Code Quiz of Day

Percentage Fill Limitation: NonMetallic Surface Raceway

March 30, 2015

Article 388 covers the use, installation, and construction specifications for surface nonmetallic raceways and associated fittings.

Mike Holt

The conductors, including splices and taps, in a nonmetallic surface raceway having a cover capable of being opened in place, shall not fill the raceway to more than ____% of its cross-sectional area at that point.

a) 38
b) 40
c) 53
d) 75

See answer and applicable Code reference

The correct answer is: d) 75

Article 388 covers the use, installation, and construction specifications for surface nonmetallic raceways and associated fittings. As noted in the second sentence of of Sec. 388.56, "The conductors, including splices and taps, shall not fill the raceway to more than 75% of its area at tht point."

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.