How to install cable tray support arms

Proper installation of cable tray support arms ensures structural stability, load-bearing capacity, and compliance with electrical standards.

Key Components

Cable tray support systems typically include:

• Support arms or cross arms: Horizontal elements that hold the tray.
• Suspension rods (lead screws): Vertical connectors linking the ceiling or overhead structure to the support arms.
• Hoisting frames: Used for small-sized trays, providing low-cost, easy installation.
• Cross arms: Designed for large trays, offering robust stability and long-term maintenance ease.
• Fastening kits: Five-piece kits including bolts, nuts, and washers to secure connections.
• Mounting hardware: Expansion bolts or clamps to attach supports to walls, ceilings, or beams .

Installation Guidelines

1. Planning and Layout:
   • Determine tray size, load, and route.
   • Ensure support spacing follows recommended ratios: typically 1 hoisting frame or cross arm per 1.5–2 meters of tray .
   • Avoid cutting or drilling structural members without project approval .
2. Mounting Support Arms:
   • Attach support arms to suspension rods or directly to structural beams using clamps or expansion bolts.
   • For small trays, use a single suspension rod per hoisting frame; for large trays, use two rods per cross arm .
   • Ensure arms are level and aligned with the tray route.
3. Securing Cable Trays:
   • Place the tray on the support arms and fasten using the provided hardware.
   • Use clamps or hold-down devices to prevent lateral movement and maintain stability under load .
   • Check that the tray can withstand the weight of cables and any future additions.
4. Load and Safety Considerations:
   • Verify that the support system meets the load requirements, including dynamic forces such as short-circuit events .
   • Ensure deflection limits are not exceeded and that all components are compatible and tested together .
   • Avoid using trays as walkways or for supporting personnel.
5. Material and Environmental Considerations:
   • Use steel or stainless steel supports with appropriate galvanization for corrosion protection .
   • Consider environmental factors such as moisture, temperature, and chemical exposure when selecting materials.

Best Practices

• Install supports before laying cables to ensure proper alignment.
• Maintain consistent spacing and secure all fasteners tightly.
• Inspect the system periodically for wear, corrosion, or loosening of hardware.
• Follow manufacturer instructions and relevant standards (BS EN 61537, DIN EN 61537) for compliance and safety . By following these guidelines, cable tray support arms can be installed safely and effectively, providing a durable and reliable cable management system.