Mitsubishi Electric MSH-CB50VB- E1 Service Manual

SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS

INDOOR UNIT

SERVICE MANUAL

Wireless type
Models

No. OB440

MSH-CB50VB -

MSH-CB50VB

E1

Outdoor unit service manual
MUH-GA·VB Series (OB368)

CONTENTS

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

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

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

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

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

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

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

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

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

10. DISASSEMBLY INSTRUCTIONS·····················17

11. PARTS LIST······················································19

12. OPTIONAL PARTS ···········································21

NOTE:

This service manual describes technical data of the indoor unit.

1

Grille

(When the grille is opened)

Remote controller

Operation section

Display section

Emergency operation switch

Operation indicator lamp

Air inlet

To Breaker
Power supply cord

Remote control

receiving section

Air cleaning filter (option)
(White bellows type)

Horizontal vane

Vertical vanes

Catechin air filter

Remote control

receiving section

Front panel

1
2
3
4
5
6
7

Installation plate
Installation plate fixing screw 4 o 25 mm
Remote controller holder
Fixing screw for 3 o 3.5 o 1.6 mm (Black)
Battery (AAA) for remote controller
Wireless remote controller
Felt tape (Used for left or left-rear piping)

1
7
1
2
2
1
1

MSH-CB50VB

TECHNICAL CHANGES

MSH-GA50VB -

1. Panel logo has been changed.

2

PART NAMES AND FUNCTIONS

➔MSH-CB50VB -

INDOOR UNIT

MSH-CB50VB

E1E1

ACCESSORIES

Indoor unit

2

REMOTE CONTROLLER

ON/OFF

TOO

COOL

PM

AM

TOO

WARM

ON/OFF

FAN

TOO

WARM

TOO

COOL

VANE

MODE

ECONO COOL

STOP

START

HR.

MIN.

WIDE VANE

LONG

I FEEL

COOL

HEAT

DRY

PM

CLOCK

AM

RESET CLOCK

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

HR. button

MIN. button

(TIME SET button)

ON-TIMER button

RESET button

ECONO COOL button

VANE button

(Horizontal vane button)

CLOCK SET button

LONG button

WIDE VANE button

(Vertical vane button)

Indication of remote controller
model is on back.

MSH-CB50VB

3

3

90

80

70

60

50

40

30

20

10

63 125 250 500 1000 2000 4000 8000

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

BAND CENTER FREQUENCIES, Hz

Test conditions,
Cooling : Dry-bulb temperature 27: Wet-bulb temperature 19:

APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE

42

SPL(dB(A)) LINE

High

FAN SPEED

Heating : Dry-bulb temperature 20: Wet-bulb temperature 15.5:

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

Indoor model

Function

Power supply

Air flow

(High/Med./Low)
Power outlet
Running current
Power input
Auxiliary heater
Power factor
Fan motor current
Model
Winding
resistance(at 20:)
Dimensions WOHOD
Weight
Air direction
Sound level(High/Med./Low)
Fan speed(High/Med./Low)
Fan speed regulator
Remote controller model

K /h

A
A

W

A(kW)

%

A

"

mm

kg

dB

rpm

MSH-CB50VB

Single phase

230V, 50Hz

768/642/528

10

0.3
60
—
87

0.30

RC4V32-AA

WHT-BLK 293

BLK-RED 146

1,100O325O258

16

5

42/38/34

1,070/920/780

3

KP0A

Cooling

Heating

Electrical

data

Fan

motor

Special

remarks

Capacity

INDOORUNIT

WALL

MICROPHONE

0.8m

1m

SPECIFICATION

NOTE: Test conditions are based on ISO 5151.

