Mitsubishi Electronics MSZGE15NA Air Conditioner Service manual

SPLIT-TYPE AIR CONDITIONERS

INDOOR UNIT

SERVICE MANUAL

No. OBH548

Models

MSZ-GE06NA

MSZ-GE09NA

MSZ-GE12NA

MSZ-GE15NA

MSZ-GE18NA

MSY-GE09NA

MSY-GE12NA

MSY-GE15NA

MSY-GE18NA

NOTE:

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

Outdoor unit service manual

MUZ-GE•NA MUY-GE•NA Series (OBH549)

MXZ-A·NA Series (OB444)

CONTENTS

1. TECHNICAL CHANGES ······································· 2

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

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

4. OUTLINES AND DIMENSIONS ························ 5

5. WIRING DIAGRAM ············································ 6

6. REFRIGERANT SYSTEM DIAGRAM ··············· 7

7. SERVICE FUNCTIONS ····································· 8

8. MICROPROCESSOR CONTROL ··················· 10

9. TROUBLESHOOTING ····································· 16

10. DISASSEMBLY INSTRUCTIONS ···················· 28

PARTS CATALOG (OBB548)

1 TECHNICAL CHANGES

MSZ-GE06NA MSZ-GE09NA MSZ-GE12NA MSZ-GE15NA MSZ-GE18NA

MSY-GE09NA MSY-GE12NA MSY-GE15NA MSY-GE18NA

1. New model

2 PART NAMES AND FUNCTIONS



Air filter

(Catechin air filter)

Front panel

Air cleaning filter

(Anti-Allergy Enzyme

Filter)

Air inlet

Heat exchanger

Remote controller

Air outlet

Horizontal vane

Remote control receiving section

Operation indicator lamp

Emergency operation switch (E.O. SW)

ACCESSORIES

Installation plate

Installation plate fi xing screw 4 × 25 mm

Remote controller holder

Fixing screw for 3.5 × 1.6 mm (Black)

Battery (AAA) for remote controller

Wireless remote controller

Felt tape (Used for left or left-rear piping)

2

1

2

1

5

2

1

1

3 SPECIFICATION

Indoor model

MSZ-GE06NA

Power supply V, phase, Hz

Max. fuse size (time delay)/ Disconnect switch A

Min. circuit ampacity A

Fan motor F.L.A

Airfl ow

Super High - High - Med. -

Low - Quiet

COOL Dry

(Wet) CFM

HEAT Dry CFM 406-321-233-170-145

Moisture removal pt./h –

Sound level


Low - Quiet

Cooling dB(A)

Heating dB(A)

Cond. drain connection O.D.

in.

Dimensions

W

D

H in.

Weight

External fi nish

Ib.

Control voltage (by built-in transformer)

43-37-30-22-19

MSZ-GE09NA

MSY-GE09NA

208/230, 1, 60

MSZ-GE12NA

MSY-GE12NA

15

1.0

0.76

399-321-237-170-145

(364-286-201-134-109)

406-321-237-170-145

1.5

2.5

5/8

31-7/16

9-1/8

11-5/8

22

Munsell 1.0Y 9.2/0.2

12 - 24 VDC

45-37-30-22-19

43-37-30-22-19

Indoor model

Power supply V, phase, Hz

Max. fuse size (time delay)/ Disconnect switch A

Min. circuit ampacity A

Fan motor F.L.A

Airfl ow


Low - Quiet

COOL Dry

(Wet) CFM

HEAT Dry CFM

Moisture removal pt./h

Sound level


Low - Quiet

Cooling dB(A)

Heating dB(A)

Cond. drain connection O.D.

in.

Dimensions

W

D

H in.

Weight

External fi nish

Ib.

Control voltage (by built-in transformer)

NOTE

: Test conditions are based on ARI 210/240.

MSZ-GE15NA

MSY-GE15NA

533-420-335-272-205

(498-385-300-237-170)

463-367-304-247-205

2.7

49-44-38-32-26

MSZ-GE18NA

MSY-GE18NA

208/230, 1, 60

15

1.0

0.76

533-420-339-275-230

( 498-385-304-240-194)

512-431-339-275-230

4.6

49-44-38-33-28

46-40-35-30-26 48-43-38-33-28

5/8

31-7/16

9-1/8

11-5/8

22

Munsell 1.0Y 9.2/0.2

12 - 24 VDC

3

3-1. OPERATING RANGE

(1) POWER SUPPLY

Rated voltage

Indoor unit

208/230 V

1 phase

60 Hz

Guaranteed voltage (V)

