Is welding allowed at cable tray bends

Welding is generally not allowed at cable tray bends because it can compromise structural integrity and damage installed cables.

Structural and Safety Considerations

Cable trays, including bends, are designed to support cables while maintaining proper spacing and bend radius. Welding on bends can weaken the tray material, distort the bend geometry, and create sharp edges that may damage cable insulation or shielding, potentially leading to electrical faults or corona discharge issues . Cable trays are intended to be installed as manufactured, with bends and fittings designed to meet mechanical and electrical safety standards .

Standards and Best Practices

• Cable trays should comply with BS EN 61537 or equivalent standards, which specify that trays are for cable support and not for modification through welding .
• Bends must maintain the minimum bend radius to prevent cable damage, and welding could alter this radius, causing insulation stress or conductor deformation .
• Installation guides recommend using pre-fabricated bends, elbows, or fittings rather than modifying trays on-site .

Recommended Alternatives

Instead of welding, consider:

• Using factory-made bends or elbows that match the tray type and material.
• Employing mechanical fasteners or clamps to join tray sections securely.
• Ensuring proper support spacing to maintain structural integrity without altering the tray material .

Conclusion

Welding at cable tray bends is not recommended and is typically prohibited by electrical installation standards. Modifying bends through welding can compromise both the mechanical strength of the tray and the safety of the cables it supports. Always use pre-fabricated fittings and follow manufacturer and standard guidelines to ensure safe and compliant installation .