Mitsubishi MCFH-A12WV- E1 (WH), MCFH-A18WV- E1 (WH), MCFH-A24WV- E1 (WH) Service Manual

SERVICE MANUAL

(When installed on the ceiling)

(When installed on the floor)

FLOOR AND CEILING TYPE AIR CONDITIONERS

Wireless type
Models

(WH)

MCFH-A12WV­MCFH-A18WV-

E1

E1

(WH)

Revision A:

● Power input of SPECIFICATION has modified.

● Model name of remote controller has been

added to PARTS LIST.

Please void OB336.

No. OB336

REVISED EDITION-A

MCFH-A24WV-

Indication of
model name

MCFH-A12WV­MCFH-A18WV­MCFH-A24WV-

E1

(WH)

CONTENTS

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

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

3. SPECIFICATION·················································4

4. NOISE CRITERIA CURVES·······························5

E1

5. OUTLINES AND DIMENSIONS·························6

E1

6. WIRING DIAGRAM ············································7

E1

7. REFRIGERANT SYSTEM DIAGRAM················8

8. SERVICE FUNCTIONS ······································9

9. TROUBLESHOOTING ······································11

10. DISASSEMBLY INSTRUCTIONS·····················19

11. PARTS LIST ······················································21

12. OPTIONAL PARTS ···········································23

NOTE:

• This manual describes technical data of indoor units

• As for outdoor units MUCFH-A18/A24WV- , refer to the service manual OB337 REVISED EDITION-A.

• As for outdoor unit MUH-A12YV- , refer to the service manual OB331 REVISED EDITION-A.

• As for outdoor units MXZ-A18/A26/A32WV- , refer to the service manual OB319.

E1

E1

E1

(When installed on the floor)

(When the air inlet grille is opened.)

Deodorizing filter
(gray sponge type)(option)

Air filter

Air inlet

Operation section

Air cleaning filter
(white bellows type)(option)

Front panel

Receiving section

Operation indicator lamp

Horizontal vane

Vertical vanes

Emergency
operation switch

(When installed on the ceiling)

ACCESSORIES

Item

Installation plate
Unit fixing screw
5 o 12mm
Wireless remote
controller
Remote controller
mounting hardware
Fixing screw for

3.5 o 16mm (Black)
Battery (AAA) for
remote controller
Drain hose
Drain pipe cover
Knockout cover
Screw for 4 o 10mm

2
2

1

1
2
2

1
1
1
2

Q'ty

Remote controller

Revision A:

•Power input of SPECIFICATION has modified.

•Model name of remote controller has been added to PARTS LIST.

1

MCFH-13NV- ➔ MCFH-A12WV-

1. Rated voltage has changed. (220-240V ➔ 230V)

2. Indoor electronic control P.C. board has changed.

3. Horizontal vane has changed.

4. Terminal block has changed.

5. Indoor heat exchanger has changed.

6. Remote controller has changed.
Econo cool operation has been added.

7. Indoor fan motor has changed. (RB4V25-AB ➔ RB4V25-AC)

MCFH-24NV- ➔ MCFH-A24WV-

1. Rated voltage has changed. (220-240V ➔ 230V)

2. Indoor electronic control P.C. board has changed.

3. Horizontal vane has changed.

4. Terminal block has changed.

5. Indoor heat exchanger has changed.

6. Remote controller has changed.
Econo cool operation has been added.

7. Liquid of union has changed. ({9.52 ➔ {6.35)

8. Indoor fan motor has changed. (RB4V36-AB ➔ RB4V36-DB)

2

TECHNICAL CHANGES

E1E4

E1E3

PART NAMES AND FUNCTIONS

MCFH-18NV- ➔ MCFH-A18WV-

1. Rated voltage has changed. (220-240V ➔ 230V)

2. Indoor electronic control P.C. board has changed.

3. Horizontal vane has changed.

4. Terminal block has changed.

5. Indoor heat exchanger has changed.

6. Remote controller has changed.
Econo cool operation has been added.

7. Gas of union has changed. ({15.88 ➔ {12.7)

8. Indoor fan motor has changed. (RB4V36-AB ➔ RB4V36-AC)

E1E3

MCFH-A12WV - MCFH-A18WV - MCFH-A24WV -

INDOOR UNIT

E1E1E1

2

MCFH-A12WV -

ON/OFF

FAN

TOO

WARM

TOO

COOL

VANE

MODE

ECONO COOL

STOP

START

HR.

MIN.

I FEEL

COOL

HEAT

DRY

PM

CLOCK

AM

RESET CLOCK

ON/OFF

TOO

COOL

PM

AM

TOO

WARM

Open the front lid.

