Requirements for cable fixing clamps inside cable trays

Cable fixing clamps inside cable trays must securely restrain cables, withstand mechanical and short-circuit forces, and comply with relevant standards such as BS EN 61537 and BS 7671. Key Requirements1. Mechanical Security and Load Resistance Cable clamps must hold cables firmly to prevent movement under their own weight or external forces, including vibrations, wind, or short-circuit events.

The clamps should be capable of withstanding the forces generated by the cables during a short circuit, as specified in BS 6946 and related guidance. 2. Material and Corrosion Resistance Clamps should be made from materials compatible with the cable tray and the environment.

Common materials include stainless steel, galvanized steel, aluminum, or corrosion-resistant composites. Non-metallic banding is recommended where possible to avoid rust stains or contamination of stainless steel products. 3.

Spacing and Support Intervals Cables must be supported at appropriate intervals to prevent undue mechanical strain. The spacing depends on cable type, diameter, and weight.

B

S 7671 and IET guidance provide recommended distances for different cable sizes, ensuring that cables are not exposed to excessive stress or sagging. 4. Compatibility with Cable Tray Design Clamps should fit the tray's slot patterns or mesh design to allow secure attachment without damaging the cables.

Cable trays often feature slots or perforations to facilitate optimal positioning of clamps and cable ties. 5. Fire Safety Considerations All cable supports, including clamps, must be fire-resistant to prevent premature failure during a fire.

This ensures that the cable system remains supported and functional for as long as possible under fire conditions. 6.

Installation Best Practices

Cables should be bundled and balanced at the center when using multiple clamps. Avoid over-tightening clamps to prevent cable damage. Use clamps designed and tested as part of the same system to ensure safe use.

By following these requirements, cable fixing clamps will provide secure, compliant, and durable support for cables within tray systems, ensuring both operational safety and longevity.