Cable trays at corners are installed using pre-fabricated elbows or custom bends, ensuring proper support, minimum bend radius, and grounding continuity.

Use of Elbows and Bends

At corners, pre-fabricated 90° or 45° elbows are commonly used to maintain the cable tray path without sharp bends that could damage cables or exceed the minimum bend radius of the largest cable in the tray . For non-standard angles, custom bends can be fabricated, ensuring the radius is sufficient to prevent cable stress .

Support and Fixing

• Supports should be installed within 300 mm of joints or elbows to maintain stability and prevent sagging .
• Vertical and horizontal trays must be aligned with building features and fixed using appropriate bolts and channels according to load requirements .
• For hollow block walls, expansion bolts and C-channels are used to secure the tray at corners .

Grounding and Continuity

• Earth continuity strips should be installed at all joints and elbows to maintain electrical grounding .
• A separate grounding cable may be connected to the earth bar for additional safety .

Installation Steps

1. Review approved shop drawings to identify corner locations and required elbow types .
2. Inspect materials for damage and verify dimensions before installation .
3. Mark the corner locations on the wall or ceiling and install support channels or brackets .
4. Attach the elbow or bend to the straight tray sections, ensuring proper alignment and spacing .
5. Secure the tray and elbow with bolts and clamps, checking for level and alignment .
6. Apply protective coatings to cut edges to prevent corrosion if using galvanized steel .
7. Verify grounding continuity and ensure all joints are properly bonded .

Additional Considerations

• Maintain the minimum bend radius for the largest cable to avoid damage .
• Ensure adequate clearance from other services and allow for future cable additions .
• Follow BS EN 61537 and other relevant standards for safe installation .

By following these steps, cable trays can be safely and efficiently routed around corners while maintaining structural integrity, cable protection, and electrical safety.