Belimo AFB24-S Actuator

The Belimo AFB24-S is a heavy-duty spring return damper actuator engineered for on/off control in demanding HVAC applications. Delivering a robust 180 in-lb torque, this unit is designed to operate reliably within 24VAC or 24VDC circuits, ensuring failsafe positioning for fire and smoke dampers or large control air valves during power loss. The integrated auxiliary switches (2x SPDT) provide precise position feedback to the building management system, simplifying troubleshooting and sequence verification. Built with a rugged NEMA 2 housing, it supports direct mounting on shafts up to 1.05 inches using a universal clamp. This electronic actuator minimizes power consumption in holding mode, while the brushless DC motor ensures consistent timing and long-term mechanical endurance. For commercial HVAC maintenance, the AFB24-S remains a standard for replacing legacy 180 in-lb actuators in air handling units and pressurized zones.

• High Torque Output: Provides 180 in-lb (20 Nm) to drive large dampers or high-pressure valves.
• True Mechanical Spring Return: Ensures 100% fail-safe operation upon loss of power for safety-critical zones.
• Dual Auxiliary Switches: Includes two internal SPDT switches for end-stop signaling and interlocking.
• Universal Compatibility: Mounts easily to round, square, or hexagonal shafts with the standard multi-function clamp.
• Manual Override: Features a hand crank for manual positioning during commissioning or system testing.

Is the Belimo AFB24-S suitable for outdoor installation?
The standard NEMA 2 rating requires protection from direct rain. For exposed installations, a NEMA 4X weather shield is recommended to protect the internal electrical components.

Can I adjust the auxiliary switch trip points?
Yes, one of the two SPDT switches is fixed at 10 degrees, while the second is fully adjustable from 10 to 90 degrees for custom feedback signaling.

What is the typical run time for this actuator under load?
The AFB24-S typically features a motor run time of less than 75 seconds and a spring return time of approximately 20 seconds at ambient temperature.

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.