Segregation of Power and Signal Cables: Power (high-voltage) and signal (low-voltage) cables should be routed separately, using dedicated trays to minimize electromagnetic interference. These rules shall be applied in the cabling engineering workflow for all subjects concerning or in relationship with cabling in the ITER facility. Not respecting. Question 1: Can mechanical utility piping or tubing containing water or compressed air be installed in cable trays with electrical cables? Answer: No. Cable trays are a support system for electrical cables, power, signal, and communication and optical fiber cables. 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. Installation of Cable in Cable Trays involves precise routing on support systems, NEC/IEC compliance, grounding, ampacity derating, bend radius control, segregation of services, fire safety, labeling, and reliable cable management for industrial and commercial facilities.