Mitsubishi Electric MSZ-JP12WA-U User manual

Outdoor unit service manual
MUZ-JP•WA Series (OBH821)
PARTS CATALOG (OBB820)
MSZ-JP09WA
INDOOR UNIT
SERVICE MANUAL
INDOOR UNIT
Models
MSZ-JP09WA -U1
MSZ-JP12WA -U1
No. OBH820
REVISED EDITION-A
OBH820 is void.
Revision A:
• 9-7. TEST POINT DIAGRAM AND
VOLTAGE has been modied.
CONTENTS
1. TECHNICAL CHANGES· ·····························2
2. PART NAMES AND FUNCTIONS ··················3
3. SPECIFICATION ········································4
4. OUTLINES AND DIMENSIONS ·····················6
5. WIRING DIAGRAM ·····································7
6. REFRIGERANT SYSTEM DIAGRAM ·············8
7. SERVICE FUNCTIONS································9
8. MICROPROCESSOR CONTROL················· 11
9. TROUBLESHOOTING·······························15
10. DISASSEMBLY INSTRUCTIONS·················27
MITSUBISHI
ELECTRIC
SPLIT-TYPE AIR CONDITIONERS

2
1TECHNICAL CHANGES
MSZ-JP09WA - U1
MSZ-JP12WA - U1
1. New model
Use the specied refrigerant only
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the spec labels provided with our products.
We will not be held responsible for mechanical failure, system malfunction, unit breakdown or accidents caused by failure to
follow the instructions.
<Preparation before the repair service>
Prepare the proper tools.
Prepare the proper protectors.
Provide adequate ventilation.
After stopping the operation of the air conditioner, turn off the power-supply breaker and pull the power plug.
Discharge the capacitor before the work involving the electric parts.
<Precautions during the repair service>
Do not perform the work involving the electric parts with wet hands.
Do not pour water into the electric parts.
Do not touch the refrigerant.
Do not touch the hot or cold areas in the refrigeration cycle.
When the repair or the inspection of the circuit needs to be done without turning off the power, exercise great caution not to
touch the live parts.
WARNING
• When the refrigeration circuit has a leak, do not execute pump down with the compressor.
• When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes.
The compressor may burst if air etc. get into it.
• When opening or closing the valve below freezing temperatures, refrigerant may spurt out from the gap
between the valve stem and the valve body, resulting in injuries.
Revision A:
• 9-7. TEST POINT DIAGRAM AND VOLTAGE has been modied.
OBH820A
•
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3
2PART NAMES AND FUNCTIONS
MSZ-JP09WA MSZ-JP12WA
ACCESSORIES
Installation plate 1
Attachment screws for the installation plate
4 × 25 mm 5
Battery (AAA) for remote controller 2
Wireless remote controller 1
Felt tape (For left or left-rear piping) 1
Remote controller holder 1
Screws for the remote controller holder
3.5 × 16 mm (Black) 2
Horizontal vane
Air outlet
Air filter
Air inlet
Heat exchanger
Front panel
Air cleaning filter
(Anti-Allergy Enzyme
Filter, option)
Remote controller
Operation indicator lamp
Remote control receiving section
Emergency operation switch
OBH820A
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3 SPECIFICATION
Indoor model MSZ-JP09WA MSZ-JP12WA
Power supply V, phase, Hz 115, 1, 60
Max. fuse size (time delay)/ Disconnect switch A 15 20
Min. circuit ampacity A 1.4
Fan motor F.L.A 1.07
Airow
Super High - High - Med. - Low
COOL Dry
(Wet)
CFM 399 - 321 - 237 - 170
(364 - 286 - 201 - 134)
HEAT Dry CFM 406 - 321 - 237 - 170
Moisture removal pt./h 1.5 2.5
Sound level
Super High - High - Med. - Low
Cooling dB(A) 43 - 37 - 30 - 22 45 - 37 - 30 - 22
Heating dB(A) 43 - 37 - 30 - 22
Fan speed
Super High - High - Med. - Low
Cooling rpm 1,020 - 860 - 670 - 530
Heating rpm 1,040 - 860 - 670 - 530
Cond. drain connection O.D. in. 5/8
Dimensions
W
in.
