Cable tray shaft supports are typically installed using trapeze, cantilever, or center-hung systems, ensuring proper load distribution, secure attachment, and compliance with standards.

Types of Cable Tray Supports

1. Trapeze or Swing Support: The most common method for vertical shafts, where two vertical hangers support a horizontal cross member that holds the tray. This allows for easy adjustment and cable installation from both sides .
2. Cantilever Wall Brackets: Mounted directly to walls for vertical or horizontal runs along shaft walls, suitable for shorter spans or lighter loads .
3. Center-Hung Supports: Ideal for large trays or heavy cable loads, allowing cables to be deposited from both sides and providing balanced support .

Installation Steps

1. Preparation:
   • Determine the tray type (ladder, ventilated trough, or solid-bottom) and calculate cable fill according to NEC 392.22 .
   • Identify support spacing based on manufacturer load charts and anticipated cable weight. Maximum support spacing is typically 3.6 m for center-hung supports .
2. Mounting Vertical Hangers:
   • Drill or punch holes in the cross member slightly larger than the all-thread diameter (1/16" to 1/8") to allow adjustment .
   • Thread hex nuts 25–50 mm above the tray bottom, slide on square washers, and insert the cross member.
3. Attaching the Tray:
   • Thread a second set of hex nuts to secure the cross member to the tray underside.
   • Ensure the cross member is level and allows horizontal adjustment for tray clips.
   • Install tray clips either inside or outside the tray rungs, depending on interference with connectors .
4. Load and Safety Considerations:
   • Maximum load per hanger ranges from 318 kg to 340 kg (700–750 lbs), .
   • Avoid overfilling trays to prevent overheating and mechanical stress .
   • Use compatible system components to ensure safety and compliance with BS EN 61537 or equivalent standards .

Additional Tips

• Use trapeze supports for long vertical runs to maintain stability and allow easy cable installation.
• For corrosive or high-moisture environments, consider stainless steel or FRP trays .
• Always verify alignment and level of supports before final tightening to prevent sagging or uneven load distribution. By following these methods, cable tray shaft supports can be installed safely, efficiently, and in compliance with industry standards, ensuring long-term reliability and ease of maintenance.