Horizontal cable ladder trays should be installed on level supports with proper spacing, secure fastenings, and adequate clearance for cable pulling and maintenance.

Planning and Layout

Before installation, review the approved shop drawings to determine the exact routes, lengths, and locations of the cable trays ( ). Horizontal runs should be clearly marked, avoiding clashes with other services, and maintaining sufficient clearance for cable pulling and future maintenance ( ). Ensure the area is clean and ready for installation, with civil works completed.

Support and Spacing

Cable ladders must be supported at regular intervals to prevent sagging. For horizontal runs, supports are typically spaced no more than 1.2 meters apart ( ). Use threaded rod supports with appropriate metal plugs, and fix 'L' angles or slotted 'C' channels with nuts to secure the tray ( ). Additional supports are required at bends, branches, and offsets to maintain structural integrity.

Material Handling

Store cable trays horizontally on a flat surface with timber supports at approximately 1-meter intervals to prevent deformation and protect from moisture and sunlight ( ). Inspect all materials for damage before installation and remove any unsuitable items from the site.

Installation Practices

• Use ladder-type trays without covers for maximum airflow, which helps dissipate heat from current-carrying conductors and minimizes dust accumulation ( ).
• Ensure the tray is level and properly aligned along the horizontal run.
• Secure the tray to supports firmly, avoiding excessive movement that could stress cables.
• Maintain proper rung spacing according to cable type; for small-diameter control and instrumentation cables, 6, 9, or 12-inch rung spacing is recommended ( ).

Safety and Standards

Cable ladder systems are designed to support cables, not personnel, and should comply with BS EN 61537 for cable trays and BS 6946 for channel supports ( ). Only use components designed and tested together as a system to ensure safe operation ( ). Avoid overloading the tray beyond its rated capacity, considering the weight of cables and any imposed loads such as equipment or environmental factors ( ).

Summary

Proper horizontal cable ladder installation involves careful planning, correct support spacing, secure fastening, and adherence to standards. Following these practices ensures reliable cable management, reduces mechanical stress on cables, and allows safe, efficient maintenance in the future.