31-7/16
D 9-1/8
H 11-5/8
Weight Ib. 22
External nish Munsell 1.0Y 9.2/0.2
Control voltage (by built-in transformer) 12 - 24 V DC
NOTE: Test conditions are based on AHRI 210/240.
OBH820A
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5
3-1. OPERATING RANGE
(1) POWER SUPPLY
Rated voltage Guaranteed voltage (V)
Indoor unit
115 V
1 phase
60 Hz
Min. 103 115 Max. 127
(2) OPERATION
Mode Condition
Intake air temperature (°F)
Indoor Outdoor
DB WB DB WB
Cooling
Standard temperature 80 67 95 —
Maximum temperature 90 73 115 —
Minimum temperature 67 57 14 —
Maximum humidity 78% —
Heating
Standard temperature 70 60 47 43
Maximum temperature 80 67 75 65
Minimum temperature 70 60 -4 -5
3-2. OUTLET AIR SPEED AND COVERAGE
Model Mode Function Airow
(CFM)
Air speed
(ft./s.)
Coverage
(ft.)
MSZ-JP09WA
HEAT Dry 406 20.6 29.5
COOL Dry 399 20.2 29.0
Wet 364 18.4 26.5
MSZ-JP12WA
HEAT Dry 406 20.6 29.5
COOL Dry 399 20.2 29.0
Wet 364 18.4 26.5
● The air coverage is the figure up to the
position where the air speed is 1 ft./s.,
when air is blown out horizontally from
the unit properly at the High speed
position.
The coverage should be used only as a
general guideline since it varies accord-
ing to the size of the room and furniture
arranged inside the room.
OBH820A
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6
Unit: inch
MSZ-JP09WA MSZ-JP12WA
4OUTLINES AND DIMENSIONS
11/16
5-1/2
2-1/4
Piping
Insulation ø1 - 3/8 O.D
Liquid line ø1/4 19 - 11/16 (Flared connection ø1/4)
Gas line ø3/8 16 - 15/16
(Flared connection: ø3/8)
Drain hose Insulation ø1-1/8 O.D Connected part ø5/8 O.D
OBH820A
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5WIRING DIAGRAM
MSZ-JP09WA MSZ-JP12WA
OBH820A
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FROM 1/JTIIOOR UNIT IIE ,-------------------7
CONNECTING WIRES
1- - -
-, , TB LD201 (T)
( POWER SUPPLY) -+--, /:-7 I F 11 '
115V AC ~ 1 1 L __ c SI
60Hz : : I '----- NRll
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52
UNIT ' ' ' 53
CONNECTING -_!__--,
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WIRES L__,-'J L_
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2
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24
V TO OUTDOOR UNIT ---7
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I INDOOR TERMINAL I
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NOTES: I.About the outdoor side electronic wiring refer to the
IIEMA/llllS:
outdoor unit electronic wiring diagram for servicing.
2. Use copper supply wire.
3. Symbols indicate. ITIIJ : Terminal block
[QQll]l] : Connector
IIE A disconnect should be
required by local code.
I.Pour le cablage electronique cote exterieur,
se reporter au schema d'entretien du cablage
E!lectronique de l 'appareil extE!rieur,
2.Utiliser des fits d'alimentation en cuivre.
3,Les symboles ont les ITIIJ : Borne
significations suivantes. IQQQQl : Connecteur
* Se procurer un sectionneur conforrne
aux r~glementations locales
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11 I I RED
I
3 i BLK
SYMBOL NAME
Fl 1
FUSE
03. 15AL25DV)
MF FAN MOTOR
MV
VANE MOTOR
CHOR I ZONTAU
NRl 1 VARISTOR
Rl 11
RESISTOR
RTl 1
ROOM TEMP.
