Methods for fixing cable trays in vertical shafts

Vertical cable trays should be securely supported using brackets, hangers, or center suspensions, with proper spacing and load considerations to ensure safety and stability.

Inspection and Preparation

Before installation, inspect all cable trays and components for damage and ensure they are stored properly to prevent deformation or corrosion. Verify that the tray type (ladder, mesh, or solid-bottom) is suitable for vertical installation and the expected cable load ( ).

Support and Fixing Methods

Wall or Shaft Brackets: Attach cable trays to the shaft walls using wall-mounted brackets or support arms. Ensure brackets are rated for the tray load and environmental conditions ( ). Suspended Supports: For long vertical runs, use suspended supports or center suspensions to prevent sagging and maintain alignment.

These supports should be spaced according to manufacturer recommendations and load calculations ( ). Load Considerations: Design the tray system to carry the weight of cables, including any additional loads such as covers, conduit, or environmental factors like wind or seismic forces ( ).

Spacing and Alignment

Maintain support spacing as recommended by the manufacturer or standards (typically every 1. 5–3 meters for vertical runs, depending on tray type and load) ( ). Ensure the tray is plumb and aligned vertically to prevent cable stress and maintain proper bend radii at transitions ( ).

Connections and Bends

Use vertical bends, elbows, or tees to transition cables from the vertical shaft to horizontal runs at each floor. Ensure bends respect the minimum bend radius of the cables to avoid damage ( ). For branching, a vertical down tee or a combination of horizontal and vertical elbows can be used to guide cables safely to floor-level trays ( ).

Safety and Compliance

Follow relevant standards such as BS EN 61537 for cable tray systems and BS 6946 for channel supports ( ). Avoid using cable trays as walkways or for supporting personnel. Ensure all fasteners, brackets, and supports are rated for the expected load and environmental conditions, including potential water, dust, or chemical exposure ( ).

Final Checks

Verify that all trays are securely fastened, plumb, and free from deformation. Check that cables can be installed without exceeding bend radii or causing mechanical stress. Confirm that covers or protective elements are installed where required to prevent damage to cables ( ).

By following these steps, vertical cable trays can be safely and effectively installed in shafts, ensuring long-term stability and compliance with electrical installation standards.