Min. 187 208 230 Max. 253

(2) OPERATION

Mode Condition

Cooling

Heating

Standard temperature

Maximum temperature

Minimum temperature

Maximum humidity

Standard temperature

Maximum temperature

Minimum temperature

DB

80

90

67

70

80

70

Indoor

78%

Intake air temperature (°F)

WB

67

73

57

DB

95

115

14

60

67

60

47

75

-4

Outdoor

—

WB

—

—

—

43

65

-5

3-2. OUTLET AIR SPEED AND COVERAGE

Model

MSZ-GE06NA

MSZ-GE09NA

MSY-GE09NA

MSZ-GE12NA

MSY-GE12NA

MSZ-GE15NA

MSY-GE15NA

MSZ-GE18NA

MSY-GE18NA

Mode Function

HEAT

COOL

HEAT

COOL

HEAT

COOL

HEAT

COOL

HEAT

COOL

Wet

Dry

Dry

Wet

Dry

Dry

Wet

Dry

Dry

Wet

Dry

Dry

Wet

Dry

Dry

286

463

420

385

321

286

406

321

Airfl ow

(CFM)

406

321

286

406

512

420

385

Air speed

(ft./s.)

20.6

16.3

14.5

20.6

16.3

14.5

20.6

16.3

14.5

23.4

21.3

19.5

25.9

21.3

19.5

Coverage (ft.)

29.5

23.5

21.0

29.5

23.5

21.0

29.5

23.5

● 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 according to the size of the room and furniture arranged inside the room.

21.0

33.5

30.5

28.0

36.9

30.5

28.0

4

4 OUTLINES AND DIMENSIONS



7/16×1 Oblong hole

3-1/8

Installation plate

8-7/8 8-7/8

31-7/16

30-15/16 1/4

Unit: inch

7/16×13/16 Oblong hole

3-1/8

3/16

9-1/8

Indoor unit

2-3/8 13-5/16

Air in

6-1/8 6-1/8

13-9/16

Installation plate

Piping

2-1/8

Wall hole ø2-9/16

1-3/4

2- 5/16 3/4

1-15/16

2-3/16

24-3/8

1-15/16

5-1/8

4/3/16

4-3/8

1-5/8

Drain hose

Air out

Insulation

Liquid line

Gas line

Drain hose

ø1 - 3/8 O.D

ø1/4 19 - 11/16 (Flared connection ø1/4)

ø3/8 16 - 15/16

(Flared connection: ø3/8 (GE06/09/12NA), ø1/2 (GE15/18NA))

Insulation ø1-1/8 O.D Connected part ø5/8 O.D

5

5 WIRING DIAGRAM



6

6 REFRIGERANT SYSTEM DIAGRAM



Indoor heat exchanger

Refrigerant pipe ø3/8 ( MSZ-GE06/09/12NA, MSY-GE09/12NA)

ø1/2 ( MSZ-GE15/18NA, MSY-GE15/18NA)

(with heat insulator)

Indoor coil thermistor

RT12 (main)

Flared connection


RT13 (sub)

Room temperature thermistor

RT11

Flared connection

Refrigerant pipe ø1/4

(with heat insulator)

Refrigerant flow in cooling

Refrigerant flow in heating

Unit: inch

7

7 SERVICE FUNCTIONS



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 press the RESET button.

J1 J2

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

No. 1 unit

No. 2 unit

No. 3 unit

No. 4 unit

1 unit operation

No modifi cation

—

—

—

2 units operation

Same as at left

Solder J1

—

—

3 units operation

Same as at left

Same as at left

Solder J2

—

4 units operation

Same as at left

Same as at left

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 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.

8

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 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.)

Indoor electronic control P.C. board

JR07

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.

9

8 MICROPROCESSOR CONTROL



WIRELESS REMOTE CONTROLLER

E.g.: MSZ type

Signal transmitting section

Operation display section

OPERATE/STOP

(ON/OFF) button

Temperature buttons

FAN SPEED CONTROL button

OPERATION SELECT button

ECONO COOL button

VANE CONTROL button

SMART SET button

RESET button

Indication of remote controller model is on back

OFF TIMER button

ON TIMER button

TIME SET buttons

FORWARD button

BACKWARD button

CLOCK SET button

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 the indication.

Indication Operation state Room temperature Lighted

Blinking

Not lighted

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 temperature

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

Standby mode

(Only during multi system operation)

-

10

8-1. COOL ( ) OPERATION

(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

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.