THERMISTOR
RT12
COIL TEMP.
THERMISTOR ( MAIN)
RT13
COIL TEMP,
THERMISTOR ( SUB)
Tl 11 TRANSFORMER
TB TERMINAL BLOCK

8
Unit: inch (mm)
6REFRIGERANT SYSTEM DIAGRAM
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Flared connection
Refrigerant pipe ø3/8 (ø9.52)
(with heat insulator)
Refrigerant pipe ø1/4 (ø6.35)
(with heat insulator)
Indoor coil
thermistor
RT12 (main)
Indoor coil
thermistor
RT13 (sub)
Refrigerant flow in cooling
Refrigerant flow in heating
MSZ-JP09WA MSZ-JP12WA
OBH820A
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7-1. TIMER SHORT MODE
For service, the set time can be shortened by bridging of the timer short point on the indoor electronic control P.C. board.
The time will be shortened as follows. (Refer to 9-7.)
• The set time for the ON/OFF timer can be reduced to 1 second for each minute.
• After the breaker is turned on, the time for starting the compressor, which normally takes 3 minutes, can be reduced to
3 seconds. Restarting the compressor, which takes 3 minutes, cannot be reduced.
7-2. REMOTE CONTROLLER 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, the remote controller P.C. boards 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:
7SERVICE FUNCTIONS
MSZ-JP09WA MSZ-JP12WA
J2
J1
The remote controller 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.
NOTE: For modification, take out the
batteries and press the STOP/
OPERATE (OFF/ON) button 2
or 3 times at first.
After finish modification, put
back the batteries then press
the RESET button.
Table 1
1 unit operation 2 units operation 3 units operation 4 units operation
No. 1 unit No modication Same as at left Same as at left Same as at left
No. 2 unit — Solder J1 Same as at left Same as at left
No. 3 unit — — Solder J2 Same as at left
No. 4 unit — — — 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 will only accept 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 is turned OFF, or the power supply is shut down.
Please conduct the above setting once again after the power has been restored.
OBH820A
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10
NOTE:
• The operation settings are memorized when 10 seconds have passed after the indoor unit 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 turned 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 the breaker from tripping OFF due to the rush of starting current, systematize other home appliance 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.
7-3. AUTO RESTART FUNCTION
When the indoor unit is controlled with the remote controller, the operation mode, the 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 shut-off of the main power.
Operation
If the main power has been cut, the operation settings remain.
After 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.)
How to disable “AUTO RESTART FUNCTION”
Turn OFF the main power of the unit.
Solder the Jumper wire JR07 on the indoor electronic control P.C. board. (Refer to 9-7.)
CN111CN112
CN151
CN10A
Indoor electronic
control P.C. board
JR07
OBH820A
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WIRELESS REMOTE CONTROLLER
NOTE: Last setting will be stored after the unit is turned OFF with the remote controller. Indoor unit receives the signal of the
remote controller with beeps.
8MICROPROCESSOR CONTROL
MSZ-JP09WA MSZ-JP12WA
Fan speed control button
Operation select button
Timer mode select button
Time set buttons
RESET button
Vane control button
Temperature buttons
ECONO COOL button
Signal transmitting section
Operation display section
OFF/ON (stop/operate) button
Operation Indicator lamp
The operation indicator at the right side of the indoor unit indicates the operation state.
•The following indication applies regardless of shape of the indication.
Indication Operation state Room temperature
The unit is operating to
reach the set temperature
About 4°F (2°C) or more
away from set temperature
The room temperature is
approaching the set tem-
perature
About 2 to 4 °F (1° to 2°C)
from set temperature
Lit
Blinking
Not lit
8-1. COOL ( ) OPERATION
(1) Press STOP/OPERATE (OFF/ON) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select COOL mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature.
