Cable tray allows for the clean organization and routing of cable and offers advantages over conduit because cables are easier to access for installation, repair, removal and future development. When properly selected and installed, cable trays simplify routing, improve accessibility, and support future expansion while. 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. 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. 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.