Only approved tray-rated cables should be installed. Grounding and bonding are mandatory for metallic trays. Tray fill limits must be calculated properly. 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. Cable tray types, fill rules for single-conductor and multiconductor cables, ampacity derating, separation requirements, and when to use tray vs conduit. Cable tray is the preferred wiring method for industrial facilities, data centers, and large commercial buildings where routing dozens or. 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. A rung spacing of 6 to 9 inches (150 to 230 mm) is preferable when. After determining the routing of the cabling, a network cabling project initially needs to consider the laying of cable trays, which can be made of metal, conduit, or plastic (PVC) tubes based on the material used. The flexibility and scalability of cable trays make them an ideal choice for environments where cable density and organization can. This document deals with cables trays, cables and connector installation and segregation, cable trays earthing and E. These rules shall be applied in the cabling engineering workflow for all subjects concerning or in relationship with cabling in the ITER facility.