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 ( ) OPERATION



(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.)

8-3. HEAT ( ) OPERATION (MSZ)



(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.

8-4. FAN( )OPERATION (MSY)



(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” ( ) OPERATION (MSY)

(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 temperature at start-up of the operation.

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

• Under the ON TIMER ( operation.

) operation, mode is determined according to the room temperature at the start-up of

11

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

Initial room temperature Model

79°F (26°C) or more

COOL mode of

"I FEEL CONTROL"

77 to 79°F (25 to 26°C)

Initial set temperature

75°F (24°C)

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

Less than 79°F (25°C)

DRY mode of

"I FEEL CONTROL"

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

(5) TEMPERATURE buttons

In “I FEEL CONTROL” ( ) mode, set temperature is decided by the microprocessor based on the room temperature.

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.

•

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 does not change.

TOO

COOL

TOO

WARM

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

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 2°F (1°C) below the set temperature.

HEAT mode changes to COOL mode when about 15 minutes have passed with the room temperature 2°F (1°C) above the set temperature.

NOTE1

If two or more indoor units are operating in multi system, there might be a case that the indoor unit, which is operating in

(AUTO), cannot change over to the other operating mode (COOL ↔ HEAT(MSZ)) and becomes a state of standby.

Refer to NOTE2 "FOR MULTI SYSTEM AIR CONDITIONER".

NOTE2

FOR MULTI SYSTEM AIR CONDITIONER

OUTDOOR UNIT: MXZ series

Multi system air conditioner can connect two or more indoor units with one outdoor unit.

• When you try to operate two or more indoor units with one outdoor unit simultaneously, one for the cooling and the others for heating, the operation mode of the indoor unit that operates first is selected. Other indoor units cannot operate, and operation indicator lamp flashes as shown in the figure below. In this case, please set all the indoor units to the same operation mode.

<Operation indicator lamp>

Lighted

Blinking

Not lighted

• When indoor unit starts the operation while the defrosting of outdoor unit is being done, it takes a few minutes (max.

10 minutes) to blow out the warm air.

• In the heating operation, though indoor unit that does not operate may get warm or the sound of refrigerant flowing may be heard, they are not malfunction. The reason is that the refrigerant continuously flows into it.

12

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.

Confirming of standard position is performed in the following cases:

(a) The operation starts or finishes (including timer operation).

(b) The test run operation starts.

(c) Standby mode (only during multi system operation) starts or finishes.

(4) VANE AUTO ( ) mode

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

In COOL and DRY operation

Vane angle is fixed to Horizontal position.

In HEAT operation

Vane angle is fixed to Angle 5.

Horizontal position

5

(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 or 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.

NOTE: When 2 or more indoor units are operated with multi outdoor unit, even if any indoor unit turns thermostat OFF, this control does not work in the indoor unit.

(9) To change the airflow direction not to blow directly onto your body.

To change the air fl ow direction

Pressing and holding

VANE CONTROL button for 2 seconds or more, the horizontal vane reverses and moves horizontal position.

Horizontal position

When to use this function?

Use this function if you do not want the air from the indoor unit to blow directly onto your body.

• Depending on the shape of the room, the air may blow directly onto your body.

• Press VANE CONTROL button again to return the vane to the previouslyset position.

COOL/DRY

The air conditioner starts the cooling or drying operation approx. 3 minutes after the vane has moved to the horizontal position.

• When VANE CONTROL button is pressed again, the vane returns to the previously-set position and the air conditioner starts the cool or dry operation in approx. 3 minutes.

The air conditioner starts heating operation approx. 3 minutes after the vane has moved to the horizontal position.

•

•

HEAT(MSZ)

Sometimes the area around your feet may not get warm. To warm the area around the feet, set the horizontal vane to (AUTO) or the downwardblowing position.

When VANE CONTROL button is pressed again, the vane returns to the previously-set position and the air conditioner starts the heat operation in approx. 3 minutes.

NOTE:

• If you make the airfl ow not to blow directly onto your body by pressing VANE CONTROL button, the compressor stops for 3 minutes even during the operation of the air conditioner.

• The air conditioner operates with Very Low speed until the compressor turns ON again.

13

(10) 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 changed to other operation mode.

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 AM” 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 ( and ) to set the current time.

• Each time FORWARD button ( ) is pressed, the set time increases by 1 minute, and each time BACK-

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

• 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 ( ) during operation.

