Belimo LF120-S Spring Return Damper Actuator, 35 in-lb, On/Off, 120 VAC

Description

The Belimo LF120-S is a reliable, direct-coupled spring return damper actuator engineered for On/Off control of HVAC dampers in commercial and light commercial applications. Featuring a 35 in-lb torque output and 120 VAC power supply, this actuator provides dependable fail-safe operation — automatically returning the damper to its spring-return position upon loss of power, making it ideal for safety-critical ventilation and air distribution systems.

Equipped with a built-in auxiliary switch, the LF120-S allows for end-of-travel feedback signaling to building automation systems, control panels, or other downstream devices — eliminating the need for add-on accessories and simplifying installation.

Designed for easy field installation, the LF120-S features Belimo’s industry-standard direct-coupled mounting that fits round damper shafts without the need for crank arms or linkages. Its compact, rugged housing is well-suited for tight mechanical spaces.

Key Features

• Spring return fail-safe operation — returns to safe position on power loss
• 35 in-lb (4 Nm) torque output for reliable damper control
• On/Off control signal type
• 120 VAC power supply
• Integrated auxiliary switch for end-of-travel position feedback
• Direct-coupled design — no crank arms or linkages required
• Compact, space-saving form factor for tight installations
• Manual override for commissioning and servicing

Specifications

• Brand: Belimo
• Model / SKU: LF120-S
• Torque: 35 in-lb
• Control Type: On/Off
• Power Supply: 120 VAC
• Actuator Type: Spring Return
• Auxiliary Switch: Included
• Mounting: Direct-coupled to damper shaft

Typical Applications

• Commercial HVAC air handling units (AHUs)
• Ventilation and exhaust damper control
• Building automation and energy management systems
• Outdoor air and economizer dampers
• Fire and smoke control damper actuation (verify local code requirements)