Mitsubishi Electric MU-A18ND-S1, MU-A18ND-S2, MU-A24ND-S1, MU-A30ND-S1, MU-A24ND-S2 Service Manual

SPLIT-TYPE AIR CONDITIONERS

OUTDOOR UNIT

SERVICE MANUAL

Models

Revision E:

• SPECIFICATION has been modified.

Please void OB405 REVISED EDITION-D.

No. OB405

REVISED EDITION-E

MU-A18ND­MU-A18ND­MU-A24ND­MU-A24ND­MU-A30ND­MU-A30ND-

MU-A18ND

S1

S2

S1

S2

S1

S2

Indoor unit service manual

MS-A• ND Series (OB404)

CONTENTS

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

2. PART NAMES AND FUNCTIONS······················3

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

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

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

6. REFRIGERANT SYSTEM DIAGRAM ················8

7. PERFORMANCE CURVES······························10

8. TROUBLESHOOTING······································12

9. DISASSEMBLY INSTRUCTIONS ····················21

10. PARTS LIST······················································27

11. RoHS PARTS LIST···········································30

NOTE:

• This service manual describes technical data of the outdoor units.

• RoHS compliant products have <G> mark on the spec name plate.
For servicing of RoHS compliant products, refer to the RoHS Parts List.

TM

Compressor: NH30VCD ➞ RH247NRAT
Compressor: RH277NHD

➞

RH247NRAT

Electricity receiving unit: Indoor unit ➞ Outdoor unit
Gas pipe diameter: [15.88

➞

[12.7

Rated voltage: 220V ➞ 220-230V

Frequency
New Model
Old Model

MU-18TN -

S1

w

: change

MU-A18ND -

S1

60Hz

MU-18SN -

C1

w

w
w
w

w
w
w
w

Outdoor unit:Unit size:W850mmoH605mmoD290mm ➞ W840mmoH850mmoD330mm
Outdoor unit:Unit size:W870mmoH850mmoD295mm ➞ W840mmoH850mmoD330mm
Compressor: NH38NBD

➞

PH33NPBT

Electricity receiving unit: Indoor unit ➞ Outdoor unit
Liquid refrigerant pipe diameter: [9.52

➞

[6.35

Rated voltage: 220V ➞ 220-230V

Frequency
New Model
Old Model

MU-24TN -

S1

MU-A24ND -

S1

60Hz

MU-24SN -

C2

w
w
w
w
w

w

w
w
w
w

Revision A:

• Check of solenoid valve coil has been partially modified.

Revision B:

• MU-A24ND - has been added.

S2

Revision C:

• MU-A18ND - has been added.

S2

Revision D:

• MU-A30ND - has been added.

S2

Revision E:

• SPECIFICATION has been modified.

TECHNICAL CHANGES1

MU-A30ND -

S1

New model

MU-A18ND - ➔ MU-A18ND -

• Valve cover has been added.

S2S1

MU-A24ND - ➔ MU-A24ND -

• Compressor contactor has been added.

S2S1

MU-A30ND - ➔ MU-A30ND -

• Solenoid valve and solenoid valve coil have been changed.

S2S1

2

2

2

Outdoor model

Function

Power supply

Capacity
Dehumidification
Air flow (High/Low)
Power outlet
Running current (Total)
Power input (Total)
Power factor (Total)
Starting current (Total)
Compressor motor current
Fan motor current

Model
Output
Winding
resistance (at 20:)
Model
Winding
resistance (at 20:)
Dimensions WOHOD
Weight
Sound level (High/Low)
Fan speed (High/Low)
Fan speed regulator
Refrigerant filling
capacity (R22)
Refrigeration oil (Model)

kW

R/h

K /h

A

A
W
%

A

A

A

W

"

"

mm

kg

dB

rpm

kg

cc

Cooling

Single phase

220-230V, 60Hz

2,880

58

0.66

PH33NPBT

1,500
C-R 0.84
C-S 2.09

RA6N75-BA

WHT-BLK 65.0

BLK-RED 65.4

67
54

790

1

2.20

900 (MS32N1)

Electrical

data

Compressor

Fan

motor

Special

remarks

Coefficient of performance (C.O.P) (Total)

Capacity

2,480

15

40

0.55

RH247NRAT

1,200
C-R 1.43
C-S 2.06

RA6V60-MA

WHT-BLK 71.2

BLK-RED 89.3

850o605o290

44
54

945

1

1.40

520 (MS56)

ISO 5151

5.10

2.3

8.52
1,800
96-92

7.60

2.83

SSA 385

5.9

2.7

20( )

12.42
2,650

97

11.39

2.23

ISO 5151

6.6

3.2

15( )

10.54
2,250

97-93

9.50

2.93

SSA 385

6.6

3.2

17.52
3,700

96

16.49

1.78

ISO 5151

8.1

4.3

14.25
3,010
96-92

13.22

2.69

SSA 385

4.40

1.8

9.94

2,100

96

9.02

2.10

MU-A24ND MU-A30ND

2,880/1,380

25

78

0.66

NH44NAVT

2,000
C-R 0.62
C-S 1.40

RA6N75-AA

WHT-BLK 64.2 BLK-YLW 32.9

YLW-RED 32.7

76

55/51

790/490

2

2.40

1,300 (MS32N1)

840o850o330

S2

S1

MU-A18ND

PART NAMES AND FUNCTIONS

OUTDOOR UNIT

MU-A18ND

Air inlet

Piping

Drain hose

Air outlet

MU-A24ND MU-A30ND

Air inlet

(back and side)

3

NOTE: Test conditions are based on ISO 5151 / SSA 385

SPECIFICATION

Cooling : Indoor DB27°C WB19°C / DB29°C WB19°C

Indoor-Outdoor piping length: 5 / 7.5 m

Outdoor DB35°C WB24°C / DB46°C WB24°C

Drain outlet

3

Air outlet

OUTLINES AND DIMENSIONS4

100mm or more

350mm or more

100mm or more

100mm or more

REQUIRED SPACE

500mm or more

100

157

161

Liquid refrigerant

pipe joint

Refrigerant pipe

(Flared) [6.35

Service panel

183

500

850

30

50

20350

35

248

605

292

20

310

290

345

Air in

Air out

Drainage
3holes [33

50

90

Air in

Drainage
hole [16.2

355

74

30-

35

-

Gas refrigerant
pipe joint
Refrigerant pipe
(flared) [12.7

MU-A18ND -

S1

OUTDOOR UNIT

Unit: mm

MU-A18ND -

S2

355

Drainage
hole [16.2

Air in

20350

35

248

90

Air in

Drainage
3holes [33

Air out

605

292

20

50

183

500

850

50

74
81

290

157

30

100

REQUIRED SPACE

345

310

4

100mm or more

Service panel

Liquid refrigerant

Refrigerant pipe

30-

161

Gas refrigerant
pipe joint
Refrigerant pipe
(flared) [12.7

100mm or more

500mm or more

pipe joint

(Flared) [6.35

-

35

100mm or more

350mm or more

MU-A24ND MU-A30ND

OUTDOOR UNIT

299

66

51

34

330

850

430

515

121

500

840

40

REQUIRED SPACE

100mm or more

360

Open as a rule

80

500mm or more if the back,
both sides and top are open

155

90

198

Open as a rule
500mm or more if
the front and both
sides are open

100mm or more
200mm or more if
there are obstacles
to both sides

350mm or more

Service panel

Liquid refrigerant
pipe joint
Refrigerant pipe
(flared) [6.35(MU-A24ND)

[9.52(MU-A30ND)

30-

35-

Gas refrigerant
pipe joint
Refrigerant pipe
(flared) [15.88

5

5

R

S

2

N

L

TB2

RED

ORN

BLU

BRN

WHT

GRN/YLW

C2

RED

MF

BLACK

4

WHITE

ORANGE

321

BLK

L

N

TB1

BRN

BLU

C1

RED

C

MC

BLU

220-230V~

CONNECTING

TO INDOOR UNIT

POWER SUPPLY

220-230V ~/N 60Hz

F

BLU

DSAR

220-230V~

WHT

1.About the indoor side electric wiring refer to the indoor unit electric wiring diagram for servicing.