(b) Set the time of the timer using TIME SET buttons ( and ).

OFF timer setting

(a) Press OFF TIMER button ( ) during operation.

(b) Set the time of the timer using TIME SET buttons ( and ).

Each time FORWARD button ( ) is pressed, the set time increases by 10 minutes: each time BACKWARD

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

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.

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

The unit turns ON at 5:00 PM, and OFF at 9:00

PM.

PM

AM

PM

PM

NOTE : If the main power is turned OFF or a power failure occurs while ON/OFF timer is active, the timer setting is cancelled. As these models are equipped with an auto restart function, the air conditioner starts operating with timer cancelled when power is restored.

14

8-9. SMART SET ( ) OPERATION

1. How to SET SMART SET operation


(2) Select COOL, HEAT(MSZ) or ECONO COOL mode.

(3) Press SMART SET button.

(4) Set the temperature, fan speed, and airfl ow direction for SMART SET operation.

NOTE:

• SMART SET operation cannot be selected during DRY or AUTO mode operation.

• The setting range of HEAT mode in SMART SET operation is 50°F (10°C) and 61 - 87°F (16 - 31°C). (MSZ)

• 2 groups of setting can be saved. (One for COOL/ECONO COOL, one for HEAT) (MSZ)

• 1 group of setting can be saved. (MSY)

2. How to cancel operation

• Press SMART SET button again.

• SMART SET operation can also be cancelled by pressing OPERATION SELECT button to change the operation mode.

The same setting is select from the next time by simply pressing SMART SET button.

8-10. EMERGENCY/TEST OPERATION

In case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the right side 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 runs at High speed and the system is in continuous operation (The thermostat does not work).

After 30 minutes of test run operation, the system shifts to

EMERGENCY COOL/HEAT(MSZ) MODE with a set temperature of

75°F (24°C). The fan speed shifts to Med.

In the test run or emergency operation, the horizontal vane operates in VANE AUTO ( ) mode.

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.

Operation mode

Set temperature

Fan speed

Horizontal vane

The operation mode is indicated by the Operation

Indicator lamp as following

MSZ

EMERGENCY

COOL

EMERGENCY

HEAT

↓

↓

COOL

75°F(24°C) 75°F(24°C)

Med.

Auto

HEAT (MSZ)

MSY

Med.

Auto

EMERGENCY

COOL

STOP

↓

Lighted

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

STOP

8-11. 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.

8-12. 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 instrument.

15

9 TROUBLESHOOTING



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 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 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) When the P.C. board seems 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.

Press RESET button with a thin instrument, 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

: 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.

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

Operational procedure

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.

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. 1

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

Judgment of indoor/outdoor abnormality

Yes

(Blinks)

Before blinking, does upper lamp of

OPERATION INDICATOR lamp stay ON for 3 seconds?

Stays ON for 3 seconds (without beep):

The outdoor unit is abnormal.

No

Yes

No

(OFF)

1 Regardless of normal or abnormal condition, a short beep is emitted once the signal is received.

E.g.: MSZ type

Indoor unit is normal.

But the outdoor unit might be abnormal because there are some abnormalities that can not be recalled with this way.

Confi rm if outdoor unit is abnormal according to the detailed outdoor unit failure mode recall function.

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. 2

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.)

Make sure to check at least two consecutive blinking cycles. 3

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.

Repair the defective 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 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.

NOTE

: 1. Make sure to release the failure mode recall function once 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:

2.5-second OFF

Blinking at 0.5second interval 2.5-second OFF

Blinking at 0.5second interval

ON

OFF

Beeps

Repeated cycle

Beeps

Repeated cycle

Beeps

Repeated cycle

3.Blinking pattern when the outdoor unit is abnormal:

Blinking at 0.5-

2.5-second OFF 3-second ON second interval

ON

OFF

No beep

Repeated cycle

Beeps

2.5-second OFF 3-second ON

No beep

Repeated cycle

Blinking at 0.5second interval

Beeps

17

Repeated cycle

2. Indoor unit failure mode table

Upper lamp of OP-

ERATION INDICA-

TOR lamp

Not lighted

Abnormal point

(Failure mode)

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

Condition Remedy

Normal


—

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.

Serial signal

Indoor fan motor

Indoor control system

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

The rotational frequency feedback signal is not emitted for 12 seconds after the indoor fan motor is operated.

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 (9-7.2.).

Refer to the characteristics of the main indoor coil thermistor, the sub indoor coil thermistor (9-7.2.).

