Belimo BFN24-T-ST - spring-return actuator for fire dampers

Belimo BFN24-T-ST actuator

Spring-return actuator with BAT thermal release (72°C), designed for 90° fire and smoke dampers in ventilation and air-conditioning systems. When powered, the actuator moves the damper to the operating position and tensions the spring; when the power supply is interrupted, the spring moves it 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.
• Auxiliary switches: 2x SPDT, switching points 5° / 80°.
• 12x12 mm form-fit connection, hollow through shaft; motor direction of rotation selected by L/R mounting.
• BAT thermal release: trip temperature of thermal fuses inside and outside the duct 72°C.
• Power consumption during operation: 3.2 W; in idle position: 1.2 W; wire sizing power: 4.3 VA.
• Power and control connection: cable with 1 m connection plug, 2x 0.75 mm², FRNC (halogen-free); auxiliary switch connection: cable with 1 m connection plug, 6x 0.75 mm², FRNC (halogen-free).
• Degree of protection: IP54; IEC/EN protection class: III, Safety Extra-Low Voltage (SELV).

The actuator has manual override with stop and a mechanical position indicator. The scope of delivery includes a hand crank, indicator and protective bag.