Signal transmitting section

Operation display section

OPERATE /STOP

(ON /OFF)button

TEMPERATURE buttons

OPERATION SELECT button

FAN SPEED CONTROL button

OFF-TIMER button

ON-TIMER button

RESET button

ECONO COOL button

VANE CONTROL button

CLOCK SET button

HR. button

MIN. button

(TIME SET button)

Indication of remote controller model
is on back.

MCFH-A18WV ­MCFH-A24WV -

REMOTE CONTROLLER

E1

E1

E1

3

3

Indoor model

Function

Power supply

Air flow(High/Med.W/LowW)
Power outlet
Running current
Power input
Auxiliary heater
Power factor
Fan motor current
Model

Winding
resistance(at20:)

Dimensions WOHOD
Weight
Air direction
Sound level(High/Med.W/LowW)
Fan speed(High/Med.W/LowW)
Fan speed regulator
Thermistor RT11(at25:)
Thermistor RT12(at25:)
Remote controller model

K /h

A
A

W

A(kW)

%

A

"

mm

kg

dB

rpm

k"
k"

Electrical

data

Fan

motor

Special

remarks

Capacity

MCFH-A12WV-

E1

MCFH-A18WV-

E1

MCFH-A24WV-

E1

Cooling

—

Heating

—

780/636W/492W

10

0.30
66

96

0.30

RB4V25-AC

WHT-BLK 182.2 BLK-YLW 68.9

YLW-BLU 47.5 BLU-BRN 31.5

BRN-RED 22.9

25

5

46/41W/36W

1,240/1,060/845

3
10
10

KG04C

Cooling

—

Heating

—

Single phase

230V, 50Hz

840/696W/570W

10

0.36
80

97

0.36

RB4V36-AC
WHT-BLK 82.9 BLK-YLW 65.6
YLW-BLU 36.0 BLU-BRN 27.0

BRN-RED 13.7

1100 ✕ 650 ✕ 180

25

5

48/44W/39W

1,320/1,145/960

3
10
10

KG04C

Cooling

—

Heating

—

840/744W/642W

10

0.36
80

97

0.36

RB4V36-DB
WHT-BLK 84.0 BLK-YLW 46.2
YLW-BLU 37.2 BLU-BRN 45.2

BRN-RED 13.6

25

5

48/45W/42W

1,320/1,190/1,060

3
10
10

KG04C

SPECIFICATION

NOTE: Test conditions are based on ISO 5151

Cooling : Indoor DB27°C WB19°C Heating : Indoor DB20°C WB 15°C

Outdoor DB35°C WB(24°C) Outdoor DB 7°C WB 6°C

Indoor-Outdoor piping length : 5 m

w Reference value

4

4

NOISE CRITERIA CURVES

MCFH-A12WV -

E1

SPL(dB

SPEED

High

(A)) LINE

46

Test conditions,
Cooling : DB 27: WB 19:\

90

Heating : DB 20: WB 15:

80

70

60

50

40

30

APPROXIMATE

20

THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

10

63 125 250 500 1000 2000 4000 8000

BAND CENTER FREQUENCIES, Hz

NC-70

NC-60

NC-50

NC-40

NC-30

NC-20

MCFH-A18WV -

E1

SPL(dB

SPEED

High

(A)) LINE

48

Test conditions,
Cooling : DB 27: WB 19:\

90

Heating : DB 20: WB 15:

80

70

60

50

40

30

APPROXIMATE

20

THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

10

63 125 250 500 1000 2000 4000 8000

BAND CENTER FREQUENCIES, Hz

NC-70

NC-60

NC-50

NC-40

NC-30

NC-20

MCFH-A24WV -

E1

SPL(dB

SPEED

High

(A)) LINE

48

Test conditions,
Cooling : DB 27: WB 19:\

90

Heating : DB 20: WB 15:

80

70

60

50

40

30

APPROXIMATE

20

THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

10

63 125 250 500 1000 2000 4000 8000

BAND CENTER FREQUENCIES, Hz

NC-70

NC-60

NC-50

NC-40

NC-30

NC-20

INDOOR UNIT

MICROPHONE

1m

1m

WALL

5

5

(When installed on the floor)

(When installed on the ceiling)

50cm or more

50cm or more

50cm or more

50cm or more

100cm or more

650

616.5

80.8 906 112.8

114

16

1100

93

77

113

143

180

17042.5

12.7 (MCFH-A12/A18WV)

15.88 (MCFH-A24WV)