Refer to 9-6. "How to check miswiring and serial signal error".

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

Replace the indoor electronic control P.C. board.

NOTE

: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (9-4.).

18

9-3. INSTRUCTION OF TROUBLESHOOTING

Start

Indoor unit operates.

Outdoor unit does not operate.

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 fl ashing 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 normal operation in COOL or

HEAT mode.

Indoor unit operates, when

EMERGENCY

OPERATION switch is pressed.

Indoor unit does not operate, when

EMERGENCY

OPERATION switch is pressed.

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

If blinking of OPERATION INDI-

CATOR lamp cannot be checked, it can be checked with failure mode recall function.

Check room temperature thermistor.

Refer to 9-7.

"Test point diagram and voltage".

Refer to "How to check inverter/compressor".

Refer to

"Check of R.V. coil".

Refer to 9-6.

"Check of remote controller and indoor electronic control P.C. board".

1. Check indoor/outdoor 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".

Refer to outdoor unit service manual.

Upper lamp

Flash ON and OFF at

0.5-second intervals

Cause:

Indoor/Outdoor unit

• Miswiring or trouble of serial signal.

Upper lamp

2-time fl ash

Cause:

Indoor unit

• Trouble of room temperature

/ indoor coil thermistor.

Upper lamp

3-time fl ash

Cause:

Indoor unit

• Trouble of indoor fan motor.

Upper lamp

4-time fl ash

Cause:

Indoor unit

• Trouble of indoor unit control system.

Upper lamp

5-time fl ash

Cause:

Outdoor unit

• Outdoor power system abnormality.

Upper lamp

6-time fl ash

Cause:

Outdoor unit

• Trouble of thermistor in outdoor unit.

Upper lamp

7-time fl ash

Cause:

Outdoor unit

• Trouble of outdoor control system.

Upper lamp

14-time fl ash

Cause:

Outdoor unit

• Other abnormality

Refer to 9-6.

"How to check miswiring and serial signal error".

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

Refer to 9-6.

"Check of indoor fan motor".

Replace the indoor electronic control

P.C. board.

Refer to

"How to check inverter/compressor".

Refer to

"Check of outdoor thermistors".

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 function."

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 flashes.

OPERATION INDICATOR

Lighted

Blinking

Not lighted

Operation indicator lamp Symptom Condition Remedy

1

Miswiring or serial signal

Upper lamp fl ashes.

0.5-second ON

0.5-second OFF

2

3




2-time fl ash

2.5-second OFF

Indoor fan motor


3-time fl ash

2.5-second OFF

The serial signal from the outdoor unit is not received for 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.

•

•

•

Refer to 9-6. "How to check miswiring and serial signal error".

Refer to the characteristics of indoor coil thermistor, and the room temperature thermistor

(9-7.2).

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

4

Indoor control system


4-time fl ash

2.5-second OFF

5

Outdoor power system


5-time fl ash

2.5-second OFF

6

Outdoor thermistors


6-time fl ash

2.5-second OFF

7

Outdoor control system


7-time fl ash

2.5-second OFF

8

Other abnormality


14-time fl ash

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.

Indoor unit and outdoor unit do not operate.

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

•

•

Refer to "How to check of inverter/compressor".

Refer to outdoor unit service manual

Check the stop valve.

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 "Check of outdoor thermistor".


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

P.C. board.


Check the stop valve.

Confi rm 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 outdoor 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.

20

OPERATION INDICATOR

No.

Abnormal point

Operation indicator lamp

Upper lamp lights and lower lamp fl ashes.

1

MXZ type

Operation mode setting

2.5-second OFF

Symptom Condition Remedy

Outdoor unit operates but indoor unit does not operate.

The operation mode of the each indoor unit is differently set to COOL (includes DRY) and

HEAT at the same time, the operation mode of the indoor unit that has operated at fi rst has the priority.

• Unify the operation mode.


9-5. TROUBLE CRITERION OF MAIN PARTS



Part name Check method and criterion

Measure the resistance with a tester.

Room temperature thermistor (RT11)


(RT12, RT13)

Refer to 9-7. "Test point diagram and voltage", "2. Indoor electronic control

P.C. board", for the chart of thermistor.

Indoor fan motor (MF) Check 9-6.

Vane motor (MV)

Measure the resistance between the terminals with a tester.

