Revision B:
•Remote controller model has been changed.
•RoHS PARTS LIST has been added.
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
Please void OB427 REVISED EDITION-A.
INDOOR UNIT
No. OB427
REVISED EDITION-B
SERVICE MANUAL
Wireless type
Models
S1
MSH-A18ND -
MSH-A24ND -
S1
Outdoor unit service manual
MUH-A·ND Series (OB428)
CONTENTS
1. TECHNICAL CHANGES ····································2
2. PART NAMES AND FUNCTIONS······················2
3. SPECIFICATION·················································4
4. OUTLINES AND DIMENSIONS ·························5
5. WIRING DIAGRAM ············································6
6. REFRIGERANT SYSTEM DIAGRAM················7
7. SERVICE FUNCTIONS ······································8
8. TROUBLESHOOTING······································10
9. DISASSEMBLY INSTRUCTIONS ····················18
10. PARTS LIST······················································20
11. RoHS PARTS LIST···········································23
MSH-A18ND
MSH-A24ND
NOTE:
This service manual describes technical data of the indoor units.
RoHS compliant products have <G> mark on the spec name plate.
For servicing of RoHS compliant products, refer to the RoHS PARTS LIST (RoHS compliant).
TM
REMOTE CONTROLLER
MSH-A18ND
MSH-A24ND
Signal transmitting section
Operation display section
PM
AM
OPERATE /STOP
(ON /OFF) button
TOO
TOO
ON/OFF
WARM
COOL
TEMPERATURE buttons
Indication of remote controller
model is on back.
Open the front lid.
AM
TOO
TOO
COOL
ON/OFF
WARM
VANE button
(Horizontal vane button)
FAN SPEED CONTROL button
OFF-TIMER button
FAN
STOP
I FEEL COOL
VANE
START
HR.
HEAT DRY
ON-TIMER button
MODE WIDE VANE
HR. button
MIN. button
(TIME SET button)
OPERATION SELECT button
ECONO COOL button
ECONO COOL
LONG
MIN.
RESET CLOCK
CLOCK SET button
LONG button
WIDE VANE button
(Vertical vane button)
RESET button
3
3
SPECIFICATION
Indoor model
Function
MSH-A18ND
MSH-A24ND
Heating
Cooling
Heating
Cooling
Single phase
220V, 60Hz
768/642/516
0.28
Single phase
220V, 60Hz
Power supply
Capacity
Air flow (High/Med./Low)
Running current
Power input
954/822/684
954/834/726
K /h
A
W
0.37
81
60
Power factor
%
97
99
Model
Current
RC4N32-AA
0.28
RC4V40-AA
0.37
A
Winding
WHT-BLK 205.5
BLK-RED 217.6
1,100O325O258
16
WHT-BLK 138.2
BLK-RED 159.0
1,100O325O258
16
"
resistance (at 20:)
Dimensions WOHOD
Weight
mm
kg
Air direction
5
5
Sound level (High/Med./Low)
Fan speed (High/Med./Low)
Fan speed regulator
Remote controller model
dB
rpm
42/37/32
1,070/920/780
3
47/42/37
1,280/1,130/970
1,280/1,150/1,020
3
KP0A, KM04A
KP0A, KM04A
NOTE: Test conditions are based on ISO 5151.
Cooling : Indoor DB27°C WB19°C
Outdoor DB35°C WB(24°C)
Heating : Indoor DB20°C WB 15.5°C
Outdoor DB 7°C WB 6°C
Indoor-Outdoor piping length : 5m
Test conditions are based on SSA 356/366.
Cooling : Indoor DB29°C WB19°C
Outdoor DB46°C WB24°C
Heating : Indoor DB21°C
Outdoor DB 7°C WB 6°C
Indoor-Outdoor piping length : 7.5m
4
4
OUTLINES AND DIMENSIONS
Unit: mm
MSH-A18ND
MSH-A24ND
INDOOR UNIT
Installation plate
98
Indoor unit
173
1068
98
414.5
258
414.5
Wall hole [75
173
5
Liquid line [ 6.35- 0.5m
Gas line [ 12-0.43m
Insulation [ 50 O.D
[ 32 I.D
1100
Air in
Installation plate
{
{
for MSH-A18ND
Liquid line [ 9.52- 0.5m
Gas line [ 12-0.43m
Insulation [ 50 O.D
[ 32 I.D
for MSH-A24ND
56
791
253
Drain hose [16
(Connected part O.D)
Air out
Insulation [28
58
19
Wireless remote controller
5
5
WIRING DIAGRAM
MSH-A18ND
INDOOR UNIT
CN
RT12
RT11
112
TO OUTDOOR
UNIT
HIC1
CN
111
CONNECTING
TB
BLK
CN201
12V
3
N
2
RED
BLU
BRN
3
GRY
YLW
BRN
WHT
RED
CN
NR11
3
2
1
121
MF
1
3
4
C11
F11
SR141
220V~
TAB12
CN211
CN
CN
CN
ELECTRONIC CONTROL P.C. BOARD
151
102
101
15
3
3
DISPLAY
P.C.BOARD
RECEIVER
P.C.BOARD
MV2 MV2 MV1
REMOTE
CONTROLLER
SYMBOL
C11
SYMBOL
MV1
SYMBOL
RT12
NAME
NAME
NAME
INDOOR FAN CAPACITOR
FUSE (3.15A)
VANE MOTOR (HORIZONTAL)
VANE MOTOR (VERTICAL)
INDOOR COIL THERMISTOR
SOLID STATE RELAY
TERMINAL BLOCK
F11
MV2
SR141
TB
HIC1
MF
DC/DC CONVERTER
FAN MOTOR (INNER PROTECTOR)
NR11 VARISTOR
RT11
ROOM TEMPERATURE THERMISTOR
NOTES: 1.About the outdoor side electric wiring, refer to the outdoor unit electric wiring diagram for servicing.
