Mitsubishi Electric MSZ-A18YV User manual

SERVICE MANUAL
CONTENTS
1. PART NAMES AND FUNCTIONS······················2
2. SPECIFICATION·················································4
3. NOISE CRITERIA CURVES ·······························5
4. OUTLINES AND DIMENSIONS ·························6
5. WIRING DIAGRAM ············································7
6. REFRIGERANT SYSTEM DIAGRAM ················8
7. SERVICE FUNCTIONS ······································9
8. TROUBLESHOOTING······································11
9. DISASSEMBLY INSTRUCTIONS ····················20
10. PARTS LIST······················································22
11. OPTIONAL PARTS·······················BACK COVER
Models
MSZ-A18YV -
MSZ-A24YV -
MSZ-A26YV - E1
E1
E1
SPLIT-TYPE AIR CONDITIONERS
MSZ-A18YV -
MSZ-A24YV -
MSZ-A26YV - E1
E1
E1
NOTE:
This service manual describes technical data of the indoor unit.
•Refer to the service manual OB346 when MSZ-A18YV - , MSZ-A24YV - or MSZ-A26YV -
is connected with MUZ-A18YV - , MUZ-A24YV - or MUZ-A26YV - .
•Refer to the service manual OB319 when MSZ-A18YV - , MSZ-A24YV - or MSZ-A26YV -
is connected with MXZ-A26WV - or MXZ-A32WV - as multi system units.
E1E1
E1E1E1
E1E1E1
E1E1E1
No. OB345
REVISED EDITION-A
Revision A :
• Parts numbers of indoor fan motor and motor band have
been changed.
•
Another type of the electronic control P.C.board (TYPE 2)
has been added to the original one (TYPE 1).
They are both compatible with MSZ-A18/24/26YV-
.
• Some descriptions have been modified.
E
Please void OB345.
INDOOR UNIT

2
PART NAMES AND FUNCTIONS
1
INDOOR UNIT
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
MSZ-A18YV -
MSZ-A24YV -
MSZ-A26YV - E1
E1
E1
ACCESSORIES
Indoor unit
1
2
3
4
5
6
7
Installation plate
Installation plate fixing screw 4 o25 mm
Remote controller holder
Fixing screw for 3o3.5 o1.6 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
MSZ-A18YV -
MSZ-A24YV -
MSZ-A26YV -
E1
E1
E1
Use the specified refrigerant only
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the spec labels provided with our products.
We will not be held responsible for mechanical failure, system malfunction, unit breakdown or accidents caused by
failure to follow the instructions.
Revision A :
• Parts numbers of indoor fan motor and motor band have been changed.
• Another type of the electronic control P.C.board (TYPE 2) has been added to the original one (TYPE 1).
They are both compatible with MSZ-A18/24/26YV- .
• Some descriptions have been modified.
E
OB345A

REMOTE CONTROLLER
MSZ-A18YV -
MSZ-A24YV -
MSZ-A26YV - E1
E1
E1
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.
3
OB345A

SPECIFICATION
4
2
Indoor model
Function
Power supply
Air flow
(High/Med. /Low )
Power outlet
Running current
1
Power input 1
Auxiliary heater
Power factor
1
Fan motor current 1
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:)
Thermistor RT13(at 25:)
Remote controller model
K/h
A
A
W
A(kW)
%
A
"
mm
kg
dB
rpm
k"
k"
k"
MSZ-A18YV - E1
Single phase
230V, 50Hz
852/690 /498
10
0.30
60
—
87
0.30
RC4V32-AA
WHT-BLK 293
BLK-RED 146
1,100O325O258
16
5
43/38 /31
1,120/940 /720
3
10
10
10
KP0A
Cooling Heating
MSZ-A24YV - E1
Single phase
230V, 50Hz
10
0.34
69
—
87
0.34
RC4V40-AA
WHT-BLK 138.2
BLK-RED 159.0
1,100O325O258
16
5
48/40 /32
3
10
10
10
KP0A
Cooling
1,032/768 /522
1,310/1030 /750
Heating
1,032/786 /522
1,310/1050 /750
Electrical data
Fan motor
Special remarks
Capacity
w w
w w
ww
ww
ww
ww
w w
ww
ww
w w
ww
NOTE: Test conditions are based on ISO 5151.
Cooling : Indoor Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Outdoor Dry-bulb temperature 35°C Wet-bulb temperature(24°C)
Heating : Indoor Dry-bulb temperature 20°C Wet-bulb temperature 15.5°C
Outdoor Dry-bulb temperature 7°C Wet-bulb temperature 6°C
Indoor-Outdoor piping length 5m
wReference value
1 Measured under rated operating frequency.
Indoor model
Function
Power supply
Air flow
(High/Med. /Low )
Power outlet
Running current
1
Power input 1
Auxiliary heater
Power factor
1
Fan motor current 1
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:)
Thermistor RT13(at 25:)
Remote controller model
K/h
A
A
W
A(kW)
%
A
"
mm
kg
dB
rpm
k"
k"
k"
MSZ-A26YV - E1
Single phase
230V, 50Hz
10
0.34
69
—
88
0.34
RC4V40-AA
WHT-BLK 138.2
BLK-RED 159.0
1,100O325O258
16
5
48/40 /33
3
10
10
10
KP0A
Cooling
1,032/798 /564
1,310/1,060 /800
Heating
1,032/816 /564
1,310/1,080 /800
Electrical data
Fan motor
Special remarks
Capacity
w w
ww
ww
w w
ww w
ww
ww
w
•Refer to the service manual OB346 when MSZ-A18YV - , MSZ-A24YV - or MSZ-A26YV - is connected with
MUZ-A18YV - , MUZ-A24YV - or MUZ-A26YV - .
•Refer to the service manual OB319 when MSZ-A18YV - , MSZ-A24YV - or MSZ-A26YV - is connected with
MXZ-A26WV - or MXZ-A32WV - as multi system units.
E1E1
E1E1E1
E1E1E1
E1E1E1
OB345A

