Belimo BFN24-ST – actuator for fire dampers
Spring-return actuator designed for fire and smoke dampers in ventilation and air-conditioning systems. During operation, the actuator moves the damper and tensions the return spring. If the power supply is interrupted, the spring energy moves the damper to the safety position.
Key technical data
- Rated voltage: AC/DC 24 V; frequency: 50/60 Hz.
- Control: Close/Open.
- Motor torque: 9 Nm; safety function torque: 7 Nm.
- Motor running time: <60 s / 90°; safety function running time: 20 s @ -10...55°C, <60 s @ -30...-10°C.
- Angle of rotation: max. 95°.
- Power consumption during operation: 3.2 W; at rest: 1.2 W; for cable sizing: 4.3 VA.
- Auxiliary switches: 2x SPDT, switching points 5° / 80°.
- Mechanical connection: form-fit connection 12x12 mm, hollow through shaft.
- Motor direction of movement selected by L/R mounting; manual adjustment with position stop.
- Degree of protection: IP54.
The power and control connection is a cable with a 1 m connection plug, 2x 0.75 mm², FRNC (halogen-free). The auxiliary switch has a cable with a 1 m connection plug, 6x 0.75 mm², FRNC (halogen-free). The plugs allow connection to compatible communication and power supply devices.
Included: hand crank, position indicator and protective bag. The actuator is adapted and mounted on the damper by the damper manufacturer; Belimo supplies it directly to manufacturers of safety dampers.
