Cable Management Tray Size: Choose a tray size that will hold the desired amount and length of cable. 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. Here's what you need to know: Cable Types: Only use. The NEC requires that cable trays must be supported by members at an interval specified by the cable tray manufacturer, but not more than 5 feet for horizontal runs to support the weight of the cables and other loads. You should consider it as a series of instructions that make the buildings resistant to. Article Summary: A compliant cable tray installation requires a thorough understanding of NEC Article 392, proper structural support, and precise installation techniques.