Description
The Belimo AF24-SR US is a proportional spring-return damper actuator designed to deliver 15 Nm of constant torque for accurate airflow control in HVAC systems. It operates on AC/DC 24 V power and supports both 2–10 VDC and 4–20 mA control signals with integrated position feedback.
Technical Specifications
| Condition |
New/Never Used Surplus |
| Brand |
Belimo |
| Category |
Dampers & Actuators |
| Part Number |
AF24-SR US |
| Subcategory |
Damper Actuators |
| Power Supply |
24 VAC ±20% / 24 VDC ±10% |
| Nominal Frequency |
50/60 Hz |
| Power Consumption (Running) |
6 W |
| Power Consumption (Holding) |
2 W |
| Transformer Sizing |
10 VA, Class 2 |
| Control Signal |
2…10 VDC, 4…20 mA |
| Input Impedance |
100 kΩ (0.1 mA), 500 Ω |
| Feedback Output |
2…10 VDC, max. 0.5 mA |
| Torque Output |
133 in-lb (15 Nm) |
| Angle of Rotation |
0…95°, mechanically limited |
| Running Time (Motor) |
150 s constant |
| Running Time (Spring Return) |
<20 s |
| Electrical Connection |
18 GA cable, 3 ft, 1/2" conduit |
| Housing Rating |
NEMA 2 / IP54 |
| Ambient Temperature |
-30…50°C |
| Noise Level |
Max. 45 dB(A) |
| Weight |
6.0 lb (2.7 kg) |
Information About AF24-SR US
The AF24-SR US is part of Belimo’s AF series of spring-return actuators engineered for reliable proportional damper control in commercial HVAC installations. It features a zinc-coated metal housing with electronic overload protection throughout the full 0–95° rotation range, ensuring consistent torque and long operational life. The actuator accepts both voltage and current control signals, allowing flexible integration with a wide range of building automation systems. Reversible motor and spring rotation, visual position indication, and maintenance-free design support efficient installation and dependable long-term operation.
Key Features
- Spring Return Fail-Safe Operation: Integrated spring mechanism automatically drives the damper to a defined safety position upon power loss, supporting system protection and code compliance.
- Proportional Control Capability: Supports both 2…10 VDC and 4…20 mA control signals, enabling precise modulation of damper position in response to control demands.
- Constant 15 Nm Torque Output: Delivers stable 133 in-lb torque across the entire operating range, ensuring reliable damper movement regardless of load variations.
- Integrated Position Feedback: Provides a 2…10 VDC output signal for continuous damper position monitoring and closed-loop control applications.
- Reversible Direction of Rotation: Motor direction is selectable via built-in switch, while spring return direction is configurable through CW or CCW mounting.
- Manual Override Function: Supplied with a hex crank to allow manual damper positioning during commissioning, testing, or power interruptions.
- Durable Enclosed Construction: Zinc-coated metal housing rated NEMA 2 / IP54 protects internal components in mechanical room and air-handling environments.
The AF24-SR US delivers the reliability and precision required for proportional airflow control and dependable fail-safe damper operation in HVAC systems.
