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 is the preferred wiring method for industrial facilities, data centers, and large commercial buildings where routing dozens or hundreds of cables through individual conduits would be impractical and expensive. NEC Article 392 governs cable tray installations, covering tray types, fill. According to the 2005 National Electrical Code® (NEC), a cable tray system is “ unit or assembly of units or sections and associated fittings forming a structural system used to securely fasten or support cables and raceways. 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. Installation of Cable in Cable Trays involves precise routing on support systems, NEC/IEC compliance, grounding, ampacity derating, bend radius control, segregation of services, fire safety, labeling, and reliable cable management for industrial and commercial facilities. Think of a roadway bridge that supports traffic. Cable Tray Systems must provide protection to life & property against faults caused by electrical disturbances Lighting. Question 1: Can mechanical utility piping or tubing containing water or compressed air be installed in cable trays with electrical cables? Answer: No. NEC section 300-8 does not permit.