## Key Specifications

 

• Manufacturer: Belimo
• Model: LM24-SR-F/150 FSL (core model series is LM24-SR)
• Application: Control of air dampers up to approx. 0.8 m²
• Torque: 4 Nm
• Power Supply: AC/DC 24V, 50/60Hz
• Power Consumption: 4 VA (in operation), 2 W (running)
• Control Type: Modulating / Proportional
• Control Signal (Y): DC 0…10 V (The actuator moves to a position proportional to the voltage)
• Position Feedback (U): DC 0…10 V (Outputs a voltage signal indicating the current damper position)
• Running Time: 80…110 seconds for 90° rotation
• Protection Class: IP54

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## Wiring and Terminals

 

The label on the actuator indicates the following connections via its pre-wired cable:

• Terminal 1 (Black): ┴ (Ground / System Neutral)
• Terminal 2 (Red): ~ (Power / Hot, AC/DC 24 V)
• Terminal 3 (White): Y (Control Signal Input, 0…10 V)
• Terminal 5 (Orange): U (Position Feedback Output, 0…10 V)

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## Functionality

 

The Belimo LM24-SR actuator is connected to the shaft of a damper. An external controller (like a building management system or thermostat) provides a DC voltage signal between 0 and 10 volts to the ‘Y’ input.

The actuator interprets this signal and drives the damper to a corresponding position. For example:

• A 0 V signal drives the damper to the 0% (fully closed) position.
• A 5 V signal drives the damper to the 50% (half open) position.
• A 10 V signal drives the damper to the 100% (fully open) position.

Simultaneously, the actuator outputs a voltage signal on the ‘U’ terminal that reports its actual position back to the controller, confirming that the command was executed correctly. The device also features mechanical stops to limit the range of motion and a switch to select the direction of rotation

data sheet