The Belimo FSLF24.1 US is a factory-sealed 135-piece multipack of the FSLF24 US fail-safe fire & smoke damper actuator — built for mechanical contractors handling life-safety dampers in volume. Each unit delivers 30 in-lb of torque, runs on 24VAC/DC, uses on/off control, and is UL555S listed with a thermally-triggered spring-return fail-safe. Ordering the case lowers your cost per actuator versus buying singles.
Specifications per the Belimo FSLF24 US product datasheet.
Overview
Belimo FS-Series actuators are UL555S-listed fail-safe drives for life-safety fire and smoke dampers in HVAC systems. The FSLF24 US produces 30 in-lb of torque, mounts directly to the damper shaft, and on loss of power — or when its thermal sensor reaches the rated limit — springs the damper to its fail-safe position within <15 s. A UL Type 1 housing and on/off control make it a direct, code-compliant replacement actuator. This SKU ships as a 135-piece bulk case for volume stocking.
Best for
- Life-safety fire and smoke damper control in commercial HVAC (30 in-lb damper torque)
- UL555 / UL555S listed assemblies requiring a thermally-triggered fail-safe actuator
- 24VAC/DC systems using on/off control
- Mechanical contractors handling damper actuators in volume — lower cost per unit
Key Features
Thermal fail-safe
Spring-return mechanism drives the damper to its safe position on power loss, and a thermal sensor trips the fail-safe at the rated temperature limit (350°F [177°C] for 30 min).
30 in-lb torque
Sized for fire and smoke dampers requiring up to 30 in-lb, with a 15 s motor running time and <15 s fail-safe time.
UL555 / UL555S listed
Listed for use on UL-classified fire dampers (UL555) and smoke / combination fire-smoke dampers (UL555S).
On/Off control on 24VAC/DC
On/Off control signal with a 24VAC/DC supply and a UL Type 1 housing for standard duct and plenum mounting.
135-piece bulk case
Factory multipack of 135 units — lower cost per actuator and fewer POs for high-volume life-safety projects.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Belimo |
| Part Number | FSLF24.1 US |
| Base Model | FSLF24 US |
| Pack Quantity | 135 pcs (bulk case) |
| Actuator Type | Fail-Safe Fire & Smoke Damper Actuator |
| Torque | 30 in-lb |
| Control Signal | On/Off |
| Power Supply | 24VAC/DC |
| Fail-Safe | Spring return (mechanical) |
| Thermal Rating | 350°F [177°C] for 30 min |
| Motor Running Time | 15 s |
| Fail-Safe Time | <15 s |
| Auxiliary Switch | None |
| Conduit Connector | Standard |
| Housing | UL Type 1 |
| Listings | UL555, UL555S |
| Warranty | 5-Year Belimo Warranty |
| Approx. Weight (case) | 594.0 lb |
Documentation
Belimo FSLF24 US DatasheetRelated Products
Frequently Asked Questions
Is this a fail-safe actuator?
Yes. It uses a mechanical spring return that drives the damper to its safe position on loss of power, and a thermal sensor that trips the fail-safe at the rated temperature limit.
What dampers is it used on?
UL555-classified fire dampers and UL555S-classified smoke and combination fire/smoke dampers in commercial HVAC systems.
What torque does it provide?
30 in-lb, suitable for fire/smoke dampers rated up to that torque.
What does the thermal rating mean?
The actuator holds its rating at 350°F [177°C] for 30 minutes, then trips to fail-safe — meeting life-safety damper requirements.
How many actuators are in this pack?
This is a factory bulk case of 135 units of the FSLF24 US. For a single unit, order the FSLF24 US instead.
Why buy the multipack?
Volume pricing lowers the cost per actuator and reduces purchase orders for mechanical contractors on large life-safety projects.
- Actuator Type:
- Fire & Smoke Actuator
- Torque:
- 30 in-lb
- Voltage:
- 24VAC/DC
- Control Signal:
- On/Off
- Aux Switch:
- None
- Connector:
- Standard
- Housing:
- UL Type 1
- Pack Size:
- Multipack (135 pcs)
