Should cable tray bends be included in the quota item

Cable tray bends do not have a separate quota but must be properly supported and comply with minimum bend radius and mechanical standards.

Support and Installation Requirements

Cable tray bends, like straight sections, must be supported to prevent undue mechanical strain on cables. According to BS 7671, all cables should be supported at appropriate intervals to avoid damage from their own weight or mechanical stress, including at bends and terminations . IEC 61537 also emphasizes that cable trays, including bends, must withstand the load of cables and environmental factors, ensuring mechanical strength and safety .

Minimum Bend Radius

When routing cables through bends, it is essential to maintain the minimum bend radius specified for the cable type. This prevents excessive stress, deformation, or insulation damage. Technical guides recommend that bends be designed to accommodate the cable's minimum bend radius without forcing the cable into sharp angles .

Support Intervals

While there is no separate "quota" specifically for bends, support elements such as brackets, wall mounts, or hangers should be installed near bends to maintain stability and prevent sagging . Typical practice is to place supports at intervals consistent with the cable tray manufacturer's recommendations and the type of cable being installed.

Practical Considerations

• Horizontal and vertical bends should be supported at or near the bend to prevent stress on the cable.
• T-pieces, crossovers, and reductions are treated similarly to bends in terms of support requirements .
• Material selection for supports should consider environmental conditions, fire resistance, and mechanical load .

Conclusion

Cable tray bends do not require a separate quota, but they must be properly supported and designed to respect the minimum bend radius. Ensuring compliance with BS 7671, IEC 61537, and manufacturer guidelines guarantees mechanical integrity, safety, and longevity of the cable installation. Proper support at bends is critical to prevent undue strain and maintain system reliability.