Cooling : Indoor DB27°C WB19°C Heating : Indoor DB20°C WB 15.5°C

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

Indoor-Outdoor piping length : 5m

4

NOISE CRITERIA CURVES

MSH-CB50VB

4

5

258

162

19

58

47

7.5

315

255.547

2.5

98

173

98 173414.5 414.5

5

253

791

56

1068

1100

325

Air out

Air in

Insulation [28

Drain hose [16
(Connected part O.D)

Installation plate

Wall hole [75

Wireless remote controller

Installation plate

Indoor unit

{

Liquid line [ 6.35-0.5m
Gas line [ 12-0.43m
Insulation [ 50 O.D

[ 32 I.D

Power supply cord
Lead to right 2.0m
Lead to left 1.0m

OUTLINES AND DIMENSIONS

MSH-CB50VB

INDOOR UNIT

Unit: mm

5

6

WIRING DIAGRAM

MSH-CB50VB

INDOOR UNIT

TO OUTDOOR
UNIT
CONNECTING

12V

POWER
SUPPLY
CORD
~/N 230V
50Hz

PE

CIRCUIT
BREAKER

SYMBOL

C11

F11

HIC1

NOTES:

INDOOR FAN CAPACITOR
FUSE (T3.15AL250V)
DC/DC CONVERTER

MF

INDOOR FAN MOTOR (INNER FUSE)

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.

TB

3
N
L

BRN
BLU

: Terminal block

RED
BLU
BRN

GRN/YLW

NAME

MV2

: Connector

CN
151

15

MV2

SYMBOL

MV1

MV1

MV2
NR11
RT11

CN201

3
2
1

TAB12

CN
102

CN
101

3

DISPLAY
P.C.BOARD

NAME
VANE MOTOR (HORIZONTAL)
VANE MOTOR (VERTICAL)
VARISTOR
ROOM TEMPERATURE THERMISTOR

HIC1

F11

SR141

ELECTRONIC CONTROL
P.C. BOARD

3

RECEIVER
P.C.BOARD

REMOTE
CONTROLLER

SYMBOL

NR11

RT12

SR141

TB

C11

2
1

CN112

CN
121

1
3
4

CN211

CN
111

3

RT12

BLK
GRY
YLW
BRN
WHT
RED

RT11

NAME
INDOOR COIL THERMISTOR
SOLID STATE RELAY
TERMINAL BLOCK

1
2
3

MF

4
5
6

7

REFRIGERANT SYSTEM DIAGRAM

MSH-CB50VB

INDOOR UNIT

Indoor
heat
exchanger

Indoor coil
thermistor
RT12

Room temperature
thermistor
RT11

Distributor

Unit:mm

Refrigerant pipe [12.7
(with heat insulator)

Flared connection

Flared connection

Refrigerant pipe [6.35
(with heat insulator)

6

Refrigerant flow in cooling
Refrigerant flow in heating

8

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

SERVICE FUNCTIONS

MSH-CB50VB

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.

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 : KP0A

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.

J2

J1

NOTE : For remodelling, take out the bat-

teries 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.

Table 1

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.

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.

7

How to release “AUTO RESTART FUNCTION”

JR07

IC152

CN151

CN112

CN111

CN121

SW1

IC101

RA102

C11

CN201

CN211

TAB12

1Turn off the main power for the unit.
2Pull out the electronic control P.C. board, the receiver P.C.

board and the display P.C.board. (Refer to 10.2.)

3Solder jumper wire to JR07 on the indoor

electronic control P.C. board. (Refer to 9-6.)

Operation

1If the main power 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.

8

9

Lead wiring

Housing point

RESET button

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

TROUBLESHOOTING

MSH-CB50VB

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 servicing.

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

ing the horizontal vane is closed, turn off the breaker and / or disconnect the power plug.

(2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the 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 check that the connector and terminal are connected properly.
(3) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the

components for bursting and discolouration.
(4) When troubleshooting, refer to 9-2. and 9-3.

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.

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

9

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 9-6.
"Test point
diagram and
voltage".

Refer to
"Check of
outdoor unit".

Refer to 9-5.B
"Check of
remote controller
and receiver
P.C. board".