The setting range is 61 - 88°F (16 - 31°C).
1. Coil frost prevention
The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the coil
from frosting.
When the temperature of indoor heat exchanger becomes too low, the coil frost prevention mode works. The indoor fan
operates at the set speed and the compressor stops. This mode continues until the temperature of indoor heat exchanger
rises.
INDOOR UNIT DISPLAY SECTION
OBH820A
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12
8-2. DRY ( ) OPERATION
(1) Press STOP/OPERATE (OFF/ON) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select DRY mode with OPERATION SELECT button.
(3) The set temperature is determined from the initial room temperature.
1. Coil frost prevention
Coil frost prevention works the same way as that in COOL mode. (8-1.1.)
8-3. HEAT ( ) OPERATION
(1) Press STOP/OPERATE (OFF/ON) button. OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone. (2) Select HEAT mode with OPERATION SELECT button. (3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature. The setting range is 61 - 88°F (16 - 31°C).
1. Cold air prevention control
When the compressor is not operating or is starting, and the temperature of indoor heat exchanger and/or the room tem- perature is low or when defrosting is being done, the indoor fan will stop or rotate in Very Low speed.
2. High pressure protection
The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the con- densing pressure from increasing excessively. When the temperature of indoor heat exchanger becomes too high, the high pressure protection works. The indoor fan operates following the cold air prevention control. This mode continues until the temperature of indoor heat exchanger falls.
3. Defrosting
Defrosting starts when the temperature of outdoor heat exchanger becomes too low. The compressor stops once, the indoor/outdoor fans stop, the 4-way valve reverses, and the compressor re-starts. This mode continues until the temperature of outdoor heat exchanger rises or the fixed time passes.
(3) Positioning
To confirm the standard position, the vane moves until it touches the vane stopper. Then the vane is set to the selected angle. Confirmation of standard position is performed in the following cases:
(a) When the operation starts or finishes (including timer operation). (b) When the test run starts. (c) When standby mode (only during multi system operation) starts or finishes.
8-4. AUTO VANE OPERATION 1. Horizontal vane
(1) Vane motor drive
These models are equipped with a stepping motor for the horizontal vane. The rotating direction, speed, and angle of
the motor are controlled by pulse signals (approximately 12 V) transmitted from indoor microprocessor.
(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL button.
AUTO 1 2 3 4 5 SWING
OBH820A
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Horizontal
position
5
(4) VANE AUTO ( ) mode
In VANE AUTO mode, the microprocessor automatically determines the vane angle to make the optimum room tempera-
ture distribution.
(5) STOP (operation OFF) and ON TIMER standby
In the following cases, the horizontal vane returns to the closed position.
(a) When STOP/OPERATE (OFF/ON) button is pressed (POWER OFF).
(b) When the operation is stopped by the emergency operation.
(c) When ON TIMER is ON standby.
(6) Dew prevention
During COOL or DRY operation with the vane angle at Angle 4 or 5 when the compressor cumulative operation time
exceeds 0.5 - 1 hour, the vane angle automatically changes to Angle 2 for dew prevention.
(7) SWING ( ) mode
By selecting SWING mode with VANE CONTROL button, the horizontal vane swings vertically.
(8) Cold air prevention in HEAT operation.
The horizontal vane position is set to Upward.
(9) ECONO COOL ( ) operation (ECONOmical operation)
When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 4°F (2°C) higher.
Also the horizontal vane swings in various cycle.
SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher, the air
conditioner can keep comfort. As a result, energy can be saved.
ECONO COOL operation is cancelled when ECONO COOL button is pressed once again or VANE CONTROL button is
pressed or change to other operation mode.
8-5. TIMER OPERATION (ON/OFF TIMER)
1. How to set the timer
(1) Press STOP/OPERATE (OFF/ON) button to start the air conditioner.
(2) Select the timer mode by pressing the button during operation.