2.Use copper conductors only (For field wiring).

3.Symbols below indicate.

: Connector

: Terminal block,

NOTES:

SYMBOL

C1
C2

DSAR

SYMBOL

F
MC
MF

SYMBOL

TB1
TB2

NAME

NAME NAME
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER

FUSE (3.15A)
COMPRESSOR(INNER PROTECTOR)
OUTDOOR FAN MOTOR(INNER PROTECTOR)

TERMINAL BLOCK
TERMINAL BLOCK

WIRING DIAGRAM

MU-A18ND

OUTDOOR UNIT

MU-A24ND-

S1

OUTDOOR UNIT

POWER SUPPLY

~/N 220-230V 60Hz

220-230V~

220-230V~

TO INDOOR UNIT CONNECTING

SYMBOL

F
MC
MF

SYMBOL

COMPRESSOR CAPACITOR

C1
C2

DSAR

NOTES:

OUTDOOR FAN CAPACITOR
SURGE ABSORBER

1.Use copper conductors only (For field wiring).

2.Since the indoor and outdoor unit connecting wires have polarity, connect them according to the numbers (2,N,L).

3.Symbols below indicate.
: Terminal block, : Connector

NAME

BLU

F

GRN/YLW

BLU

BRN

BLU

C1

BLU
WHT

ORN

C2

RED

4
3
2
1

RED

BLK

BLK
WHT
ORN

RED

S

C

MC

R

MF

WHT

N

N

L

2

TB1

PE

TB2

L

BRN

DSAR

FUSE(3.15A)
COMPRESSOR(INNER PROTECTOR)
OUTDOOR FAN MOTOR(INNER PROTECTOR)

NAME NAME

SYMBOL

TB1
TB2

TERMINAL BLOCK
TERMINAL BLOCK

6

SYMBOL

C1
C2

DSAR

F61

LEV

MC

MF

SYMBOL

NR61
RT62
RT63
SR61
SR62

TB1
TB2

SYMBOL

T61
X52
X63

21S2

52C

NAME

DEICER
P.C. BOARD

2

N

3

N

L

12V

WHT

BLU

RED

BLU

WHT

WHT

T61

YLW

BLK

WHT

RED

BLU

TB2

5

CN730

YLW

BLK

WHT

1

52C

2

RED

C2

ORN

A1 A2BLU

52C

DSAR

WHT

C1

BLK

S

C

R

MC

BLU

NR61

3

1

TB1

GRN/YLW

BRN

SR62

SR61

F61

TAB52

COM

NO

X52

CN711

CN724

CN662

6

MF

RT62 RT63

123

21

ORN

RED

3456

LEV

COM

NO

X63

3

2

1

CN722

X52

PE

220-230V~

TO INDOOR UNIT CONNECTING

POWER SUPPLY

~/N 220-230V 60Hz

X63

21S2

NAME NAME
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER
FUSE(3.15A)
EXPANSION VALVE COIL
COMPRESSOR(INNER PROTECTOR)
OUTDOOR FAN MOTOR(INNER PROTECTOR)

VARISTOR
DISCHARGE TEMPERATURE THERMISTOR
AMBIENT TEMPERATURE THERMISTOR
SOLID STATE RELAY
SOLID STATE RELAY
TERMINAL BLOCK
TERMINAL BLOCK

TRANSFORMER
CONTACTOR
SOLENOID VALVE COIL RELAY
SOLENOID VALVE COIL
COMPRESSOR CONTACTOR

NOTES:

1.Use copper conductors only (For field wiring).

2.Since the indoor and outdoor unit connecting wires have polarity, connect them according to the numbers (3,N,2).

3.Symbols below indicate.
: Terminal block, : Connector

MU-A24ND-

OUTDOOR UNIT

S2

TB1

L

N

PE

POWER SUPPLY

~/N 220-230V 60Hz

GRN/YLW

TB2

2

220-230V~

220-230V~

TO INDOOR UNIT CONNECTING

SYMBOL

COMPRESSOR CAPACITOR

C1

OUTDOOR FAN CAPACITOR

C2

DSAR

NOTES:

SURGE ABSORBER

1.Use copper conductors only (For field wiring).

2.Since the indoor and outdoor unit connecting wires have polarity, connect them according to the numbers (2,N,L).

3.Symbols below indicate.
: Terminal block, : Connector

NAME

N

L

SYMBOL

F
MC
MF

BRN

4

C1

C2

BLU
WHT
ORN
RED

1

RED

BLK

4

3

2

1

52C

BLK
WHT
ORN

RED

BLU

BRN

F

BLU BLU

DSAR

BRN

BLU

WHT

56

52C

NAME NAME
FUSE(3.15A)
COMPRESSOR(INNER PROTECTOR)
OUTDOOR FAN MOTOR(INNER PROTECTOR)

S

MC

R

MF

SYMBOL

MU-A30ND

C

TB1
TB2
52C

WHT

TERMINAL BLOCK
TERMINAL BLOCK
COMPRESSOR CONTACTOR

OUTDOOR UNIT

7

REFRIGERANT SYSTEM DIAGRAM6

Refrigerant pipe
{6.35

(with heat insulator)

Refrigerant pipe
{12.7

(with heat insulator)

Compressor

Outdoor heat
exchanger

Flared
connection

Strainer

#100

Stop Valve

(with service port)

Stop Valve

Capillary tube
[3.0 x [1.8 x 400

MU-A18ND

OUTDOOR UNIT

Unit : mm

MU-A24ND

OUTDOOR UNIT

Refrigerant pipe
[15.88
(with heat insulator)

Flared connection

Flared connection

Refrigerant pipe
[6.35
(with heat insulator)

Stop valve
(with service port)

Accumulator

Stop valve

Capillary tube
[3.0 x [2.0 x 550

Compressor

Strainer

#100

Refrigerant flow in cooling

Outdoor
heat
exchanger

8

Outdoor
heat
exchanger

Flared connection

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve

Stop valve
(with service port)

Capillary tube
[3.6 x [2.4 x 50

Refrigerant flow in cooling

Compressor

Refrigerant pipe
[15.88
(with heat insulator)

Refrigerant pipe
[9.52
(with heat insulator)

Strainer
#100

Strainer
#100

Accumulator

Ambient
temperature
thermistor
RT63

Capillary tube
[4.0 x [2.4 x 200

Capillary tube
[4.0 x [2.4 x 100

LEV
(Expansion valve)