2.Use copper conductors only. (For field wiring)
3.Symbols below indicate.
: Terminal block
: Connector
MSH-A24ND
INDOOR UNIT
4
3
2
1
RT13
TO OUTDOOR
UNIT
HIC1
RT12
CONNECTING
TB
CN112
BLK
CN201
12V
3
N
2
RED
BLU
BRN
3
GRY
YLW
BRN
WHT
RED
CN
NR11
3
2
1
121
MF
1
3
4
C11
F11
SR141
TAB12
220V~
CN211
CN
CN
CN
CN
ELECTRONIC CONTROL P.C. BOARD
151
102
101
RT11
111
15
3
3
DISPLAY
P.C.BOARD
RECEIVER
P.C.BOARD
MV2 MV2 MV1
REMOTE
CONTROLLER
SYMBOL
C11
NAME
SYMBOL
MV2
NAME
SYMBOL
SR141
TB
NAME
INDOOR FAN CAPACITOR
FUSE (3.15A)
VANE MOTOR (VERTICAL)
VARISTOR
SOLID STATE RELAY
TERMINAL BLOCK
F11
NR11
RT11
DC/DC CONVERTER
ROOM TEMPERATURE THERMISTOR
INDOOR COIL THERMISTOR (MAIN)
INDOOR COIL THERMISTOR (SUB)
HIC1
MF
INDOOR FAN MOTOR (INNER PROTECTOR)
VANE MOTOR (HORIZONTAL)
RT12
RT13
MV1
NOTES: 1.About the outdoor side electric wiring, refer to the outdoor unit electric wiring diagram for servicing.
2.Use copper conductors only. (For field wiring)
3.Symbols below indicate.
: Terminal block
: Connector
6
6
REFRIGERANT SYSTEM DIAGRAM
Unit:mm
MSH-A18ND
MSH-A24ND
INDOOR UNIT
INDOOR UNIT
Refrigerant pipe [15.88
(with heat insulator)
Refrigerant pipe [12.7
(with heat insulator)
Indoor coil
Indoor coil
thermistor
Indoor
heat
exchanger
Indoor
heat
exchanger
thermistor
RT12
RT12(main)
Distributor
Distributor
Flared connection
Flared connection
Indoor coil
thermistor
RT13(sub)
Room temperature
thermistor
Room temperature
thermistor
RT11
RT11
Flared connection
Flared connection
Strainer
#50
Strainer
#50
Refrigerant pipe [6.35
(with heat insulator)
Refrigerant pipe [6.35
(with heat insulator)
Refrigerant flow in cooling
Refrigerant flow in heating
7
7
SERVICE FUNCTIONS
MSH-A18ND
MSH-A24ND
7-1. TIMER SHORT MODE
For service, set time can be shortened by short circuit of JPG and JPS on the electronic control P.C. board.
The time will be shortened as follows.
Set time : 1 minute ➔➔1-second
Set time : 3 minute ➔➔3-second (It takes 3 minutes for the compressor to start operation. However, the starting time is
shortened by short circuit of JPG and JPS.)
7-2. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION
A maximum of 4 indoor units with wireless remote controllers can be used in a room.
In this case, to operate each indoor unit individually by each remote controller, P.C. boards of remote controller must be
modified according to the number of the indoor unit.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below :
NOTE : For modification, take out the batteries and press the OPERATE/STOP(ON/OFF) button 2 or 3 times at first.
After modification, put back the batteries then press the RESET button.
Remote controller model : KP0A
J2
Remote controller model : KM04A
J1
J2
J1
The P.C. board has the print “J1” and “J2”. Solder “J1” and “J2” according to the number of indoor unit as shown in Table 1.
After modification, press the RESET button.
Table 1
4 units operation
Same as at left
1 unit operation
2 units operation
3 units operation
Same as at left
Same as at left
Solder J2
No. 1 unit
No. 2 unit
No. 3 unit
No. 4 unit
No modification
Same as at left
Same as at left
–
–
–
Solder J1
Same as at left
–
–
Solder both J1 and J2
–
How to set the remote controller exclusively for particular indoor unit
After you turn the breaker ON, the first remote controller that sends the signal to the indoor unit will be regarded as the
remote controller for the indoor unit.
