Belimo LF24-SR US - User Manual

Technical Data
1405
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 Ω,
1/4 W resistor)
Input Impedance 100 k Ω for 2 to 10 VDC (0.1 mA), 500 Ω 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
Torque min. 35 in-lb, for control of air dampers.
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
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.
Dimensions (Inches[mm])
2.74" [
69.6]
2.25" [
57.1]
0.73"
[
18.54]
3.23" [
82]
0.25"
[
6.25]
1.15"
[
29.3]
2.3" [
58.42]
3.15" [
80]
7.66 " [ 194.501]
0.2" [
5.08]
0.98 " [ 25] 4.72 " [ 120] 0.39 " [ 10]
0.97" [
24.6]
3.86" [
98]
1.69 " [ 43] 3.66 " [ 93]
6.1 " [ 155]
3.66 " [ 93]
6.1 " [ 155]
0.26 " [ 6.5]
LF24-SR US - Damper Actuator
Modulating, Spring Return, 24 VAC/DC, for 2 to 10 VDC or 4 to 20 mA Control Signal
800-543-9038 USA 866-805-7089 CANADA 203-791-8396 LATIN AMERICA / CARIBBEAN
Date created, 11/29/2017 - Subject to change. © Belimo Aircontrols (USA), Inc.

Summary

Technical Data

Power Supply and Consumption

Specifies voltage, running and holding power consumption for the actuator.

Electrical and Control Specifications

Details electrical protection, operating range, input impedance, and feedback output.

Mechanical and Operational Specs

Covers angle of rotation, torque, direction of rotation, and running times.

Environmental and Physical Attributes

Includes ambient conditions, housing, agency listings, noise levels, and weight.

Application and Operation

Application Overview

Describes the actuator's use for fail-safe, modulating damper control in HVAC systems.

Actuator Operation

Explains the spring return, brushless DC motor, and microprocessor control.

Dimensions

Accessories

Shaft Extension and Mounting Accessories

Lists accessories for shaft extensions, clamps, and crankarms.

Control and Signal Accessories

Details accessories for angle limiters, adapters, and signal conversion.

Enclosures and Shields

Includes weather shields and explosion-proof housing options.

Interface and Power Accessories

Covers modules for analog/digital switching, signal rescaling, and transformers.

Wiring Diagrams

Typical Specification Requirements

Actuator Mounting and Control Input

Specifies direct coupling, shaft size, torque, and control signal requirements.

Actuator Features and Certifications

Details motor type, protection, run time, feedback signal, and certifications.

Wiring Diagram Explanation

Electrical Safety Warning

Emphasizes safety precautions when working with live electrical components.

Grounding and Power Connections

Notes cULus requirements, overload protection, and DC power options.

Control Signal Configuration

Explains common connection, 4-20mA to 2-10VDC conversion, and parallel connection.

Belimo LF24-SR US Specifications

General

Control Type	Modulating
Angle of Rotation	90°
Voltage	24 VAC/DC
Protection Rating	IP54
Housing Material	UL94-5VA
Power Supply	24 VAC, 50/60 Hz
Signal Range	2-10 VDC
Control Signal	2-10 VDC
Ambient Temperature Range	-20°C to +60°C
Shaft Rotation	Clockwise/Counter-Clockwise