Belimo Lf24-sr Damper Actuator | 35 In-lb | Spg Rtn | 24v | Modulating | Blackhawk Supply
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LF24-SR | Damper Actuator | 35 in-lb | Spg Rtn | 24V | Modulating | Belimo

SKU: LF24-SR Brand: Belimo Condition: New Sale price Compare at $537.00
Regular price $179.23


Belimo part#: LF24-SR


Damper Actuator | 35 in-lb | Spg Rtn | 24V | Modulating

Torque min. 35 in-lb, for control of air dampers.


For fail-safe, modulating control of dampers in HVAC systems. Actuator sizing should be done in accordance with the damper manufacturer’s 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 arm and several mounting brackets are available for applications where the actuator cannot be direct coupled to the damper shaft. The actuator operates in response to a 2 to 10 VDC, or with the addition of a 500? 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.


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 LF series provides 95° of rotation and is provided with a graduated position indicator showing 0 to 95°. The LF24-SR US uses a brushless DC motor which is controlled by an Application Specific Integrated Circuit (ASIC) and a microprocessor. The microprocessor provides the intelligence to the ASIC to provide a constant rotation rate and to know the actuator’s exact fail-safe position. The ASIC monitors and controls the brushless DC motor’s rotation and provides a digital rotation sensing function to prevent damage to the actuator in a stall condition. The actuator may be stalled anywhere in its normal rotation without the need of mechanical end switches. Power consumption is reduced in holding mode.

Technical Data
Power Supply 24 VAC, ±20%, 50/60 Hz, 24 VDC, ±10%
Power Consumption Running 2.5 W
Power Consumption Holding 1 W
Transformer Sizing 5 VA (class 2 power source)
Shaft Diameter 3/8” to 1/2” round, centers on 1/2”
Electrical Connection 3ft [1m], 18 GA plenum cable with 1/2” conduit connector
Overload Protection electronic throughout 0° to 95° rotation
Electrical Protection actuators are double insulated
Operating Range Y 2 to 10 VDC, 4 to 20 mA w/ ZG-R01 (500 ?, 1/4 W resistor)
Input Impedance 100 k ? for 2 to 10 VDC (0.1 mA), 500 ? for 4 to 20 mA
Feedback Output U 2 to 10 VDC (max 0.7 mA) for 95°
Angle of Rotation Max. 95°,
Torque motor Min. 35 in-lbs [4 Nm]
Direction of Rotation (Motor) reversible with built-in switch
Direction of Rotation (Fail-Safe) reversible with CW/CCW mounting
Position Indication visual indicator, 0° to 95° (0° is full spring return position)
Running Time (Motor) 150 sec
Running Time (Fail-Safe)

<25 sec @ -4°F to 122°F [-20°C to 50°C],
<60 sec @ -22°F [-30°C]

Ambient Humidity max. 95% RH non-condensing
Ambient Temperature Range -22°F to 122°F [-30°C to 50°C]
Storage Temperature Range -40°F to 176°F [-40°C to 80°C]
Housing NEMA 2, IP54
Housing Material zinc coated steel
Agency Listings† cULus acc. To UL 873 and CAN/CSA C22.2 No. 24-93
Noise Level (Motor) <30 dB (A)
Noise Level (Fail-Safe) <62 dB (A)
Servicing maintenance free
Quality Standard ISO 9001
Weight 3.1 lb [1.4 kg]

†Rated Impulse Voltage 800V, Type of action 1.AA, Control Pollution Degree 3


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