Install a simple pulley system above the cable tray. Tie the new cable to the string and pull (or push) the string through the pulleys. Cable ladder systems and cable tray systems shall be manufactured in accordance with BS EN 61537, channel support. But before you lay the first tray or clamp down a single cable, you need a solid plan. This guide breaks down the process step by step. This section will guide you through the necessary steps to ensure a successful. 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 the cable tray cont d for instrumentation and control applications that require. Proper installation of cables in trays is critical for maintaining an efficient and safe electrical system.