Product Overview
Belimo LMB24-3-S 24V Non-Spring Damper Actuator with Aux Switch - Unused
You're looking at a Belimo LMB24-3-S direct-coupled damper actuator — a 24 V AC/DC, non-spring-return actuator designed for on/off or floating-point control of HVAC air dampers.
This model represents Belimo’s approach to reliable, electrically efficient damper control: deliver consistent torque across the full stroke, limit mechanical stress electronically, and hold position without wasting power once the target angle is reached.
Product Condition
Unused, New Old Stock. This actuator was never installed and is not in the manufacturer’s original packaging. It may show minor handling marks consistent with storage but has no operational wear.
Product Overview
The LMB24-3-S provides 45 in-lb (5 Nm) of torque using a sensorless brushless DC motor with ASIC-based control and digital rotation sensing. It is intended for standard commercial HVAC applications where controlled damper positioning is required without spring-return fail-safe action.
The “-S” variant includes one factory-installed, adjustable SPDT auxiliary switch for end-position indication or low-voltage control signaling.
Key Features
- Belimo LMB24-3-S non-spring-return damper actuator
- Rated 45 in-lb (5 Nm) torque across full rotation range
- 24 V AC/DC power input, suitable for common HVAC control systems
- On/off or floating-point control modes
- Direct-coupled mounting with universal clamp for 1/4 inch to 5/8 inch shafts
- Maximum rotation up to 95 degrees with adjustable mechanical end stops
- Integrated manual override push button for shaft positioning
- Built-in SPDT auxiliary switch, adjustable for position proving
- NEMA 2 / IP54 enclosure for indoor HVAC environments
Applications
- Commercial HVAC air handling units
- Zone and volume control dampers
- Building automation system integrations
- Mechanical room and plenum installations
- Replacement actuators for compatible damper assemblies
- HVAC training, testing, or bench evaluation setups
Frequently Asked Questions
Is this a spring-return actuator?
No. The LMB24-3-S is a non-spring-return actuator and will not automatically drive to a fail-safe position on power loss.
What control signals does this actuator support?
It is designed for on/off or floating-point control using standard 24 V AC/DC control signals.
What does the “-S” suffix indicate?
The “-S” designation means this actuator includes one factory-installed SPDT auxiliary switch for position indication or control interlocking.
What shaft sizes are supported?
The integral clamp supports round shafts from 1/4 inch to 5/8 inch. Larger shafts may require an accessory clamp.
Is this actuator suitable for outdoor use?
No. It carries a NEMA 2 / IP54 rating and is intended for indoor HVAC environments unless additional enclosure protection is provided.
Built to hold position efficiently and repeat it day after day, this Belimo actuator is ready to step into a control sequence where reliability matters more than theatrics.
