EGC not required same specs as phase wires in parallel installations

[SparkyRules]

My current code battle is this. We all know (300.3) that when you parallel conductors they have to be at least 1/0 AND the same, length ,type etc etc. My issue is the EGC that goes with them. This has to be sized per 250.122. As such it is NOT a paralleled conductor, it is not many smaller conductors in parallel to equal a bigger needed size, in fact you CANNOT parallel many smaller EGC to meet the size in 250.122 therefor it is NOT a parallel conductor and as such does not need to meet the requirements of 300.3(B)(1), as long as it is sized per 250.122 . Say you have 2 pipes with a 600A OC ahead of this, in each pipe you could have say 350 THWN Cu for phase and neutral as long as same conductor type etc. However for your EGC in one pipe you could have a 1 Cu and in the other you could have a 2/0 Al and be just fine, as IMHO these EGC conductors although wire in "parallel" are NOT "paralleled" conductors as I understand what that means for "paralleled" installations. Furthermore the EGC most probably would act in singulairty, someone digging thru one of the pipes and ALL the fault current will be on what ever EGC is in THAT pipe, the other's totaly not in said mix. Comments?

 

[LarryFine]

Comments?

I agree. Each EGC needs to be sized as if it was the only EGC for the feeder, but as a normally-non-current-carrying conductor, it is not subject to the paralleled-conductors rules.

If it was, then tying all EGCs in a given box would be restricted, like a 15a light circuit and a 20a receptacle circuit in one box on a kitchen counter. In fact, doing so is required.

 

[infinity]

Just remember that the rule for parallel conductors in 310.10(H) does not apply to EGC's.

310.10(H) Conductors in Parallel.
(1) General. Aluminum, copper-clad aluminum, or copper conductors, for each phase, polarity, neutral, or grounded circuit shall be permitted to be connected in parallel (electrically joined at both ends) only in sizes 1/0 AWG and larger where installed in accordance with 310.10(H)(2) through
(H)(6).