Mitsubishi Electric MSC-GA20VB- E1 User manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ····································3
2. PART NAMES AND FUNCTIONS······················3
3. SPECIFICATION·················································5
4. NOISE CRITERIA CURVES·······························6
5. OUTLINES AND DIMENSIONS ·························7
6. WIRING DIAGRAM ············································8
7. REFRIGERANT SYSTEM DIAGRAM················8
8. SERVICE FUNCTIONS ······································9
9. TROUBLESHOOTING······································11
10. DISASSEMBLY INSTRUCTIONS·····················18
11. PARTS LIST······················································20
12. OPTIONAL PARTS···········································22
Wireless type
Models
MSC-GA20VB - (WH)
MSC-GA25VB - (WH)
MSC-GA35VB - (WH)
E1
E1
E1
MSC-GA20VB -
MSC-GA25VB -
MSC-GA35VB - E1
E1
E1
No. OB385
SPLIT-TYPE, AIR CONDITIONERS
SPLIT-TYPE, HEAT PUMPAIR CONDITIONERS
Indication of model name
NOTE:
•This manual describes technical data of indoor units.
•As for outdoor units MU-GA20/GA25/GA35VB - , refer to the service manual OB386.
•As for outdoor units MUH-GA20/GA25/GA35VB - , refer to the service manual OB387.
•As for outdoor units MUX-2A28/2A59/3A60/3A63/2A70/4A73VB - , refer to the service manual
OB384.
•As for outdoor units MXZ-A14/A18/A26/A32WV - , refer to the service manual OB319 REVISED
EDITION-A. E1
E1
E1
E1
OB385-1.qxp 05.1.25 18:50 Page 1

2
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3
PART NAMES AND FUNCTIONS
2
INDOOR UNIT
MSC-GA20VB - MSC-GA25VB - MSC-GA35VB - E1E1E1
Emergency operation switch
Fan
Catechin air filter
(With deodorizer)
Air outlet
Vertical vanes
Air inlet
to Breaker
Remote control
receiving section
Display section
Air cleaning filter(option)
(white bellows type) Front panel
Power supply cord
Panel
Horizontal vane
Operation section
(When the front panel is opened)
Remote controller
Operation indicator lamp
Remote control
receiving section
TECHNICAL CHANGES
1
MSC-A07YV - ➔ MSC-GA20VB -
1. Indication of capacity has been changed. (BTU base ➔ kW)
2. P.C. board has been changed.
3. Air cleaning filter has been changed to optional parts.
4. Fan motor has been changed.
5. Fan motor capacitor has been changed.
6. Color of indoor unit has been changed.
MSC-A09YV - ➔ MSC-GA25VB -
1. Indication of capacity has been changed. (BTU base ➔ kW)
2. P.C. board has been changed.
3. Air cleaning filter has been changed to optional parts.
4. Fan motor has been changed.
5. Fan motor capacitor has been changed.
6. Color of indoor unit has been changed.
MSC-A12YV - ➔ MSC-GA35VB -
1. Indication of capacity has been changed. (BTU base ➔ kW)
2. P.C. board has been changed.
3. Air cleaning filter has been changed to optional parts.
4. Fan motor has been changed.
5. Fan motor capacitor has been changed.
6. Color of indoor unit has been changed.
E1E1
E1E1
E1E1
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4
ACCESSORIES
MSC-GA20VB -
MSC-GA25VB -
MSC-GA35VB - E1
E1
E1
Installation plate
Installation plate fixing screw 4 o25 mm
Remote controller holder
Fixing screw for 33.5 o16 mm
Battery (AAA) for remote controller
Wireless remote controller
Felt tape (Used for left or left-rear piping)
1
5
1
2
2
1
1
<Indoor unit>
1
2
3
4
5
6
7
ON/OFF
FAN
TOO
WARM TOO COOL
VANE
MODE
ECONO COOL
STOP
START
HR.
MIN.
I FEEL COOL
DRY
PM
CLOCK
AM
RESET CLOCK
HEAT
/FAN
/
Open the front lid.
ON/OFF
TOO
COOL
PM
AM
TOO
WARM
Signal transmitting section
Operation display section
OPERATE /STOP
(ON /OFF) button
TEMPERATURE buttons
Indication of remote controller model is
on back.
