CONTENTS 1. TECHNICAL CHANGES ····································2 2. PART NAMES AND FUNCTIONS······················3 3. SPECIFICATION·················································3 4. OUTLINES AND DIMENSIONS ·························4 5. WIRING DIAGRAM ············································6 6. REFRIGERANT SYSTEM DIAGRAM ················8 7. PERFORMANCE CURVES ······························10 8. TROUBLESHOOTING······································12 9. DISASSEMBLY INSTRUCTIONS ····················21 10. PARTS LIST······················································27 11. RoHS PARTS LIST···········································30 SPLIT-TYPE AIR CONDITIONERS TM MU-A18ND MU-A18ND- MU-A18ND- MU-A24ND- MU-A24ND- MU-A30ND- MU-A30ND- S2 S1 S2 S1 S2 S1 Indoor unit service manual MS-A• ND Series (OB404) No. OB405 REVISED EDITION-E SERVICE MANUAL Models OUTDOOR UNIT NOTE: • This service manual describes technical data of the outdoor units. • RoHS compliant products have <G> mark on the spec name plate. For servicing of RoHS compliant products, refer to the RoHS Parts List. Please void OB405 REVISED EDITION-D. Revision E: • SPECIFICATION has been modified.
36
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SERVICE MANUAL No. OB405 - Mitsubishi Ar … 18-24... · No. OB405 SERVICE MANUAL REVISED EDITION-E Models OUTDOOR UNIT ... RH277NHD RH247NRAT Electricity receiving unit: Indoor unit
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Transcript
CONTENTS
1. TECHNICAL CHANGES ····································22. PART NAMES AND FUNCTIONS······················33. SPECIFICATION·················································34. OUTLINES AND DIMENSIONS ·························45. WIRING DIAGRAM ············································66. REFRIGERANT SYSTEM DIAGRAM················87. PERFORMANCE CURVES······························108. TROUBLESHOOTING······································129. DISASSEMBLY INSTRUCTIONS ····················21
10. PARTS LIST······················································2711. RoHS PARTS LIST···········································30
MU-A18ND - ➔ MU-A18ND -• Valve cover has been added.
S2S1
MU-A24ND - ➔ MU-A24ND -• Compressor contactor has been added.
S2S1
MU-A30ND - ➔ MU-A30ND -• Solenoid valve and solenoid valve coil have been changed.
S2S1
Revision A:• Check of solenoid valve coil has been partially modified.
Revision B:• MU-A24ND - has been added.S2
Revision C:• MU-A18ND - has been added.S2
Revision D:• MU-A30ND - has been added.S2
Revision E:• SPECIFICATION has been modified.
OB405E.qxp 09.10.14 9:16 AM Page 2
3
PART NAMES AND FUNCTIONS2
SPECIFICATION3
Outdoor model
Function
Power supply
CapacityDehumidificationAir flow (High/Low)Power outletRunning current (Total)Power input (Total)Power factor (Total)Starting current (Total)Compressor motor currentFan motor current
1.About the indoor side electric wiring refer to the indoor unit electric wiring diagram for servicing.2.Use copper conductors only (For field wiring).3.Symbols below indicate.
: Connector: Terminal block,
NOTES:
SYMBOLC1C2
DSAR
SYMBOLF
MCMF
SYMBOLTB1TB2
NAME NAME NAMECOMPRESSOR CAPACITOROUTDOOR FAN CAPACITORSURGE ABSORBER
FUSE (3.15A)COMPRESSOR(INNER PROTECTOR)OUTDOOR FAN MOTOR(INNER PROTECTOR)
TERMINAL BLOCKTERMINAL BLOCK
MU-A24ND- S1
L
N
2
BRN
RED
BLKWHT
BLUTB2
BLUWHT
RE
D
C2
OR
N
DS
AR
TB1
GR
N/Y
LWB
RN
F
MF21
ORNRED
34
N
L
PE
BLU
MC
WHT
BLU SC
R
C1
BLK
SYMBOLC1C2
DSAR
SYMBOLF
MCMF
SYMBOLTB1TB2
NAME NAME NAMECOMPRESSOR CAPACITOROUTDOOR FAN CAPACITORSURGE ABSORBER
FUSE(3.15A)COMPRESSOR(INNER PROTECTOR)OUTDOOR FAN MOTOR(INNER PROTECTOR)
TERMINAL BLOCKTERMINAL BLOCK
NOTES: 1.Use copper conductors only (For field wiring).2.Since the indoor and outdoor unit connecting wires have polarity, connect them according to the numbers (2,N,L). 3.Symbols below indicate.
