Belimo SF24A-3 - rotary actuator for dampers with spring return

Belimo SF24A-3 – actuator for air dampers

Rotary actuator designed to control dampers in stationary heating, ventilation and air-conditioning systems. The 3-point signal controls movement to the operating position while tensioning the spring. If the power supply is interrupted, the spring moves the damper to the safety position.

Key features and specifications

• Motor and safety function torque: 20 Nm.
• Power supply: AC 24 V, 50/60 Hz; AC voltage range 19.2...28.8 V.
• Control: 3-point; motor running time: 150 s / 90°.
• Safety function running time: <20 s @ -20...50°C, <60 s @ -30°C.
• Maximum rotation angle: 95°; mechanical stop adjustment from 33% in increments of 2.5%.
• Universal shaft clamp: 10...25.4 mm; mechanical position indicator.
• Manual adjustment by crank and locking by switch.
• Power consumption during operation: 7.5 W; in the rest position: 2.5 W; sizing power: 10 VA.
• Power and control connection: 1 m cable, 4x 0.75 mm².
• Ingress protection: IP54; ambient temperature: -30...50°C.

According to the technical data sheet, the actuator is intended for air dampers with an area of up to approx. 4 m². Selection of the required torque should take into account the damper manufacturer's data and its installation and ventilation conditions.