Vermont Casting MSY-D36NA, MSZ-D30NA, MSY-D30NA, MSZ-D36NA User Manual

INDOOR UNIT

SERVICE MANUAL

Wireless type
Models

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

No. OBH501

CONTENTS

10. DISASSEMBLY INSTRUCTIONS ···················· 31

PARTS CATALOG (OBB501)

NOTE:

RoHS compliant products have <G> mark on the spec name plate.

Outdoor unit service manual

MUZ-D•NA Series (OBH502)
MUY-D•NA Series (OBH502)

1. TECHNICAL CHANGES

2. PART NAMES AND FUNCTIONS ·····················4

3. SPECIFICATION ················································ 5

4. OUTLINES AND DIMENSIONS ························7

5. WIRING DIAGRAM ············································8

6. REFRIGERANT SYSTEM DIAGRAM ···············9

7. SERVICE FUNCTIONS ···································10

8. MICROPROCESSOR CONTROL ···················12

9. TROUBLESHOOTING ·····································19

·······································

3

2

1

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

1. New model

TECHNICAL CHANGES

3

2

PART NAMES AND FUNCTIONS

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

Air cleaning filter
(Anti-Allergy Enzyme Filter)

Air filter
(Catechin air filter)

Air inlet

Front panel

ACCESSORIES

Air outlet

Horizontal vane

Installation plate 1
Installation plate screw 4 × 25 mm 7
Remote controller holder 1
Screw for × 3.5 × 1.6 mm (Black) 2
Battery (AAA) for remote controller 2
Wireless remote controller 1
Felt tape (Used for left or left-rear piping) 2
L-Joint pipe 1
Conduit plate 1
Air cleaning fi lter 2

Operation indicator
lamp

Remote control
receiving section

Emergency
switch

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

operation

Remote controller

4

4

3

Model MSZ-D30NA MSY-D30NA MSZ-D36NA MSY-D36NA

External fi nish White
Power supply V, phase, Hz
Max. fuse size (time delay)/ Disconnect switch
Min. circuit ampacity A 1.0
Fan motor F.L.A 0.76

Airfl ow
Low-Med.-High

Moisture removal pt./h 9.9 11.3 11.9

Sound level
Low-Med.-High

Cond. drain connection O.D. in. 5/8

Dimensions

Weight Ib. 40
Remote controller Wireless type
Control voltage (by built-in transformer) 12-24 VDC

NOTE : Test conditions are based on ARI 210/240.

SPECIFICATION

208 / 230 , 1 , 60

A15

HEAT Dry CFM 445-639-848 — 445-639-848 —
COOL Dry

(Wet)

Cooling dB(A) 32-42-49 32-42-49 32-42-49 32-42-49
Heating dB(A) 34-42-49 — 34-42-49 —

W in. 46-1/16
D in. 11-5/8
H in. 14-3/8

CFM 389(350)-639(576)-848(763) 389(350)-639(576)-848(763)

55

3-1. OPERATING RANGE

(1) POWER SUPPLY

Rated voltage Guaranteed Voltage

Indoor unit

208/230 V

1 phase

60 Hz

Min.187 V

208 V 230 V Max.253 V

(2) OPERATION

Mode Condition

Standard temperature 80 67 95 —

Cooling

Heating

Maximum temperature 90 73 115 —
Minimum temperature 67 57 14 —
Maximum humidity 78 % —
Standard temperature 70 60 47 43
Maximum temperature 80 67 75 65
Minimum temperature 70 60 14 13

DB WB DB WB

Indoor Outdoor

3-2. OUTLET AIR SPEED AND COVERAGE RANGE

Intake air temperature (°F)

Model Mode Function

MSZ-D30NA
MSZ-D36NA

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

HEAT Dry 848 23.6 45.0

COOL

Airlow
(CFM)

Dry 848 23.6 45.0

Wet 763 21.3 40.7

Air speed

(ft./sec.)

Coverage

range

(ft.)

to the position where the air speed is 1
ft./sec., when air is blown out horizon­tally from the unit properly at the High
speed position.

The coverage range should be used

only as a general guideline since it var­ies according to the size of the room
and furniture arranged inside the room.

The air coverage range is the figure up

66

4

OUTLINES AND DIMENSIONS

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

14-3/8

2-15/16

2-5/16

Wireless remote controller

14-3/8

33-11/16

45-1/2

46-1/16

3/4

9-1/2

1-7/8

2-3/16

Air out

2-11/16

11-5/8 1/4

Air in

5-7/8

Liquid line

Gas line

Joint

Drain hose

Indoor unit

20-7/8 17-11/16

Wall hole ø3

Installation plate

Piping

Drain hose

2-1/2

2-5/8

2-15/16

Piping

ø3/8 19-11/16
(Flared connection ø3/8)

ø5/8 16-7/8
(Joint connection ø5/8)
ø5/8
(Flared connection ø5/8)
Inslationø1-1/8 Connected part

4-11/16

ø9/16 O.D

Unit : inch

7/811-5/81-7/8

5-3/8

1/8

Insulation

ø1-1/4 O.D
ø9/16 I.D

ø1-15/16 O.D
ø1-1/4 I.D
ø1-15/16 O.D
ø1-1/4 I.D

77

Required Space (Indoor Unit)

4-11/16 or more 8-11/16 or more

4-3/16 or more

3/8 or more

In case of left,left back,
or left under piping (using spacer) 5-1/8 or more

9-3/8 or more

2-13/16 or more

14-1/2 or more

2-3/16 or more

5

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

WIRING DIAGRAM

8

6

REFRIGERANT SYSTEM DIAGRAM

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

Indoor coil
thermistor
RT13(sub)

Room temperature
thermistor
RT11

Indoor
heat
exchanger

Strainer

Indoor coil
thermistor
RT12(main)

Distributor

Unit:inch

Refrigerant pipe ø5/8
(with heat insulator)

Flared connection
Joint
Joint connection

Flared connection

Refrigerant pipe ø3/8
(with heat insulator)

Refrigerant flow in cooling

Refrigerant flow in heating

9

7

SERVICE FUNCTIONS

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

7-1. TIMER SHORT MODE

For service, set time can be shortened by short circuit of JPG and JPS the indoor electronic control P.C. board.
The time will be shortened as follows. (Refer to 9-7.)
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 twice or 3
times at first.

