Cable trays and trunking should be securely fixed using wall-mounted brackets, ceiling-mounted supports, or suspension rods, with proper spacing and alignment to ensure safety, accessibility, and compliance with standards.

General Installation Principles

Preparation and Inspection: Before installation, all materials should be inspected for damage and approved by the project engineer. Ensure the installation area is accessible, clean, and free from hazards. Components should be stored above ground, protected from moisture, sunlight, and construction debris . Support and Spacing:

• Cable trays are typically supported at intervals not exceeding 1.2 meters for straight runs, while trunking is supported at 2-meter intervals .
• Additional supports are required at bends, offsets, or where cables may fall out, with fixings placed within 150 mm of fittings .
• Supports should prevent deflection exceeding 5 mm at mid-span when fully loaded .
• Earth continuity conductors should be installed across gaps in tray or trunking runs. Mounting Options:
• Wall-Mounted Brackets: Secure trays or trunking to walls, preventing sagging and allowing easy access for maintenance .
• Ceiling-Mounted Supports: Use threaded rods or suspension systems to hang trays from ceilings, ideal for large areas or to keep cables off the floor .
• Floor-Mounted Bases: Suitable for industrial settings with heavy-duty cables or limited wall/ceiling space .
• Suspended Rods: Threaded rods with nuts and locking washers can suspend trays at the correct height, ensuring stability and accessibility . Connections and Fittings:
• Use standard connectors and expansion fittings where required.
• Cut edges should be treated and painted to prevent corrosion.
• Cable retaining bars or non-hygroscopic insulating devices should be used where cables could fall out when covers are removed .
• All unused holes should be sealed with grommets. Cable Securing:
• Cables should be tied or strapped to prevent movement.
• For large or bunched cables, cleats or metal straps are recommended .
• Maintain a minimum clearance of 40–50 mm from structural elements or floors to avoid direct contact . Safety and Compliance:
• Installation should follow relevant standards (e.g., BS EN 61537 for trays, BS 6946 for channel supports) and manufacturer recommendations .
• Personnel must be trained and follow health and safety protocols, including the use of scaffolding, lifting equipment, and personal protective equipment . Final Checks:
• Ensure trays and trunking are aligned, free of damage, and properly labeled.
• Verify that all fixings, supports, and bonding jumpers are correctly installed.
• Conduct QA/QC inspections and document the installation for consultant approval . By following these methods, cable trays and trunking can be installed securely, safely, and in a manner that allows for easy maintenance and future cable additions.