Code Q&A

When a conduit leaves a Class I, Division 1 classified paint spray room and goes under the concrete floor into a cabinet in the motor control room that is non-classified, is one sealing fitting in the paint mix room sufficient, or is an additional sealing fitting required in the non-classified area as well?

Mike Holt

Nov. 13, 2007

Q. When a conduit leaves a Class I, Division 1 classified paint spray room and goes under the concrete floor into a cabinet in the motor control room that is non-classified, is one sealing fitting in the paint mix room sufficient, or is an additional sealing fitting required in the non-classified area as well?

A. A single conduit seal in the spray area is okay, as long as it is within 10 feet of the Class I, Division 1 location boundary. There must be no fitting, except a listed explosionproof reducer, between the seal fitting and the point at which the conduit leaves the Class I, Division 1 location [516.4(A) and 501.15(A)(4)].

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.