Each time this button is pressed, the timer mode is changed in sequence:
(OFF TIMER) → (ON TIMER) → TIMER RELEASE
(3) Set the time of the timer using the button.
Each time this button is pressed, the set time increase or decrease by 1 hour to 12 hours.
2. To release the timer
Press the button until (OFF TIMER) and (ON TIMER) are not displayed.
NOTE:
• The OFF TIMER and the ON TIMER cannot be set at the same time.
• The displayed time is the time remaining and will decrease in 1-hour increments as time passes.
In COOL and DRY operation
Vane angle is fixed to Horizontal position.
In HEAT operation
Vane angle is fixed to Angle 5.
OBH820A
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14
8-6. EMERGENCY/TEST OPERATION
In the case of test run operation or emergency operation, use the emergency operation switch on the right side of the
indoor unit. Emergency operation is available when the remote controller is missing or has failed, or when the batteries in
the remote controller are running down. The unit will start and OPERATION INDICATOR lamp will light up.
The first 30 minutes of operation is the test run operation. This operation is for servicing. The indoor fan runs at High
speed and the temperature control does not work.
After 30 minutes of test run operation, the system shifts to EMERGENCY COOL/HEAT MODE with a set temperature of
75°F (24°C). The fan speed shifts to Med.
The coil frost prevention works even in the test run or the emergency operation.
In the test run or emergency operation, the horizontal vane operates in VANE AUTO ( ) mode.
Emergency operation continues until the emergency operation switch is pressed once or twice or the unit receives any
signal from the remote controller. In the latter case, normal operation will start.
NOTE: Do not press the emergency operation switch during normal operation.
Operation mode COOL HEAT
Set temperature 75°F (24°C) 75°F (24°C)
Fan speed Med. Med.
Horizontal vane Auto Auto
The operation mode is indicated by the
Operation Indicator lamp as follows:
Operation Indicator lamp
EMERGENCY COOL
↓
EMERGENCY HEAT
↓
STOP
Lit
Not lit
8-7. 3-MINUTE TIME DELAY OPERATION
When the system turns OFF, compressor will not restart for 3 minutes as 3-minute time delay function operates to protect
compressor from overload.
8-8. Changing temperature indication (°F/°C)
• The preset unit is °F.
• °F → °C: Press RESET button while the TEMPERATURE buttons are pressed.
• °C → °F: Press RESET button while the TEMPERATURE buttons are pressed.
Press RESET button gently
using a ne-tipped object.
Emergency operation switch
OBH820A
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15
9-1. CAUTIONS ON TROUBLESHOOTING
1. Before troubleshooting, check the following
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the unit first with the remote controller, and then after confirm-
ing 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 P.C. board.
3) When removing the 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 connector housing. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp on the indoor unit is blinking ON and OFF to indicate an abnormality.
To make sure, check how many times the OPERATION INDICATOR lamp is blinking ON and OFF before starting ser-
vice work.
2) Before servicing, verify that all connectors and terminals are connected properly.
3) When the electronic control P.C. board seems to be defective, check for disconnection of the copper foil pattern and
burnt or discolored components.
4) When troubleshooting, refer to 9-2, 9-3 and 9-4.
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.
Lead wiring Connector housing
<Incorrect> <Correct>
9TROUBLESHOOTING
MSZ-JP09WA MSZ-JP12WA
Insert the negative pole of the
batteries first. Check if the polarity
of the batteries is correct.
NOTE: 1. If RESET button is not pressed, the remote controller may not operate correctly.
2. This remote controller has a circuit to automatically reset the microcomputer when batteries are replaced.
This function is equipped to prevent the microcomputer from malfunctioning due to the voltage drop caused by the
battery replacement.
3. Do not use the leaking batteries.
Press RESET button with a fine-tipped object, and
then use the remote controller.
Remove the back lid and insert batteries.
Then reattach the back lid.
