Branch Circuits & WiringQuestion 204 of 521
In a 3-wire, single-phase circuit (two hots and a neutral), how is the neutral treated when counting current-carrying conductors for adjustment?
a.Always counted as current-carrying
b.Counted only if it is 12 AWG
c.Counted as one-half a conductor
d.Not counted, since it carries only unbalanced current
Explanation
Per 310.15(E), the neutral of a 3-wire single-phase circuit carries only the unbalanced current and is not counted as a current-carrying conductor. It would be counted only in a 4-wire wye supplying significant nonlinear (harmonic) load.
Law Reference: 2023 NEC §310.15(E)Practice all 521 questions free — no signup required.
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