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

Belimo BFL24-ST actuator

A spring-return actuator for fire and smoke dampers in ventilation and air-conditioning systems. During operation, the motor moves the damper to its operating position and tensions the spring. If the power supply is interrupted, the spring moves the damper to its safety position.

Key features and specifications

• Power supply: AC/DC 24 V; rated frequency 50/60 Hz.
• Control: Open/Close; 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.
• Power consumption: 2 W during operation, 0.7 W in the resting position; power for cable sizing: 2.8 VA.
• Auxiliary switches: 2x SPDT, switching points 5° / 80°.
• Mechanical connection: 12x12 mm form-fit connection, through hollow shaft; maximum rotation angle 95°.
• Motor direction of movement selected by L/R mounting; manual override with stop, with the power supply switched off.
• Power and control connection: cable with 1 m plug, 2x 0.75 mm², FRNC (halogen-free). Auxiliary switch connection: cable with 1 m plug, 6x 0.75 mm², FRNC (halogen-free).
• Protection rating: IP54; IEC/EN protection class III, Safety Extra-Low Voltage (SELV).

Included: hand crank, position indicator, protective bag and 12/10 mm form-fit insert. The actuator is adapted and installed on the damper by its manufacturer.