SERVICE MANUAL CONTENTS 1. TECHNICAL CHANGES ····································2 2. PART NAMES AND FUNCTIONS······················5 3. SPECIFICATION·················································6 4. NOISE CRITERIA CURVES ·······························8 5. OUTLINES AND DIMENSIONS ·························9 6. WIRING DIAGRAM ··········································10 7. REFRIGERANT SYSTEM DIAGRAM ··············12 8. PERFORMANCE CURVES ······························15 9. TROUBLESHOOTING······································23 10. DISASSEMBLY INSTRUCTIONS·····················30 11. PARTS LIST······················································36 Wireless type Models MU-GA50VB - MU-GA60VB - MU-GA80VB - E1 E1 E1 SPLIT-TYPE, AIR CONDITIONERS MU-GA50VB - E1 Indication of model name NOTE: •This service manual describes technical data of outdoor units. As for indoor units MS-GA50VB - , MS-GA60VB - and MS-GA80VB - , refer to the service manual OB369. E1 E1 E1 No. OB370 HFC utilized R410A
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SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ····································2 2. PART NAMES AND FUNCTIONS······················53. SPECIFICATION·················································64. NOISE CRITERIA CURVES·······························85. OUTLINES AND DIMENSIONS ·························96. WIRING DIAGRAM ··········································107. REFRIGERANT SYSTEM DIAGRAM··············128. PERFORMANCE CURVES······························159. TROUBLESHOOTING······································23
10. DISASSEMBLY INSTRUCTIONS·····················3011. PARTS LIST······················································36
Wireless typeModels
MU-GA50VB -MU-GA60VB -MU-GA80VB - E1
E1
E1
SPLIT-TYPE, AIR CONDITIONERS
MU-GA50VB - E1
Indication of model name
NOTE:•This service manual describes technical data of outdoor units.As for indoor units MS-GA50VB - , MS-GA60VB - and MS-GA80VB - , refer to the servicemanual OB369.
E1E1E1
No. OB370HFCutilized
R410A
OB370-1.qxp 04.10.14 1:45 PM Page 1
2
TECHNICAL CHANGES1
MU-A18WV - ➔MU-GA50VB -1. Oil separator has been removed.2. Model name has been changed.
Indication of capacity has been changed. (BTU➔kW)
MU-A24WV - ➔MU-GA60VB -MU-A30WV - ➔MU-GA80VB -1. Model name has been changed.
Indication of capacity has been changed. (BTU➔kW)
E1E1
E1E1
E1E1
Refri
gera
ting
oil
Ref
riger
ant
New refrigerant
R410A
HFC-32: HFC-125 (50%:50%)
Pseudo-azeotropic refrigerant
Not included
A1/A1
72.6
-51.4
1.557
64
Non combustible
0
1730
From liquid phase in cylinder
Possible
Incompatible oil
Non
Non
Previous refrigerant
R22
R22 (100%)
Single refrigerant
Included
A1
86.5
-40.8
0.94
44.4
Non combustible
0.055
1700
Gas phase
Possible
Compatible oil
Light yellow
Non
Refrigerant
Composition (Ratio)
Refrigerant handling
Chlorine
Safety group (ASHRAE)
Molecular weight
Boiling point (:)
Steam pressure [25:](Mpa)
Saturated steam density [25:](Kg/K)
Combustibility
ODP w1
GWP w2
Refrigerant charge method
Additional charge on leakage
Kind
Color
Smell
w1 :Ozone Depletion Potential : based on CFC-11w2 :Global Warming Potential : based on CO2
INFORMATION FOR THE AIR CONDITIONER WITH R410A REFRIGERANT• This room air conditioner adopts an HFC refrigerant (R410A) which never destroys the ozone layer.• Pay particular attention to the following points, though the basic installation procedure is same as that for R22 conditioners.1As R410A has working pressure approximate 1.6 times as high as that of R22, some special tools and piping parts/
materials are required. Refer to the table below.2Take sufficient care not to allow water and other contaminations to enter the R410A refrigerant during storage and
installation, since it is more susceptible to contaminations than R22.3For refrigerant piping, use clean, pressure-proof parts/materials specifically designed for R410A. (Refer to 2. Refrigerant
piping.)4Composition change may occur in R410A since it is a mixed refrigerant. When charging, charge liquid refrigerant to prevent
composition change.
