Belimo NF24A-S2 - rotary actuator for dampers with fail-safe function

Belimo NF24A-S2 damper actuator

A rotary actuator with a fail-safe function for controlling dampers in technical building systems. During operation, the drive moves the damper and tensions the return spring. If the power supply is interrupted, the spring moves the damper to the safety position. The manufacturer specifies a damper size of up to approx. 2 m².

Key features and specifications

• Motor and fail-safe function torque: 10 Nm.
• Nominal voltage: AC/DC 24 V; nominal voltage frequency: 50/60 Hz.
• Control: Close/Open.
• Motor running time: 75 s / 90°; fail-safe function running time: <20 s @ -20...50°C, <60 s @ -30°C.
• 2 integrated auxiliary switches: 2x SPDT, 1x 10% / 1x 11...100%.
• Angle of rotation: max. 95°; adjustment from 33% in steps of 2.5% using a mechanical end stop.
• Mechanical connection: universal clamp 10...25.4 mm; mechanical position indicator.
• Motor and fail-safe function direction selected by mounting L/R; manual operation by crank with locking switch.
• Power consumption during operation: 6 W; at rest: 2.5 W; sizing power: 8.5 VA.
• Power and control connection: 1 m cable, 2x 0.75 mm²; auxiliary switch connection: 1 m cable, 6x 0.75 mm².
• Protection rating: IP54; ambient temperature: -30...50°C [-22...122°F].

Direct mounting on the damper shaft is carried out using a universal clamp and an anti-rotation mechanism. The actuator is overload-protected and stops automatically when the end stop is reached.