Replacement Transformer

This fail-safe, spring-return damper actuator is a direct replacement for the Belimo AF24-S and compatible with similar HVAC control applications requiring reliable on/off damper positioning. Engineered for commercial and industrial HVAC systems, this actuator delivers 180 in-lb (20 Nm) of torque with a 95-degree rotation range, ensuring precise control of airflow dampers in heating, cooling, and ventilation applications. The actuator operates on nominal AC/DC 24 V (50/60 Hz), with acceptable input ranges of AC 19.2 to 28.8 V or DC 21.6 to 28.8 V, making it compatible with standard HVAC control voltages. Power consumption is efficient at 5 W during operation and 2.5 W in holding mode, with a transformer sizing requirement of 7.5 VA. The unit features double insulation and electronic overload protection across the full 0 to 95-degree rotation range for enhanced safety and reliability. Two built-in SPDT (Single Pole Double Throw) auxiliary switches provide critical safety signaling and status feedback. These switches operate from 1 mA to 3 A (0.5 A inductive) across DC 5 V to AC 250 V, with one switch activating at approximately 10 percent rotation and the other adjustable between 11 and 90 percent. This dual-switch configuration supports applications requiring position verification and fail-safe interlocking. The actuator is powered by a UL Class 2 supply and is suitable for applications where fail-safe operation and spring-return functionality are essential. This replacement unit is ideal for retrofit installations and new construction projects in commercial buildings, hospitals, schools, laboratories, and industrial facilities where damper control safety and reliability are critical requirements.