OBH820A
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16
9-2. FAILURE MODE RECALL FUNCTION
Outline of the function
This air conditioner can memorize the abnormal condition which has occurred once.
Even though LED indication listed on the troubleshooting check table (9-4.) disappears, the memorized failure details can
be recalled.
1. Flow chart of failure mode recall function for the indoor/outdoor unit
Does upper lamp of OPERATION INDICATOR
lamp on the indoor unit blink at the interval of 0.5
seconds?
Blinks: Either indoor or outdoor unit is abnormal.
Beep is emitted at the same timing as the
blinking of upper lamp of OPERATION
INDICATOR lamp. *2
Indoor unit is normal.
But the outdoor unit might be abnormal because there are some abnor-
malities that cannot be recalled with this way.
Check if outdoor unit is abnormal according to the detailed outdoor unit
failure mode recall function.
No
Yes
The cause of abnormality cannot be found because the abnormality does not recur.
Setting up the failure mode recall function
Turn ON the power supply.
<Preparation of the remote controller>
While pressing both OPERATION SELECT button and TOO COOL button on the
remote controller at the same time, press RESET button.
First, release RESET button.
Hold down the other 2 buttons for another 3 seconds. Make sure that the indicators on
the LCD screen shown in the right gure is all displayed.
Then release the buttons.
Press STOP/OPERATE (OFF/ON) button of the remote controller (the set temperature is
displayed) with the remote controller headed towards the indoor unit. *1
Judgment of indoor/outdoor abnormality
Before blinking, does upper lamp of
OPERATION INDICATOR lamp stay ON for 3
seconds?
When it stays ON for 3 seconds (without beep):
The outdoor unit is abnormal.
The indoor unit is abnormal.
Check the blinking pattern, and identify the abnormal point by referring to the
table of indoor unit failure mode recall function. (Refer to 9-2.2)
Make sure to check at least 2 consecutive blinking cycles. *2
Releasing the failure mode recall function
Release the failure mode recall function by the following procedures.
Turn OFF the power supply and turn it ON again.
Press RESET button of the remote controller.
The outdoor unit is abnormal.
Check the blinking pattern, and identify the abnormal point by referring
to the table of outdoor unit failure mode recall function. (Refer to outdoor
unit service manual.)
Make sure to check at least 2 consecutive blinking cycles. *3
Repair the failure parts.
Deleting the memorized abnormal condition
After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall
function" mentioned above.
Press STOP/OPERATE (OFF/ON) button of the remote controller (the set temperature is displayed)
with the remote controller headed towards the indoor unit.
Press the emergency operation switch so that the memorized abnormal condition is deleted.
Release the failure mode recall function according to "Releasing the failure mode recall function"
mentioned above.
Operational procedure
Yes
(Blinks)
No
(OFF)
NOTE: 1. Make sure to release the failure mode recall function after it is set up, otherwise the unit cannot operate properly.
2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized.
*2. Blinking pattern when the indoor unit is abnormal:
*3. Blinking pattern when the outdoor unit is abnormal:
ON
OFF
Beeps
Repeated cycle Repeated cycle
ON
OFF
No beep Beeps
Repeated cycle
2.5-second OFF
Blinking at 0.5-
second interval
2.5-second OFF 3-second ON
Blinking at 0.5-
second interval
Beeps
Repeated cycle
2.5-second OFF
Blinking at 0.5-
second interval
No beep Beeps
Repeated cycle
2.5-second OFF 3-second ON
Blinking at 0.5-
second interval
Repeated cycle
Beeps
*1 Regardless of normal or abnormal condition,
a short beep is emitted once the signal is
received.
OBH820A
CD
®
CD
®
®
©
~~~

17
2. Table of indoor unit failure mode recall function
Upper lamp of
OPERATION
INDICATOR lamp
Abnormal point
(Failure mode) Condition Remedy
Not lit Normal — —
1-time blink every
0.5-second
Room temperature
thermistor
The room temperature thermistor short or
open circuit is detected every 8 seconds dur-
ing operation.
