Installation of fireproof cable trays in Mali

Fire-resistant cable trays in Mali should be installed using approved materials, proper fireproofing methods, and strict adherence to technical and safety standards to ensure electrical safety and fire protection.

Material Selection and Tray Types

For indoor installations, painted steel or galvanized trays are recommended, while hot-dip galvanized or stainless steel trays are suitable for outdoor use. In corrosive or high-humidity environments, aluminum alloy or fiberglass-reinforced plastic trays are preferred. Tray width and thickness must be selected based on the number and weight of cables, ensuring sufficient mechanical strength to prevent deformation under full load . Fire-resistant wraps, such as FireMaster® Marine Plus blankets, can provide 30-minute hydrocarbon fire protection for instrument control cables .

Layout and Routing Principles

• Coordinate with building structure to avoid unnecessary crossings or detours.
• Shortest and straightest paths reduce cable loss and simplify maintenance.
• Segregate power and signal cables using dedicated trays to minimize electromagnetic interference .
• Vertical and horizontal alignment must be precise, with horizontal deviation ≤2mm/m and vertical deviation ≤3mm/m .

Fireproofing and Firestopping

• Seal all wall, slab, and shaft penetrations with fire-rated boards, firestop packs, firestop mastic, or fire-resistant mineral wool. Gaps between firestop packs and cables should not exceed 1 cm², with a minimum packing thickness of 24 cm .
• For large openings, install a fire-resistant backing plate before sealing. Cover plates should be square, evenly painted, and securely fixed.
• At slab penetrations, provide 20–30 mm of firestopping and a fire-support plate at the top. Floor-level trays should have a waterstop of at least 50 mm .
• Fire-resistant wraps should be tightly secured with steel banding straps at recommended intervals, with overlaps at elbows and bends to ensure continuous protection .

Installation Procedure

• Use only approved and undamaged trays and accessories (bends, tees, reducers, covers, supports, hangers, bolts).
• Follow approved shop drawings, manufacturer instructions, method statements, and project specifications .
• Ensure trays are clean, free of corrosion, and properly supported to prevent sagging. Use spirit levels or laser levels for alignment.
• Bond all trays to the main earthing system and apply color coding to distinguish power, data, and control trays .
• Conduct toolbox talks and safety briefings before starting work, and maintain safe access and clean work areas.

Compliance and Testing

• Fire-resistant cable tray systems should comply with ASTM E1725-95 and ASTM E1529 hydrocarbon fire curves, or equivalent standards referenced in API 2218 for petroleum and petrochemical environments .
• Ensure inspection and approval by QA/QC engineers, including verification of tray alignment, fireproofing, and hardware installation .

By following these guidelines, fire-resistant cable trays in Mali can be installed to maximize electrical safety, maintain system reliability, and provide effective fire protection in industrial and commercial settings.