Vertical laying of cables out of cable trays

Cables can be safely routed vertically from cable trays using proper support, securing, and spacing to maintain performance, prevent overheating, and comply with standards.

Key Considerations for Vertical Cable Runs

Support and Securing: When cables exit a horizontal tray and run vertically, they must be properly supported to prevent sagging or damage. Cables should be secured at the top and at intervals of approximately 1.5 meters along the vertical run using cable ties or clamps, ensuring even tension without over-tightening, which can damage insulation . Standard cable trays are not always designed for vertical orientation; if trays are turned on edge, additional support is required to prevent cables from sliding or piling up . Specialized vertical cable racks or rails with hooks can provide safer support for vertical stacking .

Heat Dissipation and Ampacity: Vertical stacking increases the depth of cable bundles, which can lead to heat accumulation. This requires consideration of cable de-rating factors, potentially necessitating larger cable sizes to maintain the same load capacity . Proper spacing between cables and trays is essential to allow airflow and prevent overheating .

Spacing and Segregation: Maintain minimum vertical and horizontal spacing between power and instrumentation cables to reduce electromagnetic interference (EMI). Industry standards recommend at least 300 mm (12 inches) between power and control trays, and dividers or partitions can be used where space is limited .

Hardware and Installation: Use appropriate brackets, riser clamps, or hangers to secure vertical trays or wire mesh baskets. Perforated or wire mesh trays are preferred for vertical runs due to their lighter weight and ventilation properties . Ensure that the tray or basket is structurally supported and that splice connectors maintain integrity. Avoid tight bends that could damage cables .

Best Practices:

• Lay cables straight and orderly, avoiding overlaps or crossings.
• Do not exceed 50% fill rate in vertical trays to allow airflow.
• Maintain minimum clearances from ceilings or other obstructions.
• Plan routes to minimize unnecessary bends and junctions, reducing material costs and power loss .

By following these guidelines, vertical cable runs from trays can be installed safely, efficiently, and in compliance with industry standards, ensuring long-term reliability and ease of maintenance.