: Terminal block, : Connector
TO
IND
OO
R U
NIT
CO
NN
EC
TIN
G
220-230V~
220-230V~
PO
WE
R S
UP
PLY
~/N
220
-230
V 6
0Hz
OUTDOOR UNIT
OUTDOOR UNIT
OB405E.qxp 09.10.14 9:16 AM Page 6
7
MU-A30ND
SYMBOLC1C2
DSARF61LEVMCMF
SYMBOLNR61RT62RT63SR61SR62TB1TB2
SYMBOLT61X52X63
21S252C
NAME
DEICERP.C. BOARD
2
N
3
N
L
12V
WH
T
BLU
RED
BLU
WH
T
WHT
T61
YLW
BLK
WH
T
RED
BLU
TB25
CN730
YLW
BLK
WH
T
1
52C2
REDC2ORN
A1 A2BLU 52C
DS
AR
WHT
C1
BLK
S
C
RMC
BLU
NR
61
31
TB1
GR
N/Y
LW
BRN
SR62
SR61
F61
TAB52
COM NO
X52
CN711CN724CN662
6
MFRT62 RT63
1 2 3
2 1
OR
NR
ED
3456
LEV
COM NO
X63321
CN722
X52
PE
220-230V~
TO IN
DO
OR
UN
IT C
ON
NE
CTI
NG
P
OW
ER
SU
PP
LY
~/N
220
-230
V 6
0Hz
X63 21S2
NAME NAMECOMPRESSOR CAPACITOROUTDOOR FAN CAPACITORSURGE ABSORBERFUSE(3.15A)EXPANSION VALVE COILCOMPRESSOR(INNER PROTECTOR)OUTDOOR FAN MOTOR(INNER PROTECTOR)
VARISTORDISCHARGE TEMPERATURE THERMISTORAMBIENT TEMPERATURE THERMISTORSOLID STATE RELAYSOLID STATE RELAYTERMINAL BLOCKTERMINAL BLOCK
NOTES: 1.Use copper conductors only (For field wiring).2.Since the indoor and outdoor unit connecting wires have polarity, connect them according to the numbers (3,N,2). 3.Symbols below indicate.
: Terminal block, : Connector
MU-A24ND- S2
OUTDOOR UNIT
OUTDOOR UNIT
SYMBOLC1C2
DSAR
SYMBOLF
MCMF
SYMBOLTB1TB252C
NAME NAME NAMECOMPRESSOR CAPACITOROUTDOOR FAN CAPACITORSURGE ABSORBER
FUSE(3.15A)COMPRESSOR(INNER PROTECTOR)OUTDOOR FAN MOTOR(INNER PROTECTOR)
TERMINAL BLOCKTERMINAL BLOCKCOMPRESSOR CONTACTOR
NOTES: 1.Use copper conductors only (For field wiring).2.Since the indoor and outdoor unit connecting wires have polarity, connect them according to the numbers (2,N,L). 3.Symbols below indicate.
Model Outdoor unit precharged Refrigerant piping length (one way)
15m
120
20m
195
30m
345
7m
0
10m
452,200
1,400
2,400
MU-A18ND
MU-A30ND
MU-A24ND
Unit : mm
OB405E.qxp 09.10.15 1:32 PM Page 9
10
PERFORMANCE CURVES7
The standard data contained in these specifications apply only to the operation of the air conditioner under normal conditions.Since operating conditions vary according to the areas where these units are installed. The following information has beenprovided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.
(1) GUARANTEED VOLTAGE198 ~ 253V, 60Hz
(2) AIR FLOWAir flow should be set at MAX.
(3) MAIN READINGS(1) Indoor intake air wet-bulb temperature : °CWB(2) Indoor outlet air wet-bulb temperature : °CWB(3) Outdoor intake air dry-bulb temperature : °CDB(4) Total input: WIndoor air wet/dry-bulb temperature difference on the left side of the following chart shows the difference between theindoor intake air wet/dry-bulb temperature and the indoor outlet air wet/dry-bulb temperature for your reference at service.
MU-A18ND MU-A24ND MU-A30ND
Indoor intake air WB temperature (:)
Outdoor intake air DB temperature (:)
Indoor intake air WB temperature (:)
Outdoor intake air DB temperature (:)
MS
-A30
ND
MU
-A30
ND
MS
-A24
ND
MU
-A24
ND
MS
-A18
ND
MU
-A18
ND
9.9
9.1
8.3
7.5
6.7
5.9
12.5
11.4
10.3
9.3
8.3
7.3
18.6
16.8
15.1
13.5
12.0
10.5
Wet and dry-bulbthermometers
Wet-and dry-bulbthermometers
How to measure the indoor air wet/dry-bulb temperature difference1. Attach at least 2 sets of wet and-dry-bulb thermometers to the indoor air intake as shown in the figure, and at least 2 sets
of wet-and-dry-bulb thermometers to the indoor air outlet. The thermometers must be attached to the position where airspeed is high.
