National Electrical Installation Standards

Standards as High as Your Own

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Thursday, December 30, 2021

Question:

Hello,

If I installed two conduit nipples between enclosures and ran a parallel feeder between the enclosures, can I install the A phase and B phase in one nipple, and the C phase and neutral in the other? The terminal lug arrangeme4nt in each enclosure lines up better that way.

Thanks in advance for your response.

Nathan Butler

A

Answer:

Greetings Nathan,

Based on the information in the question, it seems that installing the conductors in the arrangement suggested would result in. an induction problem. Section 300.3(B) indicates that all conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cable bus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1)through (B)(4). Conductors shall be permitted to be run in parallel in accordance with the provisions of 310.10(H). The requirement to run all circuit conductors within the same raceway, auxiliary gutter, cable tray, trench, cable, or cord shall apply separately to each portion of the paralleled installation, and the equipment grounding conductors shall comply with the provisions of 250.122. Parallel runs in cable tray shall comply with the provisions of 392.20(C).

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