Pull the cable tray in several stages when laying bends

Cable trays should be pulled and installed in stages at bends to maintain alignment, prevent damage, and ensure safe cable pulling.

Staged Installation for Bends

When laying cable trays through bends, it is recommended to install the tray in multiple stages rather than attempting to pull the entire length at once. This approach helps to:

• Maintain proper alignment of the tray along the bend.
• Prevent deformation or damage to the tray and cables.
• Reduce stress on supports and fasteners during installation.
• Facilitate easier cable pulling through the bend without snagging or excessive friction .

Recommended Procedure

1. Pre-assemble and inspect: Before installation, inspect all tray sections, bends, and fittings for damage. Ensure that all components match the approved shop drawings .
2. Install supports first: Secure supports and hangers along the planned route, especially at bends, ensuring spacing complies with standards (typically 1.2 m for straight runs and closer near bends), .
3. Pull in stages: Begin by positioning the first section of the tray and securing it. Gradually add subsequent sections, particularly around bends, checking alignment and level at each stage .
4. Use proper fittings: Connect bends and offsets using manufacturer-approved fittings. Ensure that expansion joints or flexible connectors are used if required to accommodate thermal expansion .
5. Check clearances: Maintain sufficient clearance for cable pulling and future maintenance. Avoid sharp bends that exceed the recommended bend radius for the cables being installed .
6. Secure and level: After each stage, ensure the tray is firmly fixed, level, and aligned. Use spring knots or other securing methods to prevent displacement during subsequent stages .

Additional Tips

• Avoid site fabrication of bends; use pre-manufactured fittings to maintain structural integrity .
• Protect trays from environmental exposure during installation, such as direct sunlight or moisture, to prevent damage .
• Label and tag each section for easier identification and maintenance after installation . By following a staged approach, installers can ensure that cable trays are safely and efficiently laid through bends, minimizing the risk of damage to both the tray and the cables while maintaining compliance with installation standards .