Installation of Span Cable Trays

Proper installation of span cable trays requires careful planning, correct support spacing, load management, and adherence to safety standards.

Planning and Layout

Before installation, a layout plan should be prepared by a qualified designer or engineer who considers building codes, equipment locations, and clearances for other trades . Elevations for the top or bottom of the tray run should be established using a laser level or transit to ensure consistent alignment . The tray system should follow a predetermined route to minimize unnecessary bends and maintain proper cable management .

Support and Span Considerations

Cable trays must be supported at regular intervals to prevent sagging and maintain structural integrity. Center-hung supports allow easier cable installation from both sides . Maximum support spacing typically ranges from 3.6 meters, with load capacities per hanger between 318 kg (700 lbs) and 340 kg (750 lbs) . The spacing and type of support depend on the tray material, load, and environmental conditions .

Material Selection

Cable trays are available in steel, aluminum, stainless steel, and fiberglass, each offering different corrosion resistance and mechanical properties . Aluminum is lightweight and corrosion-resistant, while stainless steel provides high durability in harsh environments. Material choice should match the installation environment and expected mechanical load .

Installation Practices

• Secure tray sections using appropriate fittings and connectors to maintain alignment and structural integrity .
• Avoid using trays as walkways or ladders, as they are designed solely for cable support .
• Maintain minimum bend radius for cables exiting the tray to prevent damage .
• Use proper banding and balancing when bundling cables to distribute weight evenly .
• Drill and cut structural members cautiously, consulting a structural engineer if necessary .

Safety and Compliance

Installation should comply with relevant standards such as BS EN 61537 for cable trays and BS 6946 for channel support systems . Only qualified personnel familiar with electrical installation practices should perform the work . Proper installation ensures mechanical support, strain relief, and safe cable routing, reducing the risk of damage or personal injury .

Summary

Successful span cable tray installation involves careful planning, correct support spacing, material selection, and adherence to safety standards. Following these guidelines ensures a durable, safe, and efficient cable management system suitable for electrical and data cabling applications .