The indoor unit only accepts the signal from the remote controller that has been assigned to the indoor unit once they are
set. The setting will be cancelled if the breaker has turned off, or the power supply has shut down.
Please conduct the above setting once again after the power has restored.
7-3. AUTO RESTART FUNCTION
When the indoor unit is controlled with the remote controller, the operation mode, set temperature, and the fan speed are
memorized by the indoor electronic control P.C. board. “Auto restart function” automatically starts operation in the same
mode just before the shutoff of the main power. However if the unit is operated in “I FEEL CONTROL” mode before power
failure, the operation is not memorized. In “I FEEL CONTROL” mode, the operation is decided by the initial room tempera-
ture.
8
How to release “AUTO RESTART FUNCTION”
1Turn off the main power for the unit.
2Pull out the electronic control P.C. board, the receiver P.C.
C11
board and the display P.C.board. (Refer to 9-2.)
3Solder jumper wire to JR07 on the indoor
electronic control P.C. board. (Refer to 8-6.)
CN201
TAB12
IC101
IC152
JR07
Operation
1If the main power has been cut, the operation settings remain.
2After the power is restored, the unit restarts automatically according to the memory.(However, it takes at least 3 minutes
for the compressor to start running.)
NOTE
•The operation settings are memorized when 10 seconds have passed after the remote controller was operated with the
remote controller.
•If main power is turned off or a power failure occurs while AUTO START/STOP timer is active, the timer setting is
cancelled.
•If the unit has been off with the remote controller before power failure, the auto restart function does not work as the
power button of the remote controller is off.
•To prevent breaker off due to the rush of starting current, systematize other home appliances not to turn on at the same
time.
•When some air conditioners are connected to the same supply system, if they are operated before power failure, the
starting current of all the compressors may flow simultaneously at restart.
Therefore, the special counter-measures are required to prevent the main voltage-drop or the rush of the starting current
by adding to the system that allows the units to start one by one.
9
8
TROUBLESHOOTING
MSH-A18ND
MSH-A24ND
8-1. Cautions on troubleshooting
1. Before troubleshooting, check the following:
(1) Check the power supply voltage.
(2) Check the indoor/outdoor connecting wire for mis-wiring.
2. Take care of the following during servicing
(1) Before servicing the air conditioner, be sure to first turn off the remote controller to stop the main unit, and then after
confirming the horizontal vane is closed, turn off the breaker and / or disconnect the power plug.
(2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic
control P.C. board.
(3) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
(4) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
Housing point
Lead wiring
3. Troubleshooting procedure
(1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.
To make sure, check how many times the abnormality indication is flashing on and off before starting service work.
(2) Before servicing, check that the connector and terminal are connected properly.
(3) When the electronic control P.C. board seems to be defective, check the copper foil pattern for disconnection and the
components for bursting and discolouration.
(4) When troubleshooting, refer to 8-2. and 8-3.
4. How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, replace the batteries to operate the remote controller normally.
1 Remove the front lid and insert batteries.
2 Press the RESET button with tip end of ball point
Then reattach the front lid.
pen or the like, and then use the remote controller.
Insert the negative pole
of the batteries first.
Check if the polarity of
the batteries is correct.
RESET button
NOTE : If the RESET button is not pressed, the remote controller may not operate correctly.
10
8-2. Instruction of troubleshooting
Start
Indoor unit
operates.
Outdoor unit
doesn't operate
normally.
Indoor unit
operates.
Outdoor unit
doesn't
Indoor unit
OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.
doesn't receive
the signal from
remote controller.
operate.
Outdoor unit
Indoor unit
operates when
the EMERGENCY when the
Indoor unit
doesn't operate
Outdoor unit
doesn't
stop even
if indoor unit
stops.
Outdoor unit
doesn't
operate
Unit doesn't
operate
normal
operation in
COOL or
HEAT mode.
operates when
the EMERGENCY
OPERATION
switch is pressed.
OPERATION
EMERGENCY
when the
switch is pressed. OPERATION
EMERGENCY
OPERATION
switch is pressed.
switch is pressed.
Check room
temperature
thermistor.
Refer to 8-6.
"Test point
diagram and
voltage".
Refer to 8-5.B
"Check of
remote controller
and receiver
P.C. board".
1. Check indoor /
outdoor
Refer to
"Check of
outdoor unit".
Refer to
"Check of
outdoor unit".
Refer to
"Check of
R.V. coil".
connecting wire.
2. Refer to 8-5.C
"Check of indoor
electronic control
P.C. board".
Flash on and
2-time flash
Cause:
Indoor unit
• Trouble of
room temp-
erature/
3-time flash
Cause:
Indoor unit
• Trouble of
indoor fan
motor
7-time flash
Cause:
Outdoor unit
• Trouble of
outdoor
4-time flash
Cause:
Indoor unit
• Trouble of
indoor unit
control
6-time flash
Cause:
off at 0.5
second
intervals
Cause:
Indoor/
-
Outdoor unit
• Trouble of
thermistor
in outdoor
unit
control
system
Outdoor unit
• Mis-wiring
indoor coil
thermistor
system
Check room
temperature
thermistor
and indoor
coil thermis-
tor.
