ECN Forum Forums General Topics of the Trade General Discussion Area Conductors in Parallel

Is there a code stating the maximum number of conductors allowed to be paralleled. I know 1/0 is minimum size but found no limit on how many. I want to use four 350KCM per phase instead of two 1000KCM. Kinda tough to work that fat stuff into the bottom fed switchgear.

Four conductors per phase can be used under NEC 310-4, if the equipment is intended for 4 cdr/ø. Keep lengths equal and similarly routed for each group. If 1000kcmil is specified and there’s code-adequate bending space, use it! Won’t kill you.

I don't think there is a Maximum number as long at the terminations are made to accept the number of the parallel conductors.

Going from a bus to a bus I would think is virtually unlimited.

To devices such a Circuit Breakers the available (listed) lug pattern for that CB would be the determining factor.

I don't believe their is a maximum # of parallel conductors, as long as they meet the conditions of 310.4 ('02), or 310-4 ('99)

I have never heard of a maximum. The more you do the harder it gets to keep them all "the same length" I have had the pleasure [said with much sarcasm] of terminating 12 runs of 500MCM paralleled myself. (And 10 runs of 600 MCM come to think of it) It is really not that bad IF you have sufficient room and you realize you are not going to finnish before lunch the day you start. (you probably won't finnish before lunch the following day either!)