Installation of electrical cable tray legs

Proper installation of cable tray legs ensures stable support, prevents sagging, and maintains safe cable routing in compliance with electrical standards.

Planning and Preparation

Before installing cable tray legs, review the approved shop drawings to determine tray routes, lengths, and locations. Ensure the installation area is clean, free of obstructions, and that all materials—including trays, legs, brackets, and fasteners—are inspected for damage and compliance with project specifications . Mark the positions for each support leg according to the tray layout, maintaining horizontal and vertical alignment.

Selecting and Positioning Supports

Cable tray legs are typically made from threaded rods, 'L' angles, or slotted 'C' channels. The choice depends on load requirements, tray type, and environmental conditions . Supports should be spaced to prevent sagging, with a maximum distance of 1.2 meters (4 feet) between legs for standard ladder or ventilated trays . Additional supports are required at bends, branches, and offsets to maintain stability.

Installation Steps

1. Fix Threaded Rods or Anchors: Drill holes and install metal plugs or anchors into the floor or ceiling. Attach threaded rods securely to these anchors.
2. Attach Support Channels: Fix 'L' angles or slotted 'C' channels to the threaded rods using nuts and washers. Ensure they are level and aligned with the tray route.
3. Mount Cable Tray: Place the tray on the supports and secure it with appropriate clamps or fasteners. Check that the tray is level and straight along its entire run.
4. Verify Clearance: Maintain sufficient clearance for cable pulling, ventilation, and future maintenance .

Additional Considerations

• Tray Type: Ladder trays are ideal for power cables due to ventilation and easy cable anchoring, while ventilated troughs provide continuous support for smaller control cables .
• Environmental Factors: In corrosive or high-moisture environments, consider fiberglass-reinforced plastic (FRP) supports for corrosion resistance and non-conductivity .
• Load and Safety Compliance: Ensure supports can handle the weight of cables and trays, including any imposed loads such as wind or maintenance personnel, following relevant standards like BS EN 61537 . By following these steps, cable tray legs will provide secure, code-compliant support, ensuring long-term stability and safe cable management in industrial or commercial installations.