Code Q&A

Aug. 14, 2006

What type of fitting can I use to terminate ground wires in a metal box?

Q. What type of fitting can I use to terminate ground wires in a metal box?

A. The termination of equipment grounding and bonding conductors must be by exothermic welding, listed pressure connectors of the set screw or compression type, listed clamps, or other listed fittings [250.8]. In addition, as shown in the Figure, equipment grounding (bonding) conductors that enter a metal box must be bonded to the box by a grounding screw that serves no other purpose or a listed device (like a ground clip) [250.148(C)].

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.