Gas line

6.35

Liquid line

Wireless remote controller

162

19

58

OUTLINES AND DIMENSIONS

MCFH-A12WV ­MCFH-A18WV ­MCFH-A24WV -

INDOOR UNIT

E1

E1

E1

Unit: mm

6

WIRING DIAGRAM6

SYMBOL

SR141~SR143

TB1, TB2

X144

SYMBOL

MV
NR11
RT11
RT12

NAME

NAME NAME
INDOOR FAN CAPACITOR
FUSE (3.15A)
DC/DC CONVERTER
INDOOR FAN MOTOR(INNER FUSE)

VANE MOTOR
VARISTOR
ROOM TEMPERATURE THERMIST OR
INDOOR COIL THERMISTOR

SOLID STATE RELAY
TERMINAL BLOCK
RELAY

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

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

3.Symbols below indicate.
: Connector

: Terminal block

NOTES:

SYMBOL

C11

F11

HIC1

MF

MCFH-A12WV ­MCFH-A18WV ­MCFH-A24WV -

INDOOR UNIT

POWER
SUPPLY

~/N 230V

50Hz

CIRCUIT BREAKER

TO OUTDOOR
UNIT
CONNECTING
12V

E1

MODELS WIRING DIAGRAM

E1

E1

TB1

PE

N

L

GRN/YLW

BLU
RED

1
2
3

CN201

BRN

TB2

BLU

N

CN CN CN

3

113 151101

5

5

REMOTE
CONTROLLER

DISP/
RECEIVER
P.C.BOARD

TAB12

6
5

4

MV

SW/THERMO
P.C.BOARD

HIC1

LDCOM

C11

TRANS

F11

ELECTRONIC CONTROL P.C BOARD

RT11

NR11

X144
SR143

SR142
SR141

CN

112

LDC11
LDC12
LDFH
LDFM
LDFL
LDFVL

2

2

WHT
ORN
RED
BLK
YLW
BLU
BRN

WHT

1

ORN

2

RED

3

BLK

4

YLW

5

BLU

6

BRN

7
8

GRN/YLW

RT12

MF

7

REFRIGERANT SYSTEM DIAGRAM7

MCFH-A12WV-

INDOOR UNIT

E1

Refrigerant pipe [12.7
(with heat insulator)

MCFH-A18WV-

INDOOR UNIT

Unit : mm

E1

Refrigerant pipe [12.7
(with heat insulator)

Indoor
heat
exchanger

Indoor coil
thermistor
RT12

Room temperature
thermistor
RT11

Distributor

MCFH-A24WV-

Flared connection

Flared connection

Refrigerant pipe
[6.35
(with heat insulator)

E1

Indoor
heat
exchanger

Indoor coil
thermistor
RT12

Room temperature
thermistor
RT11

Distributor

Flared connection

Flared connection

Refrigerant pipe
[6.35
(with heat insulator)

INDOOR UNIT

Indoor
heat
exchanger

Indoor coil
thermistor
RT12

Room temperature
thermistor
RT11

Distributor

Refrigerant pipe [15.88
(with heat insulator)

Flared connection

Flared connection

Refrigerant pipe
[6.35
(with heat insulator)

Refrigerant flow in cooling
Refrigerant flow in heating

8

SERVICE FUNCTIONS8

No. 1 unit
No. 2 unit
No. 3 unit
No. 4 unit

1 unit operation
No modification

–
–
–

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

MCFH-A12WV - MCFH-A18WV - MCFH-A24WV -

E1E1E1

8-1. TIMER SHORT MODE

For service, set time can be shortened by short circuit of JPG and JPS on the electronic control P.C. board.
The time will be shortened as follows. (Refer to page 18.)

3-minutes time delay : 3-minutes → 3-seconds
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.)

8-2. 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;

Remote controller model : KG04C

J2

NOTE : For remodelling, take out the batteries and

press the OPERATE/STOP(ON/OFF) button
twice or 3 times at first.
After finish remodelling, put back the
batteries then press the RESET button.

J1

The P.C. board has the print “J1” and “J2”. Solder “J1” and “J2” according to the number of indoor unit as shown in
Table 1. After modification, press the RESET button.

Table1.

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 accepts the signal from the remote controller that has been assigned to the indoor unit once they
are set.
The setting will be cancelled if the breaker has turned off, or the power supply has shut down.
Please conduct the above setting once again after the power has restored.

