The Belimo LF120-S US LF damper actuator includes an auxiliary SPDT switch, and is intended for On/Off, fail-safe control of dampers in HVAC systems. Actuator sizing should be done in accordance with the damper manufacturer’s specifications. Control is On/Off from an auxiliary contact, or a manual switch and the actuator is mounted directly to damper shafts 3/8” up to 1/2” in diameter, by means of its universal clamp, 1/2” shaft centered at delivery. For shafts up to 3/4” use K6-1 accessory. A crank arm and several mounting brackets are available for applications where the actuator may not be direct-coupled to the damper shaft.
The LF120-S US also provides a built-in auxiliary switch. This SPDT switch is provided for safety interfacing or signaling, for example, for fan start-up. The switching function is adjustable between 0° and 95°.
Product Specifications
| Control Input Values |
On/Off |
| Weight |
3.5 lbs (1.60 kg) |
| Ambient Temperature |
-22°F to +122°F [-30°C to +50°C] |
| Auxiliary Switch |
1 x SPDT |
| Electrical Connection |
(2) 3 ft, 18 GA appliance cables, 1/2"
conduit connector |
| Power Consumption |
running: 5.5 W, holding: 3.5 W |
| Power Supply |
120 VAC |
| Va Rating |
7.5 VA |
| Noise Level* |
less than 50 dB(A) running, spring
return less than 62dB(A) |
| Servicing |
Maintenance free |
| Shaft Diameter |
3/8" to 1/2" (standard), 1/2" to 3/4"
with K4-1 clamp acc. |
| Housing |
NEMA 2 / IP54 |
| Housing Material |
zinc coated steel |
| Angle of Rotation |
max. 95°, adjustable with mechanical
stops |
| Direction of Rotation |
spring return can be selected by CW/CCW
mounting |
| Manual Override |
None |
| Minimum Torque |
(in-lb) 35 |
| Running Time (motor) |
< 40 to 75 sec. |
| Overload Protection |
electronic throughout 0 to 95°
rotation |
| Spring Return Fail Safe |
yes |
| Quality Standards |
ISO 9001 |
| Humidity Rating |
5 to 95% RH non-condensing |
| Storage Temperature |
-40°F to +176°F [-40°C to +80°C] |
| Running Time (Spring) |
<25 sec @ -4°Fto122°F[-20°Cto50°C] <60
sec @ -22°F[-30°C] |
| Cable Option |
3 feet |
| Agency Listing |
cULus, CE |