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Code Q&A: Neutral Conductor and EGC Connection Requirements

April 23, 2019

How well do you know the NEC requirements for connecting neutral to ground?

Q. Where does the Code require that the connection be made between the neutral conductor and the equipment grounding conductor (EGC) at a service?

See the answer below.

A. A main bonding jumper [Sec. 250.28] is required to connect the neutral conductor to the equipment grounding conductor (EGC) within the service disconnect [Sec. 250.24(B)].

DANGER: If the Main Bonding Jumper is Not Installed

Dangerous voltage from a ground fault will not be removed from metal parts, metal piping, and structural steel if the service disconnect enclosure is not connected to the service neutral conductor. This is because the contact resistance of a grounding electrode to the earth is so great that insufficient fault current returns to the power supply if the earth is the only fault current return path available to open the circuit overcurrent protection device.

These materials are provided to us by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code.

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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.