9

JR07

CN151CN113CN112

CN101

CN105

SW2

CN102

CN201

SW1

IC101

C11

TAB12

8-3. AUTO RESTART FUNCTION

When the indoor unit is controlled with the remote controller, the operation mode, set temperature, and the fan speed are
memorized by the indoor electronic control P.C. board. The “AUTO RESTART FUNCTION” sets to work the moment power
has restored after power failure.Then, the unit will restart automatically. However if the unit is operated in “I FEELCON­TROL” mode before power failure, the operation is not memorized. In “I FEEL CONTROL” mode, the operation is decided
by the initial room temperature.

How to release “AUTO RESTART FUNCTION”

1Turn off the main power for the unit.
2Pull out the electronic control P.C. board. (Refer to page 19.)
3Solder jumper wire to the JR07 on the indoor electronic

control P.C. board. (Refer to page 18.)

Operation

1If the main power (230V AC) has been cut, the operation settings remain.
2After the power is restored, the unit restarts automatically according to the memory.(However, it takes at least 3 minutes

for the compressor to start running.)

NOTE

•The operation settings are memorized when 10 seconds have passed after the remote controller was operated with the

remote controller.

•If main power is turned off or a power failure occurs while AUTO START/STOP timer is active ,the timer setting is

cancelled.

•If the unit has been off with the remote controller before power failure, the auto restart function does not work as the

power button of the remote controller is off.

•To prevent breaker off due to the rush of starting current, systematize other home appliances not to turn on at the same

time.

•When some air conditioners are connected to the same supply system, if they are operated before power failure, the

starting current of all the compressors may flow simultaneously at restart.
Therefore, the special counter-measures are required to prevent the main voltage-drop or the rush of the starting current
by adding to the system that allows the units to start one by one.

10

9

TROUBLESHOOTING

MCFH-A12WV - MCFH-A18WV - MCFH-A24WV -

E1E1E1

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 mis-wiring.

2. Take care the following during service.

(1) Before servicing the air conditioner, be sure to first turn off the remote controller to stop the main unit, and then after

confirming the horizontal vane has completely closed, turn off the breaker.

(2) Be sure to unplug the power cord before removing the air inlet grille, the front panel, the cabinet, the top panel and

the electronic control P.C. boards.

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

the components for bursting and discoloration.

(3) When troubleshooting, refer to the flow chart and the check table on page 12 and 13.

4. How to replace batteries

Weak batteries may cause the remote controller malfunction.
In this case, replace the batteries to operate the remote controller normally.
1 Remove the front lid and insert batteries.

Then reattach the front lid.

2 Press the RESET button with tip end of ball point

pen or the like, and then use the remote controller.

Insert the negative pole
of the batteries first.
Check if the polarity of
the batteries are correct.

NOTE : If the RESET button is not pressed, the remote controller may not operate correctly.

INFORMATION FOR MULTI SYSTEM AIR CONDITIONER

OUTDOOR UNIT : MXZ-A18WV- MXZ-A26WV- MXZ-A32WV-

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

•Unit won’t operate in case the total capacity of indoor units exceeds the capacity of outdoor units. Do not connect
indoor units beyond the outdoor unit capacity.

Operation indicator lamp flashes as shown in the figure below.

•When you try to operate two or more indoor units with one outdoor unit simultaneously, one for the cooling and the
other for heating, the operation mode of the indoor unit that operates earlier is selected. The other indoor units that
will start the operation later cannot operate, indicating as shown in the figure below. In this case, please set all the
indoor units to the same operation mode.

RESET button

E1E1E1

Operation Indicator

•When indoor units 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.

lighted

flashing

11

9-2. Instruction of troubleshooting

Start

Indoor unit
operates.
Outdoor unit
doesn't
operate.

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

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

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

Outdoor unit
operates in
only Test Run
operation.

Outdoor unit
doesn't
operate
even in
Test Run
operation.

Indoor unit
operates, when
the EMERGENCY
OPERATION
switch is pressed.

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

Check room
temperature
thermistor.
Refer to
"Test point
diagram and
voltage" on
page 18.

Refer to
"Check of
outdoor unit".

Refer to
"Check of
outdoor unit".

Refer to B
"Check of
remote controller
and receiver
P.C. board"
on page 15.

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

• Mis-wiring
or trouble of
serial signal

2-time flash
Cause:
Indoor unit

• Trouble of
room
temperature/
indoor coil
thermistor

Check room
temperature
thermistor
and indoor
coil
thermistor.
Refer to
"Test point
diagram and
voltage"
on page 18.

4-time flash
Cause:
Indoor unit

• Trouble of
indoor
electric
P.C. board

Refer to D
"Check of
indoor
electric
control P.C.
board" on
page 16.

Refer to E
"How to
check mis­wiring and
serial signal
error (When
outdoor unit
doesn't
work)" on
page 17.

