Specifications of cable trays in cable wells

Cable trays for cable-type wells are selected based on material, type, dimensions, load capacity, ventilation, and compliance with IEC 61537 standards.

Cable Tray Types

For cable-type wells, the most commonly used trays are:

• Channel Trays: Compact, narrow trays suitable for small cable quantities and short runs. They are ideal for confined spaces like wells and can have solid or ventilated bottoms to protect cables and allow airflow .
• Wire Mesh (Basket) Trays: Flexible and lightweight, suitable for data, telecom, and light power cables. They allow easy installation and modifications in tight spaces .
• Perforated Trays: Provide ventilation to prevent heat buildup, suitable for medium cable loads in wells where cooling is a concern .

Material and Finish

• Steel: High strength, suitable for heavy loads; can be galvanized or powder-coated for corrosion resistance .
• Aluminum: Lightweight, corrosion-resistant, ideal for humid or corrosive environments .
• Fiberglass Reinforced Plastic (FRP): High resistance to corrosion and chemicals, suitable for aggressive environments .

Dimensions

• Width: Typically ranges from 50 mm to 600 mm depending on cable quantity .
• Depth/Height: 25 mm to 150 mm for channel trays; ladder trays may be deeper for heavy power cables .
• Length: Standard sections are 2–3 meters, adjustable with fittings .
• Rung Spacing: For ladder trays, 150–230 mm is recommended to support cables without sagging .

Load Capacity and Mechanical Strength

• Trays must support the weight of cables and environmental loads without excessive deflection.
• IEC 61537 specifies testing for working load, deflection, and yield strength at spans of 1 m, 1.5 m, and 2 m .

Ventilation and Fill Ratio

• Proper ventilation prevents overheating in wells.
• Fill ratio should not exceed 40% of the usable tray area to allow heat dissipation and future expansion .

Accessories and Fittings

• Bends, T-pieces, crossovers, and reducers allow routing in confined well spaces .
• Covers: Solid or ventilated covers protect cables from dust, moisture, and mechanical damage .
• Supports: Wall brackets, suspended supports, or center suspensions secure trays in wells .

Standards Compliance

• Trays should comply with IEC 61537 for mechanical strength, corrosion resistance, electrical continuity, and fire performance .
• Compliance ensures safety, durability, and compatibility with other cable management systems. In summary, channel or wire mesh trays made of steel, aluminum, or FRP with appropriate width, depth, and load capacity, along with proper ventilation and fittings, are recommended for cable-type wells, ensuring compliance with IEC 61537 standards for safety and performance .