Fireproof cable trays on slopes require careful material selection, proper slope support, and installation of fire-blocking sections to prevent fire spread and maintain cable integrity.

Material Selection

For sloped installations, choose mechanically strong and fire-resistant tray materials:

• Indoor: Painted steel or galvanized steel
• Outdoor or high-humidity/corrosive environments: Hot-dip galvanized steel, stainless steel, aluminum alloy, or fiberglass-reinforced plastic (FRP/GRP) trays
• Ensure the tray can support the weight of cables without deformation, especially on slopes where gravity adds stress .

Slope Support and Layout

• Route Planning: Align trays with the building structure, avoiding unnecessary bends or detours. Maintain the shortest and straightest path possible to reduce mechanical stress and simplify maintenance .
• Support Spacing: Use brackets or hangers at intervals recommended by IEC 61537 to prevent sagging. On slopes, supports may need to be closer together to counteract gravitational pull .
• Segregation: Separate power and signal cables to minimize interference, using dedicated trays .

Fireproofing Measures

• Fire-Blocking Sections: Install fire-blocking partitions at intervals along the tray to prevent fire propagation. Materials include fireproof boards, firestop packs, firestop mastic, or mineral wool .
• Packing and Sealing: Ensure gaps between cables and fire-blocking materials are minimal (≤1 cm²) and packing thickness meets recommended standards (≥24 cm for large openings), .
• Slab Penetrations: When trays pass through walls or slabs, use fire-resistant backing plates and seal all gaps tightly to maintain fire integrity .
• Maintenance Access: Fire-blocking sections should allow for cable addition or replacement without compromising fire protection .

Installation Sequence

1. Plan the route considering slope, load, and fire safety.
2. Install tray supports and brackets along the slope.
3. Lay the cable trays and secure them to supports.
4. Route cables according to segregation and load requirements.
5. Install fire-blocking sections at designated intervals.
6. Seal slab or wall penetrations with fire-resistant materials.
7. Inspect and test for mechanical stability and fireproof integrity .

Key Considerations

• Ensure mechanical strength to prevent tray deformation under cable weight and slope stress .
• Use fire-resistant materials compatible with environmental conditions.
• Follow IEC 61537 and local fire safety codes for tray construction and fireproofing .
• Regularly inspect and maintain fire-blocking sections to ensure long-term effectiveness . By combining proper material selection, slope-specific support, and fire-blocking measures, cable trays can be safely installed on slopes while maintaining fire safety and operational reliability.