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

• Mis-wiring

2-time flash
Cause:
Indoor unit

• Trouble of
room temp­ erature/
indoor coil
thermistor

3-time flash
Cause:
Indoor unit

• Trouble of
indoor fan
motor

6-time flash
Cause:
Outdoor unit

• Trouble of
thermistor
in outdoor
unit

7-time flash
Cause:
Outdoor unit

• Trouble of
outdoor
control
system

Refer to
9-5. D
"How to
check
mis-wiring
(When
outdoor unit
doesn't
work)".

Check room
temperature
thermistor
and indoor
coil thermis­tor.
Refer to 9-6.
"Test point
diagram and
voltage".

Refer to
9-5. A
"Check of
indoor fan
motor".

Refer to
"Check of
outdoor
thermistor".

Replace the
deicer
P.C. board.

4-time flash
Cause:
Indoor unit

• Trouble of
indoor unit
control
system

Replace the
indoor
electronic
control
P.C. board.

As for outdoor unit , refer to service manual OB368.

1. Check indoor /
outdoor
connecting wire.

2. Refer to 9-5.C
"Check of indoor
electronic control
P.C. board".

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
outdoor unit".

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

9-2. Instruction of troubleshooting

10

9-3. Troubleshooting check table

Operation Indicator

Lighted
Not lighted

No.

1

2

4

6

SymptomOperation indicator lamp Detection method

Checkpoint

0.5-second ON

0.5-second OFF

Mis-Wiring

Outdoor
thermistor

Outdoor
control
system

Indoor coil
thermistor

3 minutes after power supply turns ON, when
serial signal is not received.

<Thermistor short>
Thermistors are abnormal when they short
after compressor start-up.
<Thermistor open>
Thermistors are abnormal when they open
after compressor start-up.
However, discharge temperature thermistor is
abnormal when open circuit is detected more
than 10 minutes after compressor start-up.

When it cannot properly read data in the
nonvolatile memory of the deicer P.C. board,
outdoor unit stops.

• Shortage of refrigerant

• Check the deicer P.C.
board.
Refer to "Check of outdoor

thermistor". Refer to service

manual OB368.

• Check the deicer P.C. board.
Refer to service manual
OB368.

• Refer to 9-5. D "How to check
mis-wiring ".

3

Indoor fan
motor

Abnormal

point

Outdoor unit
does not
operate.

Room
temperature
thermistor

2-time flash

2.5-second OFF

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

• Refer to the characteristics
of main indoor coil thermistor,
sub indoor coil thermistor,
and room temperature
thermistor. (9-6)

3-time flash

2.5-second OFF

Indoor fan repeats
12 seconds ON
and 3minutes OFF.
When the indoor
fan breaks, the fan
keeps stopping.

When rotational frequency feedback signal is
not emitting during 12-second indoor fan
operation.

• Refer to 9-5. A "Check of

indoor fan motor".

4-time flash

2.5-second OFF

Indoor
control
system

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

Outdoor unit
does not
operate.

Outdoor unit
does not
operate.

• Check the indoor electronic
control P.C. board.

6-time flash

2.5-second OFF

Outdoor unit
does not
operate.

Outdoor unit
does not
operate.

5

7-time flash

2.5-second OFF

• The following indication applies regardless of shape of the indicator.

· Flashing of the OPERATION INDICATOR lamp (on the left-hand side) indicates possible
abnormalities.

· The OPERATION INDICATOR lamp (on the left-hand side) is lighting during normal operation.

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

NOTE : When the indoor unit has started operation and the above detection method has detected an abnormality (the first

detection after the power ON), the indoor electronic control P.C. board turns OFF the indoor fan motor with the

OPERATION INDICATOR lamp flashing.

11

Part name FigureCheck method and criterion

Indoor fan motor(MF)

INNER FUSE
145: CUT OFF

Color of lead wire

WHT – BLK
BLK – RED

282 " ~ 305 "
141 " ~ 152 "

Measure the resistance with a tester.
Refer to 9-6. "Test point diagram and voltage", "Indoor electronic control P.C.

board", the chart of thermistor.

