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. It also focuses on construction and installation practices for cable trays. Here is the summary of the main points found. Recognize electrical cable tray misuse that can lead to electric shock and arc-flash/blast events and fires caused by overheating. 305(a)(3), or comparable standards promulgated by States. Cable tray systems provide a safe, organized, and flexible method for supporting insulated conductors and cables in commercial and industrial electrical installations. 305(a)(3) and within various provisions of the National Electric Code (NEC).