Multi-layer cable tray overhead hoisting

Multi-layer cable trays should be hoisted using balanced slings, proper lifting points, and careful load management to prevent damage and ensure safety.

Preparation and Inspection

Before hoisting, inspect all cable trays and fittings for damage and verify that materials match approved submittals. Trays should be stored horizontally on flat surfaces with timber supports at regular intervals to prevent bending or deformation during storage. Ensure that all lifting equipment, such as cranes, slings, and shackles, are rated for the total load of the multi-layer stack.

Sling Placement and Load Balancing

Use multiple slings to distribute the weight evenly across the tray layers. Attach slings at the tray's designed lifting points, typically near the center of gravity, to prevent tilting or twisting. For multi-layer trays, stacked bundles should be banded and balanced at the center to maintain stability during lifting.

Avoid using the tray rungs or siderails as attachment points, as this can cause crushing or permanent deformation.

Hoisting Procedure

Lift slowly and steadily using an overhead crane or hoist, ensuring that the load remains level. Monitor the tray alignment continuously to prevent swinging or collision with nearby structures. Single-bundle lifts are recommended; avoid lifting multiple bundles together unless specifically designed for such loads.

Use tag lines to control rotation and sway of the trays during hoisting.

Installation and Support

Once hoisted, position the trays on pre-installed supports such as trapeze hangers, swing supports, or center-hung supports. Ensure vertical hangers and cross members are properly aligned and level before securing the trays. Maximum support spacing and load per hanger should be observed to prevent overloading; typical values range from 318 kg to 340 kg per hanger with spacing up to 3.

6 m. For multi-layer installations, install the lower tray first, then sequentially add upper layers, maintaining proper alignment and support for each tier.

Safety Considerations

Only competent personnel familiar with electrical installation and lifting safety should perform hoisting operations. Always wear appropriate personal protective equipment (PPE) and follow site-specific safety protocols. Avoid using trays as walkways or for supporting personnel during hoisting.

By following these steps, multi-layer cable trays can be hoisted and installed safely, minimizing the risk of damage to the trays or cables and ensuring a stable, reliable cable support system.