Solenoid valve

[4.2 x [3.0 x 50

MU-A30ND

Model

Piping size O.D : mm

Refrigerant piping : m

Max. length AMax. Height

difference

B

Gas

Liquid

30

MU-A18ND

MU-A24ND

MU-A30ND

{15.88

{6.35

{9.52

15

{12.7

Indoor
unit

Outdoor unit

Max. length

A

Max. Height

difference

B

Model

Outdoor unit precharged

Refrigerant piping length (one way)

15m

120

20m

195

30m

345

7m

0

10m

45

2,200

1,400

2,400

MU-A18ND

MU-A30ND

MU-A24ND

OUTDOOR UNIT

Unit : mm

MAX.REFRIGERANT PIPING LENGTH and MAX.HEIGHT DIFFERENCE

ADDITIONAL REFRIGERANT CHARGE(R22 : g)

NOTE : Calculation : Xg=15g/m ✕ (Refrigerant piping length (m)-7)

9

PERFORMANCE CURVES7

Indoor intake air WB temperature (:)

Outdoor intake air DB temperature (:)

Indoor intake air WB temperature (:)

Outdoor intake air DB temperature (:)

MS-A30ND

MU-A30ND

MS-A24ND

MU-A24ND

MS-A18ND

MU-A18ND

9.9

9.1

8.3

7.5

6.7

5.9

12.5

11.4

10.3

9.3

8.3

7.3

18.6

16.8

15.1

13.5

12.0

10.5

Wet and dry-bulb
thermometers

Wet-and dry-bulb
thermometers

MU-A18ND MU-A24ND MU-A30ND

The standard data contained in these specifications apply only to the operation of the air conditioner under normal conditions.
Since operating conditions vary according to the areas where these units are installed. The following information has been
provided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.

(1) GUARANTEED VOLTAGE

198 ~ 253V, 60Hz

(2) AIR FLOW

Air flow should be set at MAX.

(3) MAIN READINGS

(1) Indoor intake air wet-bulb temperature : °CWB
(2) Indoor outlet air wet-bulb temperature : °CWB
(3) Outdoor intake air dry-bulb temperature : °CDB
(4) Total input: W
Indoor air wet/dry-bulb temperature difference on the left side of the following chart shows the difference between the
indoor intake air wet/dry-bulb temperature and the indoor outlet air wet/dry-bulb temperature for your reference at service.

How to measure the indoor air wet/dry-bulb temperature difference

1. Attach at least 2 sets of wet and-dry-bulb thermometers to the indoor air intake as shown in the figure, and at least 2 sets
of wet-and-dry-bulb thermometers to the indoor air outlet. The thermometers must be attached to the position where air
speed is high.

2. Attach at least 2 sets of wet and dry-bulb thermometers to the outdoor air intake.
Cover the thermometers to prevent direct rays of the sun.

3. Check that the air filter is cleaned.

4. Open windows and doors of the room.

5. Press the EMERGENCY OPERATION switch once to start the EMERGENCY COOL MODE.

6. When system stabilizes after more than 15 minutes, measure temperature and take an average temperature.

7. 10 minutes later, measure temperature again and check that the temperature does not change.

INDOOR UNIT OUTDOOR UNIT

10

0.8

0.7

0.6

0.5

0.4

0.3
15

18

20
50

60

70

25

30

32

8.0

7.0

6.0

5.0

4.0

3.0

35(:)
(%)

OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT

18

50

60

70

32

35(:)

(%)

15 20 25 30

4.0

5.0

6.0

7.0

8.0

8.0

7.0

6.0

5.0

4.0

3.0
18

50 70

32

(:)

(%)

15 20 25 30 35

0.3

0.4

0.5

0.6

0.7

0.8

COOL operation

① Both indoor and outdoor units are under the same temperature/humidity condition.

Dry-bulb temperature (:)

Relative humidity (%)

20 50

25 60

30 70

➁ Air flow should be set at MAX.

3 The unit of pressure has been changed to MPa on the international system of units(SI unit system).

The conversion factor is : 1(MPa [Gauge]) =10.2(kgf/ff[Gauge])

(kgf/F [Gauge])(MPa [Gauge])

Outdoor low pressure

MU-A18ND

Outdoor unit current (A)

MU-A18ND

Ambient temperature (˚C)/Ambient humidity (%) Ambient temperature (˚C)/Ambient humidity (%)

(kgf/F [Gauge])(MPa [Gauge])

Outdoor low pressure

Ambient temperature (˚C)/Ambient humidity (%) Ambient temperature (˚C)/Ambient humidity (%)

MU-A24ND

10.0

9.0

8.0

7.0

Outdoor unit current (A)

6.0

5.0

11

MU-A24ND

18

15

20
50

25
60

32

30

35(:)

70

(%)

15 18 20

50

2560 30 32

70

35(:)
(%)

0.2

0.3

0.4

0.5

0.6

2.0

3.0

4.0

5.0

6.0

15 18 20

50

2560 30 327035(:)

(%)

9.0

10.0

11. 0

12.0

13.0

14.0

15.0

(kgf/F[Gauge])(MPa[Gauge])

Lead wiring

Housing point

MU-A30ND

MU-A30ND

Outdoor low pressure

Ambient temperature (˚C)/Ambient humidity (%) Ambient temperature (˚C)/Ambient humidity (%)

TROUBLESHOOTING8

MU-A18ND MU-A24ND MU-A30ND

8-1. Cautions on troubleshooting

1. Before troubleshooting, check the following:

1) Check the power supply voltage.

2) Check the indoor/outdoor connecting wire for mis-wiring.

2. Take care the following during servicing.

1) Before servicing the air conditioner, be sure to turn off the main 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.

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 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 discolouration.

4) When troubleshooting, refer to 8-2.

Outdoor unit current(A)

12

8-2. Instruction of troubleshooting

Start

Indoor unit
operates.
Outdoor unit
dose not
operate.

Outdoor unit
operates in
only Test Run
operation.

w

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

MU-A30ND

Outdoor unit
dose not
operate
even in
Test Run
operation.

Refer to
8-4.

A

"Check of
outdoor unit".

MU-A24ND ­MU-A30ND

Outdoor unit
dose not
stop even
if indoor unit

w

stop.

Indoor unit
operates.
Outdoor unit
dose not operate
normally.

S2

Refer to
8-4.

B

"Check of
outdoor unit".

MU-A30ND

Outdoor unit
repeats start
and stop.

Refer to
8-4.

F

"Check of
solenoid
valve coil".

Indoor unit
dose not receive
the signal from
remote controller.

Indoor unit
operates, when
EMERGENCY
OPERATION
switch is pressed.

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

OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.

Indoor unit
dose not operate,
when
EMERGENCY
OPERATION
switch is pressed.

1. Check indoor /
outdoor
connecting wire.

2. Check of
outdoor fuse.
(MU-A18/A24ND)

3. Refer to
"Check of indoor
electronic control
P.C. board".

MS-A30ND

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

• Mis-wiring

Refer to
8-4. C
"How to
check
mis-wiring
(When
outdoor unit
dose not
work)" .