After finish modification,

put back the batteries then

J1

J2

press the RESET button.

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

1 unit operation 2 units operation 3 units operation 4 units operation
No. 1 unit No modifi 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 has turned off, or the power supply has shut down.
Please conduct the above setting once again after the power has restored.

10

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. The “AUTO RESTART FUNCTION” sets to work the moment
power has restored after power failure. Then, the unit will restart automatically.

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 release “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.)

CN211CN112

CN152

JR07

CN101

BZ

CN151

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 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 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.

11

8

MICROPROCESSOR CONTROL

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

WIRELESS REMOTE CONTROLLER

Signal transmitting section

Operation display section

OPERATE/STOP
(ON/OFF) button

Temperature buttons

Indication of
remote controller
model is on back

+ These pictures show MSZ type.

VANE CONTROL button
(Horizontal vane button)

OPERATION SELECT button

ECONO COOL button

WIDE VANE button (Vertical vane button)

POWERFUL button

RESET button

FAN SPEED
CONTROL button

OFF TIMER button

ON TIMER button

TIME SET buttons
FORWARD button
BACKWARD button

CLOCK SET button

NOTE

Use the remote controller
provided with the unit only.
Do not use other 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.

INDOOR UNIT DISPLAY SECTION

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 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

Lighted

Blinking

Not lighted

is approaching the set
temperature

The room temperature

About 2 °F (1 °C) to
4 °F (2 °C) from set
temperature

12

8-1. COOL (

(1) Press OPERATE/STOP (ON/OFF) 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

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.

2. Low outside temperature operation

When the outside temperature is lower, low outside temperature operation starts, and the outdoor fan slows or stops.

8-2. DRY (

(1) Press OPERATE/STOP (ON/OFF) 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 is as same as COOL mode. (8-1.1.)

2. Low outside temperature operation

Low outside temperature operation is as same as COOL mode. (8-1.2.)

) OPERATION

) OPERATION

8-3. HEAT (

(1) Press OPERATE/STOP (ON/OFF) 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 tem­perature 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 con­densing 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.

) OPERATION (MSZ)

8-4. FAN( )OPERATION (MSY)

(1) Press OPERATE/STOP (ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit turns ON with a beep tone.
(2) Select FAN mode with OPERATION SELECT button.
(3) Select the desired fan speed. When AUTO, it becomes Low.
Only indoor fan operates. Outdoor unit does not operate.

8-5. “I FEEL CONTROL” (

(1) Press OPERATE/STOP (ON/OFF) button on the remote

controller. OPERATION INDICATOR lamp of the indoor
unit turns on with a beep tone.

(2) Select “I FEEL CONTROL” mode with OPERATION

SELECT button.

(3) The operation mode is determined by the room tempera-

ture at start-up of the operation.

) OPERATION (MSY)

Initial room temperature Mode

77 °F (25 °C) or more

more than 55 °F (13 °C),

less than 77 °F (25 °C)

COOL mode of

"I FEEL CONTROL"

DRY mode of

"I FEEL CONTROL"

• Once the mode is fixed, the mode does not change by room temperature afterwards.

• Under the ON TIMER (
operation starts.

) operation, mode is determined according to the room temperature at the set time the

13

(4) The initial set temperature is decided by the initial room temperature.

Model Initial room temperature Initial set temperature

COOL mode of "I FEEL

CONTROL"

DRY mode of "I FEEL

CONTROL"

1 When the system is restarted with the remote controller, the system operates with the previous set temperature

regardless of room temperature at restart.

The set temperature is calculated by the previous set temperature.

(5) TEMPERATURE buttons
In “I FEEL CONTROL” (

In addition, set temperature can be controlled by TOO WARM or TOO COOL buttons when you feel too cool or too
warm.
Each time the TOO WARM or TOO COOL button is pressed, the indoor unit receives the signal and emits a beep tone.

79 °F (26 °C) or more 75°F (24 °C)

77 °F (25 °C) to 79 °F (26 °C) Initial room temperature minus 4 °F (2 °C)

more than 55 °F (13 °C),

less than 77 °F (25 °C)

) mode, set temperature is decided by the microprocessor based on the room temperature.

Initial room temperature minus 4 °F (2 °C)

• Fuzzy control

When the TOO COOL or TOO WARM button is pressed, the microprocessor changes the set temperature, considering
the room temperature, the frequency of pressing TOO COOL or TOO WARM button and the user’s preference to heat or
cool. So this is called “Fuzzy control”, and works only in “I FEEL CONTROL” mode.
In DRY mode of “I FEEL CONTROL”, the set temperature doesn’t change.

··· To raise the set temperature 2 ~ 4 °F (1 ~ 2 °C)

··· To lower the set temperature 2 ~ 4 °F (1 ~ 2 °C)

1

8-6. AUTO CHANGE OVER ··· AUTO MODE OPERATION (MSZ)

Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.

Mode selection

(1) Initial mode

When unit starts the operation with AUTO operation from off;

• If the room temperature is higher than the set temperature, operation starts in COOL mode.

