Spacing between cable tray hangers and fixed supports

Cable tray supports should typically be spaced 1. 5 to 3 meters apart for horizontal runs, with hangers not exceeding 1. 5 meters, while vertical runs require supports at intervals of less than 2 meters.

Horizontal Cable Tray Runs

For straight horizontal sections, the support span between cable tray supports generally ranges from 1. 5 meters to 3 meters, depending on the tray type, material, and cable load. This spacing ensures structural stability, prevents sagging, and allows for maintenance and inspection.

At corners, bends, or T-junctions, it is recommended to install one hanger on each side, arranged symmetrically to maintain tray stability and prevent undue stress on the cables. Fixed supports should also be placed at the beginning and end of the tray and at beam locations to distribute weight effectively.

Vertical Cable Tray Runs

For vertical installations, supports should be fixed to the building structure at intervals preferably less than 2 meters. Cables within vertical trays should be secured at the top and then every 1. 5 meters to maintain order and prevent displacement.

Hanging rod supports for vertical runs should have a minimum diameter of 8 mm to ensure stability.

Cable Hangers and Flexible Systems

When using cable hangers or J-hanger installations, the spacing may vary depending on the cable type, weight, and stiffness. Flexible systems require calculations to determine the distance between supports to achieve a small deflection (typically 2%) and prevent expansion or displacement due to thermal effects. Stiffer cables, such as MDPE-sheathed types, may require greater spacing between supports compared to more flexible cables like LSOH types.

Best Practices

Always secure cables at start, end, and turns of horizontal runs, and at top and intervals in vertical runs. Avoid cable crossings or overlaps within trays to maintain organization and airflow. Use fire-resistant supports for all cable types to prevent premature failure in case of fire.

Ensure supports are installed by competent personnel familiar with electrical installation standards and safety practices. By following these guidelines, cable tray systems will maintain structural integrity, safety, and ease of maintenance, while minimizing mechanical strain on the cables.