Technical Data

1408

Power Supply

24 VAC, ±20%, 50/60 Hz, 24 VDC, ±10%

Power consumption in operation 2.5 W

Power consumption in rest

position

1 W

Transformer sizing

5 VA (class 2 power source)

Shaft Diameter

3/8...1/2” round, centers on 1/2”

Electrical Connection

18 GA plenum cable, 3 ft [1 m], with 1/2”

conduit connector

Overload Protection

electronic throughout 0...95° rotation

Electrical Protection

actuators are double insulated

Operating Range

3 kΩ NTC, 3 kΩ @ 77°F (25°C) MA setpoint

= 55°F

Input Impedance

100 kΩ

Position Feedback

2...10 V, Max. 0.7 mA

Angle of rotation

Max. 95°, adjustable with mechanical stop

Torque motor

35 in-lb [4 Nm]

Direction of motion motor

selectable with switch 0/1

Direction of motion fail-safe

reversible with cw/ccw mounting

Position indication

Mechanical

Running Time (Motor)

95 s constant, independent of load

Running time fail-safe

<25 s @ -4...122°F [-20...50°C], <60 s @

-22°F [-30°C]

override control

Minimum, Open, Closed via spring Min-

position adjusts on actuator cover between

0 and 100% (scaled 0 to 1)

Ambient humidity

max. 95% r.H., non-condensing

Ambient temperature

-22...122°F [-30...50°C]

Storage temperature

-40...176°F [-40...80°C]

Degree of Protection

IP54, NEMA 2

Housing material

galvanized steel

Agency Listing

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

3.4 lb [1.6 kg]

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

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

min-position, Integrated mixed air PI-control.

Application

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 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 3 kΩ thermistor, which allows the LF24-ECON... to retrofit

or replace Honeywell® M7415 actuators. 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 constant 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 90°. The LF24-ECON-R03 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

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. See wiring diagrams for LF24-ECON-R03 US for more details on

3-position control.

Dimensions (Inches[mm])

LF24-ECON-R03 US Damper Actuator Technical Data Sheet

Modulating, Spring Return, 24 V, Economizer, 3k

Ω Mixed Air Sensor, Built-in

Minimum Position Adjustment

800-543-9038 USA

866-805-7089 CANADA

203-791-8396 LATIN AMERICA / CARIBBEAN