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). Cable tray types, fill rules for single-conductor and multiconductor cables, ampacity derating, separation requirements, and when to use tray vs conduit. This is a description of how to select, install, and support these metal or plastic frames, on which electrical wires are installed. You should consider it as a series of instructions that make the buildings resistant to. en completely installed, without damage either to conductors or structural system use maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. Cable trays are permitted for use in.
