Requirements for the wall thickness of ladder-type cable trays

The wall thickness of ladder-type cable trays depends on material, tray width, rung spacing, load capacity, and compliance with standards such as IEC 61537 and BS EN 61537.

Material and Structural Considerations

Ladder-type cable trays are typically made from steel, stainless steel, or aluminum, and the wall thickness is a key factor in ensuring mechanical strength and load-bearing capacity. Thicker walls provide higher rigidity and resistance to bending, especially for wider trays or those supporting heavy power cables . Aluminum trays may require slightly thicker walls than steel to achieve equivalent strength due to lower material density .

Standard Compliance

• IEC 61537 specifies that cable trays must withstand the load of cables, environmental factors, and external pressure, with testing methods to validate tray strength .
• BS EN 61537 and related national standards recommend that ladder trays are designed to support cables safely without deformation, considering imposed loads such as cable weight, wind, ice, or short-circuit forces .

Tray Width and Rung Spacing

• Wider trays (e.g., 42–48 inches) require stronger rungs and potentially thicker side rails to maintain structural integrity .
• Rung spacing affects load distribution; for large power cables, 9-inch or wider rung spacing is common, while smaller instrumentation cables may use 6–12-inch spacing . Wall thickness must be sufficient to prevent excessive deflection between rungs.

Manufacturer Guidelines

• Manufacturers provide load charts that account for tray width, rung spacing, and material. Wall thickness should meet or exceed the minimum specified in these charts to ensure safety and compliance .
• Galvanized steel trays have wall thickness influenced by the coating process, with hot-dip galvanization adding a protective layer that slightly increases effective thickness .

Practical Recommendations

1. Check the tray material: Steel, stainless steel, or aluminum, and select wall thickness according to load requirements.
2. Consider tray width and rung spacing: Wider trays and larger rung spacing require thicker walls.
3. Follow standards: Ensure compliance with IEC 61537 or BS EN 61537 for mechanical strength and safety.
4. Refer to manufacturer specifications: Always verify wall thickness against the manufacturer's load charts and installation guidelines. By considering these factors, ladder-type cable trays can safely support electrical cables while maintaining compliance with international standards and ensuring long-term durability .