Installation of Trough-Type Steel Cable Trays

Trough-type steel cable trays are installed as rigid, continuous support systems for electrical and data cables, requiring proper structural support, alignment, and compliance with load and safety standards.

Overview of Trough-Type Cable Trays

A trough-type cable tray is a rigid structure with a solid or ventilated bottom and side rails, designed to support insulated electrical cables and raceways. It provides superior protection against dust, moisture, and debris, making it ideal for horizontal runs and environments where minimal cable sag is critical. Solid-bottom trays offer maximum protection for sensitive cables, while ventilated bottoms allow heat dissipation and reduce weight. The modular design enables easy customization and expansion of cable runs .

Material Selection

Steel is commonly used for trough-type trays due to its high strength and durability. Options include pre-galvanized or hot-dip galvanized steel for corrosion resistance. Stainless steel (AISI 316L) is suitable for highly corrosive environments, while aluminum trays are lighter and resistant to atmospheric corrosion. Material choice should consider environmental conditions, load requirements, and potential exposure to chemicals or moisture .

Structural Support and Load Considerations

Proper support is critical to prevent sagging or structural failure. Supports should be spaced according to the tray width, material, and load capacity. Typical support spacing ranges from 1.5 to 3 meters for steel trays, but always consult manufacturer load charts. Ensure that structural members are not cut or compromised, and avoid installing trays in hoist ways or areas prone to physical damage . The tray weight per meter must be considered when calculating total load on the support structure .

Installation Steps

1. Planning and Layout: Determine the tray route, avoiding obstructions and ensuring accessibility. Leave at least 300 mm of free space above and to the side of the tray for maintenance and cable installation .
2. Mounting Supports: Install hangers, brackets, or struts capable of supporting the tray and cable load. Use spring nuts, bolts, and washers as specified by the manufacturer .
3. Tray Assembly: Connect straight sections, elbows, T-joints, and cross-joints using the provided hardware. Ensure proper alignment and secure side rails and bottom panels .
4. Cable Routing: Insert cables carefully to avoid damage. Use rollers, sheaves, or pulling lubricants for long runs. Maintain proper spacing and avoid over-tightening cable ties to prevent jacket deformation .
5. Bonding and Grounding: Ensure all tray sections are electrically bonded and grounded according to NEC Article 392 and local codes .
6. Final Inspection: Verify alignment, secure connections, and confirm that the tray supports the intended load without sagging. Check for compliance with fill capacity and ampacity requirements .

Safety and Maintenance

• Avoid exceeding the tray's load capacity to prevent structural failure and cable damage .
• Ensure trays are accessible for inspection and maintenance.
• Periodically check for corrosion, loose connections, or physical damage, especially in industrial environments . By following these guidelines, trough-type steel cable trays can provide a safe, organized, and durable pathway for electrical and data cables, ensuring long-term reliability and compliance with industry standards.