Refer to the characteristics of the room temperature
thermistor (9-7.).
2-time blink
2.5-second OFF
Indoor coil
thermistor
The indoor coil thermistor short or open circuit
is detected every 8 seconds during operation.
Refer to the characteristics of the main indoor coil ther-
mistor, the sub indoor coil thermistor (9-7.).
3-time blink
2.5-second OFF Serial signal The serial signal from outdoor unit is not re-
ceived for a maximum of 6 minutes.
Refer to 9-6. "How to check miswiring and serial
signal error".
11-time blink
2.5-second OFF Indoor fan motor
The rotational frequency feedback signal is
not emitted for 12 seconds after the indoor fan
motor is operated.
Refer to 9-6. "Check of indoor fan motor".
12-time blink
2.5-second OFF
Indoor control
system
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
Replace the indoor electronic control P.C. board.
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (9-4.).
OBH820A
@
®

18
9-3. INSTRUCTION OF TROUBLESHOOTING
Indoor unit operates.
Outdoor unit does
not operate.
If blinking of OPERATION
INDICATOR lamp cannot be
checked, it can be checked with
failure mode recall function.
Indoor unit operates.
Outdoor unit does not
operate normally.
Indoor unit does not
receive the signal from
remote controller.
OPERATION INDICATOR
lamp on the indoor unit is
blinking ON and OFF.
Outdoor unit
operates only
in Test Run
operation. *
Outdoor unit
does not
operate even
in Test Run
operation. *
Unit does not
operate
normally in
COOL or
HEAT mode
operation.
Indoor unit
operates, when
the emergency
operation switch
is pressed.
Indoor unit does
not operate, when
the emergency
operation switch
is pressed.
Check room
temperature
thermistor.
Refer to 9-7.
"Test point
diagram and
voltage".
Refer to "How
to check
inverter/com-
pressor".
Refer to
"Check of R.V.
coil".
Refer to 9-6.
"Check of remote
controller and
indoor elec-
tronic control P.C.
board".
1. Check indoor/out-
door connecting wire.
(Check if the power is
supplied to the indoor
unit.)
2. Refer to 9-6. "Check
of indoor P.C. board
and indoor fan motor".
Upper lamp
Flash ON
and OFF at
0.5-second
intervals
Cause:
Indoor/Outdoor
unit
• Miswiring or
trouble of se-
rial signal.
Upper lamp
2-time blink
Cause:
Indoor unit
• Trouble
of room
temperature
/ indoor coil
thermistor.
Upper lamp
3-time blink
Cause:
Indoor unit
• Trouble of
indoor fan
motor.
Upper lamp
4-time blink
Cause:
Indoor unit
• Trouble
of indoor
unit control
system.
Upper lamp
5-time blink
Cause:
Outdoor unit
• Outdoor
power sys-
tem abnor-
mality.
Upper lamp
6-time blink
Cause:
Outdoor unit
• Trouble of
thermistor in
outdoor unit.
Upper lamp
7-time blink
Cause:
Outdoor unit
• Trouble of
outdoor con-
trol system.
Upper lamp
14-time blink
or more
Cause:
Outdoor unit
• Other ab-
normality
Start
Refer to
9-6. "How
to check mis-
wiring and
serial signal
error".
Check room
temperature
thermistor
and indoor
coil thermis-
tor. Refer
to 9-7."Test
point diagram
and voltage".
Refer to
9-6. "Check
of indoor fan
motor".
Replace the
indoor elec-
tronic control
P.C. board.
Refer to
"How to
check
inverter/com-
pressor".
Refer to
"Check of
outdoor ther-
mistors".
Replace the
inverter P.C.
board or
the outdoor
electronic
control P.C.
board.
Check "Flow
chart of the
detailed
outdoor unit
failure mode
recall func-
tion."