Refer to
8-5. A
"Check of
indoor fan
motor".
Replace the
indoor
electronic
control
Refer to
8-5. D
"How to
check
mis-wiring
(When
Refer to
"Check of
outdoor
Replace the
deicer
P.C. board.
thermistor".
P.C. board.
Refer to 8-6.
"Test point
diagram and
voltage".
outdoor unit
doesn't
work)".
Refer to outdoor unit service manual.
11
8-3. Troubleshooting check table
• The following indication applies regardless of shape of the indicator.
• Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
When the indoor unit has started operation and the following detection method has detected an abnormality
(the first detection after the power ON), the indoor electronic control P.C. board turns OFF the indoor fan motor with the
OPERATION INDICATOR lamp flashing.
· Flashing of the OPERATION INDICATOR lamp (on the left-hand side)
indicates possible abnormalities.
Operation Indicator
Lighted
· The OPERATION INDICATOR lamp (on the left-hand side) is lighting
during normal operation.
Not lighted
Abnormal
point
No.
1
Operation indicator lamp
0.5-second ON
Symptom
Condition
Correspondence
Outdoor unit
does not
operate.
3 minutes after power supply turns ON, when
serial signal is not received.
• Refer to 8-5. D "How to check
mis-wiring ".
Mis-Wiring
0.5-second OFF
2-time flash
• Refer to the characteristics of
main indoor coil thermistor,
sub indoor coil thermistor,
and room temperature
thermistor in 8-6.
Indoor coil
thermistor
Detect Indoor coil/room temperature
thermistor short or open circuit every 8
seconds during operation.
Outdoor unit
does not
operate.
2
Room
temperature
thermistor
2.5-second OFF
Indoor fan repeats
12 seconds ON
and 3minutes OFF.
When the indoor
fan breaks, the fan
keeps stopping.
• Refer to 8-5. A "Check of
indoor fan motor".
3-time flash
When rotational frequency feedback signal is
not emitting during 12-second indoor fan
operation.
Indoor fan
motor
3
4
2.5-second OFF
• Check the indoor electronic
control P.C. board.
When it cannot properly read data in the
nonvolatile memory of the indoor electronic
control P.C. board.
4-time flash
6-time flash
Outdoor unit
does not
operate.
Indoor
control
system
2.5-second OFF
• Shortage of refrigerant
• Check the deicer P.C.
board.
<Thermistor short>
Thermistors are abnormal when they short
after compressor start-up.
Refer to "Check of outdoor
thermistor".
Refer to outdoor unit service
manual.
<Thermistor open>
Thermistors are abnormal when they open
after compressor start-up.
However, discharge temperature thermistor is
abnormal when open circuit is detected more
than 10 minutes after compressor start-up.
Outdoor
thermistor
Outdoor unit
does not
operate.
5
6
2.5-second OFF
When it cannot properly read data in the
nonvolatile memory of the deicer P.C. board,
outdoor unit stops.
7-time flash
• Check the deicer P.C. board.
Refer to outdoor unit service
manual.
Outdoor
control
system
Outdoor unit
does not
operate.
2.5-second OFF
12
8-4. Trouble criterion of main parts
MSH-A18ND
MSH-A24ND
Part name
Check method and criterion
Measure the resistance with a tester.
(Part temperature 10˚C ~ 30˚C)
Figure
Room temperature
thermistor (RT11)
Normal
8 k" ~ 20 k"
Indoor coil thermistor
(RT12(main), RT13(sub))
Measure the resistance between the terminals with a tester.
(Part temperature 10˚C ~ 30˚C)
MSH-A18ND
MAIN
AUX
Normal
MSH-A24ND
Color of
lead wire
WHT – BLK
BLK – RED
Indoor fan motor(MF)
FUSE
MSH-A18ND
198 " ~ 214 "
209 " ~ 227 "
132 " ~ 144 "
152 " ~ 166 "
MSH-A18ND
INNER FUSE
145: CUT OFF
MSH-A24ND
MAIN
Measure the voltage power ON.
Color of lead wire
MSH-A24ND
INNER
PROTECTOR
135i 5: OPEN
AUX.
P
Normal
4.5 ~ 5.5V
BRN – YLW
(When fan revolved one time)
0V➔5V➔0V
YLW – GRY
(Approx.)
RED
Measure the resistance between the terminal with a tester.
(Part temperature 10°C ~ 30°C)
ROTOR
Horizontal vane
motor(MV1)
Vertical vane
motor(MV2)
Normal
282" ~ 306 "
YLW
BRN
ORN
GRN
P
:INNER PROTECTOR
13
8-5. Troubleshooting flow
When OPERATION INDICATOR lamp flashes 3-time.
Indoor fan motor doesn’t operate.
A
Check of indoor fan motor
Turn OFF the power supply.
Check connector CN211 visually.
No
Yes
No
Is soldered point of the connector
correctly soldered?
Are lead wires connected?