Room temperature
thermistor(RT11)

Indoor coil thermistor
(RT12(main), RT13(sub))

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

Motor part

Sensor part

Measure the resistance between the terminals with a tester.
(Part temperature 10˚C ~ 30˚C)

Color of lead wire

BRN – YLW
YLW – GRY

Normal

4.5 ~ 5.5V

Measure the voltage power ON.

(When fan revolved one time)

0V➔5V➔0V

(Approx.)

Normal

282" ~ 306 "

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

MAIN

AUX

FUSE

BLK

RED

WHT

GRY

YLW

BRN

Normal

YLW

GRNORN

BRN

RED

ROTOR

:INNER PROTECTOR

P

9-4. Trouble criterion of main parts

MSH-CB50VB

12

9-5. Troubleshoot flow

When OPERATION INDICATOR lamp flashes 3-time.
Indoor fan motor doesn’t operate.

A

Check of indoor fan motor

Turn OFF the power supply.
Check connector CN211 visually.

No

Reconnect the lead wires.

Disconnect lead wires from connector CN211 on the indoor electronic control P.C. board.
Measure resistance between lead wires No.3 and No.4 and then No.1 and No.4.

Are lead wires connected?

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

Repair or replace the indoor fan motor.

Yes

Yes ( 0 or ∞ )

Is soldered point of the connector
correctly soldered?

Yes

Turn ON the power supply. Stop it if the unit operate.
Insert screwdriver into air outlet to rotate indoor fan
motor slowly for 1 revolution or over, and measure

No

voltage between No.2(+) and No.3(-) on CN121.

(others)

No

Does voltage repeat 0V DC and 5V DC?

Replace the indoor electronic control P.C. board.

No

Resolder it.

Yes

Indoor unit operates by pressing the EMERGENCY OPERATION switch, but doesn’t 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 the 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 the RESET button. 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 switch on
the 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 CN301 No.1(+) and No.3(-) when the 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.

13

The unit doesn’t 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

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

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

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

Yes

Turn OFF the
power supply.

Replace the vane
motor.

Yes

Is winding
resistance of
vane motor 0 "?

No

Is winding
resistance of
fan motor 0 "?

Yes

Replace the fan
motor.

Turn OFF the
power supply.

No

No

Replace the fuse.

Yes

Is fuse(F11) blown?

No

Is varistor(NR11) burnt?

Yes

Replace the varistor.

Fuse (F11)

Indoor electronic
control P.C. board

No

Varistor (NR11)

Replace the indoor
electronic control
P.C. board.

14

1. Turn OFF the power supply (indoor/ outdoor unit) and disconnect indoor and outdoor
connecting wire on indoor side.

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

3. Turn ON the power supply (indoor unit) and press once EMERGENCY OPERATION switch.

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

As for outdoor unit, refer to service manual OB368.

Start

No

No

Is there 20V DC between both ends of
R132 on the indoor electronic control P.C.
board ?
( By tester, the stylus is between 0 ~ 20V. )

• Turn ON the power supply. (indoor/ outdoor unit)

• Press once EMERGENCY OPERATION switch.

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

Make them sure.

Replace the indoor electronic
control P.C. board.

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

No

Check the outdoor power supply
and connection of wiring.

Yes

No

Replace the deicer P.C. board.

Yes

No

Make the wiring between CN730
on the deicer P.C. board and
outdoor terminal block correct.

Replace the deicer P.C. board.

Yes

Is there 5V DC between J205 + -J101 -
on the deicer P.C. board?

Yes

Yes

After 3 minutes, mis-wiring is indicated
(0.5-second ON, 0.5-second OFF)
on OPERATION INDICATOR
lamp on indoor unit.w

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

• Turn OFF the power supply.

(indoor unit)

• Connect ON indoor/ outdoor connecting
wire.

Turn ON the power supply. (outdoor unit)

When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.
Outdoor unit doesn’t operate.