• If the room temperature is equal to or lower than the set temperature, operation starts in HEAT mode.

(2) Mode change

COOL mode changes to HEAT mode when about 15 minutes have passed with the room temperature 4 °F (2 °C) below
the set temperature.
HEAT mode changes to COOL mode when about 15 minutes have passed with the room temperature 4 °F (2 °C) above
the set temperature.

14

8-7. 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 (approx. 12 V) transmitted from indoor microprocessor.

(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL button.

(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.

(a) The operation starts or finishes (including timer operation).
(b) The test run starts.

(4) VANE AUTO ( ) mode

The microprocessor automatically determines the horizontal vane angle and operation to make the optimum room tem­perature distribution.

COOL and DRY operation

FAN operation (MSY)

Vane angle is fixed to Angle 1.

HEAT operation (MSZ)

Vane angle is fixed to Angle 4.

1

(5) STOP (operation OFF) and ON TIMER standby

In the following cases, the horizontal vane returns to the closed position.
(a) OPERATE/STOP (ON/OFF) button is pressed (POWER OFF).
(b) The operation is stopped by the emergency operation.
(c) ON TIMER is ON standby.

(6) Dew prevention

During COOL or DRY operation with the vane angle at Angle 4 ~ 5 when the compressor cumulative operation time
exceeds 1 hour, the vane angle automatically changes to Angle 1 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 (MSZ)

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 3.6 °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, when the VANE CONTROL
or POWERFUL button is pressed, or operation mode is changed.

(10) POWERFUL ( ) operation.

The air conditioner automatically adjusts the fan speed and the set temperature, and operates the POWERFUL mode.
The POWERFUL mode is cancelled automatically 15 minutes after operation starts, or when POWERFUL but­ton is pressed once again within 15 minutes after operation starts. The operation mode returns to the mode prior to
POWERFUL operation. POWERFUL mode also is cancelled, when the ECONO COOL or FAN SPEED SELECT button
is pressed within 15 minutes after operation starts, or operation mode is changed.

15

2. Vertical vane

(1) Vane motor drive

These models are equipped with a stepping motor for the vertical vane. The rotating direction, speed, and angle of the
motor are controlled by pulse signals (approx. 12 V) transmitted from microprocessor.

(2) The vertical vane angle and mode change as follows by pressing WIDE VANE button.

23

(3) Positioning

The vane is once pressed to the vane stopper to confirm the standard position and then set to the desired angle.
Confirming of standard position is performed in the following cases.
(a) OPERATE/STOP (ON/OFF) button is pressed (POWER ON/OFF).
(b) SWING is started or finished.
(c) The power supply turns ON.

(4) SWING MODE ( )

By selecting SWING mode with WIDE VANE button, the vertical vane swings horizontally.
The remote controller displays “

(5) WIDE MODE ( )

By selecting WIDE mode with WIDE VANE button, indoor fan speed becomes faster than setting fan speed on the
remote controller ( ). The remote controller displays “ ”.

NOTE : The position of vane angle 3, angle 4 and angle 5 are different in COOL operation and HEAT operation.

Indoor fan speed becomes faster than setting fan speed on the remote controller even when or is select-

ed.

”.

45SWING

61

16

8-8. TIMER OPERATION

1. How to set the time

(1) Check that the current time is set correctly.

NOTE : Timer operation will not work without setting the current time. Initially “0:00” blinks at the current time display

of TIME MONITOR, so set the current time correctly with CLOCK SET button.

How to set the current time

(a) Press the CLOCK set button.
(b) Press the TIME SET buttons (

• Each time FORWARD button (
BACKWARD button (

) is pressed, the set time decreases by 1 minute.

and

) to set the current time.

) is pressed, the set time increases by 1 minute, and each time

• Pressing those buttons longer, the set time increases / decreases by 10 minutes.

(c) Press the CLOCK set button.
(2) Press OPERATE/STOP (ON/OFF) button to start the air conditioner.
(3) Set the time of timer.

ON timer setting

(a) Press ON TIMER button(
(b) Set the time of the timer using TIME SET buttons (

) during operation.

and

) .

OFF timer setting

(a) Press OFF TIMER button
(b) Set the time of the timer using TIME SET buttons (

Each time FORWARD button (

) is pressed, the set time decreases by 10 minutes.

during operation.

( )

) is pressed, the set time increases by 10 minutes; each time BACKWARD button (

and

).

2. To release the timer

To release ON timer, press ON TIMER button (
To release OFF timer, press OFF TIMER button (

).

).

TIMER is cancelled and the display of set time disappears.

PROGRAM TIMER

• OFF timer and ON timer can be used in combination. The timer of the set time that is reached first will operate first.

• “ ” and “ ” display shows the order of OFF timer and ON timer operation.

(Example 1) The current time is 8:00 PM.

The unit turns off at 11:00 PM, and on at 6:00 AM.

PM

AM

NOTE : If the main power is turned OFF or a power failure occurs while ON/OFF timer is active, the timer setting is can-

celled. As these models are equipped with an auto restart function, the air conditioner starts operating with timer
cancelled when power is restored.

(Example 2) The current time is 11:00 AM.

The unit turns on at 5:00 PM, and off at 9:00 PM.

PM

PM

17

8-9. EMERGENCY/TEST OPERATION

In case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the front of the indoor
unit. Emergency operation is available when the remote controller is missing, has failed or the batteries of the remote
controller run down. The unit will start and OPERATION INDICATOR lamp will light.
The first 30 minutes of operation is the test run operation. This operation is for servicing. The Indoor fan speed runs at
High speed and the system is in continuous operation (with thermostat ON).
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.
All protective operations such as the coil frost prevention works even in emergency operation.
In the test run or emergency operation, the horizontal vane operates in VANE AUTO (
Emergency operation continues until EMERGENCY OPERATION switch is pressed once or twice or the unit receives any
signal from the remote controller. In case of latter normal operation will start.

