Belimo BFL24-SR - spring-return actuator for fire dampers

Belimo BFL24-SR – actuator for fire dampers

Spring-return actuator for 90° fire and smoke dampers in ventilation and air-conditioning systems. The analogue control signal Y sets the damper to its operating position and simultaneously tensions the spring. When the power supply is interrupted, the spring moves the damper to the safety position.

Key features and specifications

• AC/DC 24 V supply, frequency 50/60 Hz; AC voltage range 19.2...28.8 V / DC 21.6...28.8 V.
• Modulating control: operating range Y 2...10 V; position feedback signal U 2...10 V.
• Motor torque 4 Nm; safety function torque 3 Nm.
• Motor running time <60 s / 90°; safety function running time 20 s @ -10...55°C, <60 s @ -30...-10°C.
• Two auxiliary switches 2x SPDT with switching points at 5° / 80°.
• 12x12 mm form-fit connection, through hollow shaft; max. rotation angle 95°.
• Direction of movement selectable by L/R mounting; manual override with position stop and mechanical position indicator.
• Power consumption during operation 2.3 W, in standby 0.6 W; sizing power 4.1 VA.
• Power and control cable: 1 m, 4x 0.75 mm², halogen-free; auxiliary switch cable: 1 m, 6x 0.75 mm², halogen-free.
• IP54 protection rating; IEC/EN protection class III, Safety Extra-Low Voltage (SELV).

Included: hand crank, indicator, protective cover and insert for the 12/10 mm form-fit connection. The actuator is adapted and installed on the damper by the damper manufacturer; according to Belimo documentation, it is supplied directly to manufacturers of safety dampers.