How to install cable tray supports with bends

Cable tray supports at bends should be installed using properly spaced brackets or hangers, with additional support at the bend to maintain structural integrity and prevent cable stress.

Key Principles for Supporting Cable Trays at Bends

1. Use Appropriate Fittings: At bends, use horizontal or vertical bend fittings designed for the specific tray type (ladder, ventilated, or solid-bottom). These fittings maintain the correct bend radius for cables, preventing damage and ensuring compliance with standards like BS EN 61537 and NEC Article 392 . 2. Support Spacing:

• Standard straight runs have typical support spacing based on tray type and load.
• At bends, additional supports are required because the tray experiences higher stress due to cable weight and directional change.
• Center-hung or wall-mounted brackets can be used to reinforce the bend, reducing deflection and maintaining alignment . 3. Types of Supports:
• Trapeze hangers: Ideal for ceiling suspensions, can support multiple bends along a run.
• Cantilever wall brackets: Suitable for vertical or horizontal bends along walls.
• Center-hung supports: Useful for long bends or heavy cable loads, allowing cables to be deposited from both sides . 4. Maintain Minimum Bend Radius: Ensure the bend radius is not smaller than the minimum recommended for the cable type, which prevents conductor damage and maintains ampacity. Use bend fittings that match the tray width and cable size . 5. Load Considerations:
• Evaluate the total cable weight and any additional environmental loads (wind, vibration, snow) at the bend.
• Supports at bends should be rated to handle maximum expected load, often requiring closer spacing than straight sections . 6. Installation Tips:
• Secure the tray to the support using bolts or clamps compatible with the tray system.
• Ensure the tray is level and aligned before pulling cables.
• For complex routing, consider intermediate supports between bends to reduce stress on fittings . By following these guidelines, cable trays at bends remain structurally sound, compliant with standards, and safe for cable installation and maintenance. Properly supported bends also reduce the risk of cable damage and facilitate future upgrades or inspections.