NOTE : Do not press EMERGENCY OPERATION switch during normal operation.

) mode.

Operation mode COOL

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 following

E.O.

SW

E.O.

EMERGENCY OPERATION switch

Operation Indicator lamp

(MSZ type)

EMERGENCY COOL

SW

EMERGENCY HEAT

↓

HEAT

(MUZ)

Lighted

Not lighted

↓

STOP

(MSY type)

EMERGENCY COOL

↓

STOP

8-10. 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.

8-11. 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 or remove

•
the batteries .

Press RESET button gently using
a thin stick.

18

9

TROUBLESHOOTING

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

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 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.

Lead wiring Housing point

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) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the
components for bursting and discoloration.

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.

Remove the front lid and insert batteries.

Then reattach the front lid.

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.

Press RESET button with tip end of ball point pen

or the like, and then use the remote controller.

RESET button

19

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.
This mode is very useful when the unit needs to be repaired for the abnormality which doesn't recur.

1. Flow chart of failure mode recall function for the indoor/outdoor unit

Operational procedure

The cause of abnormality cannot be found because the abnormality doesn't 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.

And release the other two buttons after all LCD in operation display section of the

remote controller is displayed after 3 seconds.

Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is
displayed) with the remote controller headed towards the indoor unit.

Does the left 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 the left lamp of OPERATION
INDICATOR lamp. 2

Judgment of indoor/outdoor abnormality

Releasing the failure mode recall function

Deleting the memorized abnormal condition

NOTE: 1. Make sure to release the failure mode recall function once it's 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:

ON

OFF

3.Blinking pattern when the outdoor unit is abnormal:

ON

OFF

Before blinking, does the left lamp of OP­ERATION INDICATOR lamp stay ON for 3
seconds?
Stays ON for 3 seconds (without beep):
The outdoor unit is abnormal.

The indoor unit is abnormal.
Check the blinking pattern, and confi rm the abnormal point with the indoor unit
failure mode table. (Refer to 9-2.2)
Make sure to check at least two consecutive blinking cycles.

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.

Repair the defective parts.

After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall

function" mentioned above.
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed)

with the remote controller headed towards the indoor unit.
Press 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.

2.5-second OFF

Repeated cycle Repeated cycle

2.5-second OFF 3-second ON

Yes
(Blinks)

No

Blinking at 0.5­second interval

Beeps

No beep Beeps

Repeated cycle

2.5-second OFF

Yes

Blinking at 0.5­second interval

1

No
(OFF)

The outdoor unit is abnormal.
Check the blinking pattern, and confi rm the abnormal point with the
outdoor unit failure mode table. (Refer to outdoor unit service manual.)

2

Blinking at 0.5­second interval

Beeps

2.5-second OFF 3-second ON

Make sure to check at least two consecutive blinking cycles.

1. Regardless of normal or abnormal condition, a short

Indoor unit is normal.
But the outdoor unit might be abnormal because there are some abnor­malities that can't be recalled with this way.
Confi rm if outdoor unit is abnormal according to the detailed outdoor unit
failure mode recall function.

beep is emitted once the signal is received.

Repeated cycle

No beep Beeps

Repeated cycle

2020

Beeps

Blinking at 0.5­second interval

3

Repeated cycle

2. Indoor unit failure mode table

Left lamp of OP-

ERATION INDICA-

TOR lamp

Not lighted Normal — —

1-time fl ash every

0.5-second

2-time fl ash

2.5-second OFF
3-time fl ash

2.5-second OFF

11-time fl ash

2.5-second OFF

12-time fl ash

2.5-second OFF

Abnormal point

(Failure mode)

Room temperature
thermistor

Indoor coil thermis­tor

Serial signal

Indoor fan motor

Indoor control
system

Condition Correspondence

The room temperature thermistor short or open
circuit is detected every 8 seconds during op­eration.

The indoor coil thermistor short or open circuit
is detected every 8 seconds during operation.

The serial signal from outdoor unit is not re­ceived for a maximum of 6 minutes.

The rotational frequency feedback signal is
not emit during the 12 seconds the indoor fan
operation.

It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.

Refer to the characteristics of the room temperature
thermistor (9-7.).

Refer to the characteristics of the main indoor coil
thermistor, the sub indoor coil thermistor (9-7.).

Refer to 9-6.
signal error".

Refer to 9-6. "Check of indoor fan motor".

Replace the indoor electronic control P.C. board.

"How to check miswiring and serial

NOTE : Blinking patterns of this mode differ from the ones of Troubleshooting check table (9-4.).

2121

9-3. INSTRUCTION OF TROUBLESHOOTING

Start

Indoor unit oper­ates.
Outdoor unit
doesn't operate.

Outdoor unit
operates only
in Test Run
operation.

Check room
temperature
thermistor.
Refer to 8-7.
"Test point
diagram and
voltage".

Outdoor

unit doesn't

operate even

in Test Run

operation.

Refer to "How

to check

inverter/

compressor".

Indoor unit operates.
Outdoor unit doesn't
operate normally.

Unit doesn't
operate normal
operation in
COOL or HEAT
mode.

Refer to
"Check of R.V.
coil".

Indoor unit
doesn't receive
the signal from
remote controller.

Indoor unit
operates, when
EMERGENCY
OPERATION
switch is pressed.