2-time flash
Cause:
Indoor unit

• Trouble of
room temp­ erature/
indoor coil
thermistor

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

3-time flash
Cause:
Indoor unit

• Trouble of
indoor fan
motor

Refer to
"Check of
indoor fan
motor".

4-time flash
Cause:
Indoor unit

• Trouble of
indoor
control
system

Replace the
indoor
electronic
control
P.C. board.

MU-A30ND

6-time flash
Cause:
Outdoor unit

• Trouble of
thermistor
in outdoor
unit

Refer to
8-4.

E

"Check of
outdoor
thermistor".

MU-A30ND

7-time flash
Cause:
Outdoor unit

• Trouble of
outdoor
control
system

Replace the
deicer
P.C. board.

MU-A30ND

10-time flash
Cause:
Outdoor unit

• Trouble of
low discharge
temperature
protection

Refer to indoor unit service manual.

w

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

13

Refer to
8-4.

D

"Check of
LEV".

8-3. Trouble criterion of main parts

Part name FigureCheck method and criterion

Measure the resistance between the terminals with a tester.
(Coil wiring temperature -10°C ~ 40°C)

Compressor
(MC)

INNER
PROTECTOR
155i 5: OPEN
90i10: CLOSE

Normal

MU-A18ND

Color of

lead wire

C – R

C – S

1.26 " ~ 1.55 "

1.81 " ~ 2.23 "

MU-A24ND

0.74 " ~ 0.91 "

1.84 " ~ 2.26 "

MU-A30ND

0.54 " ~ 0.67 "

1.23 " ~ 1.52 "

LEV(Expansion valve)

MU-A30ND

Color of lead wire

WHT – RED
RED – ORN

YLW – BRN

BRN – BLU

Normal

37.4 " ~ 53.9 "

Measure the resistance with a tester.
(Part temperature : 0˚C ~ 40˚C)

Measure the resistance with a tester.
(Part temperature –10˚C ~ 40˚C)

Discharge temperature
thermistor(RT62)

MU-A30ND

Ambient temperature
thermistor(RT63)

MU-A30ND

Measure the resistance with a tester.
Before measurement, hold the thermistor with your hands to warm it up.
(Part temperature 0˚C ~ 40˚C)

Refer to 8-5. "Test point diagram and voltage", "Outdoor deicer P.C. board",
the chart of thermistor.

Refer to 8-5. "Test point diagram and voltage", "Outdoor deicer P.C. board",
the chart of thermistor.

MU-A18ND MU-A24ND MU-A30ND

Measure the resistance between the terminals with a tester.
(Coil wiring temperature -10°C ~ 40°C)

Color of

lead wire

WHT – BLK

BLK – RED
BLK – YLW

YLW – RED

63 " ~ 77 "

79 " ~ 96 "

–
–

57 " ~ 70 "
58 " ~ 71 "

–
–

57 " ~ 69 "

–

29 " ~ 35 "
29 " ~ 35 "

Normal

Outdoor fan motor
(MF)

INNER
PROTECTOR
135i 5: OPEN
87i15: CLOSE

Measure the resistance with a tester.
(Part temperature : –10˚C ~ 40˚C)

Solenoid valve coil
(21S2)

MU-A30ND

Normal

MU-A30ND -

S1

1,738 " ~ 2,125 "

MU-A30ND -

S2

1,230 " ~ 1,330 "

WHT

BLK YLW

RED

ORN

MAIN

AUX.

MAIN

AUX.

WHTBLK RED ORN

MU-A18/A24ND

MU-A30ND

RED

WHT

BLK

P

C

SR

:INNER PROTECTOR

P

LEV

WHT

6

RED1

ORN4

YLW5

BRN2

BLU3

MU-A18ND MU-A24ND MU-A30ND

14

8-4. Troubleshooting flow

Compressor and / or outdoor fan motor dose not operate.

Check of outdoor unit

A

Turn ON the power supply.

MU-A30ND

Is there 220-230V AC to

L-N on the

between
outdoor terminal block?

Yes

Check the deicer P.C.
board. Refer to 8-5.
Is there 5V DC?

Press the EMERGENCY
OPERATION switch.
3-minute time delay works.
Test run operation
operates for 30 minutes.

Is there 220-230V AC
between A1 and A2 on the
compressor contactor (52C)?

Is there 220-230V AC between
2 on the compressor
contactor(52C) and N on
the outdoor terminal block?

No

Check the outdoor power supply
and connection of wiring.

Compressor
dose not operate.

Yes

Yes

Yes

Outdoor fan motor
dose not operate.

No

Is there 220-230V AC CN730
on the deicer P.C. board?

Replace the
deicer P.C. board.

No

No

Replace the
deicer P.C. board.

Replace the compressor
contactor(52C).

Check the compressor.

Yes

No

Make the connection
of wiring correct.

Check the deicer P.C.
board. Refer to 8-5.
Is there 5V DC?

Press the EMERGENCY
OPERATION switch.
3-minute time delay works.
Test run operation
operates for 30 minutes.

Is there 220-230V AC
CN711 1-3 or 2-3 on
the deicer P.C. board?

Check the outdoor fan
motor. Refer to 8-3.

Yes

Yes

No

Is there 220V AC CN730
on the deicer P.C. board?

Replace the
deicer P.C. board.

No

Replace the
deicer P.C. board.

15

Yes

No

Make the connection
of wiring correct.

Compressor and / or outdoor fan motor dose not stop.

After 30 seconds,
did compressor stop?

No

Yes

Replace the
deicer P.C. board.

Yes

1 Turn OFF the power supply.
2 After 30 seconds, turn ON the power supply again.
3 Operate the unit in COOL mode by pressing the

EMERGENCY OPERATION switch.
4 Operate the unit for 1 minute or more and stop it by
pressing the EMERGENCY OPERATION switch again.

Ok

No

After 30 seconds,
did outdoor fan stop?

Replace the
deicer P.C. board.

Yes

Ok

No

Is there 220-230V AC between
2 on the compressor
contactor(52C) and N
on the outdoor terminal
block?

Yes

Replace the compressor
contactor(52C).

No

Make the connection
of wiring correct.

Is there 220-230V AC
between A1 and A2 on the
compressor contactor (52C)?

1 Turn OFF the power supply.
2 After 30 seconds, turn ON the power supply again.
3 Operate the unit in COOL mode by pressing the

EMERGENCY OPERATION switch.
4 Operate the unit for 1 minute or more and stop it by
pressing the EMERGENCY OPERATION switch again.

After 30 seconds, does
compressor stop ?

Yes

No

Is there 220-230V AC
between 3-N on the outdoor
terminal block?

Replace the indoor
electronic control P.C.
board.

No

Make the connection
of wiring correct.

Is there 220-230V AC
between 3-N on the indoor
terminal block?

Yes

Reconnect the continuity
of indoor and outdoor
unit connection.

Is there 220-230V AC
between 1 on the compressor
contactor(52C) and N on the
outdoor terminal block?

No

Yes

Reconnect the continuity
of indoor and outdoor
unit connection.

Yes

Replace the compressor
contactor(52C).

OK

No

After 30 seconds, does
outdoor fan motor stop ?

Yes

Is there 220-230V AC
between 3-N on the indoor
terminal block?

No

OK

Replace the indoor
electronic control P.C.
board.

