When you find yourself stumped by the Code, just e-mail your question to [email protected] or visit www.mikeholt.com. Your question and Mike's answer may be posted in a future Code Q&A column.
Q. I remember being taught not to use a panel or disconnect as a raceway, but I can’t find a reference to this rule in the Code. I want to be able to justify the extra cost other than just knowing it is the right thing to do. Could you point me in the right direction?
A. Cabinets containing panelboards, cutout boxes or enclosures for switches, and meter socket enclosures can be used as a raceway through which to feed conductors if the conductors don’t fill the wiring space at any cross section to more than 40%.
In addition, splices and taps are permitted if they don’t fill the wiring space at any cross section to more than 75%.
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.