Belimo lru24-sr Spring Return Rotary Damper Actuator

Belimo LRU24-SR is a spring-return rotary damper actuator for HVAC dampers that operates from AC or DC 24 V power. It delivers 4 Nm (approximately 35 in-lb) of torque to drive a damper shaft and includes a fail-safe spring return that moves the damper to its safe position when power is removed. The actuator’s motor travel time to the operating position is about 90 seconds, while the spring-return reposition time is typically under 25 seconds in normal ambient conditions, with longer times—up to roughly 60 seconds—at colder temperatures near -30°C. The device is overload-protected and does not require external limit switches, stopping automatically at the end of travel. This direct-coupled rotary actuator is designed for reliable damper control in commercial HVAC applications, including zoning and air-handling units, where a predictable fail-safe position is essential during power loss. As part of Belimo’s LRU-series, the LRU24-SR is specifically built to provide consistent performance with 24 V power and is suited for dampers that demand a dependable spring-return operation without additional sensing or actuation hardware.