Yes

No

Is there 220-230V AC
between 3-N on the outdoor
terminal block?

Make the connection
of wiring correct.

Is there 220-230V AC
between 3 on the compressor
contactor(52C) and N on the
outdoor terminal block?

Yes

Replace the compressor
contactor(52C).

No

Yes

No

B

Check of outdoor unit

MU-A24ND -

S2

MU-A30ND

16

When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.
Outdoor unit dose not operate.

How to check mis-wiring

C

• Turn ON the power supply.

• Press EMERGENCY OPERATION switch once.

When the unit has mis-wiring, in 3 minutes,
OPERATION INDICATOR lamp on indoor unit
flash on and off at 0.5 second intervals. w

MU-A30ND

Start

w Short circuit of JPG and JPS on the indoor electronic control
P.C. board enables self -check to be displayed in 3 seconds.

Make them sure.

1. Turn OFF the power supply and disconnect only terminal
block 3 of indoor/ outdoor connecting wire on indoor side.

2. Short-circuit terminal block N-3 by lead wire.

3. Turn ON the power supply and press EMERGENCY OPERATION switch once.

Yes

Is this mis-wiring, poor contact,
or wire disconnection?

No

Is there 1V DC detected between both ends
of PS132 on the indoor electronic control P.C.
board ?
However, the stylus of a tester would be
between 0 and 20V.

• Turn OFF the power supply.

• Disconnect the lead wire that terminal

block N-3 is short-circuited.

Connect ON indoor/outdoor connecting wire.

•

Turn ON the power supply.

Is there 220-230V AC between L-N
on the outdoor terminal block?

Is there 5V DC between J101 + -J401 - ?
(Refer to 8-5.)

When EMERGENCY OPERATION
is operated, is there 10V DC between both
ends of R601 on the deicer P.C. board?
(Refer to 8-5.)
However the stylus of a tester would be
between 5 ~10V.

Replace the deicer P.C. board.

Yes

Yes

Yes

Yes

No

No

No

No

Replace the indoor electronic
control P.C. board.

Check the outdoor power supply
and connection of wiring.

Replace the deicer P.C. board.

Make the wiring between CN730
on the deicer P.C. board and
outdoor terminal block correct.
(Refer to 8-5.)

Refer to indoor unit
service manual.

17

When OPERATION INDICATOR lamp flashes 10-time.
Cooling mode dose not operate.

Check of LEV (Expansion valve)

D

MU-A30ND

Remote controller model : KP0B

Turn ON the power supply.
1 While pressing OPERATION
SELECT button on the remote
controller, press RESET button.
2 Release RESET button to confirm
if all LCD in operation display
section of the remote controller is
displayed.
3 Release OPERATION SELECT
button.

With remote controller set toward the indoor unit, press
OPERATE/ STOP(ON/ OFF) button and confirm one beep tone.

LEV operates in full-opening
direction.

Do you hear the expansion valve
"click, click·······"?
Do you feel the expansion valve
vibrate on touching it?

Remote controller model : KM04B

Turn ON the power supply.
1 While pressing both OPERATION
SELECT button and TOO COOL
button on the remote controller at the
same time, press RESET button.
2 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.

Yes

Ok

No

Is LEV properly fixed to
the expansion valve?

No

Properly fix LEV coil to
the expansion valve.

Yes

Does the resistance of LEV
have the characteristics
on 8-3?

Yes

Replace the
deicer P.C. board.

No

Replace the LEV.

KP0B

CLOCK

AMPM

AMPM

KM04B

˚C

NOTE : After check of LEV, do the undermentioned operation.

1. Turn OFF the power supply and turn ON again.

2. Press the RESET button on the remote controller.

˚C

CLOCK

AMPM

AMPM

When OPERATION INDICATOR lamp flashes 6-time.
Thermistors in the outdoor unit are abnormal.

Check of outdoor thermistor

E

MU-A30ND

w Disconnect the connectors CN662 from the deicer P.C. board. (Check the characteristics of each thermistor.)

Discharge temperature
thermistor(RT62)

Measure

Turn OFF the
power supply.

resistance
between CN 662
1 and 2.

Ambient temperature
thermistor(RT63)

Measure
resistance
between CN 662
3 and 4.

Does the
resistances of
thermistor have
the characteristics
on 8-5.?

No

Replace the
thermistor.

Connect CN662.
Turn ON the power

Yes

supply and press
the EMERGENCY
OPERATION
switch.

W Defective contact of the connector is considered.

Replace the deicer P.C.

board.

Does the unit operate
10 minutes or more?

Ok W

No

Yes

18

F

ON

OFF

46.2:49.2:

Ambient temperature thermistor
RT63 temperature

Solenoid valve

Check of solenoid valve coil

Outdoor unit repeats start and stop.

Turn ON the power supply.
Operate the unit in COOL mode by pressing
the EMERGENCY OPERATION switch.

After 1minute or more has passed since the
compressor started, operate the solenoid valve coil
by heating or cooling the ambient temperature
thermistor.
(Refer to Solenoid valve control.)

MU-A30ND

Do you hear "click" from the
solenoid valve coil

?

Yes

Ok

No

Turn ON the
solenoid valve coil.
(Refer to Solenoid
valve control.)

Is there 220-230V AC
CN722 on the deicer
P.C. board?

Check of the
solenoid valve coil.
(Refer to 8-3.)

Yes

No

Replace the
deicer P.C. board.

Solenoid valve control

The solenoid valve opens when the ambient temperature thermistor RT63 temperature reaches 49.2: or more after 1
minute has passed since the compressor turned on. Then, the solenoid valve maintains to open until the ambient tem-

perature thermistor RT63 temperature falls 46.2: or less.

NOTE: The solenoid valve remains to close when the ambient temperature thermistor RT63 temperature is 49.2: or

less after 1 minute has passed since the compressor turned on.

19

8-5. Test point diagram and voltage

Temperature(:)

Discharge temperature thermistor(RT62)

Resistance(k")

0 102030405060708090100110120

0

100

200

300

400

500

600

700

800

900

Ambient temperature thermistor (RT63)

-20 -10 0 10 20 30 40

0

10

20

30

40

50

60

70

80

90

100

Temperature(:)

Resistance(k")

MU-A30ND

Outdoor deicer P.C. board

CN662 1-2
Discharge temperature
thermistor (RT62)

(Refer to 8-4.E.)

J101

+

}

5V

DC

J401

(Refer to
8-4. C.)

CN662 3-4
Ambient tempera­ture thermistor
(RT63)

(Refer to 8-4.E.)

20

LEV
connector
(CN724)

Fan motor
connector
(CN711)

+

}

R601
10V DC

Varistor
(NR62)

(Refer to
8-4. C.)

Solenoid
valve coil
(CN722)

+

12V DC

}

Fuse

3.15A / 250V

Varistor (NR61)

CN7301-3

}

220-230-240V
AC

(Refer to
8-4. A or C.)

9

(1) Slide the sleeve and check if there is a locking lever or not.

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

1Slide the sleeve.
2Pull the terminal while

pushing the locking
lever.

1Hold the sleeve, and
pull out the terminal
slowly.

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.