1. Check indoor /
outdoor
connecting wire.

2. Refer to C
"Check of indoor
electronic control
P.C. board"
on page 16.

Outdoor unit
doesn't
stop even
if indoor unit
stops.

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

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

6-time flash
Cause:
Outdoor unit

• Trouble of
thermistor
in outdoor
unit

MXZ type
MUCFH-A24WV

7-time flash
Cause:
Outdoor unit

• Trouble of
outdoor
control
system

Refer to
"Check of
outdoor
thermistor".

MUCFH-A24WV

Replace the
deicer
P.C. board.

MXZ type

Replace the
outdoor
electronic
control
P.C. board.

MXZ type

5-time flash
Cause:
Outdoor unit

• Outdoor
power
system
abnormality

Refer to
"Check of
inverter/
compressor"
and "Check
of power
supply".

As for outdoor unit MUCFH type, refer to the service manual OB337 REVISED EDITION-A.
As for outdoor unit MUH type, refer to the service manual OB331 REVISED EDITION-A.
As for outdoor unit MXZ type, refer to the service manual OB319.

12

1. Troubleshooting check table

OPERATION
INDICATOR
lamp

Operation Indicator

Lighted
Flashing

2.5-second OFF

Before taking measures, make sure that the symptom reappears, for accurate troubleshooting.
Self check table

NO.

Abnormal

point

Indication

Symptom

Detect method

Check point

Mis-wiring
or Serial

1

signal

Indoor coil
thermistor

2

Room
tempera­ture ther­mistor

Indoor
control

3

P.C.
board

Outdoor

4

thermistor

MCFH­A24WV
MXZ type

5

Outdoor
control
P.C.
board

MXZ type

❈

Outdoor

6

power
system

MXZ type

❈

Operation

7

mode
setting

0.5-second ON

0.5-second OFF

2-time flash

2.5-second OFF

4-time flash

6-time flash

7-time flash

5-time flash

2.5-second OFF

2.5-second OFF

2.5-second OFF

2.5-second OFF

Outdoor unit
does not run.

Outdoor unit
does not run.

Indoor unit
does not run

Outdoor unit
does not run

Outdoor unit
does not run

Outdoor unit
does not run

Outdoor unit
operates but
indoor unit does
not operate.

When serial signal stops for 4
to 5 seconds.

Detect Indoor coil/room tem­perature thermistor short or
open circuit every 8 seconds
during operation.

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

When the outdoor thermistors
short or open after the
compressor start-up.

When it cannot properly read
data in the nonvolatile
memory of the outdoor deicer
P.C. board or outdoor
electronic control P.C. board.

When the compressor
operation is continuously

three times interrupted by
over current protection within
1 minute after start-up , it
stops operation.

When the operation mode of
each indoor unit is differently
set to COOL(includes DRY)
and HEAT at same time, the
operation mode of indoor unit
that has operated at first has
the priority.

● Check wiring (visual check and conductiv­ity check).

● Check indoor electronic control
P.C.board.

● Check outdoor deicer P.C. board.

● Check electrical parts.

● Check resistance of thermistor.

● Reconnect connector.

● Check indoor electronic control P.C.

board.

● Check indoor electronic control P.C.
board.

● Check outdoor deicer P.C. board.

● Check resistance of thermistor.

● Reconnect connector.

Refer to service manual
OB337 REVISED EDITION-A,
OB331 REVISED EDITION-A or OB319.

● Check the outdoor deicer P.C. board or
outdoor electronic control P.C. board.
Refer to service manual
OB337 REVISED EDITION-A or OB319.

● Check the inverter output.

● Check the compressor.

Refer to service manual OB319.

● Unify the operation mode.
Refer to service manual OB319.

❈The indication is shown only when the indoor unit connects with the outdoor unit MXZ type.

13

2. Trouble criterion of main parts

MCFH-A12WV - MCFH-A18WV - MCFH-A24WV -

Part name

Room
temperature
thermistor (RT11)

Indoor coil
thermistor (RT12)

Indoor fan
motor
(MF)

INNER FUSE
145 i 5: CUT OFF

Vane
motor
(MV)

Measure the resistance with a tester.
(Part temperature 10°C ~ 30°C)

Normal

8kΩ ~ 20kΩ

Measure the resistance between the terminals with a tester.
(Part temperature10°C ~ 30°C)

Color of lead

wire

MCFH-A12WV

WHT-BLK

BLK-YLW 63~69Ω66~72Ω
YLW-BLU 34~38Ω45~50Ω
BLU-BRN 25~29Ω30~33Ω

BRN-RED 13~15Ω22~24Ω

Measure the resistance between the terminals with a tester.
(Part temperature10°C ~ 30°C)

