For high-voltage power cables, a ladder-type cable tray with a thickness of 2.0 mm to 3.0 mm is generally recommended to ensure structural integrity and heat dissipation.

Recommended Thickness

High-voltage cable trays must support heavy power cables over long spans while allowing adequate airflow to prevent overheating. Ladder cable trays, which are ventilated, are preferred because they maximize heat dissipation and reduce mutual heating effects among cables . For these trays:

• Heavy-duty ladder trays: 2.0 mm to 3.0 mm thickness is recommended for industrial substations, thermal power plants, and utility-scale installations .
• Perforated or trough trays: Typically thinner (1.2 mm to 2.0 mm) and suitable for lighter instrumentation or control cables, not for high-voltage power runs .
• Solid-bottom trays: Generally avoided for high-voltage cables due to poor heat dissipation; if used, derating calculations are required .

Factors Affecting Thickness Selection

1. Cable Load and Span: Thicker trays are required for heavier cable bundles or longer unsupported spans (2.5–3 meters or more) to prevent sagging and mid-span bowing .
2. Material and Environment: Hot-dip galvanized steel or stainless steel trays of 2.0 mm or higher are recommended in corrosive, marine, or outdoor environments for durability and long-term performance .
3. Structural Classifications: Cable trays are categorized as light, medium, or heavy duty. High-voltage installations typically fall under heavy-duty classifications, necessitating thicker side rails and rungs to resist vertical buckling and thermal expansion .
4. Ventilation and Heat Management: Open ladder designs are essential to maintain ampacity and prevent insulation degradation. Solid trays should only be used where physical protection is critical and heat generation is minimal .

Practical Guidelines

• Ensure trays are filled to 40–50% of their width to allow proper ventilation and future expansion .
• For long spans or high cable density, choose the upper end of the thickness range (2.5–3.0 mm) to maintain rigidity and safety margins.
• Always comply with NEMA, NEC, or local standards for high-voltage installations to ensure regulatory compliance and long-term reliability . By following these guidelines, engineers can select a cable tray that safely supports high-voltage cables, maintains ampacity, and ensures structural stability over the system's operational life.