The load a wall-mounted cable tray can support depends on the tray type, span between supports, cable weight, and environmental factors, with typical support spacing ranging from 6 to 20 feet depending on tray length and load.

Key Considerations for Wall-Mounted Cable Trays

1. Load Components The total load on a wall-mounted cable tray includes:

• Cable weight: Sum of all installed cables along the tray length.
• Tray weight: The self-weight of the cable tray system.
• Environmental loads: Wind, snow, ice, or seismic forces if applicable, especially for outdoor installations .

2. Support Span and Bracket Placement

• Short-span trays (typically indoor, non-industrial) are supported every 6–8 feet.
• Intermediate-span trays are supported every 10–12 feet.
• Long-span trays can be supported every 14–20 feet, with 20 feet being common.
• Extra-long spans may exceed 20 feet, often used outdoors to reduce the number of supports .
• The support span is the distance between wall brackets; the tray length should be equal to or longer than the support span. Only one splice plate should be placed between supports to maintain structural integrity .

3. Material and Tray Type

• Cable trays are typically made of steel, stainless steel, or aluminum, with galvanization or coatings for corrosion protection .
• Tray types include solid-bottom, ventilated, ladder, or mesh trays, each with different load capacities. Ladder and mesh trays are common for wall mounting due to their strength and ventilation.

4. Standards and Testing

• IEC 61537 and BS EN 61537 define mechanical strength, load testing, and installation requirements for cable trays .
• Trays must be tested to withstand the maximum expected load, including cables and environmental forces. Safe working load is typically derived from these tests.

5. Practical Installation Tips

• Ensure brackets are anchored to a structurally sound wall capable of supporting the combined load.
• Consider thermal expansion and contraction, especially for long spans or outdoor installations .
• Avoid using cable trays as walkways or for supporting personnel, as they are designed only for cable loads .

Summary

To determine the wall support load for a cable tray:

1. Calculate the total weight of cables and tray per unit length.
2. Include environmental loads if applicable.
3. Select a tray type and material rated for the calculated load.
4. Choose support spacing according to span type (short, intermediate, long, extra-long).
5. Follow IEC 61537 or relevant national standards for testing and installation .

Proper design ensures safety, prevents tray deformation, and maintains reliable cable management over the system's lifetime.