Resolder it.
Yes
Reconnect the lead wires.
Disconnect lead wires from connector CN211 on the indoor electronic control P.C. board.
Measure resistance between lead wires No.3 and No.4 and then No.1 and No.4.
Turn ON the power supply. Stop it if the unit operate.
Insert screwdriver into air outlet to rotate indoor fan
motor slowly for 1 revolution or over, and measure
voltage between No.2(+) and No.3(-) on CN121.
Is resistance 0 (short circuit) or ∞ (open circuit)?
No
(others)
Yes ( 0 or ∞ )
No
Repair or replace the indoor fan motor.
Does voltage repeat 0V DC and 5V DC?
Yes
Replace the indoor electronic control P.C. board.
Indoor unit operates by pressing the EMERGENCY OPERATION switch, but doesn’t operate with the remote controller.
B Check of remote controller and receiver P.C. board
w Check if the remote controller is exclusive for this air conditioner.
Press OPERATE/STOP(ON/OFF)
button on the remote controller.
No
Is LCD display on the the remote
Replace the batteries.(Refer to 8-1.4.)
controller visible?
(not clear)
Yes
Remove the batteries, then set them back
and press the RESET button. Check if the
unit operates with the remote controller.
Turn on a radio to AM and press
OPERATE/STOP(ON/OFF) button on the
remote controller.
No
Does the unit operate with the
remote controller?
Yes
OK
No
Replace the remote controller.
Is noise heard from radio?
Yes
Are there any fluorescent lights of
inverter or rapid-start type within
the range of 1m?
Yes
➔➔Reinstall the unit away from lights.
➔➔Attach a filter on receiving part.
No
Measure the voltage between receiver P.C. board connector CN301 No.1(+) and No.3(-) when the remote
controller button is pressed.
Yes
Replace the indoor electronic control P.C.
Is the voltage approx. 4V DC?
board.
No(5V or 0V DC)
Replace the receiver P.C. board.
14
The unit doesn’t operate with the remote controller. Also, the OPERATION INDICATOR lamp doesn’t light up by press-
ing the EMERGENCY OPERATION switch.
C Check of indoor electronic control P.C. board
Check the both “parts side” and “pattern
side” of indoor electronic control P.C.
Varistor (NR11)
board visually.
Turn OFF the power supply.
Remove indoor fan motor connector CN211 and
vane motor connector CN151 from the indoor electronic
control P.C. board and turn ON the power supply.
Fuse (F11)
Indoor electronic
control P.C. board
Does the unit operate with the remote controller?
Does the OPERATION INDICATOR lamp light up
by pressing the EMERGENCY OPERATION switch?
No
Yes
Replace the vane
motor.
Turn OFF the
power supply.
Turn OFF the
power supply.
Replace the fuse.
Yes
Yes
Is fuse(F11) blown?
No
Is winding
resistance of
vane motor 0 "?
No
Is winding
resistance of
fan motor 0 "?
Replace the indoor
electronic control
P.C. board.
No
Is varistor(NR11) burnt?
Yes
No
Yes
Replace the varistor.
Replace the fan
motor.
15
When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.
Outdoor unit doesn’t operate.
D How to check mis-wiring
wShort circuit of JPG and JPS on the indoor electronic control
P.C. board enables self -check to be displayed in 3 seconds.
Start
• Turn ON the power supply. (outdoor unit)
• Press EMERGENCY OPERATION switch once.
After 3 minutes, mis-wiring is indicated
(0.5-second ON, 0.5-second OFF)
on OPERATION INDICATOR
lamp on indoor unit.w
Yes
Is this mis-wiring, poor contact,
or wire disconnection?
Correct them.
No
1. Turn OFF the power supply (outdoor unit) and disconnect indoor and outdoor connecting
wire 3 on indoor side.
2. Short-circuit terminal block N-3 by lead wire.
3. Turn ON the power supply (outdoor unit) and press EMERGENCY OPERATION switch once.
Is there 20V DC between both ends of
PS132 on the indoor electronic control P.C.
board ?
No
Replace the indoor electronic
control P.C. board.
( By tester, the stylus is between 0 ~ 20V. )
Yes
• Turn OFF the power supply. (outdoor unit)
• Connect ON indoor/ outdoor connecting
wire.
Turn ON the power supply. (outdoor unit)
No
Is there 5V DC between J205 + -J101 -
/ J101 + -J401 - on the deicer P.C. board?
Replace the deicer P.C. board.
Yes
During EMERGENCY OPERATION, is there
10V DC between both ends of R601 on the
deicer P.C. board?
Make the wiring between CN730
on the deicer P.C. board and
outdoor terminal block correct.
No
(By tester, the stylus is between 5 ~10V.)
Yes
Replace the deicer P.C. board.
Refer to outdoor unit service manual.
16
8-6. Test point diagram and voltage
MSH-A18ND MSH-A24ND
Indoor electronic control P.C. board
Fan motor power supply
Power supply input
}
220V AC
5V DC
}
+
Fuse (F11)
250V AC 3.15A
Room temperature ther-
mistor(RT11)
Indoor coil
thermistor(RT12(main))
PS132
MSH-A24ND
Indoor coil
thermistor(RT13(sub))
Emergency operation
switch
Timer short mode point
(JPS, JPG)
(Refer to 7-1.)
