Installation of cable trays against the wall in vertical shafts

Cable trays can be installed vertically against walls, but careful consideration of support, cable spacing, and heat dissipation is required to ensure safety and functionality.

Feasibility and Considerations

Cable trays are designed primarily for horizontal runs, but vertical installations are possible. When placing a tray against a wall:

• Support and Stability: Vertical trays must be securely anchored to the building structure. Supports should be spaced preferably less than 2 meters apart to prevent sagging and maintain cable stability . Ladder-type trays provide convenient rungs for tying down cables in vertical runs .

• Cable Positioning: Simply turning a horizontal tray on its side is not recommended. In such a configuration, cable ties alone must prevent cables from sliding, which can lead to piling, uneven load distribution, and potential de-rating of cable ampacity . Specialized vertical cable rack systems with hooks or rails are preferred for vertical stacking of horizontal cable runs .

• Heat Dissipation: Vertical placement against a wall can reduce airflow around cables. Ladder trays without covers are ideal for vertical runs because they maximize air circulation and minimize heat buildup . Solid or enclosed trays may require additional consideration for heat dissipation.

• Spacing and Maintenance: Adequate clearance from the wall is recommended to allow for inspection, maintenance, and cable expansion. Minimum vertical spacing between trays or from the wall should follow manufacturer guidelines, typically around 150 mm, to ensure structural integrity and proper ventilation .

• Cable De-rating: Vertical stacking increases the effective depth of cable layers, which can reduce ampacity. Larger cable sizes or additional de-rating factors may be necessary for power cables .

Best Practices

1. Use vertical-specific cable support systems rather than simply rotating horizontal trays.
2. Secure cables at the top and at intervals (e.g., every 1.5 meters) to maintain order and prevent stress .
3. Ensure adequate airflow to prevent overheating, especially for power or high-current cables.
4. Follow manufacturer and local electrical codes for vertical installations, including load capacity and spacing requirements .

Conclusion

While cable trays can be installed vertically against walls, it is critical to use proper support systems, maintain cable organization, allow for ventilation, and account for ampacity de-rating. Using trays designed for vertical applications or specialized vertical racks is generally safer and more efficient than simply rotating horizontal trays.