All conductors of a circuit, including the neutral and equipment grounding conductors, must be run in the same raceway, cable, trench, cord, or cable tray; except as permitted by 300. The primary rulebook used in the safe use of cable trays is NEC Article 392. This is a description of how to select, install, and support these metal or plastic frames, on which electrical wires are installed. Here is the summary of the main points found in NEC Article. Article 300 contains the general requirements for wiring methods and materials for power and lighting [300. It includes the general requirements for all wiring methods included in the NEC, but does not apply to twisted-pair cable and coaxial cable (covered in Chapters 7 and 8) unless Article. Cable tray systems provide a safe, organized, and flexible method for supporting insulated conductors and cables in commercial and industrial electrical installations.
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