Step-1: Confirm the actual layout, dimensions & mounting height of cable trays & conduits. Step-3: Coordinate with other trades to prevent interference during installation. This publication is intended as a practical guide for the proper and safe* installation of cable ladder systems, cable tray systems, channel support systems and associated supports. This guide breaks down the process step by step. Ladder trays are great for high-voltage cables. Whether you're a contractor, inspector, or engineer, understanding these pitfalls—and how to avoid them—is. NEC Article 392 outlines the key rules for installing and maintaining industrial cable tray systems. These systems, made from metal or plastic, are open structures designed to support electrical conductors, ensuring proper organization and safety.