Code Q&A: Bushing Requirements

Aug. 7, 2019

Test your NEC knowledge.

Ecmweb Com Sites Ecmweb com Files 344 46 01 N0

Q. What is the NEC rule for the installation of bushings on rigid metal conduit (RMC)?

See the answer below.

A. To protect conductors from abrasion, a metal or plastic bushing must be installed on conduit threads at terminations, regardless of conductor size, unless the box, fitting, or enclosure is designed to provide this protection [Sec. 344.46].

Informational Note: Conductors 4 AWG and larger that enter an enclosure must be protected from abrasion, during and after installation, by a fitting that provides a smooth, rounded, insulating surface, such as an insulating bushing, unless the design of the box, fitting, or enclosure provides equivalent protection, in accordance with Sec. 300.4(G).

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.