<"Terminal with locking mechanism" Detaching points>

Connector

Sleeve

Locking lever

DISASSEMBLY INSTRUCTIONS

9-1. MU-A18ND

OUTDOOR UNIT

OPERATING PROCEDURE PHOTOS

1. Removing the cabinet

(1) Remove the screws of the cabinet.
(2) Hold the bottom of the cabinet on both sides to remove the

cabinet.

(3) Remove the screws of the service panel and remove the

service panel.

(4) Remove the screw of the valve cover and remove the valve

cover (MU-A18ND- ).

S2

Photo 1

Screws
of the
cabinet

Photo 2

Screws
of the
Service
panel

Screw of
the valve
cover

Photo : MU-A18ND -

S2

Screws
of the
cabinet

21

OPERATING PROCEDURE

PHOTOS

2. Removing the electrical parts

(1) Remove the service panel and the cabinet.
(2) Remove the following parts.

•Compressor capacitor (C1)

•Outdoor fan capacitor (C2)

•Terminal blocks (TB1,TB2)

3. Removing the outdoor fan motor

(1) Remove the cabinet. (Refer to 1.)
(2) Disconnect the connector remove the hooked lead wire

from the fan motor.
(3) Remove the propeller nut and remove the propeller.
(4) Remove screws fixing the fan motor.

Photo 3

Compressor capacitor(C1)

Photo 4

Propeller
nut

Set screws of
outdoor fan motor

Outdoor fan capacitor(C2)

Terminal
blocks(TB1,TB2)

Hook

4. Removing the compressor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the soundproof felt.
(3) Remove the terminal cover on the compressor.
(4) Disconnect lead wires from the glass terminal of the com-

pressor.
(5) Recover gas from the refrigerant circuit.

NOTE:

Recover gas from the pipes until the pressure gauge

shows 0 kg/cm2(0MPa).
(6) Disconnect the welded part of the discharge pipe.
(7) Disconnect the welded part of the suction pipe.
(8) Remove nuts fixing the compressor.
(9) Remove the compressor.

22

Propeller

Photo 5

Compressor

Set screws of
Outdoor fan motor

Discharge
pipe

Suction
pipe

Compressor nuts

9-2. MU-A24ND

OUTDOOR UNIT

OPERATING PROCEDURE

1.Removing the cabinet

(1) Remove the screw of the service panel.
(2) Remove the screws of the top panel.
(3) Remove the screw of the valve cover.
(4) Remove the service panel.
(5) Remove the top panel.
(6) Remove the valve cover.
(7) Remove the screws of the front panel.
(8) Remove the front panel.
(9) Remove the screws of the back panel.
(10)

Remove the back panel.

Photo 3

Screws
of the
back
panel

Screw of the motor support

Photo 1

Screws
of the
cabinet

Photo 2

Screws
of the
front
panel

PHOTOS

Screw of the top panel

Screws of the cabinet

Screw of the service panel

Screws
of the
top
panel

Set screws of the back panel

2. Removing the electrical parts

(1) Remove the service panel and the cabinet.
(2) Remove the following parts.

•Compressor capacitor (C1)

•Outdoor fan capacitor (C2)

•Terminal blocks (TB1,TB2)

•Compressor contactor (52C) (MU-A24ND- )

Screw
of the
valve
cover

Photo 4

Compressor
contactor

(MU-A24

S2

ND-)

S2

Screws
of the
relay
panel

23

Compressor
capacitor (C1)

Screws of the relay panel

Terminal

blocks

(TB1,TB2)

Screws
of the

Outdoor fan
capacitor (C2)

relay
panel

Photo : MU-A24ND -

S2

OPERATING PROCEDURE

PHOTOS

3. Removing the propeller and the outdoor fan motor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the propeller nut and the propeller.

NOTE : Loose the propeller in the rotating direction for

removal.

When attaching the propeller, align the mark on the
propeller and the motor shaft cut section.
Set the propeller in position by using the cut on the
shaft and the mark on the propeller.

(3) Remove the clamp of outdoor fan motor lead wire and

disconnect the outdoor fan motor connector.
(4) Remove the screws fixing the outdoor fan motor.
(5) Remove the outdoor fan motor.

Photo 5

Propeller

nut

Propeller

Set screws of the
outdoor fan motor

Set screws of
the outdoor fan motor

Photo : MU-A24ND -

S2

4. Removing the compressor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the relay panel.
(3) Remove the soundproof felt.
(4) Remove the terminal cover on the compressor.
(5) Disconnect lead wires from the compressor.
(6) Recover gas from the refrigerant circuit.

NOTE:

Recover gas from the pipes until the pressure gauge

shows 0 kg/cm2 (0 MPa).
(7) Disconnect the welded part of the discharge pipe.
(8) Disconnect the welded part of the suction pipe.
(9) Remove nuts fixing the compressor.

)

(

Remove the compressor.

10

Photo 6

Discharge pipe

Terminal cover

Suction pipe

Compressor nuts

24

9-3. MU-A30ND

OUTDOOR UNIT

OPERATING PROCEDURE

1.Removing the cabinet

(1) Remove the screw of the service panel.
(2) Remove the screws of the top panel.
(3) Remove the screw of the valve cover.
(4) Remove the service panel.
(5) Remove the top panel.
(6) Remove the valve cover.
(7) Remove the screws of the front panel.
(8) Remove the front panel.
(9) Remove the screws of the back panel.
(10)

Remove the back panel.

Photo 3

Screw of the motor support

Photo 1

Screws
of the
cabinet

Photo 2

PHOTOS

Screw of the top panel

Screws of the cabinet

Screw of the service panel

Screws
of the
back
panel

Set screws of the back panel

2. Removing the deicer P.C. board

(1) Remove the service panel and the cabinet.
(2) Disconnect all the connectors and the terminals on the

deicer P.C. board.

(3) Remove the deicer P.C. board.

Screws
of the
front
panel

Photo 4

Screws
of the
relay
panel

Deicer P.C. board

Screws
of the
top
panel

Screw
of the
valve
cover

Terminal blocks

(TB1,TB2)

Screws
of the
relay
panel

25

Compressor
contactor
(52C)

Compressor
capacitor(C1)

Outdoor fan
capacitor (C2)

OPERATING PROCEDURE

PHOTOS

3. Removing the propeller and the outdoor fan motor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the propeller nut and the propeller.

NOTE : Loose the propeller in the rotating direction for

removal.

When attaching the propeller, align the mark on the
propeller and the motor shaft cut section.
Set the propeller in position by using the cut on the
shaft and the mark on the propeller.

(3) Remove the clamp of outdoor fan motor lead wire and

disconnect the outdoor fan motor connector.
(4) Remove the screws fixing the outdoor fan motor.
(5) Remove the outdoor fan motor.

Photo 5

Set screws of the
outdoor fan motor

Propeller

nut

Propeller

Set screws of the

outdoor fan motor

Compressor

4. Removing the compressor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the relay panel.
(3) Remove the soundproof felt.
(4) Remove the terminal cover on the compressor.
(5) Disconnect lead wires from the compressor.
(6) Recover gas from the refrigerant circuit.

NOTE:

Recover gas from the pipes until the pressure gauge

shows 0 kg/cm2 (0 MPa).

(7) Disconnect the welded part of the discharge pipe.
(8) Disconnect the welded part of the suction pipe.
(9) Remove nuts fixing the compressor.

