Belimo CMB24-SR-L Actuator

The Belimo CMB24-SR-L is a compact, non-spring return rotary actuator engineered for precise control of HVAC zone valves and small dampers. This modulating actuator operates on a 24VAC/DC power supply and responds to a 2-10VDC control signal, providing 18 in-lb of torque for reliable positioning. Designed for high-duty cycle applications, the CMB24-SR-L features a brushless DC motor controlled by an Application Specific Integrated Circuit (ASIC), which monitors and adapts the motor's operation to ensure consistent performance and precise airflow control. The "L" designation indicates a counter-clockwise (CCW) rotation relative to the scale, simplifying integration into specific HVAC piping configurations. Field technicians value this unit for its electronic stall protection, which eliminates the need for mechanical limit switches and prevents motor burnout during unexpected obstructions. Its compact footprint makes it an ideal replacement actuator for tight mechanical plenums where space is at a premium.

• Precise Control: Provides a stable 2-10VDC proportional feedback signal for accurate system monitoring.
• Enhanced Reliability: Microprocessor-controlled brushless DC motor ensures long-term performance without brush failure.
• Simplified Installation: Universal spindle design and small form factor allow for quick mounting on various valve bodies.
• Overload Protection: Automatic electronic stall sensing protects the gear train without requiring manual resets.
• Low Power Consumption: Optimized energy usage during holding and runtime phases for improved system efficiency.

What is the difference between the CMB24-SR and the CMB24-SR-L?
The -L suffix denotes the specific rotational direction (counter-clockwise) and the relative position of the mounting bracket and scale, which is critical for matching existing valve linkages.

Can the CMB24-SR-L be used in 3-point floating control systems?
No, this model is specifically designed for 2-10VDC (modulating) control signals. For floating or on/off control, a different CMB series variant is required.

Does this actuator require a specific transformer?
It operates on Class 2 power supplies (24VAC/DC). Always calculate total VA draw when daisy-chaining multiple actuators on a single transformer to prevent voltage drops.

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.