Belimo LF24-SR US : Fail-Safe Damper Actuator, 35 in-lb Torque, 24VAC/DC, Modulating 2-10VDC Control Signal, 5-Year Warranty
The Belimo LF24-SR US is an ideal solution for achieving fail-safe, modulating control of dampers in HVAC systems. Designed for hassle-free installation, this actuator is directly mounted to damper shafts ranging from 3/8" to 1/2" in diameter using its universal clamp, with a default 1/2" shaft centering. For larger shafts up to 3/4", you can utilize the K6-1 accessory. In cases where direct coupling is not possible, various mounting brackets and a crank arm are available for versatile applications. The actuator operates smoothly in response to either a 2-10 V or, with the inclusion of a 500Ω resistor, a 4-20 mA control input from an electronic controller or positioner. Furthermore, it provides a 2-10 V feedback signal for precise position indication.
What sets the LF24-SR apart is its true spring return operation, ensuring dependable fail-safe functionality and airtight damper sealing. With 95 degrees of rotation, it also boasts a graduated position indicator. Its efficiency is attributed to a brushless DC motor controlled by an Application Specific Integrated Circuit (ASIC) and a microprocessor. This intelligent design maintains a constant rotation rate and accurately detects the actuator's fail-safe position. The ASIC keeps a close eye on the motor's rotation and offers digital rotation sensing to prevent damage in case of a stall. Importantly, mechanical end switches are not required, allowing stalling at any point in its normal rotation while minimizing power consumption during holding mode.
For those seeking a reliable and versatile solution, this actuator fits the bill. It eliminates the need for a crank arm and linkage, easily mounts to shafts up to 3/4" in diameter, and provides a minimum output torque of 35 in-lbs. It's compatible with 2-10 VDC or 4-20 mA control inputs from electronic controllers, and its brushless DC motor, microprocessor control, and constant run time make it a dependable choice. Additionally, it offers a 2-10 feedback signal for accurate position feedback. Designed for both clockwise and counter-clockwise fail-safe operation, this cULus listed actuator comes with a 5-year warranty and is manufactured under ISO 9001 International Quality Control Standards, ensuring a high level of quality and reliability. When it comes to actuation solutions, the Belimo LF24-SR is the trusted choice.
Specifications
| Voltage AC/DC | AC/DC 24 V |
| Power Consumption (Running) | 2.5 W |
| Power Consumption (Holding) | 1 W |
| Power Consumption For Wire Sizing | 5 VA |
| Torque | 35 in-lb [4 Nm] |
| Control Type | DC 2...10 V |
| Direction Of Motion Motor | selectable with switch 0/1 |
| Direction of Rotation (Fail-Safe) | Reversible with cw/ccw mounting |
| Angle of Rotation | 95 |
| Running Time (Motor) | 150 s / 90° |
| Running Time (Fail-safe) | <25 s |
| Protection category | IP42 |
| Degree Of Protection NEMA | NEMA 2 |
| Enclosure Type | UL Enclosure Type 2 |
| Ambient Temeprature | -22...122°F [-30...50°C] |
Datasheets
 | Belimo LF24-SR Technical Data sheet |
| Belimo LF Series Installation Instructions |
| Belimo Mounting Methods Guide |
| Belimo Master Format |
- Actuator Type:
- Fail-Safe
- Torque:
- 35 in-lb
- Voltage:
- 24VAC/DC
- Control Signal:
- 2-10VDC
- Auxillary Switch:
- None
- NEMA 4X Enclosure:
- No
