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Monday, August 13, 2018

Question:

Best resource available. Does the NEC allow a reduced neutral for a balanced 3 phase load?  I was told this has been changed, where?

Thanks, Have a good day!!

Lowell I. (Laddie) Wolfe Jr.

A

Answer:

Hey Laddie thanks for your question and the kind words. Feeder and Service neutral loads are calculated using 220.61. You might be thinking about a change in the 2017 NEC to 310.15(B)(7). The neutral of single phase service and feeders supplied from 208Y/120 volt systems is now allowed to be sized using 310.15(B)(7)(4).

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