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3
NOTE : 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])
New Specification Current Specification
The incompatible refrigerating oil easily separates from refrigerant and is in the upper layer inside the suction muffler.Raising position of the oil back hole enables to back the refrigerating oil of the upper layer to flow back to the compressor.
Since refrigerant and refrigerating oil are compatible each, refrigerating oil backs to the compressor through the lower position oil back hole.
Compressor
Suction muffler
Oil back hole
Refrigerating oil
Refrigerant
Compressor
Suction muffler
Oil back hole
Refrigerating oil /Refrigerant
Com
pres
sor
-30 -20 -10 0 10 20 30 40 50 60-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0(MPa [Gauge])
R410A
R22
Conversion chart of refrigerant temperature and pressure
Sat
urat
ed li
quid
pre
ssur
e
(:)
NOTE : 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])
R410A tools Can R22 tools be used?
Gas leak detector
R410A has high pressures beyond the measurement range of existing gauges. Port diameters have been changed to prevent any other refrigerant from being charged into the unit.
Hose material and cap size have been changed to improve the pressure resistance.Dedicated for HFC refrigerant.
6.35 mm and 9.52 mm
Description
Clamp bar hole has been enlarged to reinforce the spring strength in the tool.
Provided for flaring work (to be used with R22 flare tool).Provided to prevent the back flow of oil. This adapter enables you to use vacuum pumps.It is difficult to measure R410A with a charging cylinder because the refrigerant bubbles due to high pressure and high-speed vaporization
No
No
No
Yes
Yes
New
New
New
Gauge manifold
Charge hose
Torque wrench
Flare tool
Flare gaugeVacuum pumpadapter
Electronic scale forrefrigerant charging
No : Not Substitutable for R410A Yes : Substitutable for R410A
No 12.7 mm and 15.88 mm
1.Tools dedicated for the air conditioner with R410A refrigerantThe following tools are required for R410A refrigerant. Some R22 tools can be substituted for R410A tools.The diameter of the service port on the stop valve in outdoor unit has been changed to prevent any other refrigerant being charged into the unit. Cap size has been changed from 7/16 UNF with 20 threads to 1/2 UNF with 20 threads.
OB370-1.qxp 04.10.14 1:45 PM Page 3
4
Electronic scale for refrigerant charging
Outdoor unit
Refrigerant gas cylinderoperating valve
Refrigerant gas cylinderfor R410A with siphon
Refrigerant (liquid)
Service port
Gauge manifold valve (for R410A)
Union
Liquid pipe
Gas pipe
Stop valve
Indoor unit
Charge hose (for R410A)
R410A
Pipe diameter
mm
6.35
9.52
12.7
15.88
17
22
26
29
Dimension of flare nut
R22
17
22
24
27
2Flaring work and flare nutFlaring work for R410A pipe differs from that for R22 pipe.For details of flaring work, refer to Installation manual “FLARING WORK”.
3.Refrigerant oilApply the special refrigeration oil (accessories: packed with indoor unit) to the flare and the union seat surfaces.
4.Air purge• Do not discharge the refrigerant into the atmosphere.
Take care not to discharge refrigerant into the atmosphere during installation, reinstallation, or repairs to the refrigerant circuit.
• Use the vacuum pump for air purging for the purpose of environmental protection.
5.Additional chargeFor additional charging, charge the refrigerant from liquid phase of the gas cylinder. If the refrigerant is charged from the gas phase, composition change may occur in the refrigerant inside the cylinder and theoutdoor unit. In this case, ability of the refrigerating cycle decreases or normal operation can be impossible. However, charging the liquid refrigerant all at once may cause the compressor to be locked. Thus, charge the refrigerant slowly.