(Temperature: 50 - 86°F (10 - 30°C))

Color of the lead wire

RED - BLK

Normal

223 - 268 Ω

Figure

BLK

BLK

RED

ROTOR

BLK BLK

21

9-6. TROUBLESHOOTING FLOW

A Check of indoor fan motor

The indoor fan motor error has occurred, and the indoor fan does not 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.

No

Pay enough 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 EMER-

GENCY OPERATION switch is pressed.

If more than 12 seconds passes, turn OFF the power supply and turn it

ON again, then measure the voltage.

<Indoor power P.C. board>

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

2. Measure the voltage between CN211 (+) and (–).

<Indoor electronic control P.C. board>

3. Measure the voltage between CN10A (+) and JPG(GND)(–).

If more than 12 seconds passes after EMERGENCY OPERATION switch is pressed, the voltage measured at 2. above goes 0 VDC although the indoor P.C. board is normal.

Is there 294/325 VDC between CN211 (+) and (–) ?

No

Yes

Replace the indoor power

P.C. board and the indoor terminal P.C. board.

Does the voltage between CN211

(+) and (–) on the power P.C. board rise to the range of 2 to 6 VDC within

12 seconds after EMERGENCY

OPERATION switch is pressed?

No

Yes

Yes

Does the voltage between CN10A

(+) and JPG (GND)(–) on the indoor electronic control P.C. board fall to

2 V or less within 12 seconds after

EMERGENCY OPERATION switch is pressed?

No

Replace the indoor fan motor.


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)

No

(Changed)

Measure the voltage CN10A (+) and JPG (GND)(–) on the indoor electronic control P.C board when the fan motor is rotaring.


Replace the indoor power P.C. board and the indoor terminal P.C. board.

Yes

(Unchanged)

Is it unchanged holding

0 or 15 VDC?

No

(Changed)


22

B Check of remote controller and indoor electronic control P.C. board

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

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

Is LCD display on the remote controller visible?

Yes

No

(Not clear)

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

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

Turn ON a radio to AM and press OP-

ERATE/STOP (ON/OFF) button 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.(1m) ?

No

No

Yes

Replace the remote controller.

•

•

Reinstall the unit away from lights.

Attach a fi lter on receiving part.

Replace the indoor electronic control

P.C. board. (Including the receiver)

23

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


Remove indoor fan motor connector CN211 from indoor power P.C. board and vane motor connector CN151 from the indoor electronic control P.C. board and turn ON the power supply.

Measure the resistance of indoor fan motor.

(Refer to 9-5.)

Short circuit:


Does the unit operate with the remote controller?

Does OPERATION INDICATOR lamp light up by pressing EMERGENCY OPERATION switch?

No

Yes


Check both “parts side” and “pattern side” of the indoor terminal P.C. board visually.

Measure the resistance of the vane motor coil.

(Refer to 9-5.)

Replace the varistor (NR11) and fuse (F11). 3

Yes

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

No

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

Is the fuse (F11) blown only?

Yes

No

Measure the resistance between

CN211 (+) and (-) of indoor fan motor connector. 1, 2

Is the resistance 1MΩ or more?

Yes

No

Short circuit:

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

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

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

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

3. Please replace the fuse after removing the indoor terminal P.C. board from the electrical box.

Replace the fuse (F11) and the indoor fan motor. 3

Replace the fuse (F11). 3

Measure the resistance of resistor

(R111) on the indoor power P.C. board.

Indoor electronic control

P.C. board JPG (GND)

Fuse

(F11)

CN10A

12 VDC

5 VDC

Indoor terminal

P.C. board

Varistor

(NR11)

Indoor power P.C. board

R111

CN211

Is the resistance of resistor (R111) approx. 4

Ω?

Yes

No

Replace the indoor power P.C. board, the indoor terminal P.C. board and the indoor fan motor.

Is the approx. 5 VDC between 5 V

(+) and JPG (GND) (-) of the indoor electronic control P.C. board?

Is there approx. 9 to 13 VDC between

12 V (+) and JPG (GND) (-) of the indoor electronic control P.C. board.

No

Yes


Are connector CN10A on the indoor electronic control P.C. board or lead wires disconnected?

No

Yes

Connect the connector or repair disconnection.


24

D How to check miswiring and serial signal error


Is there rated voltage in the power supply?

Yes


Yes

No

Check the power supply.

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

No

Check the wiring.

Press EMERGENCY OPERATION switch once.

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

Yes

Is serial signal error indicated 6 minutes later?

Yes

No

No

B

A


Check once more if the indoor/outdoor connecting wire is not miswiring.

