Belimo BF24 - spring-return actuator for fire dampers

Belimo BF24 actuator

BF24 is a spring-return actuator for 90° fire and smoke control dampers in ventilation and air-conditioning systems. During operation, the motor moves the damper to its operating position and tensions the spring. When the power supply is interrupted, the spring's stored energy moves the damper to the safety position.

Key features and specifications

• Nominal supply: AC/DC 24 V; frequency: 50/60 Hz.
• Control: Close/Open.
• Motor torque: 18 Nm; safety function torque: 12 Nm.
• Motor running time: <120 s / 90°; safety function running time: 16 s @ 20°C.
• Rotation angle: max. 95°; motor rotation direction selected by L/R mounting.
• Power consumption during operation: 7 W; at rest: 2 W; sizing power: 10 VA.
• Auxiliary switches: 2x SPDT, switching points 5° / 80°.
• Mechanical connection: 12x12 mm form-fit connection, blind hollow shaft.
• Manual override with position stop; mechanical position indicator.
• Degree of protection: IP54; IEC/EN protection class: III, Safety Extra-Low Voltage (SELV).

Power and control connection: 1 m cable, 2x 0.75 mm² (halogen-free). Auxiliary switch connection: 1 m cable, 6x 0.75 mm² (halogen-free). Included: manual crank, indicator, protective bag and 12/10 mm form-fit connection insert.

The actuator is adapted to the damper and installed by the manufacturer of the fire or smoke control damper; according to Belimo documentation, it is supplied directly to manufacturers of such dampers.