5
NOISE CRITERIA CURVES
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
43
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
MSZ-A18YV - E1 MSZ-A24YV -
MSZ-A26YV - E1
E1
2.5+ 440V
250V 3.15A
MP20/MP20
TNR10V511K410
S201DH1N
3P
INDOOR UNIT
Item Model
Indoor fan capacitor
Fuse
Vane motor
Varistor
Solid state relay
Terminal block
Indoor fan motor thermal fuse
(C11)
(F11)
(MV1/ MV2)
(NR11)
(SR141)
(TB)
MSZ-A24YV -E1
MSZ-A18YV -E1 MSZ-A26YV -E1
145:
Specifications and rating conditions of main electric parts
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
Test conditions,
Cooling : Dry-bulb temperature 27: Wet-bulb temperature 19:
48
SPL(dB(A)) LINE
High
FAN SPEED
Heating : Dry-bulb temperature 20: Wet-bulb temperature 15.5:
INDOORUNIT
WALL
MICROPHONE
0.8m
1m
OB345A

6
OUTLINES AND DIMENSIONS
4
258
159
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
{
Liquid line [9.52- 0.5m
Gas line [12-0.43m
Insulation [50 O.D
[32 I.D
for MSZ-A18/A24YV
for MSZ-A26YV
Power supply cord
Lead to right 2.0m
Lead to left 1.0m
INDOOR UNIT
MSZ-A18YV -
MSZ-A24YV -
MSZ-A26YV - E1
E1
E1 Unit: mm
OB345A

