National Electrical Installation Standards

Standards as High as Your Own

 
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Friday, November 18, 2022

Question:

Good morning, Code Friends, a previous CQD on 10/10 was regarding a new subpanel being and fed from another location. Wouldn’t 250.32B apply where they should not be installing a new grounding electrode system (ground rod) but rather run an equipment grounding conductor from the supply as stated in 250.118? I am confused by the answer given as it seems to verify his installation as correct, but this is not how I have always understood the requirement. Wouldn’t the grounding electrode system be required at the meter / main location? Thanks for the insight, Tony Rickard
A

Answer:

Tony, thanks for your question. The answer is Yes. Based on the information provided in the question from October 10th, the sub-feed panel is installed remote from the renovated seawall, on a “Structure” built from Unistrut. Section 250.32(A) states: A Building(s) or Structure(s) supplied by a feeder are required to have grounding electrode system and grounding electrode conductor(s) to be installed per Part III of Article 250. The Unistrut Structure described in the original question, meets the Article 100 definition of a Structure (That which is built or constructed, other than equipment), therefore Section 250.32(A) would also apply.

 Additionally, Section 250.32(B)(1) requires the feeder supplying this sub-feed panel to have a qualifying equipment grounding conductor as listed in Section 250.118 and sized in accordance with Table 250.122, accompanying the supply conductors.

So both a grounding electrode system and equipment grounding conductor are required for this particular feeder because the feeder is located at a structure not connected to the same building as the supplying the feeder.

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