328

Check method and criterion

Abnormal

Open or short-circuit

Normal

MCFH-A18WV

79~87Ω175~190Ω

MCFH-A24WV

80~88Ω
44~49Ω
35~39Ω
43~47Ω
13~15Ω

Normal Abnormal

~356

Ω

Open or

short-circuit

E1E1E1

Figure

ROTOR

WHT

FUSE

GRNORN

GRN

YLW

Abnormal

Open or

short-circuit

BLK RED ORNYLWBLU BRN

RED

YLW
BRN

14

Indoor fan does not operate.

A

Check of indoor fan motor

Turn OFF power supply.
Check connector (Fan motor) visually.

No

Reconnect the lead wires.

Are lead wires connected?

Yes

Disconnect lead wires from connector (Indoor fan motor).
Measure resistance between lead wires No.1 and No.4 and then No.3 and No.4 of the indoor fan
motor.

Is resistance 0 (short circuit) or ∞ (open circuit)?

Yes ( 0 or ∞ )

Replace the indoor fan motor.

Is soldered point of the connector
correctly soldered?

(others)

Yes

Replace the indoor electronic control
P.C. board.

No

No

Resolder it.

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

Check of remote controller and receiver P.C. board

B

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

Switch on the remote controller.

Is LCD display on remote
controller visible?

Yes

Remove the batteries, then set them back
and press the RESET button. Check if the
unit operates with the remote controller.

Does the unit operate with remote
controller?

Yes

OK

No
(not clear)

No

Replace the batteries.(Refer to page 11.)

Turn on a radio to AM and press switch
on remote controller.

Is noise heard from radio?

Yes

Are there any fluorescent lights of
inverter or rapid-start type within
the range of 1m?

No

Measure the voltage between receiver P.C.board connector CN101 No.2 and No.1
when remote controller button is pressed.

Is the voltage approx. 4V DC ?

No(5V or 0V DC)

Replace the receiver P.C. board.

No

Yes

Yes

Replace the remote controller.

● Reinstall the unit away from lights.

● Attach a filter on receiving part.

+

Replace the indoor electronic control
P.C. board.

–

15

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

Check of indoor electronic control P.C. board

C

Replace the fuse.

Yes

Is fuse(F11)blown?

No

Check both “parts side”and “pattern
side” of indoor electronic control P.C.
board visually.

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

Is varistor(NR11)burnt?

Replace the varistor.

When OPERATION INDICATOR lamp flashes 4 - time.

Indoor unit does not operate.

Check of indoor electronic control P.C. board

D

Trouble of the indoor electronic
control P.C. board.

No

Yes

Turn off the power supply.

Replace the indoor electronic
control P.C. board.

16

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

How to check mis-wiring and serial signal error (when outdoor unit does not work)

E

Start

w 1 Short circuit of JPG and JPS

on the electronic control P.C.
board enables self-check to
be displayed in 3 seconds.

Repair wiring.

3 minutes later, is there 20V DC between both ends
of R132? w 1
(By tester, the stylus is between 0 ~ 20V.)

•Turn OFF power supply.

•Reconnect indoor/ outdoor unit connecting wire.

•Turn ON power supply.

3 minutes later, when EMERGENCY OPERATION switch is pressed ,
is there 12V DC between outdoor terminal block and ?

Is there 5V DC between J9 -J8 (MUCFH-A18WV)/
J101 -J401 (MUCFH-A24WV) on the deicer P.C. board?

–

+

Yes

1. Turn OFF power supply and disconnect indoor/ outdoor unit connecting wire of the indoor unit.

2. Short-circuit between indoor terminal block and .

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

Yes

Yes

–

+

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

No

3

N

No

N

3

Replace the indoor electronic control
P.C. board.

No

No

Rectify indoor/ outdoor unit
connecting wire.

Check and rectify fuse and varistor on the
deicer P.C. board.

Yes

Is there 10V DC between both ends of R601 on the deicer P.C.
board?
(By tester, the stylus is between 5 ~10V DC)

Yes

Replace the deicer P.C. board.

As for outdoor unit MUCFH type, refer to the service manual OB337 REVISED EDITION-A.
As for outdoor unit MUH type, refer to the service manual OB331 REVISED EDITION-A.
As for outdoor unit MXZ type, refer to the service manual OB319.

17

No

Rectify indoor/ outdoor unit
connecting wire.