)

(

Remove the compressor.

10

Photo 6

Discharge
pipe

Suction
pipe

Terminal cover

Compressor nuts

26

PARTS LIST (non-RoHS compliant)10

MU-A18ND -

S1

Symbol

in Wiring

Diagram

Q'ty/unit

Remarks

Part No. Part Name

No.

MU-A18ND -

S2

E02 817 233
E02 A27 233
E02 817 232
E02 817 521
E02 141 501
E02 496 515
E02 075 506
E02 949 900
E02 817 290
E02 A27 290
E02 140 661
E02 139 662
E02 819 650
E02 817 245
E02 818 301
E02 561 630
E02 A27 630
E02 890 383
E02 795 374
E02 798 374
E02 895 351
E02 816 353
E02 817 009
E02 627 936
E02 A49 382
E07 001 241

1

2
3
4
5
6
7

8

9
10
11
12
13

14

15
16
17
18
19
20
21
22
23

BACK PANEL
BACK PANEL
CABINET
GRILLE
PROPELLER
MOTOR SUPPORT
COMPRESSOR RUBBER SET
COMPRESSOR
BASE
BASE
STOP VALVE(GAS)
STOP VALVE(LIQUID)
VALVE COVER
SERVICE PANEL
OUTDOOR FAN MOTOR
OUTDOOR HEAT EXCHANGER
OUTDOOR HEAT EXCHANGER
SURGE ABSORBER
TERMINAL BLOCK
TERMINAL BLOCK
OUTDOOR FAN CAPACITOR
COMPRESSOR CAPACITOR
HANDLE
CAPILLARY TUBE
FUSE
FUSE HOLDER

1

1
1
1
1
3
1
1

1
1

1
1
1

1
1
1
1
1
1
1
1
1

3RUBBERS/SET
RH247NRAT

{12.7
{ 6.35

RA6V60 -

3P
3P

3.0+/440V AC
35+/440V AC

{3.0o{1.8o400

3.15A

MC

MF

DSAR

TB2
TB1

C2
C1

F

1
1
1
1
1
3
1

1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1

MU-A18ND
10-1. OUTDOOR UNIT

STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS

20

19

18

1

17

16

15

2

14

13

3

12

11

10

Part numbers that are circled are not shown in the illustration.

456

27

7

8

9

PARTS LIST (non-RoHS compliant)

MU-A24ND MU-A30ND
10-2. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS

AND FUNCTIONAL PARTS

26

27

1

2

3

4

5

7

8

9

24

25

6

23

A

B

17

22

21

20

19

18

17

16

15

14

10

28

11 12

13

PARTS LIST (non-RoHS compliant)

MU-A24ND MU-A30ND
10-2. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS

AND FUNCTIONAL PARTS

Part numbers that are circled are not shown in the illustration.

S1

Q'ty/unit

MU-

S2

A24ND -

1

1
1

1
1
1

1
1
1
4
1

1
1

1
1
1

1
1

1
1

1

1
1
1
1

1

1

1

No.

E02 819 297

1

E02 890 630

2

E02 947 630
E02 950 301

3

E02 951 301
E02 214 501

4

E07 070 508

5

E02 889 290

6

E02 890 290
E02 819 232

7

E02 819 009

8

E02 819 521

9

E02 527 506

10

E02 784 900

11

E02 951 900
E02 889 661

12

E02 947 662

13

E02 890 662
E02 889 932

14

E02 819 650

15

E02 819 245

16

E02 819 309

17

E02 890 383

18

E02 795 374

19

E02 889 374
E02 817 374

20

E02 890 351

21

E02 951 451

22

E02 A19 340

23

E02 951 340
E02 889 353

24

E02 816 353
E02 819 233

25

E02 817 009

26

E02 726 515

27

E02 890 640

28

E02 819 493

29

E02 A49 382

30

E02 336 385

31

E02 948 936

32

E02 948 937
E02 262 936
E02 527 936

33

E02 625 936
E02 947 490

34

E02 947 492

35

E07 001 241

36

Part No.

Part Name

TOP PANEL
OUTDOOR HEAT EXCHANGER
OUTDOOR HEAT EXCHANGER
OUTDOOR FAN MOTOR
OUTDOOR FAN MOTOR
PROPELLER
PROPELLER NUT
BASE
BASE
CABINET
HANDLE
FAN GUARD
COMPRESSOR RUBBER SET
COMPRESSOR
COMPRESSOR
STOP VALVE(GAS)
STOP VALVE(LIQUID)
STOP VALVE(LIQUID)
ACCUMULATOR
VALVE COVER
SERVICE PANEL
THERMISTOR
SURGE ABSORBER
TERMINAL BLOCK
TERMINAL BLOCK
TERMINAL BLOCK
OUTDOOR FAN CAPACITOR
DEICER P.C. BOARD
COMPRESSOR CONTACTOR
COMPRESSOR CONTACTOR
COMPRESSOR CAPACITOR
COMPRESSOR CAPACITOR
BACK PANEL(OUT)
HANDLE
MOTOR SUPPORT
EXPANSION VALVE
EXPANSION VALVE COIL
FUSE
VARISTOR
CAPILLARY TUBE(TAPER PIPE)
CAPILLARY TUBE(TAPER PIPE)
CAPILLARY TUBE
CAPILLARY TUBE
CAPILLARY TUBE
SOLENOID VALVE COIL
SOLENOID VALE
FUSE HOLDER

Symbol

in Wiring

Diagram

MF
MF

MC
MC

RT62, RT63

DSAR

TB2
TB2
TB1

C2

52C
52C

C1
C1

LEV
F,F61
NR61

21S2

MU­A24ND -

1

1
1

1
1
1

1
1
1
4
1

1
1

1
1
1

1
1

1
1

1
1
1
1

1

1

1

MU-

S1

A30ND -

1
1

1
1
1

1
1
1
1
4

1
1

1
1
1
1
1
1

1
1
1
1

1
1

1
1
1
1
1
1
1
1
1
1
1

1
1

Remarks

RA6N75­RA6N75-

4RUBBERS/SET
PH33NPBT
NH44NAVT

{15.88
{6.35
{9.52

DISCHARGE, AMBIENT

3P
3P
3P

4.0+/440V AC

FIGUREB
FIGUREA
55+/440V AC
35+/440V AC

3.15A

{4.2x{3.0x50
{3.6x{2.4x50
{4.0x{2.4x200
{4.0x{2.4x100
{3.0x{2.0x550

29

RoHS PARTS LIST (RoHS compliant)11

MU-A18ND
11-1. OUTDOOR UNIT

STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS

20

1

2

3

19

18

17

16

15

14

13

12

11

10

456

30

7

8

9

MU-A18ND -

S1

Symbol

in Wiring

Diagram

Q'ty/unit

Remarks

Part No. Part Name

No.