+
Receiver P.C. board
12V DC
Indoor coil thermistor(RT12(main), RT13(sub))
Room temperature thermistor (RT11)
Release of “Auto restart function”
Solder jumper wire to JR07.
(Refer to 7-3.)
17
9
DISASSEMBLY INSTRUCTIONS
<"Terminal with locking mechanism" Detaching points>
The terminal which has the locking mechanism can be detached as shown below.
There are two types ( Refer to (1) and (2)) of the terminal with locking mechanism.
The terminal without locking mechanism can be detached by pulling it out.
Check the shape of the terminal before detaching.
(1) Slide the sleeve and check if there is a locking lever or not.
(2) The terminal with this connector has the
locking mechanism.
Sleeve
1Slide the sleeve.
1Hold the sleeve, and
2Pull the terminal while
pushing the locking
pull out the terminal
slowly.
Locking lever
lever.
Connector
MSH-A18ND MSH-A24ND
INDOOR UNIT
OPERATING PROCEDURE
PHOTOS
1. Removing the front panel
Photo 1
(1) Remove the screw caps of the front panel.
Remove the screws.
Front panel
(2) Pull the panel down to your side slightly and unhook the
catches at the top.
Screws
Photo 2
2. Removing the electronic control P.C. board, the receiver
P.C. board and the display P.C. board
(1) Remove the front panel. (Refer to 1.)
(2) Remove the screw of the electrical cover.
Remove the electrical cover.
Screws of the ground wire
(3) Remove the screws of the V.A. clamp.
Remove the V.A. clamp.
(4) Remove the screw of the terminal block.
(5) Remove the screws of the ground wire.
(6) Disconnect all the connectors and all the lead wires on the
electronic control P.C. board.
Fan motor
connectors
Vane motor
connector
(7) Remove the R.L holder.
Indoor
(8) Remove the electronic control P.C. board.
(9) Open the R.L holder, remove the receiver P.C. board and
the display P.C. board.
electronic
control
P.C.board
Screw of
the electrical
cover
Screw of
the terminal
block
Screw of the
V.A. clamp
R.L
holder
Receiver
P.C.
board
18
OPERATING PROCEDURE
PHOTOS
3. Removing the electrical box
Photo 3
Screws of the ground wire
(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical cover. (Refer to 2.)
(3) Disconnect the connector of the indoor coil thermistor.
(4) Disconnect the motor connector (CN211 and CN121) and
the vane motor connector (CN151) on the electronic
control P.C. board.
Screw of the
electrical cover
(5) Remove the screws of ground wire.
(6) Remove the fan motor lead wire and indoor coil thermistor
from the electrical box.
(7) Remove the lead wire of vane motor from the bottom of
electrical box.
Screw of the
electrical box
(8) Remove the screw fixing the electrical box and remove the
electrical box.
Photo 4
4. Removing the vane motor
(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical cover. (Refer to 2.)
(3) Remove the lead wire of vane motor. (Refer to 3.)
(4) Remove the R.L. holder.
(5) Pull out the drain hose from the nozzle assembly and
remove the nozzle assembly.
Vane motors
Screws
of the
vane
motor
(6) Remove the screws of the vane motor and disconnect the
connector.
(7) Remove the vane motor.
Screws of the
vane motor
Photo 5
Vane motor
Photo 6
5. Removing the line flow fan and the indoor fan motor
(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical box. (Refer to 3.)
(3) Pull out the drain hose from the nozzle assembly and
remove the nozzle assembly.
Screws fixing
the left side
of the heat
exchanger
(4) Remove the water cut.
(5) Slide the hole cover and remove the hole cover.
(6) Remove the hexagon socket set screw from the line flow
fan.
(7) Remove the screws fixing the fan motor and remove the
fan motor. (Be careful not to drop the fan motor because it
is heavy.)
(8) Remove the screws fixing the left side of the heat
exchanger.
Photo 7
Indoor
coil
thermistor
(9) Lift the left side of the heat exchanger.
(
10) Remove the line flow fan.
Photo 8
Water cut
Hole
cover
Screws fixing the fan motor
19
10
PARTS LIST (non-RoHS compliant)
MSH-A18ND
MSH-A24ND
10-1. INDOOR UNIT STRUCTURAL PARTS
10-2. INDOOR UNIT HEAT EXCHANGER
1
2
11
3
4
9
8 (See 10-5.)
5
12
13
6
7
10-1. INDOOR UNIT STRUCTURAL PARTS
Part number that is circled is not shown in the illustration.
Q'ty/unit
Symbol
in Wiring
Diagram
NO.
Part No.
