The Belimo LRB24-SR is a high-performance proportional control actuator designed for use with pressure-independent characterization valves and standard zone valves. This non-spring return actuator delivers 45 in-lb (5 Nm) of torque while operating on a standard 24VAC/DC power supply. It utilizes a 2 to 10 VDC control signal, providing precise modulation for fluid control in demanding HVAC systems. This unit is the direct engineered replacement for legacy models including the LR24-SR, LR24A-SR, and the LR24-SR-2.0, ensuring seamless mechanical and electrical backward compatibility. Built with a brushless DC motor and secondary diagnostics, the LRB24-SR actuator eliminates the need for limit switches by employing electronic stall protection. Its compact NEMA 2 (IP54) housing facilitates installation in tight mechanical plenums, while the manual override button allows for quick system positioning during commissioning or maintenance cycles. Universal Compatibility: Serves as a drop-in replacement for the discontinued LR24-SR series, maintaining the same mounting footprint and wiring schematics. High Precision Control: Features a 2-10 VDC feedback signal for real-time position monitoring via the Building Automation System (BAS). Energy Efficient Performance: Consumes only 0.4W in holding mode, reducing the overall transformer load in large-scale commercial deployments. Field Reliability: The brushless DC motor technology prevents burnout and ensures consistent cycle times across varying temperature ranges. Ease of Installation: Includes a standard universal clamp for simple shaft attachment and a reversible rotation switch for adaptable field configuration. Common Questions: What is the difference between the LRB24-SR and the LR24-SR? The LRB24-SR is the current production model that supersedes the LR24-SR. It offers identical torque and control characteristics but incorporates modernized electronics for improved lifecycle performance. Can I use this actuator for on/off control? While optimized for 2-10 VDC modulating signals, it can be configured for 3-point floating or on/off control depending on the specific field controller wiring and the 4-12 mA conversion requirements. Does this unit have a mechanical fail-safe? No, this is a non-spring return actuator. It will maintain its last position upon loss of power unless a backup power source is integrated into the control circuit. 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.
