These cables run inside large metal trays (Cable Trays) or drop vertically through enclosed channels (Electrical Shafts / Risers). Every time these channels pierce fire-rated walls or slabs, they create enormous holes (much larger than a single pipe). Cable trays are a support system for electrical cables, power, signal, and communication and optical fiber cables. NEC section 300-8 does not permit any tube, pipe, or equal for water, air gas, drainage, steam, or any service other than electrical in raceways or cable trays containing. A cable shaft is a central component of underground infrastructure. It serves the safe accommodation, routing, distribution, and maintenance of power and data lines in cities, industrial plants, transportation structures, and tunnels. Cable ladder systems and cable tray systems shall be manufactured in accordance with BS EN 61537, channel support.
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