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 CONTROL button
CLOCK SET button
REMOTE CONTROLLER
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5
SPECIFICATION
3
Indoor model
Function
Indoor unit power supply
Air flow(High/Med. /Low )
Power outlet
Running current
Power input
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
Thermistor RT11(at 25:)
Thermistor RT12(at 25:)
Remote controller model
K/h
A
A
W
%
A
"
mm
kg
dB
rpm
k"
k"
MSC-GA20VB - E1
Single phase
230V,50Hz
10
0.17
35
90
0.17
RC4V19-JA
WHT-BLK 283
BLK-RED 188
815O278O244
9
5
3
10
10
KP1A
Cooling
474/372 /276
36/31 /25
900/750 /600
Heating
510/420 /342
36/31 /25
950/820 /700
MSC-GA25VB - E1
Single phase
230V,50Hz
10
0.17
35
90
0.17
RC4V19-JA
WHT-BLK 283
BLK-RED 188
815O278O244
9
5
3
10
10
KP1A
Cooling
474/384 /306
36/31 /25
900/770 /650
Heating
588/456 /342
39/32 /25
1,050/870 /700
MSC-GA35VB - E1
Single phase
230V,50Hz
10
0.19
40
92
0.19
RC4V19-HA
WHT-BLK 224
BLK-RED 318
815O278O244
10
5
3
10
10
KP1A
Cooling
582/444 /324
40/33 /26
930/760 /600
Heating
606/498 /396
39/33 /26
960/830 /700
Electrical data
Fan motor
Special remarks
Capacity
w w
w w
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NOTE: 1. Test conditions are based on ISO 5151.
Cooling : Indoor DB27°C WB19°C Heating : Indoor DB20°C
Outdoor DB35°C WB24°C Outdoor DB7°C WB6°C
Indoor-Outdoor piping length 5m
WReference value
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6
NOISE CRITERIA CURVES
4
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
APPROXIMATE
TERESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
Test conditions,
Cooling : DB27:WB19:
Heating : DB20:WB -:
MSC-GA20VB- E1 COOLING
High
FUNCTIONFAN SPEED
36
HEATING
SPL(dB(A)) LINE
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
APPROXIMATE
TERESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
Test conditions.
Cooling : DB27:WB19:
Heating : DB20:WB -:
MSC-GA25VB- E1 COOLING
High
FUNCTIONFAN SPEED
36
HEATING 39
SPL(dB(A)) LINE
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
APPROXIMATE
TERESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
Test conditions.
Cooling : DB27:WB19:
Heating : DB20:WB -:
MSC-GA35VB- E1 COOLING
FUNCTIONFAN SPEED
40
HEATING
High 39
SPL(dB(A)) LINE
INDOORUNIT WALL
MICROPHONE
0.8m
1m
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7
OUTLINES AND DIMENSIONS
5
MSC-GA20VB -
MSC-GA25VB - E1
E1
INDOOR UNIT
244
242 5
7 or more
90
110
30
149
606
278
60
815
783
Power supply cord
Lead to right 1.0m
Lead to left 0.3m
Air out
Installation plate
Insulation [28
Drain hose [16
(Connected part O,D)
Air in
Liquid line [6.35-0.5m
Gas line [9.52-0.43m
Insulation [37 O.D
[21 I.D
{
Wireless remote controller
162
19
58
81.5
81.5
41
2.5
42
271
231.5
4.5
81.5 133.5
326326
Wall hole [65
Indoor unit
Installation plate
Unit: mm
MSC-GA35VB - E1
INDOOR UNIT
244
242
218.5
258
81.581.5
41
42
2.5
17.5
161.5161.5
326326
5
7 or more
90
110
30
149
606
278
60
815
783
Power supply cord
Lead to right 1.0m
Lead to left 0.3m
Air out
Indoor unit
Installation plate
Wall hole [65
Installation plate
Insulation [28
Drain hose [16
(Connected part O,D)
Liquid line [6.35-0.5m
Gas line [9.52-0.43m
Insulation [37 O.D
[21 I.D
{
Wireless remote controller
162
19
58
Air in
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8
REFRIGERANT SYSTEM DIAGRAM
7
MSC-GA20VB - MSC-GA25VB - MSC-GA35VB - E1E1E1
INDOOR UNIT
Indoor
heat
exchanger
Room temperature
thermistor
RT11
Refrigerant pipe [9.52
(with heat insulator) Unit:mm
Indoor coil
thermistor
RT12
Flared connection
Flared connection
WIRING DIAGRAM
6
MSC-GA20VB - MSC-GA25VB - MSC-GA35VB - E1E1E1
MODELS WIRING DIAGRAM
SYMBOL
NR11
RT11
RT12
SR141
NAME NAME NAME
INDOOR FAN CAPACITOR
FUSE(3.15A)
INDOOR FAN MOTOR (INNER FUSE)
VANE MOTOR
VARISTOR
ROOM TEMPERATURE THERMISTOR
INDOOR COIL THERMISTOR
SOLID STATE RELAY
TERMINAL BLOCK
SYMBOL
C11
F11
MF
MV
SYMBOL
TB
T11 TRANSFORMER
MF
1
2
3
4
5
6
125
CNCN
109
5
REMOTE
CONTROLLER
23
POWER MONITOR
RECEIVER P.C.BOARD
GRN
LD103
PE
12V
FOR
MU OR
MUX TYPE
FOR MUH OR
MXZ-A TYPE
MV
GRN/YLW
POWER
SUPPLY
CORD
~/N 230V
50Hz
TO OUTDOOR
UNIT
CONNECTING
12V
1
2
N
3
LBRN
BLU
BLK
WHT
BLU
RED
BRN
5
CN
151
1
2
CN202
1
2
3
CN201
LD105
CN211
ELECTRONIC CONTROL P.C. BOARD
F11
T11
NR11
RT11
RT12
CN
112
CN
111
5
3
1
CN
121
BLK
GRY
YLW
BRN
3
WHT
RED
C11
SR141
CIRCUIT BREAKER
TB
INDOOR UNIT
NOTE: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.
