Description Belimo SM24A-SR Modulating Damper Actuator – 20Nm, 24V
The Belimo SM24A-SR
This actuator is part of Belimo’s trusted product line, known across the HVAC industry for reliability, energy efficiency, and advanced control capability. By combining a robust design with easy integration into existing systems, the SM24A-SR ensures that engineers and building operators can achieve superior environmental comfort, optimised energy usage, and reduced maintenance costs.
Key Features of the Belimo SM24A-SR
Torque of 20Nm suitable for air dampers up to 4 m².
Modulating control with a standard input signal of 0–10 V for precise positioning.
Position feedback 2–10 V signal for monitoring and coordination with other devices.
Universal shaft clamp and anti-rotation device for easy, secure installation.
Manual override with push-button for fast intervention when needed.
Adjustable rotation angle up to 95°, with mechanical end stops for fine adjustment.
High functional reliability due to overload protection and maintenance-free design.
Low noise operation at 45 dB(A) ensures suitability for sensitive environments.
Technical Data
Electrical Data
Nominal Voltage: AC/DC 24 V
Voltage Range: 19.2...28.8 V
Frequency: 50/60 Hz
Power Consumption in Operation: 2 W
Power Consumption at Rest: 0.4 W
Power Consumption for Sizing: 4 VA
Connection: 1 m cable, 4 x 0.75 mm²
Parallel Operation: Yes (observe performance data)
Functional Data
Torque: 20 Nm
Operating Range: 2...10 V
Position Feedback: 2...10 V (max. 1 mA)
Input Impedance: 100 kΩ
Position Accuracy: ±5%
Direction of Motion: Selectable via switch (ccw/cw)
Manual Override: Lockable push-button
Angle of Rotation: Max. 95° (adjustable with end stops)
Running Time: 150 s / 90°
Sound Power Level: 45 dB(A)
Mechanical Interface: Universal shaft clamp 10...20 mm
Position Indication: Mechanical, pluggable
Safety Data
Protection Class: III (SELV)
Degree of Protection: IP54 / NEMA 2
EMC: CE 2014/30/EU
Low Voltage Directive: CE 2006/95/EC
Certification: IEC/EN 60730-1 / IEC/EN 60730-2-14
UL Approval: cULus, CAN/CSA E60730-1
Environmental Data
Ambient Temperature: -30…50°C
Storage Temperature: -40…80°C
Humidity: 95% RH, non-condensing
Hygiene Test: VDI 6022 compliant, low-emission, cleanable
Weight: 0.95 kg
Performance and Application Benefits
The Belimo SM24A-SR actuator is specifically engineered to provide smooth modulating control of air dampers in ventilation and air-handling systems. Its 20 Nm torque output makes it suitable for a wide variety of duct sizes and damper loads.
Because the actuator operates on a 24V AC/DC supply, it integrates seamlessly into standard building control systems. The modulating input ensures that damper positioning is not limited to open or closed states but can instead be continuously adjusted based on real-time demand. This allows for more accurate airflow regulation, reduced energy wastage, and improved indoor comfort.
The built-in feedback output (2–10 V) allows system controllers or other actuators to monitor exact damper position. This is especially useful in larger installations where multiple dampers and actuators must work together to maintain consistent pressure and airflow balance.
Installation and Operation
The SM24A-SR is designed for direct mounting on damper shafts using the supplied universal clamp. The clamp accommodates shafts from 10 mm to 20 mm and includes an anti-rotation mechanism for secure fixing. This ensures fast installation with minimal tools, reducing downtime during new builds or system upgrades.
A manual override button allows engineers to adjust damper position without power or signal input. This is vital for commissioning, troubleshooting, or emergency intervention. The gear train disengages when the button is pressed and re-engages automatically when released.
Adjustable mechanical end stops enable installers to limit rotation to the required angle, avoiding over-adjustment and unnecessary energy use. The actuator’s internal overload protection guarantees reliability by automatically stopping the motor when end positions are reached.
Accessories and Options
Belimo provides a wide range of accessories to enhance the flexibility of the SM24A-SR, including:
Auxiliary switches for additional control options.
Feedback potentiometers for customised position signals.
Signal converters and positioners for specialised applications.
Actuator arms, shaft extensions, crank arms, and anti-rotation devices.
Mounting kits and pluggable position indicators.
These accessories allow the actuator to be adapted to a variety of HVAC system configurations.
Energy Efficiency and Sustainability
Modern building installations demand not only reliability but also efficiency. The SM24A-SR operates at just 2 W under load, making it highly energy efficient. The actuator is designed to be maintenance-free , reducing both operating costs and environmental impact over its service life.
The device is also hygiene tested to VDI 6022, meaning it is suitable for cleanroom environments, healthcare facilities, and other sensitive applications. Its low-emission construction ensures compliance with strict environmental standards, making it a responsible choice for long-term building operation.
Why Choose the Belimo SM24A-SR?
Trusted Belimo engineering ensures long service life and industry-leading performance.
Smooth modulating control improves comfort and system efficiency.
Easy mounting and manual override simplify installation and maintenance.
Extensive accessories increase versatility across HVAC systems.
Certified to international standards for safety and quality.
When reliability and precision matter, the Belimo SM24A-SR is the preferred solution for engineers, contractors, and facilities managers across the UK and beyond.
Order with Confidence
We supply only genuine Belimo products , ensuring you receive a high-quality actuator with full manufacturer support. All orders include free UK delivery, and technical support is available to assist with product selection and installation queries.
For bulk orders, project pricing, or further technical guidance, please contact our customer service team.
Related Products
Belimo AM24-SR Actuator – 10 Nm, 24V
Belimo LM24A-SR Actuator – Compact 5 Nm option
Belimo NM24A-SR Actuator – 8 Nm standard range
Explore our full Belimo actuator range for different torque ratings and control options.
About Us
We specialise in supplying high-quality HVAC components and spare parts across the UK, with a strong focus on service, technical expertise, and value for money. All products are sourced directly from trusted manufacturers to guarantee authenticity and performance.
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