National Electrical Installation Standards

Standards as High as Your Own

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Monday, February 19, 2018

Question:

Is the interior of a bell box (weather-proof) considered a wet location, when mounted on the exterior of a building? NM cable from inside building is located inside the box for an exterior receptacle. 

Thanks, Alan Chech

A

Answer:

Hey Alan thanks for your question. No, the interior of a weatherproof enclosure, mounted on the exterior of a building, is not a wet location as that term is defined in Article 100. The interior of enclosures installed underground are considered wet locations as stated in 300.5(B). In 300.9 for above grade installations only raceways are included, the word "enclosure" is not used. NM cable is commonly used to supply boxes that face outwards for outside receptacles on dwellings but make sure the local AHJ agrees because NM cable is not allowed in damp locations as stated in 334.12(B)(4).

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