2. Attach at least 2 sets of wet and dry-bulb thermometers to the outdoor air intake.Cover the thermometers to prevent direct rays of the sun.
3. Check that the air filter is cleaned.4. Open windows and doors of the room.5. Press the EMERGENCY OPERATION switch once to start the EMERGENCY COOL MODE.6. When system stabilizes after more than 15 minutes, measure temperature and take an average temperature.7. 10 minutes later, measure temperature again and check that the temperature does not change.
INDOOR UNIT OUTDOOR UNIT
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11
10.0
9.0
8.0
7.0
6.0
5.015 18 20
50 60 7025 30 32 35(:)
(%)
MU-A24ND MU-A24ND
Out
door
low
pre
ssur
e
Out
door
uni
t cu
rren
t (A
)
Ambient temperature (˚C)/Ambient humidity (%) Ambient temperature (˚C)/Ambient humidity (%)
0.8
0.7
0.6
0.5
0.4
0.315 18 20
50 60 7025 30 32
8.0
7.0
6.0
5.0
4.0
3.0 35(:) (%)
(kgf/F [Gauge])(MPa [Gauge])
� Both indoor and outdoor units are under the same temperature/humidity condition.
OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENTCOOL operation
➁ Air flow should be set at MAX.
Dry-bulb temperature (:) Relative humidity (%)
20 50
25 60
30 70
3 The unit of pressure has been changed to MPa on the international system of units(SI unit system).The conversion factor is : 1(MPa [Gauge]) =10.2(kgf/ff [Gauge])
18 50 60 70
32 35(:)(%)
15 20 25 304.0
5.0
6.0
7.0
8.0
MU-A18ND MU-A18ND
Out
door
low
pre
ssur
e
Out
door
uni
t cu
rren
t (A
)
Ambient temperature (˚C)/Ambient humidity (%) Ambient temperature (˚C)/Ambient humidity (%)
8.0
7.0
6.0
5.0
4.0
3.018
50 7032 (:)
(%)15 20 25 30 35
0.3
0.4
0.5
0.6
0.7
0.8
(kgf/F [Gauge])(MPa [Gauge])
OB405E.qxp 09.10.14 9:16 AM Page 11
12
MU-A30ND
15 18 2050
2560
30 32 70
35(:) (%)
0.2
0.3
0.4
0.5
0.6
2.0
3.0
4.0
5.0
6.0
15 18 20 50
2560
30 3270
35(:) (%)
9.0
10.0
11.0
12.0
13.0
14.0
15.0
Out
door
low
pre
ssur
e
Out
door
uni
t cu
rren
t(A
)
(kgf/F[Gauge])(MPa[Gauge]) MU-A30ND
Ambient temperature (˚C)/Ambient humidity (%) Ambient temperature (˚C)/Ambient humidity (%)
3. Troubleshooting procedure1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.
To make sure, check how many times the abnormality indication is flashing on and off before starting service work.2) Before servicing that the connector and terminal are connected properly.3) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the
components for bursting and discolouration.4) When troubleshooting, refer to 8-2.
TROUBLESHOOTING8
8-1. Cautions on troubleshooting1. Before troubleshooting, check the following:
1) Check the power supply voltage.2) Check the indoor/outdoor connecting wire for mis-wiring.
2. Take care the following during servicing.1) Before servicing the air conditioner, be sure to turn off the main unit first with the remote controller, and then after
confirming the horizontal vane is closed, turn off the breaker and / or disconnect the power plug.
2) Be sure to turn OFF the power supply before removing the front panel,the cabinet, the top panel and the electronic control P.C. board.
3) When removing the electronic control P.C. board, hold the edge of theboard with care NOT to apply stress on the components.
4) When connecting or disconnecting the connectors, hold the housing ofthe connector. DO NOT pull the lead wires. Lead wiring Housing point
MU-A18ND MU-A24ND MU-A30ND
OB405E.qxp 09.10.14 9:16 AM Page 12
13
Start
Indoor unit operates.Outdoor unit dose not operate.
Indoor unit dose not receive the signal from remote controller.
OPERATION INDICATORlamp on the indoor unit is flashing on and off.
Outdoor unit operates in only Test Run operation.
MU-A30NDOutdoor unit dose not operate even in Test Run operation.
Indoor unit operates, when EMERGENCY OPERATION switch is pressed.
Indoor unit dose not operate, when EMERGENCY OPERATION switch is pressed.
Check room temperature thermistor.Refer to "Test point diagram and voltage".
