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alkizmo
join:2007-06-25
Pierrefonds, QC

alkizmo to tomupnorth

Member

to tomupnorth

Re: Bare ground need conduit ??

said by tomupnorth:

Well this has gotten complicated hasn't it. Since there are no "authorities" where I live

No actually it gets quite simple: Do what the NEC says to do (AKA Nunya/Whizkid).
tomupnorth
join:2005-01-14
UpperMidwest

tomupnorth

Member

said by alkizmo:

said by tomupnorth:

Well this has gotten complicated hasn't it. Since there are no "authorities" where I live

No actually it gets quite simple: Do what the NEC says to do (AKA Nunya/Whizkid).

Ha, ha! Good one!

Yes, in TX everyone is supposed to go by the NEC.
said by nunya:

At an outbuilding with a feeder other than a branch circuit (E.G. sub-panel) then a grounding electrode is required (doesn't have to be a ground rod, but that's typically the defacto choice). The 4-wire circuit is required too. Technically, the feeder EGC does not need to be a #6 and is sized by 250.122.
If you drill down through the code far enough 250.32 (and this one is a tough one), you'll wind up at section III and 250.66.
There GEC at that location (the outbuilding) is sized by 250.66, where the minimum size GEC is #8 copper.
If you look at 250.66 it answers all the questions. No GEC going to a ground rod shall be required to be larger than #6 copper regardless of table 250.66.
If you go back to 250.53, they say that can't just use a single ground rod unless the resistance can be proved to 25 ohms. Most inspectors aren't going to call anybody out on this.
Any additional ground rads at the location (outbuilding) must be bonded together by, you guessed it, #6. Even if the GEC is a #8, and the EGC is a #10, the bond between rods "at the location" must be #6 minimum.

The code writers could do a much better job with article 250. It's a mess and hard to decipher. Especially for "multi-hat" inspectors who may not have an electrical background.