Series-DDB-DDD

The DDB-DDD series from Dwyer offers a highly reliable, feature-rich electric actuator solution engineered for HVAC dampers and control valves, delivering torque ranges from 88 to 265 in-lb (10 to 30 Nm) and designed for 24 VAC power. 

Installation is streamlined thanks to the direct-mount design which allows the actuator to clamp onto shafts between 0.4″ and 0.75″ diameter without additional linkage. A clear travel indicator provides visual confirmation of position, while a push-button manual override enables convenient hand operation during setup or maintenance. The magnetic clutch overload protection guards internal mechanism integrity from stalled or over-torqued conditions, all while keeping noise levels under 45 dB. 

Control flexibility is a hallmark of this series. The DDB models accept floating (two-position) control signals—ideal for simple open/close damper operation. Meanwhile, the DDD models support modulating control signals (4–20 mA or 0–10 VDC) and provide 0–10 VDC position feedback - making them suitable for building automation systems and precise modulation of air or fluid flow. 

Mechanically the series is built for longevity, with a nominal cycle life of up to 60,000 full cycles, and an adjustable stroke of 95° enabling both clockwise and counter-clockwise rotation. The actuator is rated for ambient temperatures from -22 °F to 122 °F (-30 °C to 50 °C) and houses electrical connections in a NEMA 2 (IP42) enclosure for indoor use. With torque options spanning 88 in-lb to 265 in-lb, this series covers a broad range of damper sizes and valve actuator demands. 

In essence, the DDB-DDD series combines installation ease, robust design, and flexible controls - making it an excellent choice for HVAC engineers, building management integration, and facility retrofit projects.