Instructions for Installing Cable Trays in Vertical Shafts

Vertical cable tray installations require careful planning, secure support, and adherence to safety standards to prevent cable damage and hazards.

Safety Considerations

Installing cable trays in vertical shafts is inherently risky due to the weight of hanging cables and potential for free fall. It is essential to engage professional installers experienced in vertical cable systems, especially for high-voltage or long vertical runs, as improper handling can lead to serious injury or cable damage (Cableizer). Fail-safe mechanisms, such as secondary steel wires or synchronized cable pushers, are recommended to prevent uncontrolled cable descent during installation.

Structural Support and Tray Selection

Cable trays must be securely supported using vertical hangers or rods, with proper spacing to handle the load of the cables. Maximum support spacing typically ranges from 3. 6 m, with each hanger capable of supporting 318–340 kg depending on the system used (Unitray).

Vertical ladder or channel trays should be installed according to manufacturer specifications, ensuring clamps, washers, and hex nuts are properly positioned to maintain stability.

Cable Securing and Thermal Management

Cables must be secured to every rung or support point to prevent slippage, especially in vertical configurations. Over-tightening cable ties can damage insulation, while insufficient securing can allow cables to slide and pile up, increasing heat accumulation and reducing ampacity (Eng-Tips). Consider ventilated or open designs to allow heat dissipation and avoid thermal stress on cables (ABB Technical Guide).

Material and Compliance

Select cable tray materials based on the environmental conditions, such as galvanized steel for corrosion resistance or aluminum for lightweight applications. All installations should comply with relevant standards, such as BS EN 61537 for cable trays and BS 6946 for channel support systems, ensuring mechanical integrity and safety (BEAMA Guide).

Installation Best Practices

Align and balance cable bundles to prevent uneven loading. Avoid closed loops of ferromagnetic steel when fixing cables to metal structures to prevent electromagnetic interference. Plan cable routing to maintain minimum bend radii and prevent conductor elongation or insulation cracking.

Consider pushing cables upward rather than pulling downward when feasible, as it reduces gravitational stress on the cable.

Summary

Vertical cable tray installations demand careful structural planning, secure cable fastening, thermal management, and adherence to safety standards. Using proper materials, fail-safe mechanisms, and professional installation practices ensures both mechanical stability and long-term cable performance.