Q. What uses are permitted by the NEC for nonmetallic-sheathed (NM) cable?
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A. Type NM and Type NMC cables can be used in the following situations [334.10], except as prohibited in Sec. 334.12:
(1) One- and two-family dwellings of any height and their attached/detached
garages or storage buildings.
(2) Multifamily dwellings permitted to be of Types III, IV, and V construction.
(3) Other structures permitted to be of Types III, IV, and V construction. Cables must be concealed within walls, floors, or ceilings that provide a thermal barrier of material with at least a 15-min. finish rating, as identified in listings of fire-rated assemblies.
Informational Note 1: Building constructions are defined in NFPA 220-2015, Standard on Types of Building Construction, the applicable building code, or both.
Informational Note 2: See Annex E of the NEC for the determination of building types [NFPA 220, Table 3-1].
(4) Cable trays permitted in Types III, IV, or V structures where the cable is identified for the use.
(5) Where within raceways permitted to be installed in Types I and II construction.
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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.