NEC Article 392 covers the requirements for cable tray systems, including the types of trays recognized, which wiring methods can be installed in them, where they can and cannot be used, how they must be supported, and the rules for grounding, cable fill, and ampacity. 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. Article Summary: A compliant cable tray installation requires a thorough understanding of NEC Article 392, proper structural support, and precise installation techniques. This compliance is not merely a regulatory formality; it significantly enhances the safety and reliability of the electrical system, ensuring that installations can pass inspections and function. Whether you're building a commercial setup or upgrading an industrial plant, proper cable tray installation ensures neat wiring, safe access, and easy maintenance. But before you lay the first tray or clamp down a single cable, you need a solid plan. This guide breaks down the process step by step.