/: Terminal block, : Connector
Refrigerant pipe [6.35
(with heat insulator)
Refrigerant flow
in cooling
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9
SERVICE FUNCTIONS
8
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.
8-1. TIMER SHORT MODE
For service, set time can be shortened by short circuit of JPG and JPS the electronic control P.C. board.
The time will be shortened as follows. (Refer to 9-6.)
Set time : 1 minute ➔ 1-second
Set time : 3 minutes ➔ 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.)
How to modify the remote controller P.C. board
Remove batteries before modification. The board has a print as shown below :
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.
The P.C. board has the print “J1” and “J2”. Solder “J1” and “J2” according to the number of indoor unit as shown in Table 1.
After modification, press the RESET button.
Table 1
No. 1 unit
No. 2 unit
No. 3 unit
No. 4 unit
1 unit operation
No 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
MSC-GA20VB -
MSC-GA25VB -
MSC-GA35VB - E1
E1
E1
Remote controller model : KP1A J2
J1
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.
Slide switch Type
The position
of the slide
switch
COOL ONLYCOOL & HEAT
8-3. REMOTE CONTROLLER (How to set the type)
This remote controller setting needs to be switched according to the type of air conditioner (COOL & HEAT or COOL
ONLY).
If the setting is incorrect, the air conditioner does not operate normally. Therefore, check if the setting corresponds to the
type of air conditioner. If not, correct the setting as shown below.
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10
NOTE
•The operation settings are memorized when 10 seconds have passed after the remote controller was operated.
•If main power is cut while AUTO START/STOP timer is active, the timer setting is cancelled.
•If the unit has been off with the remote controller before power failure, the auto restart function does not work as the
power button of the remote controller is off.
•To prevent breaker off due to the rush of starting current, systematize other home appliance not to turn on at the same
time.
•When some air conditioners are connected to the same supply system, if they are operated before power failure, the
starting current of all the compressors may flow simultaneously at restart.
Therefore, the special counter-measures are required to prevent the main voltage-drop or the rush of the starting current
by adding system that allows the units to start one by one.
1. MU & MUX TYPE / MUH & MXZ TYPE SWITCH OVER
The indoor units for MU & MUX type and MUH & MXZ type
are common specifications. Set switch according to the
type of outdoor unit. The units are set for
MUH & MXZ type when they are shipped from the factory.
How to release “AUTO RESTART FUNCTION”
! Turn off the main power for the unit.
@ Pull out the electronic control P.C. board, and change switch(SW2-1) on the indoor electronic control P.C. board as
following figures.
SW2-1 sets the AUTO RESTART FUNCTION ON / OFF.
SW2-2 switches over the MU & MUX type / MUH & MXZ type.
When the units are shipped from the factory, SW2 is as follows.
SW2-1:AUTO RESTART FUNCTION ON
SW2-2:MUH & MXZ type
}
SW2
FRONT
12
12
IC101
CN151
SW1
CN112
CN121
L101
CN201
F11
CN202
C11
CN211
SW2
LD105
Operation
! If the main power (230V AC) has been cut, the operation settings remain.
@ After the power is restored, the unit restarts automatically according to the memory. (However, it takes at least 3
minutes for the compressor to start running.)
8-4. MU & MUX TYPE / MUH & MXZ TYPE SWITCH OVER AND AUTO RESTART FUNCTION
2. 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
FEEL CONTROL” mode before power failure, the operation is not memorized. In “I FEEL CONTROL” mode, the opera-
tion is decided by the initial room temperature. “AUTO RESTART FUNCTION” is ON when the units are shipped from
the factory.
1 2
1 2
1 2 SW2 SW2
1 2
Outdoor unit
MUH & MXZ type
Set 2 switch downside.
Outdoor unit
MU & MUX type
Set 2 switch upside.
NOTE:•If the indoor-outdoor connecting wire is incorrectly
connected on the terminal block, the unit does not
operate normally.
•If a ground is incorrect, it may cause an electric shock.
How to switch over MU & MUX TYPE / MUH & MXZ TYPE
! Turn off the main power for the unit.
@ Pull out the electronic control P.C. board, and change
switch(SW2-2) on the indoor electronic control P.C. board
according to the type of outdoor unit as following figures.
1 2 SW2 SW2
1 2 1 2
1 2
AUTO RESTART
FUNCTION ON
Set 1 switch downside.
AUTO RESTART
FUNCTION OFF
Set 1 switch upside.
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