Refer to 8-4. A "Check of outdoor unit".
Refer to "Check of remote controller and receiver P.C. board".
MS-A30NDFlash on andoff at 0.5-second intervalsCause: Indoor/Outdoor unit• Mis-wiring
3-time flash Cause:Indoor unit• Trouble of indoor fan motor
MU-A30ND6-time flash Cause: Outdoor unit• Trouble of thermistor in outdoor unit
MU-A30ND7-time flash Cause: Outdoor unit• Trouble of outdoor control system
Refer to 8-4. C"How to checkmis-wiring (When outdoor unit dose not work)" .
Check room temperature thermistor and indoor coil thermis-tor.Refer to "Test point diagram and voltage".
Refer to "Check of indoor fan motor".
Refer to 8-4. E "Check of outdoor thermistor".
Replace the deicer P.C. board.
MU-A30ND10-time flash Cause: Outdoor unit• Trouble of low discharge temperature protection
Refer to 8-4. D "Check of LEV".
4-time flash Cause:Indoor unit• Trouble of indoor control system
Replace the indoor electronic control P.C. board.
1. Check indoor / outdoor connecting wire.2. Check of outdoor fuse. (MU-A18/A24ND)3. Refer to "Check of indoor electronic control P.C. board".
MU-A24ND - S2
MU-A30NDOutdoor unit dose not stop even if indoor unit stop.
Refer to 8-4. B "Check of outdoor unit".
Indoor unit operates.Outdoor unit dose not operate normally.
MU-A30NDOutdoor unit repeats start and stop.
Refer to 8-4. F "Check of solenoid valve coil".
w
w
Refer to indoor unit service manual.
"Test Run operation" means the operation within 30 minutes after EMERGENCY OPERATION switch is pressed.w
8-2. Instruction of troubleshooting
OB405E.qxp 09.10.14 9:16 AM Page 13
14
8-3. Trouble criterion of main partsMU-A18ND MU-A24ND MU-A30ND
Part name FigureCheck method and criterion
Measure the resistance between the terminals with a tester.(Coil wiring temperature -10°C ~ 40°C)
Compressor (MC)
INNER PROTECTOR155i 5: OPEN 90i10: CLOSE
NormalMU-A18ND
Color of lead wire
C – RC – S
1.26 " ~ 1.55 "1.81 " ~ 2.23 "
MU-A24ND0.74 " ~ 0.91 "1.84 " ~ 2.26 "
MU-A30ND0.54 " ~ 0.67 "1.23 " ~ 1.52 "
LEV(Expansion valve)
MU-A30ND
Color of lead wireWHT – REDRED – ORNYLW – BRNBRN – BLU
Normal
37.4 " ~ 53.9 "
Measure the resistance with a tester.(Part temperature : 0˚C ~ 40˚C)
Measure the resistance with a tester.(Part temperature –10˚C ~ 40˚C)
Discharge temperaturethermistor(RT62)MU-A30ND
Ambient temperature thermistor(RT63)MU-A30ND
Measure the resistance with a tester. Before measurement, hold the thermistor with your hands to warm it up.(Part temperature 0˚C ~ 40˚C)Refer to 8-5. "Test point diagram and voltage", "Outdoor deicer P.C. board",the chart of thermistor.
Refer to 8-5. "Test point diagram and voltage", "Outdoor deicer P.C. board", the chart of thermistor.
MU-A18ND MU-A24ND MU-A30ND
Measure the resistance between the terminals with a tester.(Coil wiring temperature -10°C ~ 40°C)
Color oflead wire
WHT – BLKBLK – REDBLK – YLWYLW – RED
63 " ~ 77 " 79 " ~ 96 "
––
57 " ~ 70 "58 " ~ 71 "
––
57 " ~ 69 "–
29 " ~ 35 "29 " ~ 35 "
NormalOutdoor fan motor (MF)
INNER PROTECTOR135i 5: OPEN 87i15: CLOSE
Measure the resistance with a tester.(Part temperature : –10˚C ~ 40˚C)
Solenoid valve coil(21S2)MU-A30ND
NormalMU-A30ND - S1
1,738 " ~ 2,125 "MU-A30ND - S2
1,230 " ~ 1,330 "
WHTBLK YLW RED ORN
MAIN
AUX.
MAIN
AUX.
WHTBLK RED ORN
MU-A18/A24ND
MU-A30ND
RED
WHT
BLK
P
C
S R
:INNER PROTECTORP
LEV
WHT6
RED1
ORN4
YLW
5
BR
N2
BL
U3
OB405E.qxp 09.10.14 9:16 AM Page 14
15
Is there 220-230V AC to between L-N on the outdoor terminal block?