Part Name
Remarks
S1
S1
MSH-A18ND -
MSH-A24ND -
E02 527 970
E02 685 234
E02 888 000
E02 408 142
E02 685 067
E02 888 010
E02 534 100
1
2
3
4
5
6
7
8
9
INSTALLATION PLATE
BOX
FRONT PANEL ASSEMBLY
CATCH
SCREW CAP
GRILLE
CATECHIN AIR FILTER
AIR CLEANING FILTER
CORNER BOX RIGHT
LAMP PANEL
1
1
1
4
3
1
2
2
1
1
1
1
1
4
3
1
2
2
1
1
Including No.4,5,6
4PCS/ SET
3PCS/ SET
MAC-1700FT
E02 685 975
E02 888 007
10
10-2. INDOOR UNIT HEAT EXCHANGER
E02 891 620 INDOOR HEAT EXCHANGER
E02 893 620 INDOOR HEAT EXCHANGER
E02 179 667 UNION (GAS)
E02 527 666 UNION (GAS)
1
1
1
11
1
{12.7
{15.88
{6.35
12
1
1
13
UNION (LIQUID)
E02 151 667
20
PARTS LIST (non-RoHS compliant)
MSH-A18ND
MSH-A24ND
10-4. ACCESSORY AND
REMOTE CONTROLLER
10-3. INDOOR UNIT FUNCTIONAL PARTS AND
ELECTRICAL PARTS
1
2
3
20
19
23
24
4
11
18
12
5
6
14
13
10
7
8
17
9
15 16
10-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS
Part numbers that are circled are not shown in the illustration.
Q'ty/unit
Symbol
in Wiring
Diagram
NO.
Part No.
Part Name
Remarks
S1
S1
MSH-A18ND -
MSH-A24ND -
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
3
4
5
6
7
8
9
E02 527 302 LINE FLOW FAN
E02 408 509 BEARING MOUNT
E02 001 504 SLEEVE BEARING
E02 408 702 DRAIN HOSE
E02 996 235 NOZZLE
E02 685 040 VANE UPPER
E02 685 041 VANE LOWER
E02 A49 382 FUSE
F11
NR11
3.15A
E02 817 385 VARISTOR
10 E02 527 034 VANE CRANK SET
RC4V32 -
MF
MF
MV2
MV1
E02 A17 300 INDOOR FAN MOTOR ASSEMBLY
E02 527 300 INDOOR FAN MOTOR ASSEMBLY
Including RUBBER MOUNT
11
RC4V40 -
1
2
1
Including RUBBER MOUNT
2
1
1
12 E02 448 303 VANE MOTOR (VERTICAL)
13 E02 408 303 VANE MOTOR (HORIZONTAL)
RIGHT & LEFT
UP & DOWN
E02 817 333 MOTOR BAND
E02 527 333 MOTOR BAND
14
1
1
1
1
1
1
15 E02 528 329 DISPLAY P.C. BOARD
16 E02 527 468 RECEIVER P.C. BOARD
AUTO RESTART
Including No.16
E02 A17 452 ELECTRONIC CONTROL P.C. BOARD
E02 A18 452 ELECTRONIC CONTROL P.C. BOARD
17
AUTO RESTART
1
1
1
Including No.16
RT11
TB
RT12
1
1
1
18 E02 527 308
19 E02 814 375
ROOM TEMPERATURE THERMISTOR
TERMINAL BLOCK
E02 408 307
INDOOR COIL THERMISTOR
20
RT12, RT13
1
1
1
E02 527 307 INDOOR COIL THERMISTOR
E02 528 034 VANE MOTOR SUPPORT SET (RIGHT)
1
1
21
22
VANE MOTOR SUPPORT SET (LEFT)
E02 529 034
10-4. ACCESSORY AND REMOTE CONTROLLER
1
1
1
1
23 E02 529 426
24 E02 527 083
KM04A
KP0A,
REMOTE CONTROLLER
REMOTE CONTROLLER HOLDER
21
PARTS LIST (non-RoHS compliant)
10-5. AIR CLEANING FILTER
➔ AIR CLEANING FILTER removes fine dust of 0.01 micron from air by means of static electricity.
➔ Normal life of AIR CLEANING FILTER is 4 months. However, when it becomes dirty, replace it as soon as possible.
➔ Clogged AIR CLEANING FILTER may reduce the air conditioner capacity or cause frost on the air outlet.
➔ DO NOT reuse AIR CLEANING FILTER even if it is washed.
➔ DO NOT remove or attach AIR CLEANING FILTER during unit operation.
Model
Part No.
MSH-A18ND
MSH-A24ND
MAC-1700FT
Air cleaning filter (White bellows type)
22
11
RoHS PARTS LIST (RoHS compliant)
MSH-A18ND
MSH-A24ND
11-1. INDOOR UNIT STRUCTURAL PARTS
11-2. INDOOR UNIT HEAT EXCHANGER
1
2
11
3
9
4
5
8 (See 11-5.)
12
13
6
7
11-1. INDOOR UNIT STRUCTURAL PARTS
Part number that is circled is not shown in the illustration.
Q'ty/unit
Symbol
in Wiring
Diagram
NO.
Part No.