7
WIRING DIAGRAM
5
MSZ-A18YV - E1 MODEL WIRING DIAGRAM
INDOOR UNIT
CN112
1RT12
2
3
4RT13
12V
TO OUTDOOR
UNIT
CONNECTING
BRN
BLU
GRN/YLW
BLK
GRY
YLW
BRN
WHT
RED
3
SR141
4
3
1
CN
121
C11
HIC1
TRANS
MV1
151
CN
MV2
15
RT11
111
CN
CN211
NR11
ELECTRONIC CONTROL P.C. BOARD
F11
3
N
LBRN
1
2
3
CN201
MV2
BLU
RED
CN
101
CN
102
DISPLAY
P.C. BOARD
RECEIVER
P.C. BOARD
REMOTE
CONTROLLER
33
TAB12
TB
6
5
4
3
2
MF
1
POWER
SUPPLY
CORD
~/N 230V
50Hz
CIRCUIT
BREAKER
PE
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
NAME
INDOOR FAN CAPACITOR
FUSE (3.15A)
DC/DC CONVERTER
INDOOR FAN MOTOR (INNER FUSE)
SYMBOL
MV1
MV2
NR11
RT11
NAME
VANE MOTOR (HORIZONTAL)
VANE MOTOR (VERTICAL)
VARISTOR
ROOM TEMPERATURE THERMISTOR
SYMBOL
RT12
RT13
SR141
TB
NAME
INDOOR COIL THERMISTOR (MAIN)
INDOOR COIL THERMISTOR (SUB)
SOLID STATE RELAY
TERMINAL BLOCK
INDOOR UNIT
TB
TAB12
3 3
REMOTE
CONTROLLER
RECEIVER
P.C. BOARD
DISPLAY
P.C. BOARD
102
CN 101
CN
RED
BLU
MV2
CN201
3
2
1
BRN
L
N
3
F11
ELECTRONIC CONTROL P.C. BOARD
NR11
CN211
CN
111 RT11
RT12
15
MV2
CN
151
CN112
1
2
3
4RT13
MV1
TRANS
HIC1
C11
121
CN
1
3
4
SR141
3
RED
WHT
BRN
YLW
GRY
BLK
GRN/YLW
TO OUTDOOR
UNIT
CONNECTING
12V MF
CIRCUIT
BREAKER
POWER
SUPPLY
CORD
~/N 230V
50Hz
BLU
BRN
PE
SYMBOL
SR141
TB
SYMBOL
MV2
NR11
RT11
RT12
RT13
SYMBOL
C11
F11
HIC1
MF
MV1
INDOOR FAN CAPACITOR
FUSE (3.15A)
DC/DC CONVERTER
INDOOR FAN MOTOR (INNER PROTECTOR)
VANE MOTOR (HORIZONTAL)
VANE MOTOR(VERTICAL)
VARISTOR
ROOM TEMPERATURE THERMISTOR
INDOOR COIL THERMISTOR (MAIN)
INDOOR COIL THERMISTOR (SUB)
SOLID STATE RELAY
TERMINAL BLOCK
NAME NAME NAME
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:
MSZ-A24YV -
MSZ-A26YV - E1
E1 MODELS WIRING DIAGRAM
OB345A

REFRIGERANT SYSTEM DIAGRAM
8
6
MSZ-A26YV - E1
INDOOR UNIT
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT13(sub)
Flared connection
Refrigerant pipe [15.88
(with heat insulator)
Refrigerant pipe [9.52
(with heat insulator)
Indoor coil
thermistor
RT12(main)
Strainer
#50
Refrigerant flow in cooling
Refrigerant flow in heating
MSZ-A18YV - E1
INDOOR UNIT
Indoor
heat
exchanger
Room temperature
thermistor
RT11
Refrigerant pipe [12.7
(with heat insulator)
Flared connection
Flared connection
Indoor coil
thermistor
RT12(main)
Refrigerant pipe[6.35
(with heat insulator)
Distributor
MSZ-A24YV - E1
INDOOR UNIT
Indoor
heat
exchanger
Room temperature
thermistor
RT11
Refrigerant pipe [15.88
(with heat insulator)
Flared connection
Flared connection
Indoor coil
thermistor
RT12(main)
Refrigerant pipe [6.35
(with heat insulator)
Distributor
Unit:mm
Indoor coil
thermistor
RT13(sub)
Indoor coil
thermistor
RT13(sub)
OB345A

9
SERVICE FUNCTIONS
7
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. “Auto restart function” automatically starts operation in the same
mode just before the shutoff of the main power. 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 operation is decided by the initial room tempera-
ture.
7-3. AUTO RESTART FUNCTION
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
7-2. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION
A maximum of 4 indoor units with wireless remote controllers can be used in a room.
In this case, to operate each indoor unit individually by each remote controller, P.C. boards of remote controller must be
modified according to the number of the indoor unit.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below :
7-1. 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.)
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.
NOTE : For modification, take out the bat-
teries and press the
OPERATE/STOP (ON/OFF) but-
ton 2 or 3 times at first.
After finish modification, put back
the batteries then press the
RESET button.
MSZ-A18YV -
MSZ-A24YV -
MSZ-A26YV - E1
E1
E1
Remote controller model : KP0A 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 accept the signal from the remote controller that has been assigned to the indoor unit once they are
set. The setting will be cancelled if the breaker has turned off, or the power supply has shut down.
Please conduct the above setting once again after the power has restored.
OB345A

10
How to disable “AUTO RESTART FUNCTION”
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 page 20.)
3Solder jumper wire to the RESISTOR JR07 on the indoor electronic control P.C. board. (Refer to page 18. and 19)
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 indoor unit was operated with the
remote controller.
•If main power is turned off or a power failure occurs while AUTO START/STOP timer is active ,the timer setting is
cancelled.
•If the unit has been off with the remote controller before power failure, the auto restart function does not work as the
power button of the remote controller is off.
•To prevent breaker off due to the rush of starting current, systematize other home 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.
OB345A