.php?action=display&letterID=644&email=kaatnip@qconline.com
>> _______________________________________________
>>
>>
> I'm just wondering why would I care whether my ground system has real UL
> rods or not.
At least in the 2005 code, there's no particular requirement for the rod
to be UL (you can use pretty much any sort of metal you want, galvanized
pipe, for instance). The copper cladding is for corrosion protection.
There are some sort of generic notes in the front pages about using
listed components.
> And now days what would be the primary ground? Neutral from the pole?
> Neutral from the pole ties to the panel ground which ties to the ground
> rods. However neutral from the panel and grounds to the outlets are run
> separate.
The "ground" is at the service entrance, where the "grounded" conductor
(aka neutral) and the "grounding" conductor (green wire) are bonded.
The electrical safety ground(greenwire) is really more of a "equipment
bonding" conductor (there's a move afoot to actually change the wording
in the code to do away with "ground", since it's so confusing.. Maybe in
the 2011 or 2014 code..)
The whole idea is to give a low enough impedance path from equipment
back to panel so that if there is a line->case short, the breaker will
trip. For this application, no earth ground is needed.
Limiting the "touch voltage" of the case (so if you're standing in bare
feet, etc.) is a secondary goal.
As far as the actual "grounding electrode" goes.. the code (2005 and
2008, for sure, maybe earlier.. I gave my 2002 book away) requires a
Ufer ground.
---
One potential issue with counterfeits is that they *might* corrode
faster, and someone who was expecting a certain life from the rod
wouldn't get that life. (Of course, the crummy life of ground rods in
general is part of why the code doesn't allow them as the primary ground
connection means any more)
Could also make life interesting in the event of a lawsuit where, for
some reason, the ground rod becomes at issue. Who's liable here? (it
probably depends on whether you're in a strict liability state or not)
Jim
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