Belimo SM 24A Control Damper Actuator

The Belimo SM 24A is a high-performance, spring-return modulating actuator designed for the precise control of dampers in HVAC systems. Operating on 24VAC power, it provides accurate and reliable positioning for applications in VAV terminals, air handlers, unit ventilators, and more. Its fail-safe spring-return mechanism ensures the damper moves to a safe position in the event of a power failure, protecting your critical systems and occupants.

Engineered with the quality and durability synonymous with the Belimo brand, the SM 24A is the trusted choice for building automation contractors and engineers worldwide.

Key Features & Benefits

• Modulating (0-10 VDC / 2-10 VDC) Control: Delivers precise and proportional damper positioning for optimal temperature, pressure, and airflow control, improving occupant comfort and energy efficiency.

• Spring-Return (Fail-Safe) Operation: Automatically returns the damper to a predefined safe position (either fully open or closed) upon power loss, ensuring critical system safety and compliance.

• 24VAC Power Supply: Compatible with standard HVAC control system voltages, making it easy to integrate into new and existing building automation systems.

• Adjustable Torque (15/35 lb-in): Offers field-selectable torque settings, providing application flexibility and preventing potential damage to the damper and linkage.

• Direct-Coupled Linkage System: Simplifies installation and ensures a solid, slop-free connection to the damper shaft for accurate and responsive control.

• Manual Override: Features a built-in manual override lever for easy calibration, testing, and damper positioning during installation and service without the need for power.

• Robust Metal Gear Train & Housing: Built with a durable die-cast aluminum housing and metal gears for long-term reliability and performance in demanding environments.

• LED Status Indicator: Provides clear visual feedback on actuator operation and control signal reception, speeding up commissioning and troubleshooting.

Technical Specifications

• Model: SM 24A-3 (Note: The “-3” suffix typically indicates the control signal; confirm exact model for your needs).

• Power Supply: 24 VAC, 50/60 Hz

• Control Signal: Modulating, 0-10 VDC or 2-10 VDC (reversible)

• Action: Spring-Return (Failsafe)

• Torque: 15 lb-in (1.7 Nm) or 35 lb-in (4.0 Nm) – Field Selectable

• Running Time: 150 seconds (for 90° rotation)

• Auxiliary Switches: Optional, DPDT for end position feedback or auxiliary control.

• Shaft Connection: 1/4″ (6mm) square, with other sizes available.

• Housing Material: Die-cast aluminum (IP54 rated)

• Ambient Temperature Range: -4°F to 140°F (-20°C to 60°C)