Cable Shaft and Cable Tray Installation

Proper cable tray shaft installation ensures safe, supported, and code-compliant routing of cables through vertical shafts or risers.

Planning and Design

Before installation, determine the type of cable tray (ladder, ventilated, or solid-bottom) based on cable type, load, and environmental conditions. Cable trays must comply with BS EN 61537 or equivalent standards for manufacturing and installation ( ). Consider the shaft dimensions, load requirements, and future cable expansion. Vertical shafts require careful planning to maintain minimum bend radii for cables and avoid overcrowding ( ).

Support and Spacing

• Center-hung supports are recommended for vertical shafts to allow cables to be deposited from each side ( ).
• Maximum support spacing typically ranges from 3.6 m for ladder or channel trays, with a maximum load per hanger of 318–340 kg ( ).
• Ensure rung spacing of 150–230 mm (6–9 inches) for ladder trays to support cables evenly ( ).
• Use brackets, clamps, or wall-mounted supports to secure trays in shafts, preventing movement during cable installation or short-circuit events ( ).

Installation Practices

• Offloading and handling: Use cranes or forklifts carefully to avoid crushing tray siderails; single bundles per lift are recommended ( ).
• Alignment: Ensure trays are plumb and level in vertical shafts to prevent cable stress.
• Cable placement: Maintain proper separation between power and control cables to reduce electromagnetic interference ( ).
• Covers: Solid or ventilated covers can be used depending on heat generation and protection requirements ( ).

Safety and Compliance

• Cable trays are supports, not walkways; do not use them to support personnel ( ).
• Verify material suitability for environmental conditions (e.g., aluminum for corrosion resistance) ( ).
• Follow manufacturer guidelines for load ratings, temperature limits, and electrical clearances ( ).
• Ensure all components are tested and certified as a system to maintain safety and warranty compliance ( ).

Maintenance Considerations

• Inspect trays periodically for loose supports, corrosion, or damage.
• Avoid overloading trays beyond rated capacity.
• Maintain access for future cable additions or replacements.

By following these guidelines, cable tray shafts can be installed safely, efficiently, and in compliance with electrical standards, ensuring long-term reliability and protection of installed cables.