Method for fabricating cable tray installation around bends

Cable trays around bends are installed using pre-manufactured fittings, proper cutting, and support techniques to ensure cable integrity, grounding, and compliance with standards.

Planning and Preparation

Before installation, review approved shop drawings to determine the layout, bend locations, and tray lengths. Ensure all materials, including trays, bends, elbows, and accessories, are inspected for damage and compliance with project specifications . Store trays horizontally on a flat surface, protected from moisture and sunlight, to prevent warping or corrosion .

Fabrication and Cutting

• Use pre-manufactured bends and elbows whenever possible; site fabrication of bends is generally discouraged to maintain structural integrity .
• If cutting is required, use a hand-held hacksaw or jigsaw to achieve a square cut. Smooth all edges to remove burrs and apply rust-proof paint to prevent corrosion .
• Ensure the minimum permissible radius of the largest cable is maintained to avoid cable damage .

Installation Around Bends

• Position bends and elbows so that joints are close to supports to maintain stability .
• Use load-bearing cleats for vertical trays and ensure proper support spacing for horizontal runs. Typically, additional fixings are placed within 150 mm of each side of the fitting .
• Maintain a minimum clearance of 75 mm from building structures for cable access and maintenance .
• For bends where cables may fall out when covers are removed, install retaining bars or insulating devices to secure cables .

Grounding and Continuity

• Install earth continuity strips at all joints and fittings.
• Provide a separate grounding cable connected to the main earth bar to ensure electrical safety .

Fire and Expansion Considerations

• Use approved sleeves and fire-resistant sealants where trays pass through floors or fire barriers .
• Include expansion joints at building expansion points to accommodate thermal movement .

Final Checks

• Perform a continuity test after completing each section to ensure electrical integrity .
• Label trays for power and ELV services as per project requirements.
• Verify that all supports, pedestals, and roof-mounted installations comply with approved MEP coordination drawings . By following these steps, cable trays can be safely and efficiently installed around bends while maintaining cable protection, structural stability, and compliance with standards such as BS EN 61537 .