Refer to 9-6.
"Check of remote
controller and
receiver P.C.
board".

OPERATION INDICATOR
lamp on the indoor unit is
fl ashing on and off.

Indoor unit
doesn't operate,
when EMERGEN­CY OPERATION
switch is pressed.

1.Check indoor / out­door connecting wire.
(Check if the power is
supplied to the indoor
unit.)

2.Refer to 9-6. "Check
of indoor electronic
control P.C. board and
indoor fan motor".

If blinking of OPERATION INDI­CATOR lamp cannot be checked,
it can be checked with failure
mode recall function.

"Test Run operation" means the
operation within 30 minutes after
EMERGENCY OPERATION
switch is pressed.

Refer to outdoor unit service manual.

Left lamp
Flash on and
off at 0.5-sec­ond intervals
Cause:
Indoor/ Out­door unit

• Miswiring or
trouble of
serial signal

Refer to 9-6.

"How to
check miswir­ing and serial
signal error".

Left lamp
2-time fl ash
Cause:
Indoor unit

• Trouble of
room tem­perature /
indoor coil
thermistor

Check room
temperature
thermistor
and indoor
coil thermis­tor.Refer to
9-7."Test
point diagram
and voltage".

Left lamp
3-time fl ash
Cause:
Indoor unit

• Trouble of
indoor fan
motor

Refer to 9-6.

"Check of
indoor fan
motor".

Left lamp
4-time fl ash
Cause:
Indoor unit

• Trouble
of indoor
unit control
system

Replace the
indoor elec­tronic control
P.C. board.

Left lamp
5-time fl ash
Cause:
Outdoor unit

• Outdoor
power
system
abnormality

Refer to "How
to check
inverter/ com­pressor".

2222

Left lamp
6-time fl ash
Cause:
Outdoor unit

• Trouble of
thermistor in
outdoor unit

Refer to
"Check of
outdoor
thermistors".

Left lamp
7-time fl ash
Cause:
Outdoor unit

• Trouble of
outdoor con­trol system

Replace the
inverter P.C.
board or the
outdoor elec­tronic control
P.C. board.

Left lamp
14-time fl ash
Cause:
Outdoor unit

• Other ab­normality

Check "Flow
chart of the
detailed
outdoor unit
failure mode
recall func­tion."

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 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 OPERATION INDICATOR
lamp flashing.

OPERATION INDICATOR

Abnormal

No.

point

Miswiring or

1

serial signal

Indoor coil
thermistor

2

Room
temperature
thermistor

Indoor fan

3

motor

Indoor con-

4

trol system

Outdoor

5

power sys­tem

Outdoor

6

thermistors

Outdoor con-

7

trol system

Other abnor-

8

mality

Lighted
Blinking

Not lighted

Operation indicator lamp Symptom Condition Correspondence

Left lamp fl ashes.

0.5-second ON

0.5-second OFF

Left lamp fl ashes.

2-time flash

2.5-second OFF

Left lamp fl ashes.

3-time flash

2.5-second OFF

Left lamp fl ashes.

4-time flash

2.5-second OFF

Left lamp fl ashes.

5-time flash

2.5-second OFF

Left lamp fl ashes.

6-time flash

2.5-second OFF

Left lamp fl ashes.

7-time flash

Left lamp fl ashes.

14-time flash

2.5-second OFF

2.5-second OFF

Indoor unit
and outdoor
unit do not
operate.

Indoor unit
and outdoor
unit do not
operate.

Indoor unit
and outdoor
unit do not
operate.

Indoor unit
and outdoor
unit do not
operate.

Indoor unit
and outdoor
unit do not
operate.

Indoor unit
and outdoor
unit do not
operate.

Indoor unit
and outdoor
unit do not
operate.

Indoor unit
and outdoor
unit do not
operate.

The serial signal from the outdoor unit is not
received for a maximum of 6 minutes.

The indoor coil or the room temperature
thermistor is short or open circuit.

The rotational frequency feedback signal is not
emitted during the indoor fan operation.

It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.

It consecutively occurs 3 times that the
compressor stops for overcurrent protection or
start-up failure protection within 1 minute after
start-up.

The outdoor thermistors short or open circuit
during the compressor operation.

It cannot properly read data in the nonvola­tile memory of the inverter P.C. board or the
outdoor electronic control P.C. board.

An abnormality other than above mentioned is
detected.

Refer to 9-6. "How to check miswiring

•
and serial signal error".

Refer to 9-7.the characteristics of indoor

•
coil thermistor, and the room tempera­ture thermistor.

Refer to 9-6. "Check of indoor fan mo-

•
tor".

Replace the indoor electronic control

•
P.C. board.

Refer to "How to check of inverter/

•
compressor".
Refer to outdoor unit service manual.
Check the stop valve.

•

Refer to "Check of outdoor thermistor".

•
Refer to outdoor unit service manual.

Replace the inverter P.C. board or the

•
outdoor electronic control P.C. board.
Refer to outdoor unit service manual.

Confi rm the abnormality in detail using

•
the failure mode recall function for
outdoor unit.

2323

9-5. TROUBLE CRITERION OF MAIN PARTS

MSZ-D30NA
MSZ-D36NA
MSY-D30NA
MSY-D36NA

Part name Check method and criterion Figure

Room temperature
thermistor(RT11)

Indoor coil thermistor
(RT12(MAIN), RT13(SUB))

Measure the resistance with a tester.

Refer to 9-7. "Test point diagram and voltage", "Indoor electronic control P.C.
board", the chart of thermistor.

Indoor fan motor(MF) Check 9-6.