Short-circuit outdoor terminal block S2 and S3. 1


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

No

Yes

Correct them.

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.

3. Be sure to check this within 3 minutes after turning ON.

After 3 minutes, LED blinks 6 times. Even when the inverter P.C. board or the outdoor electronic control P.C. board is normal, LED blinks 6 times after 3 minutes.

(Except for outdoor unit of multi system type)

Is the bus-bar voltage of the inverter P.C. board or the outdoor electronic control P.C. board normal? (Refer to "TEST POINT DIAGRAM AND VOLTAGE" in the outdoor service manual.)

Yes

No

Check of power supply.

(Refer to the outdoor service manual.)

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-second-ON quick blinking"? 3

Yes


Remove the short-circuit between outdoor terminal block S2 and S3.


No

(Lighted or not lighted)

Replace the inverter P.C. board or the outdoor electronic control P.C. board. 2

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

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

<Confi rmation of power voltage>

Yes

No

Check the wiring

If there are any error of the indoor/outdoor connecting wire: such as the damage of the wire, intermediate connection, and/or poor contact to the terminal block, replace the indoor/ outdoor connecting wire.

Is there amplitude of 10 to 20 VDC between indoor terminal block S2 and S3? <Confi rmation of serial signal>

Yes

A

•

•

•

Turn OFF inverter-controlled lighting equipment.

Turn OFF the power supply and then turn ON again.

Press EMERGENCY OPERATION switch.

Is there 2 VDC or less between CN10A (+) and JPG (GND)(-) on the indoor electronic control P.C. board?

Yes No

No

Is there 2 VDC or less between

CN10A (+) and JPG (GND)(-) on the indoor electronic control P.C. board?

No Yes

Is serial signal error indicated 6 minutes later?

B

Yes

No

•

•

Reinstall either the unit or the light away from each other.

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

Replace the indoor power

P.C. board and the indoor terminal P.C. board

Is there 2 VDC or less between

CN10A (+) and JPG (GND)(-) on the indoor electronic control P.C. board?


No

Yes

E Electromagnetic noise enters into TV sets or radios

Is the unit grounded?

Yes

No

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

Yes

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

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.

Are the antennas damaged?

Is the coaxial cable damaged?

Is there any poor contact in the antenna wiring?

No

Yes

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

No

Yes

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.

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.

26

9-7. Test point diagram and voltage

1. Indoor power P.C. board, Indoor terminal P.C. board

Indoor terminal P.C. board

Fuse (F11)( )

Varistor (NR11)

Indoor power P.C. board

Resistor (R111)

Indoor fan motor

(CN211)

294/325 VDC

(–) GND (highvoltage DC)

15 VDC

(+)3-6 VDC

(+)0-6 V

Terminal block

Connector to indoor electronic control P.C. board (CN20A)

5 VDC 12 VDC GND

Please replace the fuse after removing the indoor terminal P.C. board from the electrical box.

2. Indoor electronic control P.C. board

Timer short mode point JPG JPS

(Refer to 7-1.)

Room temperature thermistor RT11 (CN111)

Indoor coil thermistor RT12, RT13 (CN112)

GND

Vane motor (CN151)

Room temperature thermistor (RT11)

Indoor coil thermistor (RT12, RT13)

Emergency operation switch (E.O.SW) (SW1)

Connector to

Indoor power P.C. board

(CN10A)

12 VDC

5 VDC

Release of Auto restart function

Solder the Jumper wire to JR07

(Refer to 7-3.)

32 50 68 86 104 122 140

Temperature (°F)

27

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.

(2) The terminal with this connector has the

locking mechanism.

Sleeve

Locking lever

Slide the sleeve.

Pull the terminal while pushing the locking lever.

Hold the sleeve, and pull out the terminal slowly.

Connector



NOTE: Turn OFF power supply before disassembling.

OPERATING PROCEDURE PHOTOS

1. Removing the panel

(1) Remove the horizontal vanes.

(2) Remove the screw caps of the panel. Remove the screws of the panel.

(3) Unhook the lower part ( ) of the panel.

(4) Hold the lower part of both ends of the panel and pull it slightly toward you, and then remove the panel by pushing it upward.

Photo 1

Horizontal vanes Front panel

A

Screws of the panel

28

OPERATING PROCEDURE

2. Removing the indoor electronic control P.C. board and the room temperature thermistor

(1) Remove the panel (Refer to 1.) and the corner box.

