Belimo NMB24-3 Actuator

The Belimo NMB24-3 is a high-torque damper actuator designed for reliable control in HVAC systems requiring 90 in-lb of torque. This non-spring return actuator provides flexible performance for on/off or floating point control, operating on 24VAC or 24VDC power supplies. Engineered for versatile installation, it features a universal clamp for direct mounting on damper shafts up to 1.05 inches in diameter. The brushless DC motor technology ensures precise positioning and low power consumption during operation, while the manual override button allows for easy commissioning and mechanical system checks. This rotary actuator is rated NEMA 2 / IP54, making it suitable for standard indoor air handling units and zone control systems. With an 80 to 110-second motor run time, the NMB24-3 maintains consistent air pressure and flow control in demanding commercial environments without the risk of stall-related failures.

• Universal Compatibility: Mounts directly to round or square shafts, streamlining damper actuator replacement in the field.
• High Torque Output: Delivers 90 in-lb of torque to drive dampers up to 22.5 sq. ft. without the need for additional linkages.
• Flexible Control Options: Supports both 3-wire floating point control and 2-wire on/off configurations for diverse controller requirements.
• Electronic Stall Protection: Internal circuitry protects the motor from burnout at the end of rotation, improving long-term reliability.
• Field Reversibility: Includes a simple switch to change the direction of rotation (CW/CCW) without rewiring.

How do I wire the NMB24-3 for floating control?
Connect Pin 1 to common, Pin 2 to 24V power, and use Pin 3 to drive the motor clockwise or counter-clockwise based on the signal from your DDC controller.

Can this actuator be used in smoke or fire safety applications?
No, this is a non-spring return unit designed for general HVAC airflow control. It does not have the "fail-safe" functionality required for fire/smoke dampers.

What happens if the damper becomes obstructed?
The Belimo NMB24-3 features electronic overload protection; it will stop trying to turn when it meets high resistance, preventing damage to the gear train.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.