RoHS

MU-A18ND -

S2

E12 817 233
E12 A27 233
E12 817 232
E12 817 521
E12 141 501
E12 496 515
E12 075 506
E12 949 900
E12 817 290
E12 A27 290
E12 140 661
E12 139 662
E12 819 650
E12 817 245
E12 818 301
E12 561 630
E12 A27 630
E12 890 383
E12 795 374
E12 798 374
E12 895 351
E12 816 353
E12 817 009
E12 627 936
E12 A49 382
E17 001 241

1

2
3
4
5
6
7

8

9
10
11
12
13

14

15
16
17
18
19
20
21
22
23

BACK PANEL
BACK PANEL
CABINET
GRILLE
PROPELLER
MOTOR SUPPORT
COMPRESSOR RUBBER SET
COMPRESSOR
BASE
BASE
STOP VALVE(GAS)
STOP VALVE(LIQUID)
VALVE COVER
SERVICE PANEL
OUTDOOR FAN MOTOR
OUTDOOR HEAT EXCHANGER
OUTDOOR HEAT EXCHANGER
SURGE ABSORBER
TERMINAL BLOCK
TERMINAL BLOCK
OUTDOOR FAN CAPACITOR
COMPRESSOR CAPACITOR
HANDLE
CAPILLARY TUBE
FUSE
FUSE HOLDER

G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G

1

1
1
1
1
3
1
1

1
1

1
1
1

1
1
1
1
1
1
1
1
1

3RUBBERS/SET
RH247NRAT

{12.7
{ 6.35

RA6V60 -

3P
3P

3.0+/440V AC
35+/440V AC

{3.0o{1.8o400

3.15A

MC

MF

DSAR

TB2
TB1

C2
C1

F

1
1
1
1
1
3
1

1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1

RoHS PARTS LIST (RoHS compliant)

MU-A18ND
11-1. OUTDOOR UNIT

STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS

Part numbers that are circled are not shown in the illustration.

31

RoHS PARTS LIST (RoHS compliant)

MU-A24ND MU-A30ND
11-2. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS

AND FUNCTIONAL PARTS

26

27

1

2

3

4

5

7

8

9

24

25

6

23

A

B

17

22

21

20

19

18

17

16

15

14

10

32

11 12

13

RoHS PARTS LIST (RoHS compliant)

MU-A24ND MU-A30ND
11-2. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS

AND FUNCTIONAL PARTS

Part numbers that are circled are not shown in the illustration.

Q'ty/unit

MU-

A24ND -

S2

1

1
1

1
1
1

1
1
1
4
1

1
1

1
1
1

1
1

1
1

1

1
1
1
1

1

1

1

MU-

A30ND -

No.

1

2

3

4
5

6

7
8
9

10

11

12

13

14
15
16
17
18

19

20
21

22

23

24

25
26
27
28
29
30
31

32

33

34

35

36

Part No.

RoHS

G

E12 819 297

G

E12 890 630
E12 947 630

G

E12 950 301

G

E12 951 301

G

E12 214 501

G

E17 070 508

G

E12 889 290

G

E12 890 290

G

E12 819 232

G

E12 819 009

G

E12 819 521

G

E12 527 506

G

E12 784 900

G

E12 951 900

G

E12 889 661

G

E12 947 662

G

E12 890 662

G

E12 889 932

G

E12 819 650

G

E12 819 245

G

E12 819 309

G

E12 890 383

G

E12 795 374

G

E12 889 374

G

E12 817 374

G

E12 890 351

G

E12 951 451

G

E12 B19 451

G

E12 A19 340

G

E12 951 340

G

E12 889 353

G

E12 816 353

G

E12 819 233

G

E12 817 009

G

E12 726 515

G

E12 890 640

G

E12 819 493

G

E12 A49 382

G

E12 336 385

G

E12 948 936

G

E12 B18 936

G

E12 948 937

G

E12 262 936

G

E12 527 936

G

E12 625 936

G

E12 947 490

G

E12 B19 490

G

E12 947 492

G

E12 B18 492

G

E17 001 241

G

Part Name

TOP PANEL
OUTDOOR HEAT EXCHANGER
OUTDOOR HEAT EXCHANGER
OUTDOOR FAN MOTOR
OUTDOOR FAN MOTOR
PROPELLER
PROPELLER NUT
BASE
BASE
CABINET
HANDLE
FAN GUARD
COMPRESSOR RUBBER SET
COMPRESSOR
COMPRESSOR
STOP VALVE (GAS)
STOP VALVE (LIQUID)
STOP VALVE (LIQUID)
ACCUMULATOR
VALVE COVER
SERVICE PANEL
THERMISTOR
SURGE ABSORBER
TERMINAL BLOCK
TERMINAL BLOCK
TERMINAL BLOCK
OUTDOOR FAN CAPACITOR
DEICER P.C. BOARD
DEICER P.C. BOARD
COMPRESSOR CONTACTOR
COMPRESSOR CONTACTOR
COMPRESSOR CAPACITOR
COMPRESSOR CAPACITOR
BACK PANEL (OUT)
HANDLE
MOTOR SUPPORT
EXPANSION VALVE
EXPANSION VALVE COIL
FUSE
VARISTOR
CAPILLARY TUBE (TAPER PIPE)
CAPILLARY TUBE (TAPER PIPE)
CAPILLARY TUBE (TAPER PIPE)
CAPILLARY TUBE
CAPILLARY TUBE
CAPILLARY TUBE
SOLENOID VALVE COIL
SOLENOID VALVE COIL
SOLENOID VALE
SOLENOID VALE
FUSE HOLDER

Symbol
in Wiring
Diagram

MF
MF

MC
MC

RT62, RT63

DSAR

TB2
TB2
TB1

C2

52C
52C

C1
C1

LEV
F,F61
NR61

21S2
21S2

MU-

A24ND -

S1

1

1
1

1
1
1

1
1
1
4
1

1
1

1
1
1

1
1

1
1

1
1
1
1

1

1

1

S1

1
1

1
1
1

1
1
1
1
4

1
1

1
1
1
1
1
1

1
1
1
1

1
1

1
1
1
1
1
1
1
1

1
1
1

1

1

MU-

A30ND -

S2

1
1

1
1
1

1
1
1
1
4

1
1

1
1
1
1
1
1

1
1
1

1

1
1

1
1
1
1
1
1
1

1
1
1
1

1

1

Remarks

RA6N75­RA6N75-

4RUBBERS/SET
PH33NPBT
NH44NAVT

{15.88
{6.35
{9.52

DISCHARGE, AMBIENT

3P
3P
3P

4.0+/440V AC

FIGUREB
FIGUREA
55+/440V AC
35+/440V AC

3.15A

{4.2x{3.0x50
{4.2x{3.0x50
{3.6x{2.4x50
{4.0x{2.4x200
{4.0x{2.4x100
{3.0x{2.0x550

33

34

35

TM

HEAD OFFICE: TOKYO BLDG, 2-7-3, MARUNOUCHI, CHIYODAKU, TOKYO 100-8310, JAPAN

CC

Copyright 2005 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD
Distributed in Oct. 2009. No.OB405 REVISED EDITION-E 5
Distributed in May 2006. No.OB405 REVISED EDITION-D 106
Distributed in Nov. 2005. No.OB405 REVISED EDITION-C 106
Distributed in Jun. 2005. No.OB405 REVISED EDITION-B 106
Distributed in May 2005. No.OB405 REVISED EDITION-A 106
Reprinted in Apr. 2005. No.OB405 100
Distributed in Mar. 2005. No.OB405 6
Made in Japan

New publication, effective Oct. 2009
Specifications subject to change without notice.