(2) Remove the screw of the V.A. clamp and the V.A. clamp.

(3) Remove the screw of the electrical cover and the electrical cover.

(4) Remove the screw of conduit cover and the conduit cover.

(5) Remove the screw of conduit plate, the conduit plate and the indoor/outdoor connecting wire.

(6) Open the indoor electronic control P.C. board holder (to right side)

(7) Disconnect the following connectors:

<Indoor electronic control P.C. board>

CN112 (Indoor coil thermistor)

CN151 (Vane motor)

CN10A (To the indoor power P.C. board)

(8) Unhook the catches of the indoor electronic control P.C. board holder from the nozzle and the electrical box

(right side).

(9) Remove the room temperature thermistor from the hook of the indoor electronic control P.C. board holder.

(10) Open the back side of the indoor electronic control P.C. board holder, and remove the indoor electronic control P.C. board.

(11) Remove the room temperature thermistor from the indoor electronic control P.C. board.

Photo 2

Photo 3

PHOTOS

Ground wire

Catch of indoor electronic control P.C. board holder

Indoor terminal

P.C. board

Electrical box

Screw of the electrical cover

Indoor electronic control

P.C. board holder

Upper catch

Screw of the

V.A. clamp

Indoor power

P.C. board

3. Remove the indoor power P.C. board, the indoor terminal P.C. board, and the electrical box


(2) Remove the indoor/outdoor connecting wire (Refer to

2 (2)-(5).).

(3) Remove the ground wire connected to the indoor heat exchanger from the electrical box.

(4) Unhook first the lower, then the upper catches of the electrical box, and pull out the electrical box.

(5) Disconnect all the connectors on the indoor power P.C. board and unhook all lead wires.

(6) Remove the screw of terminal block on the indoor terminal P.C. board.

(7) Remove the indoor power P.C. board and the indoor terminal P.C. board.

Terminal block

Catch of indoor electronic control

P.C. board holder

Screw of the conduit cover

Lower catch

Screw of the conduit plate

29


4. Removing the nozzle assembly


(2) Remove the indoor/outdoor connecting wire (Refer to

2 (2)-(5).).

(3) Remove the indoor electronic control P.C. board holder.

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

Photo 4

PHOTOS

Screws of horizontal vane motor unit

5. Removing the horizontal vane motor

(1) Remove the nozzle assembly. (Refer to 4.)

(2) Remove the screws of 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 from the horizontal vane motor unit.

30


6. Removing the indoor fan motor, the indoor coil thermistor, and the line flow fan


(2) Remove the indoor electronic control P.C. board holder, the electrical box and the nozzle assembly.

(3) Remove the screws fixing the motor bed.

(4) Loosen the screw fixing the line flow fan.

(5) Remove the motor bed together with fan motor and motor band.

(6) Release the hooks of the motor band. Remove the motor band. Pull out the indoor fan motor.

(8) Remove the indoor coil thermistor from the heat exchanger.

( ) Install the indoor coil thermistor in its former position when assembling it. (Refer to Photo 8)

(9) Remove the screws fixing the left side of the heat exchanger.

(10) Lift the heat exchanger, and pull out the line flow fan to the lower-left.

Photo 5

Photo 6

PHOTOS

Screws of the line flow fan

Motor band

Photo 8

Indoor coil thermistor(sub)

RT13

Screws of the motor bed

Indoor coil thermistor(main)

RT12

Photo 7

Screws of the left side of the heat exchanger

31

TM

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

© Copyright 2009 MITSUBISHI ELECTRIC CO.,LTD

Distributed in Jul. 2009. No. OBH548 5

Made in Japan

New publication, effective Jul. 2009

Specifications subject to change without notice.

Mitsubishi Electronics MSZGE15NA Air Conditioner Service manual

SPLIT-TYPE AIR CONDITIONERS

INDOOR UNIT

No. OBH548

Models

1 TECHNICAL CHANGES

2 PART NAMES AND FUNCTIONS

3 SPECIFICATION

(1) POWER SUPPLY

(2) OPERATION

● 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 according to the size of the room and furniture arranged inside the room.

4 OUTLINES AND DIMENSIONS

5 WIRING DIAGRAM

6 REFRIGERANT SYSTEM DIAGRAM

7 SERVICE FUNCTIONS

•

•

•

•

•

8 MICROPROCESSOR CONTROL

•

9 TROUBLESHOOTING

10 DISASSEMBLY INSTRUCTIONS

<"Terminal with locking mechanism" Detaching points>

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