Cable tray installation with reverse bend

Cable trays with reverse bends should be installed using proper support, alignment, and bending techniques to maintain structural integrity and cable protection.

Preparation and Planning

Before installation, ensure that the cable tray system is designed according to the project layout, including all bends, tees, and reverse bends. Verify that the tray material and finish are suitable for the environment, and check that all components comply with relevant standards such as BS EN 61537 for cable trays . Plan the support locations to maintain maximum load capacity and prevent sagging, typically spacing supports every 3.6 meters for ladder trays .

Installing the Reverse Bend

1. Fabricate the Bend: Reverse bends can be pre-fabricated or formed on-site using appropriate bending tools. Ensure the bend radius meets the minimum requirements for the cables to prevent damage .
2. Position the Tray: Place the tray section with the reverse bend in its intended location. Use temporary supports if necessary to hold the tray in place during alignment.
3. Attach Supports: Use trapeze, swing, or center-hung supports to secure the tray. Thread hex nuts and slide square washers onto the vertical hangers, then position the cross member under the tray. Ensure holes in the cross member are slightly larger than the all-thread diameter for easy adjustment .
4. Level and Align: Adjust the top and bottom nuts to level the cross member and ensure the tray is horizontal. Check that the reverse bend aligns with the incoming and outgoing tray sections.
5. Secure Tray Clips: Install tray clips either inside or outside the tray, depending on space and accessibility. This secures the tray to the support and allows minor horizontal adjustments .

Cable Considerations

• Maintain the minimum bend radius for cables at the reverse bend to prevent stress or insulation damage .
• Ensure rung spacing is appropriate (typically 150–230 mm) to support cables and prevent sagging .
• For instrumentation or control cables, consider additional protection such as solid covers or channel trays if heat or electromagnetic interference is a concern .

Safety and Best Practices

• Only lift single bundles at a time and avoid using the tray as a lifting point .
• Store trays on adequate dunnage to prevent deformation before installation .
• Ensure all installation work is performed by competent personnel familiar with electrical installation standards .
• Verify that the installed tray can withstand imposed loads, including cable weight, wind, and other environmental factors . By following these steps, a cable tray with a reverse bend can be installed safely, maintaining proper cable support, alignment, and compliance with industry standards.