Description
The Belimo AFX24-SR N4 is a 24 VAC/DC modulating spring-return damper actuator designed for precise control of large HVAC dampers in demanding indoor and outdoor environments. Delivering 180 in-lb (20 Nm) of torque with automatic fail-safe spring return, it provides accurate modulating control while ensuring the damper returns to its safety position upon power loss.
Technical Specifications
| Condition |
New/Never Used Surplus |
| Brand |
Belimo |
| Category |
HVAC Controls |
| Part Number |
AFX24-SR N4 |
| Subcategory |
Damper Actuators |
| Product Type |
Spring-Return Modulating Damper Actuator |
| Power Supply |
24 VAC/DC, 50/60 Hz |
| Power Supply Tolerance |
AC ±20%, DC -10% to +20% |
| Control Signal |
2–10 VDC, 4–20 mA (with ZG-R01 resistor) |
| Position Feedback |
2–10 VDC, Max. 0.5 mA |
| Torque |
180 in-lb (20 Nm) |
| Rotation Angle |
35°–95°, Adjustable (95° Maximum) |
| Running Time (Motor) |
95 Seconds |
| Running Time (Spring Return) |
Less than 20 Seconds |
| Power Consumption |
5.5 W (Running), 3 W (Rest Position) |
| Transformer Sizing |
8.5 VA |
| Manual Override |
5 mm Hex Crank |
| Enclosure Rating |
IP66, NEMA 4X, UL Type 4X |
| Operating Temperature |
-22°F to 122°F (-30°C to 50°C) |
| Storage Temperature |
-40°F to 176°F (-40°C to 80°C) |
| Ambient Humidity |
5–95% RH, Non-Condensing |
| Motor Noise Level |
≤40 dB(A) |
| Fail-Safe Noise Level |
<62 dB(A) |
| Electrical Connection |
18 AWG Appliance Cable with 1/2 in. Conduit Connector |
| Housing Material |
Polycarbonate |
| Weight |
4.4 lb (2.0 kg) |
Information About AFX24-SR N4
The AFX24-SR N4 is part of the Belimo AF Series of heavy-duty spring-return damper actuators developed for commercial HVAC and building automation systems. It accepts a 2–10 VDC modulating control signal or a 4–20 mA input with an external resistor while providing a 2–10 VDC position feedback signal for continuous monitoring. The actuator utilizes a brushless DC motor controlled by a microprocessor and ASIC technology, delivering constant running speed, electronic overload protection, and precise positioning throughout its full operating range. Its IP66/NEMA 4X enclosure, reversible rotation, and direct shaft mounting make it suitable for demanding environmental conditions requiring dependable fail-safe damper control.
Key Features:
- High Torque Output: Delivers 180 in-lb (20 Nm) of torque for large HVAC dampers.
- Spring-Return Fail-Safe: Automatically returns the damper to its safety position during power loss.
- Modulating Control: Supports 2–10 VDC control or 4–20 mA operation with an external resistor.
- Position Feedback: Provides a 2–10 VDC feedback signal for precise position monitoring.
- Brushless DC Motor: Uses microprocessor-controlled motor technology for accurate and reliable operation.
- Heavy-Duty Enclosure: Rated IP66, NEMA 4X, and UL Type 4X for harsh environments.
- Electronic Overload Protection: Protects the actuator throughout the full 95° rotation range.
- Manual Override: Includes a 5 mm hex crank for manual positioning during installation and servicing.
The AFX24-SR N4 delivers the reliability and precision required for modulating fail-safe damper control in commercial and industrial HVAC systems.
