Due to their exposure to the open air because of the cable trays, the wires contained within need a very durable outer covering. The regulations dictate that the cables must either be Type TC (also known as Tray Rated) or must be metal-armored (Type MC). 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. A rung spacing of 6 to 9 inches (150 to 230 mm) is preferable when. NEC Article 392 outlines the key rules for installing and maintaining industrial cable tray systems. Here's what you need to know: Cable Types: Only use. Cable tray systems provide a safe, organized, and flexible method for supporting insulated conductors and cables in commercial and industrial electrical installations. NEC section 300-8 does not permit.
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