Part Name
Remarks
S1
S1
MSH-A18ND -
MSH-A24ND -
E12 527 970
E12 685 234
E12 888 000
E12 408 142
E12 685 067
E12 888 010
E12 534 100
1
2
3
4
5
6
7
8
9
INSTALLATION PLATE
BOX
FRONT PANEL ASSEMBLY
CATCH
SCREW CAP
GRILLE
CATECHIN AIR FILTER
AIR CLEANING FILTER
CORNER BOX RIGHT
LAMP PANEL
1
1
1
4
3
1
2
2
1
1
1
1
1
4
3
1
2
2
1
1
G
G
G
G
G
G
G
G
G
G
Including No.4,5,6
4PCS/ SET
3PCS/ SET
MAC-1700FT
E12 685 975
E12 888 007
10
11-2. INDOOR UNIT HEAT EXCHANGER
E12 891 620 INDOOR HEAT EXCHANGER
E12 893 620 INDOOR HEAT EXCHANGER
E12 179 667 UNION (GAS)
G
G
G
G
G
1
1
1
11
1
{12.7
{15.88
{6.35
12
13
E12 527 666 UNION (GAS)
1
1
UNION (LIQUID)
E12 151 667
23
RoHS PARTS LIST (RoHS compliant)
MSH-A18ND
MSH-A24ND
11-4. ACCESSORY AND
REMOTE CONTROLLER
11-3. INDOOR UNIT FUNCTIONAL PARTS AND
ELECTRICAL PARTS
1
2
3
20
19
23
24
4
11
18
12
5
6
14
13
10
7
8
17
9
15 16
11-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS
Part numbers that are circled are not shown in the illustration.
Q'ty/unit
Symbol
in Wiring
Diagram
NO.
Part No.
Part Name
Remarks
S1
S1
MSH-A18ND -
MSH-A24ND -
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
3
4
5
6
7
8
9
E12 527 302 LINE FLOW FAN
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
E12 408 509 BEARING MOUNT
E12 001 504 SLEEVE BEARING
E12 408 702 DRAIN HOSE
E12 996 235 NOZZLE
E12 685 040 VANE UPPER
E12 685 041 VANE LOWER
E12 A49 382 FUSE
E12 817 385 VARISTOR
E12 527 034 VANE CRANK SET
E12 A17 300 INDOOR FAN MOTOR ASSEMBLY
E12 527 300 INDOOR FAN MOTOR ASSEMBLY
E12 448 303 VANE MOTOR (VERTICAL)
E12 408 303 VANE MOTOR (HORIZONTAL)
E12 817 333 MOTOR BAND
F11
NR11
3.15A
10
RC4V32 -
MF
MF
MV2
MV1
Including RUBBER MOUNT
11
RC4V40 -
1
2
1
Including RUBBER MOUNT
2
1
1
12
13
RIGHT & LEFT
UP & DOWN
14
1
1
1
E12 527 333 MOTOR BAND
1
1
1
15
16
E12 528 329 DISPLAY P.C. BOARD
E12 527 468 RECEIVER P.C. BOARD
E12 A17 452 ELECTRONIC CONTROL P.C. BOARD
E12 A18 452 ELECTRONIC CONTROL P.C. BOARD
AUTO RESTART
Including No.16
17
AUTO RESTART
1
1
1
Including No.16
RT11
TB
RT12
1
1
1
18
19
E12 527 308
E12 814 375
E12 408 307
ROOM TEMPERATURE THERMISTOR
TERMINAL BLOCK
INDOOR COIL THERMISTOR
20
RT12, RT13
1
1
1
E12 527 307 INDOOR COIL THERMISTOR
E12 528 034 VANE MOTOR SUPPORT SET (RIGHT)
1
1
21
22
VANE MOTOR SUPPORT SET (LEFT)
E12 529 034
11-4. ACCESSORY AND REMOTE CONTROLLER
23
24
E12 529 426
E12 527 083
1
1
1
1
REMOTE CONTROLLER
REMOTE CONTROLLER HOLDER
G
G
KP0A, KM04A
24
RoHS PARTS LIST (RoHS compliant)
11-5. AIR CLEANING FILTER
➔ AIR CLEANING FILTER removes fine dust of 0.01 micron from air by means of static electricity.
➔ Normal life of AIR CLEANING FILTER is 4 months. However, when it becomes dirty, replace it as soon as possible.
➔ Clogged AIR CLEANING FILTER may reduce the air conditioner capacity or cause frost on the air outlet.
➔ DO NOT reuse AIR CLEANING FILTER even if it is washed.
➔ DO NOT remove or attach AIR CLEANING FILTER during unit operation.
Model
Part No.
MSH-A18ND
MSH-A24ND
MAC-1700FT
Air cleaning filter (White bellows type)
25
26
27
TM
HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN
C Copyright 2005 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD
Distributed in May 2007. No.OB427 REVISED EDITION-B 6
Distributed in Feb. 2006. No.OB427 REVISED EDITION-A 106
Distributed in Nov. 2005. No.OB427 106
Made in Japan
New publication, effective May 2007
Specifications subject to change without notice.
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