The Belimo LF230 US is a compact spring-return (fail-safe) damper actuator delivering 35 in-lb [4 Nm] of torque with on/off (two-position) control on AC 230 V power. It direct-couples to round damper shafts from 3/8 in. to 1/2 in. (to 3/4 in. with the K6-1 accessory clamp) and, on loss of power, its internal spring returns the damper to a fail-safe position in under 25 seconds, making it a member of the LF platform for small commercial HVAC dampers that must fail safe.
Specifications sourced from the official Belimo LF230 US technical data sheet (rev 2026-06-17).
Overview
Belimo LF-Series actuators are compact spring-return drives for small commercial HVAC control dampers requiring fail-safe operation. The LF230 US produces 35 in-lb [4 Nm] and mounts directly to round damper shafts from 3/8 in. to 1/2 in. (to 3/4 in. with the K6-1 accessory clamp). On power loss the spring returns the damper to its fail-safe position in under 25 seconds; the fail-safe direction is reversible by CW/CCW mounting. Two-position on/off control drives the damper, and the spring returns it on signal or power loss.
Best for
- Small commercial HVAC dampers needing fail-safe (spring-return) operation
- Compact damper and zone control (35 in-lb)
- Outdoor-air and exhaust dampers that must fail safe
- Line-voltage systems (230 VAC)
Key Features
Spring-Return Fail-Safe
A mechanical spring drives the damper to a safe position on power or signal loss (under 25 seconds) — no external power needed to fail safe.
Compact 35 in-lb Actuator
Sized for small dampers; direct-couples to round damper shafts from 3/8 in. to 1/2 in. (to 3/4 in. with the K6-1 accessory clamp).
On/Off Control
Accepts two-position on/off control from a controller, relay or switch.
Reversible Fail-Safe Direction
The spring-return (fail-safe) direction is selectable clockwise or counterclockwise by mounting orientation.
Line-Voltage Power
Runs directly on 230 VAC line power — no separate 24 V transformer required.
cULus Listed & Quiet
Double-insulated (Class 2), cULus listed, ISO 9001 built and UL 2043 plenum-rated for long, maintenance-free service.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Belimo |
| Part Number | LF230 US |
| Actuator Type | Spring-Return (Fail-Safe) Damper Actuator |
| Nominal Voltage | AC 230 V |
| Nominal Frequency | 50/60 Hz |
| Power Consumption (Running) | 3.5 W |
| Torque (Motor & Spring) | 35 in-lb [4 Nm] (minimum) |
| Control Signal | On/Off (two-position) |
| Shaft Range | 3/8 in. to 1/2 in. (to 3/4 in. with K6-1 clamp) |
| Angle of Rotation | 95° (adjustable mechanical stops) |
| Running Time (Motor) | 75 s / 90° |
| Spring Return Time | < 25 s for fail-safe |
| Behavior on Power Loss | Spring returns damper to fail-safe position |
| Fail-Safe Direction | Reversible (CW/CCW) by mounting orientation |
| Electrical Connection | 18 GA plenum cable, 3 ft [1 m], 1/2" NPT conduit connector |
| Overload Protection | Electronic, full 0-95° rotation |
| Electrical Protection | Double insulated (Class 2) |
| Enclosure Rating | NEMA 2 / UL Type 2 |
| Ambient Temperature | -22 to 122°F [-30 to 50°C] |
| Agency Listing | cULus (UL60730-1A/-2-14, CAN/CSA) |
| Quality Standard | ISO 9001 |
| Plenum Rated | UL 2043 (suitable for air plenums) |
| Weight | 3.8 lb [1.7 kg] |
| Warranty | 5 Years |
Documentation
Related Products
Accessories & Mounting
Common Belimo accessories for mounting, linkage, signaling and powering the LF230 US, drawn from the LF actuator datasheet. All are stocked by ZOT Supply as an authorized Belimo distributor.
Mounting & Linkage
Electrical Add-Ons
Frequently Asked Questions
What is the Belimo LF230 US?
The Belimo LF230 US is a compact spring-return (fail-safe) damper actuator for small commercial HVAC dampers. It produces 35 in-lb [4 Nm] of torque, uses on/off (two-position) control on AC 230 V power, and on power loss its spring drives the damper to a fail-safe position in under 25 seconds.
Is the LF230 US a spring-return (fail-safe) actuator?
Yes. A mechanical spring drives the damper to its fail-safe position when power or the control signal is lost — no external power is needed to fail safe.
What happens to the LF230 US on power loss?
Its internal spring returns the damper to the fail-safe position in under 25 seconds. The fail-safe direction (CW or CCW) is set by the mounting orientation.
What shaft sizes does the LF230 US fit?
It direct-couples to round damper shafts from 3/8 in. to 1/2 in. (to 3/4 in. with the K6-1 accessory clamp) using its universal clamp. For shafts up to 3/4 in., use the K6-1 accessory clamp.
What control signal does the LF230 US use?
It uses on/off (two-position) control. Two-position on/off control is driven from a controller, relay or switch.
What voltage does the LF230 US run on?
The LF230 US is a line-voltage actuator running on 230 VAC, so no separate 24 V control transformer is required.
Is the Belimo LF230 US available from an authorized Belimo distributor?
Yes. ZOT Supply is an authorized Belimo distributor and carries the LF230 US. Every unit ships factory new with Belimo's full 5-year warranty and application support.
- Actuator Type:
- Fail-Safe
- Torque:
- 35 in-lb
- Control Signal:
- On/Off
- Voltage:
- 230 VAC
- Auxiliary Switch:
- No
- Series:
- LF