Measure the resistance between the terminals with a tester.
(Part temperature 50 ~ 86 °F)

Horizontal vane motor (MV1)
Horizontal vane motor
(MV1)
Vertical vane motor
(MV2)

Color of the lead wire Normal

BRN - other one 240 ~ 260 Ω

Vertical vane motor (MV2)

Color of the lead wire Normal

BRN - other one 282 ~ 306 Ω

.

RED

YLW
BRN

ROTOR

ORN

GRN

24

24

9-6. TROUBLESHOOTING FLOW

OPERATION INDICATOR lamp flashes 3-time.
Indoor fan does not operate.

A Check of indoor fan motor

The indoor fan motor error has occurred, and the indoor fan doesn't operate.

Turn OFF the power supply.

Is there any foreign matter that
interferes the rotation of the line
fl ow fan?

Yes

Remove the foreign matter and
adjust the line fl ow fan.

Is there 294/325 VDC between

(+) and (-), and does the

CN211
voltage between CN211
(-) rise to the range of 3 to 6 VDC
within 12 seconds after EMERGEN­CY OPERATION switch is pressed?

No

Replace the indoor electronic control P.C. board.

No

(+) and

Pay careful attention to the high voltage on the fan motor connector CN211.

Turn ON the power supply, wait 5 seconds or more, and then press
EMERGENCY OPERATION switch.
Measure the supply voltage as follows within 12 seconds after EMER­GENCY OPERATION switch is pressed.
If more than 12 seconds passes by, turn OFF the power supply and
turn ON it again, then measure the voltage.

1.Measure the voltage between CN211 (+) and (-).

2.Measure the voltage between CN211

If more than 12 seconds or more passes after EMERGENCY OPERATION

switch is pressed, the voltage mentioned above 2 goes 0 VDC although
the indoor electronic control P.C. board is normal

Yes

Replace the indoor fan motor.

(+) and (-).

Indoor electronic
control P.C. board

CN211

The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.

Measure the voltage between CN211

(+) and (-) while the fan motor is

rotating.

Is it unchanged holding
0 or 15 VDC?

Yes
(Unchanged)

Replace the indoor fan motor.

No
(Changed)

Replace the indoor electronic control P.C. board.

2525

Indoor unit operates by pressing EMERGENCY OPERATION switch, but does not operate with the remote controller.

B Check of remote controller and receiver P.C. board

Check if the remote controller is exclusive for this air conditioner.

Switch ON the remote controller.

Is LCD display on the remote controller
visible?

Yes

Remove the batteries, then set them back
and press RESET button. (Refer to 9-1.4.)
Check if the unit operates with the remote
controller.

Does the unit operate with the remote
controller?

Yes

OK

No
(not clear)

No

Replace the batteries. (Refer to 9-1.4.)

Turn ON a radio to AM and press switch
ON the remote controller.

Is noise heard from radio?

Yes

Are there any fl uorescent lights of
inverter or rapid-start type within the
range of 3.28 ft.?

No

Measure the voltage between receiver P.C. board
connector CN301 No.2(+) and No.3(-) when the
remote controller button is pressed.

No

Yes

Replace the remote controller.

Reinstall the unit away from lights.

•
Attach a fi lter on receiving part.

•

Is the voltage approx. 4VDC?

No (5 or 0 VDC)

Replace the receiver P.C. board.

2626

Yes

Replace the remote controller.

The unit does not operate with the remote controller.
Also, OPERATION INDICATOR lamp does not light up by pressing EMERGENCY OPERATION switch.

C Check of indoor electronic control P.C. board and indoor fan motor

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.

Measure the resistance between
CN211 and of the indoor fan motor
connector.

Short/open circuit:
Replace the indoor fan motor.

Does the unit operate with the remote
controller?
Does OPERATION INDICATOR lamp light
up by pressing EMERGENCY OPERATION
switch?

No

Turn OFF the power supply.
Check both “parts side” and “pattern
side” of the indoor electronic control
P.C. board visually.

Measure the resistance of the horizon­tal vane motor coil.
Refer to 9-5.

Yes

Replace the indoor elec­tronic control P.C. board.

Are the varistor(NR11)
burnt and the fuse(F11)
blown?

Be sure to check both the fuse
and the varistor in any case.

Is the fuse(F11) blown
only?

Measure the resistance between
(+) and (-) of the indoor fan motor
connector (to CN211 on the indoor
electronic control P.C. board) .

Is the resistance 1 MΩ
or more?

Yes

Yes

Yes

Short/open circuit:
Replace the horizontal vane motor and the
indoor electronic control P.C. board.

No

No

1.The fan motor connector's lead wire is red, whereas is
black.

2.Connect "+" of the tester to fan motor connector's lead

1, 2

No

wire, and "-" to lead wire, otherwise the resistance cannot
be measured properly.

Replace the indoor electronic control
P.C. board and the indoor fan motor.

Indoor electronic
control P.C. board

Varistor(NR11)

Fuse(F11)

CN211

Replace the indoor electronic
control P.C. board

Measure the resistance of cement
resistor(R111) on the indoor elec­tronic control P.C. board.

Is the resistance approx.
4 Ω?

Yes

Replace the indoor electronic control P.C. board.

No

2727

Replace the indoor electronic control P.C.
board and the indoor fan motor.

• Unit cannot operate neither by the remote controller nor by EMERGENCY OPERATION switch.
Indoor unit does not operate.

• OPERATION INDICATOR lamp flashes ON and OFF every 0.5-second.
Outdoor unit does not operate.

D How to check miswiring and serial signal error

Turn OFF the power supply.

Is there rated voltage AC in
the power supply?

Yes

Turn ON the power supply.

Is there rated voltage between
outdoor terminal block S1 and
S2?

