Requirements for Fire Cable Tray Installation

Fire-resistant cable tray supports must be made of fireproof materials, installed at proper intervals, and comply with relevant standards to maintain cable integrity during fire and mechanical stress.

Material and Fire Resistance

All cable tray supports must be manufactured from fire-resistant materials to prevent premature failure in the event of a fire. Common materials include galvanized steel, stainless steel, aluminum alloys, or fireproof composites, depending on environmental conditions such as indoor, outdoor, or corrosive environments . Both the cable tray and its supports should meet fire performance standards like EN 50200 or BS 476 to ensure the system maintains integrity under fire conditions .

Support Spacing and Mechanical Requirements

Supports should be installed at intervals recommended by the manufacturer, typically 1.5–2 meters for horizontal runs . The spacing must account for the weight of the cables and prevent undue mechanical strain on terminations or the tray itself . Supports must be compatible with the tray material and load capacity, and sections should be aligned carefully to avoid gaps or stress points . For vertical runs or changes in direction, additional supports or brackets may be required to maintain stability.

Installation Best Practices

• Route Planning: Align trays with the building structure, avoiding unnecessary crossings or detours, and maintain separation between power and signal cables to reduce interference .
• Tray Assembly: Use manufacturer-specified splice plates or couplers to join sections securely .
• Cable Fill: Ensure the tray is not overcrowded; calculate fill based on cable diameter and tray cross-section .
• Fireproofing at Penetrations: Seal openings at walls, slabs, or shafts with firestop packs, fire-resistant boards, or mineral wool, ensuring gaps do not exceed 1 cm² and packing thickness is at least 24 cm . Install fire-support plates at slab penetrations and maintain waterstops of at least 50 mm at floor level .
• Maintenance Access: Layout and positioning should allow for easy installation, inspection, and maintenance .

Compliance with Standards

• BS 7671: Requires wiring systems to be supported to prevent collapse during fire and avoid mechanical strain .
• IEC 61537: Specifies load ratings, material standards, and joint design for cable tray systems .
• Manufacturer Guidelines: Always follow the specific instructions for assembly, support spacing, and fastening, as these are critical for fire-resistance performance . By adhering to these requirements, fire-resistant cable tray supports will maintain structural integrity, protect cables during fire events, and comply with safety and electrical standards.