The Belimo LF120 US LF Spring Return Damper Actuator is intended to 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 US provides true spring-return operation for reliable fail-safe application and positive close off on air tight dampers. The spring return system provides consistent torque to the damper with, and without, power applied to the actuator. Provides 95° of rotation and is provided with a graduated position indicator showing 0° to 95°.
Product Specifications
| Power supply |
120 VAC ± 10% 50/60 Hz |
| Power consumption |
running 5.5 W, holding 3.5 W |
| Transformer sizing |
7.5 VA |
| Electrical connection |
3 ft, 18 GA appliance cable, 1/2”
conduit connector |
| Overload protection |
electronic throughout 0 to 95°
rotation |
| Electrical protection |
actuators are double insulated |
| Angle of rotation |
max 95°, adjust. with mechanical stop |
| Torque |
35 in-lb [4 Nm] constant torque |
| Direction of rotation |
reversible with cw/ccw mounting |
| Position indication |
visual indicator, 0° to 95° (0° is
spring return position) |
| Running time motor |
< 40 to 75 sec |
| Running time (nominal) spring |
< 25 sec @-4°F to 122°F [-20°C to
50°C], < 60 sec @-22°F [-30°C] |
| Humidity |
5 to 95% RH non-condensing |
| Ambient temperature |
-22°F to 122°F [-30°C to 50°C] |
| Storage temperature |
-40°F to 176°F [-40°C to 80°C] |
| Housing |
NEMA type 2 / IP54 |
| Housing material |
zinc coated steel |
| Agency listings |
cULus acc. to UL 873 and CAN/CSA C22.2
No. 24-93 |
| Noise level (max) running |
< 50 db (A) |
| Noise level (max) spring return |
62 dB (A) |
| Servicing |
maintenance free |
| Quality standard |
ISO 9001 |
| Weight |
3.4 lbs (1.54 kg) |
| Auxiliary switch |
1 x SPDT 3A (0.5A) @ 250 VAC, UL
Approved adjustable 0° to 95° |