Right-angle external bend of cable tray

A right-angle external bend in a cable tray is achieved using elbow fittings designed to maintain cable integrity while changing direction by 90 degrees.

Purpose and Function

A right-angle external bend, also called an external elbow, allows a cable tray to turn around an outside corner while supporting the cables and maintaining proper bend radius to prevent damage or excessive stress on the cables . These bends are essential in routing cable trays along walls, ceilings, or around structural obstacles.

Types of Cable Trays and Bends

• Ladder Tray Bends: Ladder-type trays use pre-fabricated 90-degree elbows that provide a smooth, gradual curve for cables, reducing strain and maintaining airflow for heat dissipation . They are typically made of steel or aluminum and can be mounted to floors, walls, or ceilings.
• Wire Mesh Tray Bends: Wire mesh trays can be bent on-site using bolt cutters or specialized tools. The cut ends are protected with rubber caps to maintain safety and prevent cable damage . This method allows flexibility for live adjustments during installation.
• Solid-Bottom Tray Bends: Solid-bottom trays use pre-formed elbows or fabricated bends to maintain cable support and prevent sagging. These are often used for power cables or environments requiring additional protection .

Installation Considerations

1. Bend Radius: Ensure the bend radius is sufficient for the type of cable being installed. Exceeding the minimum bend radius can damage insulation or reduce cable performance .
2. Support: External bends should be supported at intervals to prevent sagging and maintain structural integrity. Supports may include brackets, hangers, or wall mounts .
3. Fittings Compatibility: Use fittings from the same manufacturer or system to ensure proper alignment, load capacity, and compliance with standards such as BS EN 61537 or NEMA guidelines .
4. Safety and Protection: For wire mesh trays, cover cut ends with protective caps. For metal trays, ensure edges are smooth to prevent cable abrasion .

Summary

Right-angle external bends are critical components in cable tray systems, allowing safe and efficient routing of cables around corners. Choosing the correct type of bend, maintaining proper bend radius, and providing adequate support ensures cable longevity, system reliability, and compliance with installation standards .