Press EMERGENCY OPERATION switch once.

Does the left lamp of OPERATION INDICATOR
lamp light up? <Confi rmation of the power to
the indoor unit>

Is serial signal error indicated 6 minutes later?

Turn OFF the power supply.
Check once more if the indoor/outdoor

B

connecting wire is not miswiring.
Short-circuit outdoor terminal block S2
and S3.

Yes

Yes

Yes

A

1

No

No

Check the power supply.

Check the wiring.

No

Is there any miswiring, poor
contact, or wire disconnec­tion of the indoor/outdoor

No

connecting wire?
Is fuse (F65) broken?

1. Miswiring may damage indoor electronic control
P.C. board during the operation.

Be sure to confi rm the wiring is correct before

the operation starts.

No

Yes

Correct them.

A

Turn OFF inverter-controlled lighting

•
equipment.
Turn OFF the power supply and then

•
turn ON again.
Press EMERGENCY OPERATION

•
switch.

Reinstall

•
either the unit
or the light
each other

No

•

away.
Attach a fi lter
on remote
control receiv­ing section
of the indoor
unit.

Is serial signal
error indicated 6
minutes later?

Yes

B

Turn ON the power supply.

Does the LED on the inverter P.C. board or
the outdoor electronic control P.C. board
repeat "3.6-second-OFF and 0.8-second­ON quick blinking"?

Yes

Turn OFF the power supply.
Remove the short-circuit between out­door terminal block S2 and S3.
Turn ON the power supply.
Is there amplitude of 10 to 20 VDC
between outdoor terminal block S2 and
S3? <Confi rmation of serial signal>

Yes

Is there rated voltage between
indoor terminal block S1 and S2?
<Confi rmation of power voltage>

Yes

Replace the indoor electronic control P.C. board.

Be sure to release the failure-mode recall function
after checking.

No

No

No
(Lighted
or not
lighted)

2828

Replace the inverter P.C. board or the
outdoor electronic control P.C. board.

2

2. Be careful to the residual
voltage of smoothing capacitor.

Is there any error of the in­door/outdoor connecting wire,
such as the damage of the wire,
intermediate connection, poor
contact to the terminal block?

No

Is there any error of the in­door/outdoor connecting wire,
such as the damage of the wire,
intermediate connection, poor
contact to the terminal block?

No

Replace the indoor/out-

Yes

door connecting wire.

Replace the indoor/out­door connecting wire.

Yes

E Electromagnetic noise enters into TV sets or radios

Is the unit grounded?

Yes

Is the distance between the antennas
and the indoor unit within 9.91 ft., or is
the distance between the antennas and
the outdoor unit within 9.91 ft.?

No

Is the distance between the TV sets or
radios and the indoor unit within 3.28
ft., or is the distance between the TV
sets or radios and the outdoor unit
within 9.91 ft.?

No

Are the antennas damaged?
Is the coaxial cable damaged?
Is there any poor contact in the anten­na wiring?

No

Is the indoor/outdoor connecting wire of
the air conditioner and the wiring of the
antennas close?

No

Yes

Yes

Yes

Yes

Ground the unit.

Extend the distance between the antennas and
the indoor unit, and/or the antennas and the
outdoor unit.

Extend the distance between the TV sets and/or
radios and the indoor unit, or the TV sets or
radios and the outdoor unit.

Replace or repair the antenna.
Replace or repair the coaxial cable.

Extend the distance between the indoor/outdoor
connecting wire of the air conditioner and the wir­ing of the antennas.

No

Even if all of the above conditions are fulfi lled, the electromagnetic noise may enter, depending on the electric fi eld strength
or the installation condition (combination of specifi c conditions such as antennas or wiring).
Check the followings before asking for service.

1. Devices affected by the electromagnetic noise
TV sets, radios (FM/AM broadcast, shortwave)

2. Channel, frequency, broadcast station affected by the electromagnetic noise

3. Channel, frequency, broadcast station unaffected by the electromagnetic noise

4. Layout of ;
indoor/outdoor unit of the air conditioner, indoor/outdoor wiring, grounding wire, antennas, wiring from antennas, receiver

5. Electric fi eld intensity of the broadcast station affected by the electromagnetic noise

6. Presence or absence of amplifi er such as booster

7. Operation condition of air conditioner when the electromagnetic noise enters in

1) Turn OFF the power supply once, and then turn ON the power supply. In this situation, check for the electromagnetic
noise.

2) Within 3 minutes after turning ON the power supply, press OPERATE/STOP (ON/OFF) button on the remote controller
for power ON, and check for the electromagnetic noise.

3) After a short time (3 minutes later after turning ON), the outdoor unit starts running. During operation, check for the
electromagnetic noise.

4) Press OPERATE/STOP (ON/OFF) button on the remote controller for power OFF, when the outdoor unit stops but the
indoor/outdoor communication still runs on. In this situation, check for the electromagnetic noise.

2929

9-7. TEST POINT DIAGRAM AND VOLTAGE

MSZ-D30NA MSZ-D36NA MSY-D30NA MSY-D36NA

Indoor electronic control P.C. board

Cement resistor (R111)

Release of Auto restart function
Solder the Jumper wire JR07
(Refer to 7-3.)

