Historically, the NEC has allowed cable trays, but has lacked specific guidelines for sizing conductors and using smaller conductors like PV wire and DG cable on rooftops. The primary rulebook used in the safe use of cable trays is NEC Article 392. This is a description of how to select, install, and support these metal or plastic frames, on which electrical wires are installed. You should consider it as a series of instructions that make the buildings resistant to. NEC Article 392 explains cable trays, their components, appropriate wiring methods for cable trays, and instances where they are and are not permitted for use. Here is the summary of the main points found in NEC Article. (i) Metal raceways, cable trays, cable armor, cable sheath, enclosures, frames, fittings, and other metal noncurrent-carrying parts that are to serve as grounding conductors, with or without the use of supplementary equipment grounding conductors, shall be effectively bonded where necessary to. The use and installation of cable trays is covered by legally enforceable OSHA regulations in 29 CFR 1910. 305(a)(3), or comparable standards promulgated by States operating OSHA-approved State plans. Cable tray is the preferred wiring method for industrial facilities, data centers, and large commercial buildings where routing dozens or. In this installment of our Code Corner series, Ryan Mayfield focuses on the 2023 National Electrical Code (NEC) changes concerning cable trays, particularly section 690.