A 400A service is made up of two 200A main breaker panelboards that are nippled together. Can the service conductors pass through one of the cabinets to supply the other panelboard?
Q. A 400A service is made up of two 200A main breaker panelboards that are nippled together. Can the service conductors pass through one of the cabinets to supply the other panelboard?
A. Yes. Cabinets, cutout boxes, and meter socket enclosures can be used as a raceway for conductors that feed through if the conductors don’t fill the wiring space at any cross section to more than 40% [312.8].
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.
