The Belimo LM Series represents a line of direct coupled actuators designed for damper control in HVAC systems. These actuators utilize brushless DC motor technology and are intended as replacements for rack and pinion type actuators, specifically offering compatibility with existing LM24 control systems. The documentation details specifications relating to torque, power supply, control signals, feedback signals, and run times. These actuators are applicable to VAV units and small zone dampers, with a capacity for damper areas up to 8 square feet.
Overview of the LM Series
The LM Series actuators are characterized by their compact size and relatively high torque output, providing a minimum of 35 in-lb of torque. They are designed for direct coupling, simplifying installation in certain applications. The documentation highlights their suitability as replacements for existing Belimo actuators, aiming to minimize disruption to established control systems. The series incorporates features such as adjustable run times, left/right rotation switches, and angle of rotation limiting, both mechanical and electronic.
Technical Specifications
The following specifications are derived directly from the provided documentation:
- Torque: 35 in-lb
- Power Supply: 24 VAC/DC
- Motor Type: Brushless DC motor (BDCM)
- Control Signal: On-off, floating point, proportional 2 to 10 VDC, multi-function.
- Feedback Signal: 2 to 10 VDC, VDC variable. Feedback potentiometers are available in 10kΩ and 5kΩ configurations.
- Run Time: 95 seconds (standard). Adjustable range of 75 to 300 seconds. Specific run times are also noted for different torque levels:
- 80 to 110 seconds for 0 to 35 in-lb
- 25 to 35 seconds for 0 to 18 in-lb
- Cable: Plenum rated, 18 GA
- Terminal Strip: Screw terminal strip
- Auxiliary Switch: Built-in
Application Areas
The documentation specifically identifies the following areas of application for the LM Series actuators:
- VAV (Variable Air Volume) Units
- Small Zone Dampers
The actuators are designed for damper areas up to 8 sq-ft, based on a loading of 4 in-lb/ft. The documentation notes compatibility with the Quiet Plus VAV terminal unit by Warren Technology. Installation with existing pneumatic actuators may require linkage.
Installation Considerations
The documentation references general wiring instructions (page 169 of the manual) and start-up/checkout procedures (page 171). The actuators feature a left/right rotation switch, allowing for field adjustment of the rotation direction. Both mechanical and electronic angle of rotation limiting are incorporated, providing flexibility in configuring the actuator’s range of motion. The use of a plenum rated cable is specified, indicating suitability for installation within plenum spaces.
Compatibility and Replacement
The LM Series is presented as a direct replacement for existing Belimo rack and pinion type actuators, specifically the LM24. This compatibility is intended to simplify upgrades and reduce the need for extensive modifications to existing control systems. The documentation states the LM Series can directly couple to VAV actuators and existing pneumatic bypass damper shafts, although the latter may require linkage.
Features and Components
The LM Series actuators incorporate several features designed to enhance functionality and ease of installation:
- Brushless DC Motor Technology: Provides reliable and efficient operation.
- Adjustable Run Time: Allows for customization of the actuator’s speed and response.
- Rotation Switch: Enables field adjustment of the rotation direction.
- Angle of Rotation Limiting: Offers both mechanical and electronic methods for controlling the actuator’s range of motion.
- Built-in Auxiliary Switch: Provides additional functionality for control and monitoring.
- Feedback Potentiometer: Available in 5kΩ and 10kΩ configurations for position feedback.
Control Signal Details
The LM Series actuators support a variety of control signals, offering flexibility in integration with different control systems:
- On-off: Simple open/close control.
- Floating Point: Allows for proportional control based on a floating signal.
- Proportional 2 to 10 VDC: Provides precise control based on a 2-10 VDC signal.
- Multi-function: Supports a range of control modes and configurations.
The actuators also provide feedback signals, allowing the control system to monitor the actuator’s position and status. These feedback signals are available as 2 to 10 VDC signals or through the use of feedback potentiometers.
Safety and Regulatory Information
The provided documentation does not contain specific safety warnings or regulatory compliance information beyond the specification of a plenum rated cable. Users should consult the full product manual and relevant local codes and standards for complete safety and installation guidelines.
Conclusion
The Belimo LM Series direct coupled actuators offer a compact and powerful solution for damper control in HVAC systems. Their compatibility with existing Belimo actuators and support for multiple control signals make them a versatile choice for both new installations and upgrades. The adjustable run time, rotation switch, and angle of rotation limiting provide flexibility in configuring the actuator to meet specific application requirements. The documentation highlights the importance of proper wiring and adherence to safety guidelines during installation.