No Check the outdoor power supply and connection of wiring.
Yes
Check the deicer P.C. board. Refer to 8-5.Is there 5V DC?
Compressor dose not operate.
YesPress the EMERGENCY OPERATION switch. 3-minute time delay works. Test run operation operates for 30 minutes.
Outdoor fan motor dose not operate.
No Make the connectionof wiring correct.
Check the compressor.
Replace the compressorcontactor(52C).
Turn ON the power supply.
Yes
Is there 220-230V AC between 2 on the compressor contactor(52C) and N on the outdoor terminal block?
Yes
Is there 220-230V AC CN730 on the deicer P.C. board?
Replace thedeicer P.C. board.
Replace the deicer P.C. board.
No
No
No
Yes
Yes
Check the deicer P.C. board. Refer to 8-5.Is there 5V DC?
Yes
Is there 220-230V AC CN711 1-3 or 2-3 on the deicer P.C. board?
No Make the connectionof wiring correct.
Check the outdoor fan motor. Refer to 8-3.
Yes
Is there 220V AC CN730 on the deicer P.C. board?
Replace the deicer P.C. board.
Replace the deicer P.C. board.
No
No
Press the EMERGENCY OPERATION switch. 3-minute time delay works. Test run operation operates for 30 minutes.
Is there 220-230V AC between A1 and A2 on the compressor contactor (52C)?
Check of outdoor unitA
8-4. Troubleshooting flowCompressor and / or outdoor fan motor dose not operate.
MU-A30ND
OB405E.qxp 09.10.14 9:16 AM Page 15
16
Compressor and / or outdoor fan motor dose not stop.
After 30 seconds, did compressor stop?
No
Yes
Replace the deicer P.C. board.
Yes
1 Turn OFF the power supply.2 After 30 seconds, turn ON the power supply again.3 Operate the unit in COOL mode by pressing the EMERGENCY OPERATION switch.4 Operate the unit for 1 minute or more and stop it by pressing the EMERGENCY OPERATION switch again.
Ok
No
After 30 seconds, did outdoor fan stop?
Replace thedeicer P.C. board.
Yes
Ok
No
Is there 220-230V AC between 2 on the compressor contactor(52C) and N on the outdoor terminal block?
Yes
Replace the compressor contactor(52C).
No Make the connectionof wiring correct.
Is there 220-230V AC between A1 and A2 on the compressor contactor (52C)?
MU-A30ND
1 Turn OFF the power supply.2 After 30 seconds, turn ON the power supply again.3 Operate the unit in COOL mode by pressing the EMERGENCY OPERATION switch.4 Operate the unit for 1 minute or more and stop it by pressing the EMERGENCY OPERATION switch again.
After 30 seconds, does compressor stop ?
Yes
NoIs there 220-230V AC between 3-N on the outdoor terminal block?
Replace the indoor electronic control P.C. board.
No Make the connection of wiring correct.
Is there 220-230V AC between 3-N on the indoor terminal block?
Yes
Reconnect the continuity of indoor and outdoor unit connection.
Is there 220-230V AC between 1 on the compressor contactor(52C) and N on the outdoor terminal block?
No
Yes
Reconnect the continuity of indoor and outdoor unit connection.
Yes
Replace the compressor contactor(52C).
OK
No
After 30 seconds, does outdoor fan motor stop ?
Yes
Is there 220-230V AC between 3-N on the indoor terminal block?
No
OK
Replace the indoor electronic control P.C. board.
Yes
NoIs there 220-230V AC between 3-N on the outdoor terminal block?
Make the connection of wiring correct.
Is there 220-230V AC between 3 on the compressor contactor(52C) and N on the outdoor terminal block?
Yes
Replace the compressor contactor(52C).
No
Yes
No
MU-A24ND - S2
Check of outdoor unitB
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17
How to check mis-wiringC
1. Turn OFF the power supply and disconnect only terminal block 3 of indoor/ outdoor connecting wire on indoor side.
2. Short-circuit terminal block N-3 by lead wire. 3. Turn ON the power supply and press EMERGENCY OPERATION switch once.
When EMERGENCY OPERATION is operated, is there 10V DC between both ends of R601 on the deicer P.C. board? (Refer to 8-5.)However the stylus of a tester would be between 5 ~10V.
Start
No
NoIs there 1V DC detected between both ends of PS132 on the indoor electronic control P.C. board ?However, the stylus of a tester would be between 0 and 20V.
• Turn ON the power supply.• Press EMERGENCY OPERATION switch once.
Is this mis-wiring, poor contact, or wire disconnection?Make them sure.
Replace the indoor electronic control P.C. board.
Is there 220-230V AC between L-N on the outdoor terminal block?
