Code Q&A: NM Cable Rules

Dec. 5, 2013
Your most pressing National Electrical Code (NEC) questions answered

Q. Can I pull Type NM cable in a PVC sleeve located in a ground floor slab for the kitchen counter island?

A.  No. Type NM cable must not be used in wet or damp locations [334.12(B)(4)].

The interior of enclosures or raceways installed in an underground installation are considered to be a wet location [300.5(B)]. Cables and insulated conductors installed in underground enclosures or raceways must be listed for use in wet locations, according to 310.10(C).

The definition of a “Wet Location” (as noted in Art. 100) includes installations underground, in concrete slabs in direct contact with the earth, locations subject to saturation with water, and unprotected locations exposed to weather. If raceways are installed in wet locations above grade, the interior of these raceways is also considered to be a wet location [300.9].

About the Author

Mike Holt

Mike Holt is the owner of Mike Holt Enterprises (www.MikeHolt.com), one of the largest electrical publishers in the United States. He earned a master's degree in the Business Administration Program (MBA) from the University of Miami. He earned his reputation as a National Electrical Code (NEC) expert by working his way up through the electrical trade. Formally a construction editor for two different trade publications, Mike started his career as an apprentice electrician and eventually became a master electrician, an electrical inspector, a contractor, and an educator. Mike has taught more than 1,000 classes on 30 different electrical-related subjects — ranging from alarm installations to exam preparation and voltage drop calculations. He continues to produce seminars, videos, books, and online training for the trade as well as contribute monthly Code content to EC&M magazine.

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