How to check mis-wiring

D

15

9-6. Test point diagram and voltage

Indoor coil thermistor(RT12(main), RT13(sub))

Room temperature thermistor (RT11)

Resistance(k")

MSH-CB50VB

Indoor electronic control P.C. board

Fuse (F11)
250V AC 3.15A

R132

Fan motor power supply

Power supply input

}

230V AC

5V DC

}

+

Room temperature ther­mistor(RT11)

Indoor coil
thermistor(RT12(main))

Receiver P.C. board

Release of “Auto restart function”
Solder jumper wire to JR07.
(Refer to 8-3.)

+

}

12V DC

Emergency operation
switch

Timer short mode point
(JPS, JPG)
(Refer to 8-1.)

16

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

Sleeve

mechanism.

1Slide the sleeve.
2Pull the terminal while

Locking lever

pushing the locking
lever.

MSH-CB50VB
INDOOR UNIT

OPERATING PROCEDURE PHOTOS

1. Removing the front panel

(1) Remove the screw caps of the front panel.

Remove the screws.

(2) Pull the panel down to your side slightly and unhook the

catches at the top.

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

Connector

Photo 1

Front panel

Screws

2. Removing the electronic control P.C. board, the receiver
P.C. board and the display P.C. board

(1) Remove the front panel. (Refer to 1.)
(2) Remove the screw of the electrical cover.

Remove the electrical cover.

(3) Remove the screws of the V.A. clamp.

Remove the V.A. clamp.
(4) Remove the screw of the terminal block.
(5) Remove the screws of the ground wire.
(6) Disconnect all the connectors and all the lead wires on the

electronic control P.C. board.
(7) Remove the R.L holder.
(8) Remove the electronic control P.C. board.
(9) Open the R.L holder, remove the receiver P.C. board and

the display P.C. board.

17

Photo 2

R.L
holder

Screws of the ground wire

Screw of
the terminal
block

Receiver
P.C.
board

Fan motor
connectors

Vane motor
connector

Indoor
electronic
control
P.C. board

Screw of
the electrical
cover

Screw of the
V.A. clamp

OPERATING PROCEDURE

PHOTOS

3. Removing the electrical box

(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical cover. (Refer to 2.)
(3) Disconnect the connector of the indoor coil thermistor.
(4) Disconnect the motor connector (CN211 and CN121) and

the vane motor connector (CN151) on the electronic

control P.C. board.
(5) Remove the screws of ground wire.
(6) Remove the fan motor lead wire and indoor coil thermistor

from the electrical box.
(7) Remove the lead wire of vane motor from the bottom of

electrical box.
(8) Remove the screw fixing the electrical box and remove the

electrical box.

4. Removing the vane motor

(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical cover. (Refer to 2.)
(3) Remove the lead wire of vane motor. (Refer to 3.)
(4) Remove the R.L. holder.
(5) Pull out the drain hose from the nozzle assembly and

remove the nozzle assembly.

(6) Remove the screws of the vane motor and disconnect the

connector.

(7) Remove the vane motor.

Photo 5

Screws of the
vane motor

Photo 3

Photo 4

Screws of the ground wire

Vane motors

Screw of the
electrical cover

Screw of the
electrical box

Screws
of the
vane
motor

Vane motor

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

(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical box. (Refer to 3.)
(3) Pull out the drain hose from the nozzle assembly and

remove the nozzle assembly.
(4) Remove the water cut.
(5) Slide the hole cover and remove the hole cover.
(6) Remove the hexagon socket set screw from the line flow

fan.
(7) Remove the screws fixing the fan motor and remove the

fan motor. (Be careful not to drop the fan motor because it

is heavy.)
(8) Remove the screws fixing the left side of the heat

exchanger.
(9) Lift the left side of the heat exchanger.
(

10

) Remove the line flow fan.

Photo 8

Hole

cover

Photo 6

Screws fixing
the left side
of the heat
exchanger

Photo 7

Indoor
coil
thermistor

Water cut

Screws fixing the fan motor

18

11

MSH-CB50VB -

E1

E02 527 970
E02 685 234
E02 888 000
E02 408 142
E02 685 067
E02 888 010
E02 534 100
E02 685 975
E02 A62 007

INSTALLATION PLATE
BOX
FRONT PANEL ASSEMBLY
CATCH
SCREW CAP
GRILLE
CATECHIN AIR FIL TER
CORNER BOX RIGHT
LAMP PANEL

Symbol

in Wiring

Diagram

Q'ty/unit

Including No.4,5,6

4PCS/ SET
3PCS/ SET

RemarksPart No.

