Ground wire size

[Jhaney]

If I have 2 ground rods and my service conductor size is 2/0 then my ground wire to the first rod would have to be #4 per table 250.66 now this is where i get confused. the ground wire from the first rod to the second rod doesn't have to larger than #6 per 250.66(A), Is my understanding of this correct?
And what about multiple rods more than 20ft long because per 250.52(A)(4) it would need to be 2 AWG or does that only matter if it circles a building?:-?

 

[charlie b]

If I have 2 ground rods and my service conductor size is 2/0 then my ground wire to the first rod would have to be #4 per table 250.66 . . . the ground wire from the first rod to the second rod doesn't have to larger than #6 per 250.66(A), Is my understanding of this correct?

As I read it, the last few words of 250.66 (before the table) tell us that sub-article (A) overrules the table. So if the GEC connects to a rod, then the GEC need not be larger than #6 copper, regardless of what the table says.

And what about multiple rods more than 20ft long because per 250.52(A)(4) it would need to be 2 AWG or does that only matter if it circles a building?

250.52(A)(4) is not talking about rods. It is talking about a conductor that encircles the building. If the conductor is at least 20 feet long (it would take more than that to encircle the building, unless you have a really small building) and at least #2 in size, then it can be credited as being a grounding electrode.

 

[Jhaney]

Thanks charlie this was on a test prep question and it got me totally confused