Code Q&A: Smallest Approved Conductor

March 6, 2014

Your most pressing National Electrical Code (NEC) questions answered

Q. What is the smallest conductor allowed by the NEC for branch circuits? The answer is based on 2011 NEC.

A. The smallest conductor permitted for branch circuits in residential, commercial, and industrial locations is 14 AWG copper, except as permitted elsewhere in the Code [Table 310.106(A)].

There’s a misconception that 12 AWG copper is the smallest conductor permitted in commercial or industrial facilities. Although this isn’t true based on NEC rules, it may be a local code requirement.

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.