Ground-Fault Protection of Service Equipment

As defined by Sec. 230.95, the rating of the service disconnect shall be considered to be the rating of the largest _____ that can be installed or the highest continuous current trip setting for which the actual overcurrent device installed in a circuit breaker is rated or can be adjusted.

Mike Holt

June 2, 2015

a) fuse
b) circuit
c) conductor
d) all of the above

See answer and applicable Code reference

The correct answer is: a) fuse

Article 230 covers service conductors and equipment for control and protection of services. Part VII of this Article focuses on the overcurrent protection requirements for service equipment. As noted in a portion of Sec. 230.95, "The rating of the service disconnect shall be considered to be the rating of the largest fuse that can be installed or the highest continuous current trip setting for which the actual overcurrent device installed in a circuit breaker is rated or can be adjusted."

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.