This guide covers the cable tray types and their appropriate applications, the fill rules for each configuration, ampacity derating requirements, separation of power and signal cables, and the decision criteria for choosing cable tray over conduit. This standard specifies the requirements for nonmetallic cable trays and associated fittings designed for use in accordance with the rules of the Canadian Electrical Code (CEC) Part 1, and the National Electrical Code® (NEC). These regulations ensure that the metal or plastic frames that contain the wires are robust enough to ensure that they will not catch fire or break down. These systems provide an efficient and adaptable solution for managing a wide range of cables, including power cables, control. association representing the major electrical equipment manufac-turers in the U. Cable tray is the preferred wiring method for industrial facilities, data centers, and large commercial buildings where routing dozens or. Here is the summary of the main points found in NEC Article 392: Cable trays can be used as a support system for various wiring methods, including service conductors, feeders, branch circuits, communications circuits, control circuits, and signaling circuits (392. Cable trays are used not just.