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Maximum allowable number of wires to be threaded through cable trays
Annex C is used to determine the maximum number of conductors or fixture wires that can be placed inside a conduit, tubing, or cable tray when all conductors are of the same size and insulation type. 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. You should consider it as a series of instructions that make the buildings resistant to. 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. Historically, the NEC has allowed cable trays, but has lacked specific guidelines for sizing conductors and using smaller. (i) Metal raceways, cable trays, cable armor, cable sheath, enclosures, frames, fittings, and other metal noncurrent-carrying parts that are to serve as grounding conductors, with or without the use of supplementary equipment grounding conductors, shall be effectively bonded where necessary to.
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