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. Once the new cable is in position, release it from the. Article Summary: A compliant cable tray installation requires a thorough understanding of NEC Article 392, proper structural support, and precise installation techniques. Cable ladder systems and cable tray systems shall be manufactured in accordance with BS EN 61537, channel support. These pulleys facilitate the smooth movement of cables and wires, ensuring efficient and safe operations. Understanding their construction and functionality is crucial for optimal usage. The cable tray pulleys are composed of several key components, including the wheel, axle, and bracket.