No Check the outdoor power supply and connection of wiring.
Is there 5V DC between J101 + -J401 - ?(Refer to 8-5.)
Yes
NoReplace the deicer P.C. board.
Yes
NoMake the wiring between CN730 on the deicer P.C. board and outdoor terminal block correct.(Refer to 8-5.)
Replace the deicer P.C. board.
Yes
Yes
Yes
When the unit has mis-wiring, in 3 minutes, OPERATION INDICATOR lamp on indoor unit flash on and off at 0.5 second intervals. w
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. • Disconnect the lead wire that terminal block N-3 is short-circuited.• Connect ON indoor/outdoor connecting wire.
Turn ON the power supply.
Refer to indoor unitservice manual.
When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.Outdoor unit dose not operate.
MU-A30ND
OB405E.qxp 09.10.14 9:16 AM Page 17
18
Check of outdoor thermistor
Measure resistance between CN 662 3 and 4.
No
Yes
Replace the thermistor.
Measure resistance between CN 662 1 and 2.
Connect CN662.Turn ON the power supply and press the EMERGENCY OPERATION switch.
Does the resistances of thermistor have the characteristics on 8-5.?
No
Yes
Does the unit operate 10 minutes or more?
Replace the deicer P.C. board.
Ok W
Turn OFF the power supply.
Discharge temperature thermistor(RT62)
Ambient temperature thermistor(RT63)
W Defective contact of the connector is considered.
w Disconnect the connectors CN662 from the deicer P.C. board. (Check the characteristics of each thermistor.)
E
When OPERATION INDICATOR lamp flashes 6-time.Thermistors in the outdoor unit are abnormal.
Check of LEV (Expansion valve)D
With remote controller set toward the indoor unit, press OPERATE/ STOP(ON/ OFF) button and confirm one beep tone.
LEV operates in full-opening direction.
Is LEV properly fixed to the expansion valve?
Ok
Do you hear the expansion valve "click, click·······"?Do you feel the expansion valve vibrate on touching it?
Does the resistance of LEV have the characteristics on 8-3?
No
Yes
Yes
Yes
No
No Properly fix LEV coil to the expansion valve.
Replace the deicer P.C. board.
NOTE : After check of LEV, do the undermentioned operation.
1. Turn OFF the power supply and turn ON again.
2. Press the RESET button on the remote controller.Replace the LEV.
Remote controller model : KP0BTurn ON the power supply.1 While pressing OPERATION SELECT button on the remote controller, press RESET button.2 Release RESET button to confirm if all LCD in operation display section of the remote controller is displayed.3 Release OPERATION SELECT button.
Remote controller model : KM04BTurn ON the power supply.1 While pressing both OPERATION SELECT button and TOO COOL button on the remote controller at the same time, press RESET button.2 First, release RESET button. And release the other two buttons after all LCD in operation display section of the remote controller is displayed after 3 seconds.
KP0B KM04B
AMPMCLOCK
C̊
AMPM
AMPMCLOCK
C̊
AMPM
When OPERATION INDICATOR lamp flashes 10-time. Cooling mode dose not operate.
MU-A30ND
MU-A30ND
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Ok
Do you hear "click" from the solenoid valve coil?
No
Yes
After 1minute or more has passed since the compressor started, operate the solenoid valve coil by heating or cooling the ambient temperature thermistor.(Refer to Solenoid valve control.)
Turn ON the power supply.Operate the unit in COOL mode by pressing the EMERGENCY OPERATION switch.
Yes
Check of the solenoid valve coil.(Refer to 8-3.)
Is there 220-230V AC CN722 on the deicer P.C. board?
Replace thedeicer P.C. board.
NoTurn ON the solenoid valve coil.(Refer to Solenoid valve control.)
Check of solenoid valve coilF
Outdoor unit repeats start and stop.
Solenoid valve controlThe solenoid valve opens when the ambient temperature thermistor RT63 temperature reaches 49.2: or more after 1minute has passed since the compressor turned on. Then, the solenoid valve maintains to open until the ambient tem-perature thermistor RT63 temperature falls 46.2: or less.
NOTE: The solenoid valve remains to close when the ambient temperature thermistor RT63 temperature is 49.2: orless after 1 minute has passed since the compressor turned on.
