LF24-ECON-R03 US | Belimo | Damper ActuatorDamper Actuator, 35 in lbs [4 Nm], Spring return, AC DC 24 V, 3 k? NTC For fail safe, modulating control of mixed air setpoint on economizer dampers in HVAC systems. Actuator sizing should be done in accordance with the damper manufacturers specifications. The actuator is mounted directly to a damper shaft from 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