DE00R697B

To the indoor
electronic control
P.C.board CN113

Indoor coil thermistor (RT12)
Room temperature thermistor (RT11)

RT11

EMERGENCY OPERATION switch

TH113

CH313

GILMS

12

0

0

10

20

30

40

10 20 30 40 50 60

Temperature ( C)

Resistance (K')

TEST POINT DIAGRAM AND VOLTAGE
MCFH-A12WV ­MCFH-A18WV ­MCFH-A24WV -

E1

E1

E1

Indoor electronic control P.C. board

Fan motor power supply 230V AC

Very
Low

Low

Med.

High

75643218

Fuse (F11)
250V AC

3.15A
Varistor (NR11)

Power supply
input 230V AC

R132 about 20V DC
(Refer to page 17.)

+

5V DC

}

–

–

12V DC

}

+

No.2 No.1

Receiver P.C.

– +

board connector
(CN101)

Room temperature
thermistor(RT11)

Solder jumper wire to the
JR07 on the indoor electronic
control P.C. board.
(Refer to page 10.)

Room temperature thermistor (RT11)

Time short point JPG and JPS
(Refer to page 9.)

Indoor coil thermistor (RT12)

18

DISASSEMBLY INSTRUCTIONS10

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

1Slide the sleeve.
2Pull the terminal while

pushing the locking
lever.

In case of terminal with lock mechanism, detach the terminal as shown below.
There are two types ( Refer to (1) and (2)) of the terminal with lock mechanism.
The terminal with no lock mechanism can be removed by pulling it out.
Check the shape of the terminal and work.

<"Terminal with lock mechanism" Detaching points>

Sleeve

Locking lever

10-1. MCFH-A12WV- MCFH-A18WV- MCFH-A24WV-

INDOOR UNIT

OPERATING PROCEDURE PHOTOS

1. Removing the electronic control P. C . board.

(1) Pull out the upper part of the grille. (Photo 1)
(2) Remove the screws of the grille.
(3) Remove screws of terminal block cover.

Remove the terminal block cover and remove the terminal

block.
(4) Remove the screws of the electronic box cover.
(5) Pull out the electronic control P. C. board.

Photo 3

Photo 1

Photo 2

E1E1E1

Screws

Electronic control P.C. board

19

Electronic box Terminal block

OPERATING PROCEDURE PHOTOS

2. Removing the indoor fan motor

(1) Remove the grille. (Refer to 1(1) (2).)
(2) Remove the fan casing.(upper)
(3) Disconnect the connector of the indoor fan motor.
(4) Disconnect the ground wire of the fan motor.
(5) Remove the screws of the motor band and remove the

catch.

(6) Take out the sirocco fan and the indoor fan motor.

3. Removing the indoor heat exchanger.

(1) Remove the grille. (Refer to 1(1) (2).)
(2) Remove the screws on both side and in front of the front

panel. (Photo 5)
(3) Remove the screws of the nozzle assembly. (Photo 6)
(4) Remove the electronic box. (Refer to 1.)
(5) Remove the indoor fan motor. (Refer to 2.)
(6) Remove the screws of the motor support .
(7) Remove the fan casing. (Iower)
(8) Remove the insulation of the drain pan and remove the

screws. (Photo 7)
(9) Remove the screws under the drain pan. (Photo 8)
(10) Remove the drain pan.
(11) Remove the indoor heat exchanger.

Photo 4

Fan casing
(upper)

Indoor fan motor

Photo 5

Screws

Photo 7

Motor band

Screws

Fan
casing(upper)

Photo 6

Screws

Insulation and screws

Photo 8

screws

20

PARTS LIST11

-

E1

(WH)

Q'ty/unit

1
2
3
4
5
6
7
8

9

10
11
12
13

14
15

16

VANE MOTOR
INSTALLATION METAL (L)
AIR FILTER
GRILLE (WH)
FRONT PANEL (WH)
DRAIN PAN
FAN CASING (U)
FAN CASING (L)
UNION (GAS)
UNION (GAS)
INSTALLATION METAL (R)
UNION (LIQUID)
BACK PANEL (IN)
NOZZLE (WH)
INDOOR HEAT EXCHANGER
INDOOR HEAT EXCHANGER
VANE (WH)
GRILLE CATCH (WH)

{12.7
{15.88

{6.35

3PCS/SET

1
1
2
1
1
1
2
2
1

1
1
1
1
1

1
3

1
1
2
1
1
1
2
2
1

1
1
1
1

1
1
3

1
1
2
1
1
1
2
2

1
1
1
1
1

1
1
3

MV

MCFH-A12WV

E02 227 303
E02 179 971
E02 179 100
E02 179 010
E02 179 000
E02 215 700
E02 179 237
E02 179 238
E02 179 667
E02 138 666
E02 179 972
E02 138 667
E02 179 231
E02 227 235
E02 823 620
E02 824 620
E02 227 040
E02 179 142

No.

