LF24-MFT(-S)-20 US

LF24-MFT(-S)-20 US
LF24-MFT(-S)-20 US
Proportional, Spring Return, 24 V, for 6 to 9 VDC
Output Power Supply 20 VDC Provides Power to Controllers
Torque min. 35 in-lb
Control 6 to 9 VDC (DEFAULT)
Feedback 2 to 10 VDC (DEFAULT)
20 VDC power output
For proportional modulation of dampers and control valves in HVAC systems. The
LF24-MFT(-S)-20 US provides mechanical spring return operation for reliable fail-safe
Default parameters for 6 to 9 VDC applications of the LF24-MFT(-S)-20 US actuator
are assigned during manufacturing. If required, custom versions of the actuator can be
ordered. The parameters noted in the Technical Data table are variable.
These parameters can be changed by three means:
Power supply
24 VAC, ± 20%, 50/60 Hz
24 VDC, ±10%
1.5 W
6 VA (Class 2 power source)
3 ft, 18 GA, appliance cable
1/2” conduit connector
electronic throughout 0 to 95° rotation
6 to 9 VDC (Default), P-10005
100 kΩ for 2 to 10 VDC (0.1 mA)
500 Ω for 4 to 20 mA
1500 Ω for PWM, floating point and
on/off control
2 to 10 VDC, 0.5 mA max
35 in-lb (4 Nm)
reversible with cw/ccw mounting
reversible with built-in switch
max 95°, adjustable with mechanical stop
limited to 95°
150 sec constant
<25 sec @-4°F to 122°F [-20°C to 50°C]
<60 sec @-22°F [-30°C]
off (default)
Min. (Min Position) = 0%
- ZS (Mid. Position) = 50%
- Max. (Max. Position) = 100%
visual indicator, 0° to 95°
(0° is spring return position)
5 to 95% RH, non-condensing
-22 to 122° F (-30 to 50° C)
-40 to 176° F (-40 to 80° C)
NEMA 2, IP54
zinc coated metal
< 30 db (A)
62 dB (A)
cULus acc. to UL 873 and
CAN/CSA C22.2 No. 24-93
ISO 9001
maintenance free
3.1 lbs (1.40 kg)
3.2 lbs (1.45 kg)
Power consumption
Transformer sizing
Electrical connection
(-S models have 2 cables)
Overload protection
Operating range Y*
Input impedance
Feedback output U*
Direction of rotation*
Angle of rotation*
Mechanical angle of rotation*
Running time
Angle of rotation adaptation*
Override control*
Position indication
Ambient temperature
Storage temperature
Housing material
Noise level
spring return
Agency listings
Quality standard
LF24-MFT-20 US
LF24-MFT-S-20 US
• Pre-set configurations from Belimo
• Custom configurations from Belimo
• Configurations set by the customer using the MFT PC tool software application.
The LF24-MFT(-S)-20 US actuator provides 95° of rotation and is provided with a
graduated position indicator showing 0° to 95°. The actuator will synchronize the 0°
mechanical stop or the damper or valves mechanical stop and use this point for its
zero position during normal control operations.
The actuator 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 (DRS) function to prevent damage to the actuator in
a stall condition. The position feedback signal is generated with out the need for
mechanical feedback potentiometers using DRS. The actuator may be stalled
anywhere in its normal rotation without the need of mechanical end switches.
The LF24-MFT(-S)-20 US is mounted directly to control shafts up to 3/4” diameter by
means of its universal clamp and anti-rotation bracket. A crank arm and several
mounting brackets are available for damper applications where the actuator cannot be
direct coupled to the damper shaft. The spring return system provides minimum
specified torque to the application during a power interruption. The LF24-MFT(-S)-20
US actuator is shipped in the zero position, compression against seats or gaskets for
tight shut-off is accomplished manually.
Dimensions (Inches [mm])
7.67" [195]
6.10" [155]
3/8" to 1/2"
0.256" [6.5]
0.39" [10]
3/8" to 7/16"
3.15" [80]
1/2" to 3/4"
3.66" [93]
0.71" [18]
4.92" [125]
0.74" [18.7]
3.23" [82]
0.25" [6.3]
* Variable when configured with MFT options
LF24-MFT-S-20 US
Auxiliary switches
1 x SPDT 3A (0.5A) @ 250 VAC, UL approved
adjustable 0° to 95° (double insulated)
800-543-9038 USA
866-805-7089 CANADA
203-791-8396 LATIN AMERICA
M40024 - 05/10 - Subject to change. © Belimo Aircontrols (USA), Inc.
LF24-MFT(-S) -20 US
Technical Data
LF24-MFT(-S)-20 US
Proportional, Spring Return, 24 V, for 6 to 9 VDC
Output Power Supply 20 VDC Provides Power to Controllers
Wiring Diagrams
Provide overload protection and disconnect as required.
CAUTION Equipment Damage!
Actuators may be connected in parallel.
Power consumption and input impedance must be observed.
Actuators may be connected in parallel if not mechanically mounted to the
same shaft. Power consumption and input impedance must be observed.
Actuator may also be powered by 24 VDC.
For end position indication, interlock control, fan startup, etc., LF24MFT(-S)-20 US incorporates one built-in auxiliary switch: 1 x SPDT, 3A
(0.5A) @250 VAC, UL Approved, adjustable 0° to 95°.
24 VAC: Black/Blue
120 VAC: White
240 VAC: White/Black
Belimo modulating actuators are 24 VAC/DC, if 120 or 240 is available an
external transformer is required.
Maximum of 2
MP-52XX-500 models include internal SPDT auxiliary switch.
Meets cULus requirements without the need of an electrical ground connection.
G Live Electrical Components!
Multiple LF24-MFT(-S)-20 US actuators from one controller
24 VAC Transformer
Blk (1) Common
Red (2) + Hot
Wht (3) Y Input, 6 to 9V
Control Signal
6 to 9 VDC (+)
Power to Controller
Wht (4) Output +20 VDC
Wht (5) U Output 2 to 10V
Wht (6) Common +20 VDC
Controller Common (–)
Feedback 2-10 VDC
LF24-MFT(-S)-20 US
6 to 9 VDC control of LF24-MFT(-S)-20 US
M40024 - 05/10 - Subject to change. © Belimo Aircontrols (USA), Inc.
During installation, testing, servicing and troubleshooting of this product, it may be
necessary to work with live electrical components. Have a qualified licensed electrician or other
individual who has been properly trained in handling live electrical components perform these
tasks. Failure to follow all electrical safety precautions when exposed to live electrical components could result in death or serious injury.
Typical Control Wiring for MP-52XX Series Actuators to Controllers
Requiring External 20 VDC Power Supply.
Auxiliary switch of LF24-MFT(-S)-20 US
800-543-9038 USA
866-805-7089 CANADA
203-791-8396 LATIN AMERICA
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