ONOFF
46.2:49.2:
Ambient temperature thermistor RT63 temperature
Solenoid valve
MU-A30ND
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8-5. Test point diagram and voltage
MU-A30ND
Outdoor deicer P.C. board
Varistor(NR62)
Fuse 3.15A / 250V
} 12V DC
}5V DC
+
+
Temperature(:)
Discharge temperature thermistor(RT62)
Res
ista
nce
(k"
)
0 10 20 30 40 50 60 70 80 90 100 110 1200
100
200
300
400
500
600
700
800
900
Ambient temperature thermistor (RT63)
-20 -10 0 10 20 30 400
10
20
30
40
50
60
70
80
90
100
Temperature(:)
Res
ista
nce
(k"
)
CN662 1-2Discharge temperaturethermistor (RT62)(Refer to 8-4.E.)
CN662 3-4Ambient tempera-ture thermistor(RT63)(Refer to 8-4.E.)
LEV connector(CN724)
Fan motorconnector(CN711)
Varistor (NR61)CN7301-3220-230-240V AC
}(Refer to 8-4. C.)
}
R60110V DC
(Refer to 8-4. C.)
(Refer to 8-4. A or C.)
J101
J401
+
Solenoidvalve coil(CN722)
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DISASSEMBLY INSTRUCTIONS9
(1) Slide the sleeve and check if there is a locking lever or not. (2) The terminal with this connector has the locking mechanism.
1Slide the sleeve.2Pull the terminal while pushing the locking lever.
1Hold the sleeve, and pull out the terminal slowly.
The terminal which has the locking mechanism can be detached as shown below.There are two types ( Refer to (1) and (2)) of the terminal with locking mechanism.The terminal without locking mechanism can be detached by pulling it out.Check the shape of the terminal before detaching.
<"Terminal with locking mechanism" Detaching points>
Connector
Sleeve
Locking lever
OPERATING PROCEDURE PHOTOS
1. Removing the cabinet(1) Remove the screws of the cabinet.(2) Hold the bottom of the cabinet on both sides to remove the
cabinet.(3) Remove the screws of the service panel and remove the
service panel.(4) Remove the screw of the valve cover and remove the valve
cover (MU-A18ND- ).S2
9-1. MU-A18NDOUTDOOR UNIT
Photo 1
Photo 2
Screwsof thecabinet
Screw ofthe valvecover
Screwsof theServicepanel
Photo : MU-A18ND - S2
Screwsof thecabinet
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OPERATING PROCEDURE PHOTOS
2. Removing the electrical parts(1) Remove the service panel and the cabinet.(2) Remove the following parts.
•Compressor capacitor (C1)•Outdoor fan capacitor (C2)•Terminal blocks (TB1,TB2)
Photo 3
Compressor capacitor(C1)
3. Removing the outdoor fan motor(1) Remove the cabinet. (Refer to 1.)(2) Disconnect the connector remove the hooked lead wire
from the fan motor.(3) Remove the propeller nut and remove the propeller.(4) Remove screws fixing the fan motor.
4. Removing the compressor(1) Remove the cabinet. (Refer to 1.)(2) Remove the soundproof felt.(3) Remove the terminal cover on the compressor.(4) Disconnect lead wires from the glass terminal of the com-
pressor.(5) Recover gas from the refrigerant circuit.
NOTE:Recover gas from the pipes until the pressure gauge shows 0 kg/cm2 (0MPa).
(6) Disconnect the welded part of the discharge pipe.(7) Disconnect the welded part of the suction pipe.(8) Remove nuts fixing the compressor.(9) Remove the compressor.
Photo 4 Hook
Propeller
Propeller nut
Outdoor fan capacitor(C2)
Terminalblocks(TB1,TB2)
Set screws of Outdoor fan motor
Set screws of outdoor fan motor
Photo 5
Compressor
Dischargepipe
Suctionpipe
Compressor nuts
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9-2. MU-A24NDOUTDOOR UNIT
OPERATING PROCEDURE PHOTOS
1.Removing the cabinet(1) Remove the screw of the service panel.(2) Remove the screws of the top panel.(3) Remove the screw of the valve cover.(4) Remove the service panel.(5) Remove the top panel.(6) Remove the valve cover.(7) Remove the screws of the front panel.(8) Remove the front panel.(9) Remove the screws of the back panel.(10) Remove the back panel.
Photo 2
Photo 1
Photo 3
Screw of the top panel
Screws of the cabinet
Screwsof thecabinet
Screwsof thetoppanel
Screw of the motor support
Set screws of the back panel
Screwsof thefrontpanel
2. Removing the electrical parts(1) Remove the service panel and the cabinet.(2) Remove the following parts.
3. Removing the propeller and the outdoor fan motor(1) Remove the cabinet. (Refer to 1.)(2) Remove the propeller nut and the propeller.NOTE : Loose the propeller in the rotating direction for
removal.When attaching the propeller, align the mark on the propeller and the motor shaft cut section.Set the propeller in position by using the cut on the shaft and the mark on the propeller.
