
• Inside an enclosure that is installed indoors
• Operating ambient temperature
−10 to +60 °C (+14 to +140 °F) (non-freezing)
−10 to +70 °C (+14 to +158 °F) for MDA1238
• Operating ambient humidity 85% or less (non-condensing)
• Area that is free of explosive atmosphere or toxic gas (such as
sulfuric gas) or liquid
• Area not exposed to direct sun
• Area free of excessive amount of dust, iron particles or the like
• Area not subject to splashing water (rains, water droplets), oil (oil
droplets) or other liquids
• Area not subject to continuous vibration or excessive shocks
• Area free of radioactive materials, magnetic fields or vacuum
• Area free of excessive electromagnetic noise (from welders,
power machinery, etc.)
When using near a switching circuit or high-frequency power
supply, the induced current may flow inside the fan due to
electromagnetic noise (conductive noise, radiative noise). If the
induced current flows, the electric corrosion is caused in the
bearings of the fan. As a result, it may generate the noise or
shorten the service life of the products. Use the fan in the
environment that the electromagnetic noise does not cause.
How to install the fan
Install the fan onto an appropriate flat metal plate having excellent
vibration resistance and heat conductivity. See the panel cut-out,
mounting-hall reference drawing for information on how to provide
mounting holes on the equipment used and secure the fan with
screws. For air orientation and rotational direction, see the
indications shown on the fan’s side frame.
Model Screw size Tightening torque
MDA625 M3 0.4 N·m (3.5 lb-in)
Other MDA series M4 0.6 N·m (5.3 lb-in)
Connector housings · Contacts
Manufacturer: J.S.T. Mfg Co., Ltd.
Housings model: SMR-03V-N (3 poles), SMR-04V-N (4 poles)
Contacts model: SYM-001T-P0.6
Connection of the power supply
[Connection Diagrams]
Red
Black
Yellow
GND
Alarm output
+ DC powe
supply
Low-speed alarm, contact alarm type
Red
Black
White (Orange)
Blue
GND
Alarm output
+DC powe
supply
Check the voltage specification on the product identification plate
and input the correct voltage. Use a DC power supply having a rise
time of 100 ms or less.
Connection and specifications of the alarm
Low-speed alarm, electronic alarm type
Output mode: Open collector output
Output condition: Normal operation L level, Alarm output H level
• MDA625, MDA825, MDA925
The yellow wire is lead wire for
the alarm circuit. Connect this
wire to the client’s as shown in
the figure.
[Alarm activation speed]
MDA625, MDA825:
2300±400 r/min or less
MDA925:
1900±400 r/min or less
Yellow
Black
Fan
Client's circuit
R
15 mA
or less
GND
30 VDC or less
0 V
Note The low-speed alarm type of fan is not equipped with a
delayed trip-point alarm circuit. Therefore, an external
delay function is necessary to avoid the detection of fan
start. The set time of the delay function should be at least
10 seconds.
• MDA1225
The yellow wire is lead wire for
the alarm circuit. Connect these
wires to the client’s circuit as
shown in the figure.
[Alarm activation speed]
2100±400 r/min or less
30 VDC or less
Yellow
Black
Fan
Client's circuit
15 mA
or less R
GND
0 V
Note The low-speed alarm type of fan is equipped with an
internal delayed-start alarm circuit. The alarm function
becomes effective within 10 seconds of the fan start.
• MDA1238, MDA1451, MDA1751
Yellow
Black
Fan
Client's circuit
15 mA or
less∗
30 VDC or less∗
R
GND
0 V
The yellow wire is lead wire for the
alarm circuit. GND is common to
the sensor and power supply.
Connect these wires to the client’s
circuit as shown in the figure.
[Alarm activation speed]
MDA1238:
2200±220 r/min or less
MDA1451,MDA1751:
1800±400 r/min or less
∗ MDA1238 = 28 VDC or less,
10 mA or less
Note The low-speed alarm type of fan is equipped with an
internal delayed-start alarm circuit. The alarm function
becomes effective within 10 seconds of the fan start.
Low-speed alarm, contact alarm type
The white (Orange) ∗ and blue
wires are lead wires for the alarm
circuit. An alarm (H level) signal is
output when the fan’s rotation
speed falls below 1800±400 r/min.
∗ ( ) indicate the color of the lead
wire for the extension cable type.
White
(Orange)∗
Blue
Fan
Client's circuit
R
30 VDC or less
0 V
30 mA
or less
Note The low-speed alarm type of fan is equipped with an
internal delayed-start alarm circuit. The alarm function
becomes effective within 10 seconds of the fan start.
Overheat protection
The fan is equipped with an internal protective circuit against
overheating. In the event a lock-up condition is detected, this
function automatically controls the current flow to the fan motor’s
windings, thus preventing the fan blades from locking and burning
out. The fan resumes operation automatically as soon as it is
released from the locked condition. Be sure to shut off the power to
the fan before performing an inspection.
• Unauthorized reproduction or copying of all or part of this manual is
prohibited.
• Characteristics, specifications and dimensions are subject to change
without notice.
• and are registered trademarks or trademarks
of Oriental Motor Co., Ltd., in Japan and other countries.
© Copyright ORIENTAL MOTOR CO., LTD. 2008
Published in August 2017
echnical Support Tel:(800)468-3982
8:30 A.M. to 5:00 P.M., P.S.T. (M-F)
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www.orientalmotor.com
Schiessstraße 44, 40549 Düsseldorf, Germany
echnical Support Tel:00 800/22 55 66 22
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el:01256-347090
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Tel:02-93906346
www.orientalmotor.it
el:+55-11-3266-6018
www.orientalmotor.com.br
• Please contact your nearest Oriental Motor oce for further information.
4-8-1Higashiueno,Taito-ku,Tokyo 110-8536
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Tel:03-6744-0361
www.orientalmotor.co.jp
Tel:0800-060708
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Tel:1800-888-881
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Tel:+91-80-41125586
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