NO.

Part Name

1
2
3
4
5
6
7
8
9

1
1
1
4
3
1
2
1
1

E02 891 620
E02 179 667
E02 151 667

INDOOR HEAT EXCHANGER
UNION (GAS)
UNION (LIQUID)

{12.7
{6.35

10
11
12

1
1
1

PARTS LIST

MSH-GA50VB

11-1. INDOOR UNIT STRUCTURAL PARTS

1
2

3

4
5

6

7

11-1. INDOOR UNIT STRUCTURAL PARTS

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

11-2. INDOOR UNIT HEAT EXCHANGER

10

8
Optional

parts
(See 12.)

11

12

11-2. INDOOR UNIT HEAT EXCHANGER

19

E02 527 302
E02 408 509
E02 001 504
E02 408 702
E02 996 235
E02 685 040
E02 685 041
E02 A49 382
E02 817 385
E02 527 034
E02 817 300
E02 448 303
E02 408 303
E02 817 333
E02 528 329
E02 527 468
E02 891 452
E02 527 308
E02 819 375
E02 408 307
E02 528 034
E02 529 034

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18
19
20
21
22

LINE FLOW FAN
BEARING MOUNT
SLEEVE BEARING
DRAIN HOSE
NOZZLE ASSEMBLY
VANE UPPER
VANE LOWER
FUSE
VARISTOR
VANE CRANK SET
INDOOR FAN MOTOR ASSEMBLY
VANE MOTOR (VERTICAL)
VANE MOTOR (HORIZONTAL)
MOTOR BAND
DISPLAY P.C. BOARD
RECEIVER P.C. BOARD
ELECTRONIC CONTROL P.C. BOARD
ROOM TEMPERATURE THERMISTOR
TERMINAL BLOCK
INDOOR COIL THERMISTOR
VANE MOTOR SUPPORT SET(RIGHT)
VANE MOTOR SUPPORT SET(LEFT)

Symbol

in Wiring

Diagram

Q'ty/unit

T3.15AL250V

RIGHT & LEFT
UP & DOWN

RemarksPart No.

NO.

Part Name

F11

NR11

MF
MV2
MV1

RT11

TB

RT12

1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1

RC4V32 ­Including RUBBER MOUNT

AUTO RESTART
Including No.16

MSH-CB50VB -

E1

MSH-CB50VB

23
24

E02 529 426
E02 527 083

REMOTE CONTROLLER
REMOTE CONTROLLER HOLDER

1
1

KM04A

11-3. INDOOR UNIT FUNCTIONAL PARTS AND

ELECTRICAL PARTS

1

20

19

11-4. ACCESSORY AND

REMOTE CONTROLLER

23 24

2

3

4

12

11

18

5
6

14

13

10

7

8

9

15

16

17

11-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS

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

11-4. ACCESSORY AND REMOTE CONTROLLER

20

12

Air cleanig filter (White bellows type)

Model Part No.

MAC-1700FT

MSH-CB50VB -

E1

OPTIONAL PARTS

AIR CLEANING FILTER

● AIR CLEANING FILTER removes fine dust of 0.01 micron from air by means of static electricity.

● Normal life of AIR CLEANING FILTER is 4 months. However, when it becomes dirty, replace it as soon as possible.

● Clogged AIR CLEANING FILTER may reduce the air conditioner capacity or cause frost on the air outlet.

● DO NOT reuse AIR CLEANING FILTER even if it is washed.

● DO NOT remove or attach AIR CLEANING FILTER during unit operation.

21

22

23

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

CC

Copyright 2005 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD
Distributed in Dec. 2005. No.OB440 6
Made in Japan

New publication, effective Dec. 2005
Specifications subject to change without notice.