Q. Can I use SER cable in a 4-story multifamily dwelling?
A. NM and SE cables can only be used in multifamily dwellings permitted to be of Types III, IV, and V construction [334.10(A) and 338.10(B)(4)(a)]. The number of stories does not enter into the requirements. Types of construction are covered in the applicable building codes (such as the International Building Code), and are not covered in the NEC. In a nutshell, the type of construction means the types of material a building can be constructed of, such as wood, concrete and steel. Because this is a difficult topic for electricians to deal with, your best bet is to consult with the building official of the city/county you're working in.
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.