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 trays are a support system for electrical cables, power, signal, and communication and optical fiber cables. Grounding: Metallic trays can serve as equipment grounding conductors (EGC) if they meet NEC requirements. Fill Rules for Multiconductor Cables 3. Ampacity Derating. A common question arises: Can power cables and instrumentation/communication cables be run in the same cable tray? This article explores technical standards, safety considerations, and best practice. Technical Standards and Regulations NEC (National Electrical Code) Article 300. 3 (C) (1):. 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.
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