Fireproof cable trays in stairwells

Fireproof cable trays in stairwells are designed to maintain electrical functionality and structural integrity during a fire, typically rated for 30 to 90 minutes depending on the system.

Purpose and Importance

Fireproof cable trays in stairwells are critical for ensuring safe evacuation routes and maintaining power to emergency systems such as lighting, alarms, and communication during a fire. They prevent cable collapse, reduce heat transfer, and avoid toxic smoke generation, which is essential in escape routes and high-risk areas .

Types and Materials

Common fire-resistant cable trays include:

• Epoxy-based intumescent trays: Form a dense insulating char under high temperatures, reducing heat transfer and protecting cables .
• Metal-reinforced trays: Incorporate internal metal plates for structural stability and long-span support, preventing deformation or fracture during fire .
• Standard steel or galvanized trays with fireproof coatings: Suitable for indoor stairwell installations, often combined with fire-rated fasteners .

Fire Ratings

Fireproof cable trays are tested to maintain mechanical stability and electrical functionality under fire conditions:

• E30, E60, E90 ratings: Indicate the system can support cables and maintain operation for 30, 60, or 90 minutes during a fire .
• Systems like RKS-Magic® and SKS-Magic® have proven stability for 30–90 minutes when installed according to manufacturer specifications .

Installation Guidelines

Proper installation is essential for fireproof performance:

• Mounting: Trays can be mounted on walls, ceilings, or under false ceilings using brackets and threaded rods to prevent bending during fire .
• Spacing: Maintain minimum clearances from ceilings or walls as specified in fire tests to allow heat dissipation and prevent multi-layer interference .
• Segregation: Power and signal cables should be separated to reduce interference and maintain safety .
• Inspection: Regular checks for coating integrity, sealing effectiveness, and mechanical stability are required to ensure long-term fire protection .

Additional Considerations

• Ventilation: Some fireproof trays include ventilation grilles to prevent heat accumulation and cable aging .
• Compliance: Always follow local building codes, international standards (e.g., EN 1363-1), and manufacturer installation instructions .
• Qualified Installation: Only trained personnel should install fire-resistant cable trays to ensure proper fastening and adherence to fire safety standards . Using fireproof cable trays in stairwells ensures that critical electrical systems remain operational during emergencies, supporting safe evacuation and minimizing fire-related hazards.