Power monitor
receiver P.C. board

Varistor (NR11)

Power supply input

208 / 230 VAC Fuse (F11)

}

250 V 3.15 A

Indoor fan motor
(CN211)

294 / 325 VDC

(-) Fiducial terminal of
cathode side on measur­ing high-voltage DC

15

VDC

(+)3-6 VDC

(+)0 VDC or 15 VDC

5 VDC

Indoor coil thermis­tor RT12(MAIN)
RT13(SUB)
(CN112)

SW P.C. board

12 VDC

Horizontal vane
motor(CN151)

Room temperature
thermistor(RT11)
(CN111)

Timer short
mode point

}

JPG, JPS

Vertical vane motor (CN152)

Indoor coil thermistor [RT12 (MAIN), RT13 (SUB)]
Room temperature thermistor (RT11)

40

30

20

Resistance (kΩ)

10

0

32 50 68 86 104 122 140

Temperature (°F)

(Refer to 7-1.)

30

10

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.

Sleeve

Slide the sleeve.
Pull the terminal while

Locking lever

pushing the locking
lever.

(2) The terminal with this connector has the
locking mechanism.

10-1. MSZ-D30NA MSZ-D36NA MSY-D30NA MSY-D36NA

OPERATING PROCEDURE

1. Removing the panel

(1) Press and unlock the knobs on both sides of the front

panel and lift the front panel until it is level, and then pull

the hinges forward to remove the front panel.
(2) Remove the screw caps of the panel.
Remove the screws of the panel.
(3) Hold the lower part of both ends on the panel and pull it

slightly toward you, and then remove the panel by pushing

it upward.
(4) Remove the screw of the corner box. Remove the corner

box.

Photo 1

Hold the sleeve, and
pull out the terminal
slowly.

Connector

PHOTOS

Front panel

Screws

Screw of the
corner box

2. Removing the electrical box, the electronic control P.C.
board, the power monitor receiver P.C. board and the SW
P.C. board

(1) Remove the panel and corner box. (Refer to 1.)
(2) Remove the screw of the electrical cover. Remove the elec-

trical cover.
(3) Remove the screw of the V.A. clamp.
(4) Remove the V.A. clamp, then remove the indoor/outdoor

connecting wire.
(5) Disconnect TAB of the ground wire connected to the indoor

heat exchanger.
(6) Remove the screw of the electrical side cover. Remove the

electrical side cover.
(7) Disconnect all the connectors, TAB and TAB4 on the indoor

electronic control P.C. board.
(8) Remove the screw on lower side of the electrical box. (See

photo 3) Remove the electrical box.
(9) Remove the indoor electronic control P.C. board.
(

10

) Remove the SW holder from the electrical box.
(11) Open the SW holder and pull out the SW P.C. board.
(12) Remove the power monitor receiver holder from the electri-

cal box.

(13) Open the power monitor receiver holder and pull out the

power monitor receiver P.C. board.

31

Photo 2

Water cut

Ground wire to indoor
heat exchanger

Power monitor
receiver holder

Screw of
electrical side
cover

Screw of elec­trical cover

Screw of V.A.
clamp

SW holder

OPERATING PROCEDURE

3. Removing the nozzle assembly

(1) Remove the panel and the corner box. (Refer to 1.)
(2) Remove the electrical cover. (Refer to 2.)
(3) Remove the electrical side cover, disconnect the vane

motor connector.

(4) Pull out the drain hose from the nozzle assembly, and

remove the nozzle assembly.

PHOTOS

Photo 3

Screw of electrical

box

4. Removing the vertical vane motor

(1) Remove the nozzle assembly. (Refer to 3.)
(2) Remove the crank of the vertical vane motor unit from the

vertical vane.

(3) Remove the screw of the vertical vane motor unit, and pull

the vertical vane motor unit.
(4) Remove the screws of the vertical vane motor unit cover.
(5) Remove the crank of the vertical vane motor unit from the

shaft of the vertical vane motor.
(6) Remove the vertical vane motor from the vertical vane

motor unit.
(7) Disconnect the connector of vertical vane motor from the

vertical vane motor.

5. Removing the horizontal vane motor

(1) Remove the nozzle assembly. (Refer to 3.)
(2) Remove the screws of the horizontal vane motor unit, and

pull out the horizontal vane motor unit.
(3) Disconnect the connector from the horizontal vane motor.
(4) Remove the screws of the horizontal vane motor.
(5) Remove the horizontal vane motor.

Photo 4

Screws of the vertical
vane motor unit

Crank of the vertical
vane motor unit

Screws of the vertical vane motor unit cover

Photo 5

Crank of the vertical
vane motor unit

Screws of the vertical
vane motor unit

Screws of the vertical vane motor unit cover

Photo 6

Screws of the
horizontal vane
motor

32

Screws of the horizontal vane motor unit

OPERATING PROCEDURE

6. Removing the line flow fan and the indoor fan motor

(1) Remove the panel and the corner box. (Refer to 1.)
(2) Remove the electrical box. (Refer to 2.)
(3) Remove the nozzle assembly. (Refer to 3.)
(4) Remove the water cover.
(5) Loosen the screw of the line flow fan.
(6) Remove the screws of the motor bed.
(7) Remove the lead wire of the indoor coil thermistor from the

hooks of the motor bed.

(8) Remove the motor band and the motor bed together with

indoor fan motor. (Be careful not to drop the indoor fan
motor because it is heavy.)

(9) Remove the screw of the motor band, and remove the

motor band then pull out the indoor fan motor.

(10)

Remove the screws of the left side of the heat exchanger.

(11)

Lift the left side of the heat exchanger.

(12)

Remove the line flow fan to the lower-left.

Photo 9

PHOTOS

Photo 7

Screw of the motor band

Screws of the motor bed

Lead wire of the indoor
coil thermistor

Photo 8

Screws of the left
side of the heat
exchanger

Screw of the line
flow fan

333435

TM

HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN

Copyright 2008 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD
Distributed in Feb. 2008. No. OBH501 7
Made in Japan

New publication, effective Feb. 2008
Specifications subject to change without notice.