How does the fire alarm turn on and off?
Cable shafts for automatic fire alarm systems shall be installed separately with power, lighting, low voltage distribution lines and cable shafts. If the condition is limited, the two cables shall be arranged on both sides of the shaft.
Fire control, communication and alarm circuit with dark laying, should use the metal tube or plastic tube to protect the flame retardant treatment, and should be laid in the structure layer burning body, and the protective layer thickness of not less than 30mm. When used for laying, metal or metal groove shall be used for protection, and fire protection measures shall be adopted on metal tubes or metal wire grooves.
The transmission line of automatic fire alarm system should be made of metal tube, flame retardant plastic pipe or sealed wire slot.
The selection of the core section of transmission line of automatic fire alarm system should meet the requirement of technical condition of automatic alarm device, and also meet the requirement of mechanical strength. Minimum sectional area of copper core insulated conductor and copper core cable core.
Transmission line of fire automatic alarm system and power supply control line below 50V shall adopt copper core insulated wire or copper core cable with voltage class not less than AC 250V. AC core or insulated wire or copper core cable with voltage class not less than AC 500V shall be adopted for power supply or control circuit of AC 220/380V.
