• Code Q&A

    A conductor passing through a box unbroken counts as one conductor, so if I loop a conductor through the box unbroken and strip off enough insulation to terminate on a receptacle without cutting the wire, does the conductor count as one or two conductors for box sizing?
    Sept. 27, 2007

    Q. A conductor passing through a box unbroken counts as one conductor, so if I loop a conductor through the box unbroken and strip off enough insulation to terminate on a receptacle without cutting the wire, does the conductor count as one or two conductors for box sizing?

    A. It counts as two conductors. Each conductor that runs through a box and does not have 6 inches of free conductor for splices or terminations in accordance 300.14, and each conductor that terminates in a box is counted as a single conductor volume in accordance with Table 310.16(B). If the conductor includes a loop long enough to terminate on a device legally (at least 12 inches), it must be counted as two conductors [314.16(B)(1)]. According to 300.14, at least 6 inches of free conductor, measured from the point in the box where the conductors enter the enclosure, must be left at each outlet, junction, and switch point for splices or terminations of luminaires or devices.

    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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