Code Q&A: Sizing Bonding Jumper for Single Raceway

June 25, 2015

NEC rules on sizing bonding jumpers

Q. What are the rules in sizing a supply side bonding jumper sized for a single raceway containing service conductors?

Find the Answer

A. The supply-side bonding jumper (SSBJ) at a service ensures the required electrical conductivity between metal parts required to be connected [Art. 100 definition]. In single raceway installations, the supply-side bonding jumper is sized in accordance with Table 250.102(C)(1) of the 2014 NEC, based on the largest ungrounded conductor within the raceway [250.102(C)(1)], as shown in the Figure.

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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.