(3) Remove the clamp of outdoor fan motor lead wire and disconnect the outdoor fan motor connector.
(4) Remove the screws fixing the outdoor fan motor.(5) Remove the outdoor fan motor.
4. Removing the compressor(1) Remove the cabinet. (Refer to 1.)(2) Remove the relay panel.(3) Remove the soundproof felt.(4) Remove the terminal cover on the compressor.(5) Disconnect lead wires from the compressor.(6) Recover gas from the refrigerant circuit.
NOTE:Recover gas from the pipes until the pressure gauge shows 0 kg/cm2 (0 MPa).
(7) Disconnect the welded part of the discharge pipe.(8) Disconnect the welded part of the suction pipe.(9) Remove nuts fixing the compressor.(10) Remove the compressor.
Compressor nuts
Photo 5
Set screws of theoutdoor fan motor
Propellernut
Propeller
Set screws of the outdoor fan motor
Photo : MU-A24ND - S2
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9-3. MU-A30NDOUTDOOR UNIT
OPERATING PROCEDURE PHOTOS
1.Removing the cabinet(1) Remove the screw of the service panel.(2) Remove the screws of the top panel.(3) Remove the screw of the valve cover.(4) Remove the service panel.(5) Remove the top panel.(6) Remove the valve cover.(7) Remove the screws of the front panel.(8) Remove the front panel.(9) Remove the screws of the back panel.(10) Remove the back panel.
Photo 2
Photo 1
Photo 3
Screw of the top panel
Screws of the cabinet
Screwsof thecabinet
Screwsof thetoppanel
Screw of the motor support
Set screws of the back panel
Screwsof thefrontpanel
2. Removing the deicer P.C. board(1) Remove the service panel and the cabinet.(2) Disconnect all the connectors and the terminals on the
deicer P.C. board.(3) Remove the deicer P.C. board.
Screw of the service panel
Screwof thevalvecover
Screwsof thebackpanel
Photo 4 Deicer P.C. board
Screwsof therelaypanel
Terminal blocks(TB1,TB2)
Compressorcapacitor(C1)
Outdoor fancapacitor (C2)
Screwsof therelaypanel
Compressorcontactor(52C)
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Photo 6
Suction pipe
Discharge pipe
Terminal cover
OPERATING PROCEDURE PHOTOS
3. Removing the propeller and the outdoor fan motor(1) Remove the cabinet. (Refer to 1.)(2) Remove the propeller nut and the propeller.NOTE : Loose the propeller in the rotating direction for
removal.When attaching the propeller, align the mark on the propeller and the motor shaft cut section.Set the propeller in position by using the cut on the shaft and the mark on the propeller.
(3) Remove the clamp of outdoor fan motor lead wire and disconnect the outdoor fan motor connector.
(4) Remove the screws fixing the outdoor fan motor.(5) Remove the outdoor fan motor.
Photo 5
Set screws of theoutdoor fan motor
Propellernut
4. Removing the compressor(1) Remove the cabinet. (Refer to 1.)(2) Remove the relay panel.(3) Remove the soundproof felt.(4) Remove the terminal cover on the compressor.(5) Disconnect lead wires from the compressor.(6) Recover gas from the refrigerant circuit.
NOTE:Recover gas from the pipes until the pressure gauge shows 0 kg/cm2 (0 MPa).
(7) Disconnect the welded part of the discharge pipe.(8) Disconnect the welded part of the suction pipe.(9) Remove nuts fixing the compressor.(10) Remove the compressor.
Propeller
Compressor nuts
Compressor
Set screws of theoutdoor fan motor
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PARTS LIST (non-RoHS compliant)10
MU-A18ND10-1. OUTDOOR UNIT
STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS
Part numbers that are circled are not shown in the illustration.
MU-A24ND MU-A30ND11-2. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS
AND FUNCTIONAL PARTS
RoHS PARTS LIST (RoHS compliant)
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HEAD OFFICE: TOKYO BLDG, 2-7-3, MARUNOUCHI, CHIYODAKU, TOKYO 100-8310, JAPAN
CC Copyright 2005 MITSUBISHI ELECTRIC ENGINEERING CO.,LTDDistributed in Oct. 2009. No.OB405 REVISED EDITION-E 5Distributed in May 2006. No.OB405 REVISED EDITION-D 106Distributed in Nov. 2005. No.OB405 REVISED EDITION-C 106Distributed in Jun. 2005. No.OB405 REVISED EDITION-B 106Distributed in May 2005. No.OB405 REVISED EDITION-A 106Reprinted in Apr. 2005. No.OB405 100Distributed in Mar. 2005. No.OB405 6Made in Japan
New publication, effective Oct. 2009Specifications subject to change without notice.