Based on the 2020 NEC.
Q. What is required by the NEC where conductors transition from a cable tray to raceways or enclosures?
See answer below.
A. A box is not required where cables or conductors are installed in a bushed raceway used for support, for protection against physical damage, or where conductors or cables transition to a raceway from the cable tray (Sec. 392.46).
392.46(A) Through Bushed Conduit or Tubing. Individual conductors or multiconductor cables with entirely nonmetallic sheaths can enter enclosures where they are terminated through nonflexible bushed conduit or tubing installed for their protection, provided they are secured at the point of transition from the cable tray and the raceway is sealed at the outer end using an approved means to prevent debris from entering the equipment through the raceway.
392.46(B) Flanged Connections. Individual conductors or multiconductor cables with entirely nonmetallic sheaths can enter enclosures through openings associated with flanges from cable trays where the cable tray is attached to the flange and the flange is mounted directly to the equipment. The openings must be made such that the conductors are protected from abrasion and the openings must be sealed or covered to prevent debris from entering the enclosure through them.
Informational Note: One method of preventing debris from entering the enclosure is to seal the outer end of the raceway or the opening with duct seal.
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.