* "Test Run operation" means the
operation within 30 minutes after
the emergency operation switch
is pressed.
Refer to outdoor unit service
manual.
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19
9-4. TROUBLESHOOTING CHECK TABLE
Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
When the indoor unit has started operation and detected an abnormality of the following condition (the first detection after the
power ON), the indoor fan motor turns OFF and OPERATION INDICATOR lamp blinks.
OPERATION INDICATOR Lit
Blinking
Not lit
No. Abnormal
point Operation indicator lamp Symptom Condition Remedy
1
Miswiring
or serial
signal
Upper lamp blinks.
0.5-second ON
0.5-second OFF
Indoor unit and
outdoor unit do
not operate.
The serial signal from the outdoor unit is not
received for 6 minutes.
• Refer to 9-6. "How to check
miswiring and serial signal er-
ror".
2
Indoor coil
thermistor
Upper lamp blinks.
2-time blink
2.5-second OFF
The indoor coil or the room temperature ther-
mistor is short or open circuit.
• Refer to the characteristics of
indoor coil thermistor, and the
room temperature thermistor
(9-7.).
Room
temperature
thermistor
3Indoor fan
motor
Upper lamp blinks.
3-time blink
2.5-second OFF
The rotational frequency feedback signal is
not emitted during the indoor fan operation. • Refer to 9-6. "Check of in-
door fan motor".
4
Indoor
control
system
Upper lamp blinks.
4-time blink
2.5-second OFF
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
• Replace the indoor electronic
control P.C. board.
5
Outdoor
power
system
Upper lamp blinks.
5-time blink
2.5-second OFF
It consecutively occurs 3 times that the com-
pressor stops for overcurrent protection or
start-up failure protection within 1 minute after
start-up.
• Refer to "How to check of in-
verter/compressor".
Refer to outdoor unit service
manual
• Check the stop valve.
6Outdoor
thermistors
Upper lamp blinks.
6-time blink
2.5-second OFF
The outdoor thermistors short or open circuit
during the compressor operation.
• Refer to "Check of outdoor
thermistor".
Refer to outdoor unit service
manual.
7
Outdoor
control
system
Upper lamp blinks.
7-time blink
2.5-second OFF
It cannot properly read data in the nonvolatile
memory of the inverter P.C. board or the out-
door electronic control P.C. board.
• Replace the inverter P.C. board
or the outdoor electronic control
P.C. board.
Refer to outdoor unit service
manual.
8Other
abnormality
Upper lamp blinks.
14-time blink or more
2.5-second OFF
An abnormality other than above mentioned
is detected.
• Check the stop valve.
• Check the 4-way valve.
• Check the abnormality in detail
using the failure mode recall
function for outdoor unit.
9
Outdoor
control
system
Upper lamp lights up.
Outdoor unit
does not
operate
It cannot properly read data in the nonvolatile
memory of the inverter P.C. board or the out-
door electronic control P.C. board.
• Check the blinking pattern of
the LED on the inverter P.C.
board or the outdoor electronic
control P.C. board.
OBH820A
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20
9-5. TROUBLESHOOTING CRITERION OF MAIN PARTS
MSZ-JP09WA MSZ-JP12WA
Part name Check method and criterion Figure
Room temperature
thermistor (RT11)
Indoor coil thermistor
(RT12, RT13)
Measure the resistance with a multimeter.
Refer to 9-7. "Test point diagram and voltage", 1 or 2. "Indoor electronic
control P.C. board", for the chart of thermistor.
Indoor fan motor (MF) Check 9-6.
Horizontal vane motor (MV)
Measure the resistance between the terminals with a multimeter.
(Part temperature 50 - 86°F (10 - 30°C))
Color of the lead wire Normal
RED-BLK 223 - 268 Ω
BLK
BLK
RED
BLK BLK
ROTOR
ROTOR
OBH820A
®