LF24-SR-S US | Damper Actuator | 35 in-lb | Spg Rtn | 24V | Modulating | Belimo
Damper Actuator, 35 in-lb [4 Nm], Spring return, AC/DC 24 V, 2...10 V, 1 x SPDT, modulating
Documents and manuals
Belimo LF24-SR-S US Documents
Overview
Details for LF24-SR-S US
Damper Actuator | 35 in-lb | Spg Rtn | 24V | Modulating
Application
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 500Ω 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.
Operation
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-S 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. The LF24-SR-S US version is provided with one 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.
Specifications
- Actuator Type
- Spring return
- Angle of Rotation
- 95
- Auxiliary Switches
- 1 x SPDT
- Control Type
- DC 2...10 V
- Degree of Protection
- IP54 NEMA 2
- Direction of Rotation (Fail-Safe)
- Reversible with cw/ccw mounting
- Electrical Connection
- cable
- Power Consumption (Holding)
- 1 W
- Power Consumption (Running)
- 2.5 W
- Running Time (Fail-safe)
- <25 s
- Running Time (Motor)
- 150 s / 90B0
- Safety Function
- YES
- Torque
- 35 in-lb [4 Nm]
- Voltage AC/DC
- AC/DC 24 V