Part No. RemarksPart name

Symbol

in Wiring

Diagram

-

E1

(WH)

MCFH-A18WV

-

E1

(WH)

MCFH-A24WV

MCFH-A12WV - (WH)
MCFH-A18WV - (WH)
MCFH-A24WV - (WH)

E1

E1

E1

11-1. INDOOR UNIT

STRUCTURAL PARTS

1

2

3

4

15

1314

12
11

10

9

8

Part number that is circled is not shown in the illustration.

65

21

7

1
2

3
4

5
6
7

8

9
10
11

SIROCCO FAN
FAN MOTOR RUBBER MOUNT
INDOOR FAN MOTOR
INDOOR FAN MOTOR
INDOOR FAN MOTOR
TERMINAL BLOCK
TERMINAL BLOCK
RECEIVER P.C. BOARD
INDOOR COIL THERMISTOR
ELECTRONIC CONTROL P.C. BOARD
ELECTRONIC CONTROL P.C. BOARD
ELECTRONIC CONTROL P.C. BOARD
SWITCH & ROOM TEMPERATURE THERMISTOR P.C. BOARD
VARISTOR
FUSE

2
2
1

1
1
1
1
1

1
1
1

2
2

1
1

1
1
1

1
1

1
1

2
2

1
1
1
1
1

1
1
1
1

MF
MF

MF
TB2
TB1

RT12

NR11

F11

REMOTE CONTROLLER
REMOTE CONTROLLER HOLDER

SW/THERMO

P.C. BOARD

-

E1

(WH)

Q'ty/unit

MCFH-A12WV

E02 179 500
E02 179 505
E02 228 300
E02 229 300
E02 684 300
E02 826 375
E02 823 375
E02 227 468
E02 327 307
E02 826 452
E02 827 452
E02 828 452
E02 215 328
E02 820 385
E02 127 382

No. Part No.

RemarksPart name

Symbol

in Wiring

Diagram

-

E1

(WH)

MCFH-A18WV

-

E1

(WH)

MCFH-A24WV

2PCS/SET
RB4V25­RB4V36­RB4V36­3P
3P

3.15A

12
13

1
1

1
1

1
1

E02 826 426
E02 527 083

DISP/RECEIVER

P.C. BOARD

KG04C

MCFH-A12WV - (WH)
MCFH-A18WV - (WH)
MCFH-A24WV - (WH)

E1
E1
E1

11-2. INDOOR UNIT

ELECTRICAL PARTS

9 8

1
2

3
2
1

6

7

11-2. INDOOR UNIT ELECTRICAL PARTS

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

11-3. ACCESSORY AND

REMOTE CONTROLLER

5

4

1312

11-3. ACCESSORY AND REMOTE CONTROLLER

22

12

Remove the air
filter and the
deodorizing
filter together.

Separate the deodorizing
filter (gray sponge type)
from the air filter.

Remove the air
filter and the
air cleaning filter
together.

Separate the air
cleaning filter
(white bellows type)
from the air filter.

OPTIONAL PARTS

12-1. AIR CLEANING FILTER

● If the air cleaning filter is clogged, it may lower the unit’s capacity or cause condensation at the air outlet .

● The air cleaning filter is disposable . The standard usable term is about 4 months . However , if the color of the filter

turns to dark brown , replace soon .

Models

MCFH-A12WV ­MCFH-A18WV ­MCFH-A24WV -

E1
E1
E1

Part No.

MAC - 1200 FT

12-2. DEODORIZING FILTER

● Clean the filter every two weeks . When it becomes too dirt , clean it more often .

● Replace the filter with a new one when its color can not be restored even after washing or when the filter becomes dark.

● Standard interval for the filter replacement is about 1 year .

Models

MCFH-A12WV ­MCFH-A18WV ­MCFH-A24WV -

E1
E1
E1

Part No.

MAC - 1700 DF

23

HEAD OFFICE: MITSUBISHI DENKI BLDG.,2-2-3, MARUNOUCHI, CHIYODA-KU, TOKYO100-8310, JAPAN

CC

Copyright 2004 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD
Distributed in Apr. 2004. No.OB336 REVISED EDITION-A 6
Distributed in Jan. 2004. No.OB336 6
Made in Japan

New publication, effective Apr. 2004
Specifications subject to change without notice.