National Electrical Installation Standards

Standards as High as Your Own

 
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Thursday, November 25, 2021

Question:

Hello,

What is the required size aluminum equipment grounding conductor for a 400-ampere feeder circuit. The installation is not run using parallel conductors or conduits. Please provide the NEC reference.

Your guidance is appreciated.

Juan Mendoza

A

Answer:

Hello Juan,

Thanks for the question. Section 250.122(A) refers to Table 250.122 which addresses the minimum size for equipment grounding conductors. Based on the information in the question, and referencing Table 250.122, a 1 AWG sized aluminum conductor is the minimum size EGC for a 400-ampere feeder circuit. This response does not take into consideration an effects of voltage drop or sizing for EGCs in parallel arrangements.

Hope this guidance is useful.

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