Connection of fire protection network cable and cable tray

Fire protection network cables must be installed in fire-resistant cable trays with proper segregation, secure fixing, and compliance with relevant standards to ensure functionality during a fire.

Cable Tray Selection and Installation

Cable trays for fire protection networks should be made of fire-resistant materials such as painted steel, stainless steel, or hot-dip galvanized steel for indoor and outdoor use, with aluminum or fiberglass-reinforced plastic for corrosive environments . The tray width and thickness must support the weight and number of cables without deformation . Routes should follow the shortest and straightest path, avoiding unnecessary crossings and detours, and should align with the building structure to facilitate maintenance .

Fire-Resistant Cable Requirements

Cables used in fire protection networks must remain operational during a fire. Standard fire-resisting cables provide 30 minutes of survival, while enhanced fire-resisting cables can survive up to 120 minutes, suitable for high-risk or unsprinklered buildings, hospitals, and phased evacuation scenarios . Common types include mineral insulated copper (MI) cables and LSZH fire-resistant cables . Low-voltage (LV) and extra-low-voltage (ELV) circuits must be segregated or insulated to prevent interference and maintain safety .

Connection and Routing Practices

Cables should be securely fixed within the tray to prevent movement during a fire, which could compromise system operation . Segregation of power and signal cables is essential to minimize electromagnetic interference and ensure reliable operation of fire alarms, smoke control systems, and emergency lighting . Cable trays should be installed in sections to allow easy access for inspection, maintenance, or replacement of fire system cables .

Fire Protection Measures

Additional fire protection can be applied using fire-resistant coatings or tapes, such as FLAMMOTECT-A or DG-CR 0.7, which prevent flame propagation and protect cables from environmental factors like moisture, UV radiation, and chemicals . When cable trays pass through fire-resisting compartments, internal and external sealing is required to maintain the fire resistance of the building element .

Maintenance and Compliance

Regular inspection of cable trays and fire protection cables is necessary to ensure continued functionality. All installations must comply with standards such as BS 5839-1:2025, BS 7671:2018+A3, and BS EN 50200, ensuring that fire protection systems remain operational during emergencies . Proper documentation and adherence to these standards are critical for safety and regulatory compliance. By following these guidelines, fire protection network cables can be reliably connected and maintained within cable trays, ensuring system integrity and occupant safety during a fire.