Features:

• Cut labor costs with (10 min. installation) simple direct coupling. Actuator Centers on 1/2" shaft (K6-1, 3/4" clamp optional).
• True mechanical spring return - the most reliable failsafe.
• Mount for clockwise or counterclockwise fail-safe.
• Easy-to-adjust mechanical stop to limit damper rotation.
• Check damper position easily with clear position indicator.
• Don't worry about actuator burn-out. Belimo is overload-proof throughout rotation.
• Need to change control direction? Do it easily with a simple switch (modulating actuators).
• Built-in auxiliary switch is easy to use, offers feedback or signal for additional device.
• Microprocessor-controlled brushless DC motor increases actuator life span and reliability, provides constant running time (modulating actuators). Provided on Basic Models
• Rugged metal housing withstands rough handling in the mechanical room.
• 3 ft. cable and conduit connector eases installation.

The LF24-SR-S-20 is used for proportional modulation of dampers and control valves in HVAC systems. The actuator operates in response to a 2 to 10 VDC, or with the addition of a 500W resistor, a 4 to 20 mA control input from an electronic controller or positioner. A 2 to 10 VDC feedback signal is provided for position indication or master-slave applications.

The LF series actuators provide 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.

The LF24-SR-S version is provided with 1 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°. The auxiliary switch in the LF24-SR-S US is double insulated so an electrical ground in not necessary.