2.Refrigerant piping1Specifications
Use the refrigerant pipes that meet the following specifications.
• Use a copper pipe or a copper-alloy seamless pipe with a thickness of 0.8 mm (6.35, 9.52, 12.7), 1.0 mm (15.88). Never use any pipe with a thickness less than 0.8 mm (6.35, 9.52, 12.7), 1.0 mm (15.88), as the pressure resistance is insufficient.
Wallthickness
Outside diameterPipe
mm
For liquid
For gas
6.35
9.52
12.7
15.88
0.8 mm
0.8 mm
0.8 mm
1.0 mm
Heat resisting foam plastic
Specific gravity 0.045 Thickness 8 mm
Insulation material
OB370-1.qxp 04.10.14 1:45 PM Page 4
5
PART NAMES AND FUNCTIONS2
Drainage hose
Piping
Air inlet
Air inlet
Air outlet
Drain outlet
(back and side)
Air outlet
(back and side)
OUTDOOR UNIT
MU-GA50VB -MU-GA60VB - E1
E1
MU-GA80VB - E1
OB370-1.qxp 04.10.14 1:45 PM Page 5
SPECIFICATION
6
3
Outdoor model
Function
Power supply
CapacityDehumidificationAir flow(High) Power outletRunning currentPower inputPower factorStarting currentCompressor 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:
SYMBOL
C1
C2
DSAR
NAME
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER
SYMBOL
MC
MF
TB1,TB2
NAME
COMPRESSOR (INNER PROTECTOR)
OUTDOOR FAN MOTOR (INNER PROTECTOR)
TERMINAL BLOCK
SYMBOL
52C
NAME
COMPRESSOR CONTACTOR
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:
SYMBOL
C1
C2
DSAR
NAME
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER
SYMBOL
MC
MF
TB1,TB2
NAME
COMPRESSOR (INNER PROTECTOR)
OUTDOOR FAN MOTOR (INNER PROTECTOR)
TERMINAL BLOCK
SYMBOL
X1
52C
NAME
RELAY
COMPRESSOR CONTACTOR
OB370-1.qxp 04.10.14 1:45 PM Page 10
11
OUTDOOR UNIT
DEICERP.C. BOARD
YLW
BLK
WH
T
RED
BR
N
TB2
7
1
CN730
YLW
BLK
WH
T
CIRCUIT BREAKER
1
52C2
CZ WHTWHT
REDC2ORN
A1 A2BLU 52C
DS
AR
TO
IND
OO
R U
NIT
CO
NN
EC
TIN
G
12V
WHT
C1BLK
S
C
RMC
RED
BLU
NR61 35
BLU
T61
TB1
GR
N/Y
LW PO
WE
R S
UP
PLY
~ /
N 2
30V
50H
z
X52
BLU
BRN
BLU
BRN
SR62
SR61
COM NO
F61
TAB52X52
CN711CN724CN662
6
MFRT62 RT63
1 2 3
2 1
OR
NR
ED
3456
LEV
N
3
N
L
PE
SYMBOL
SR62
TB1
TB2
T61
X52
52C
SYMBOL
MC
MF
NR61
RT62
RT63
SR61
SYMBOL
CZ
C1
C2
DSAR
F61
LEV
NAME NAME NAME
CZ SURGE ABSORBER
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER
FUSE(3.15A)
EXPANSION VALVE COIL
COMPRESSOR (INNER PROTECTOR)
OUTDOOR FAN MOTOR (INNER PROTECTOR)
VARISTOR
DISCHARGE TEMPERATURE THERMISTOR
AMBIENT TEMPERATURE THERMISTOR
SOLID STATE RELAY
SOLID STATE RELAY
TERMINAL BLOCK
TERMINAL BLOCK
TRANSFORMER
CONTACTOR
COMPRESSOR CONTACTOR
NOTE 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).3. Symbols below indicate./: Terminal block, : Connector
MU-GA80VB - E1MODEL WIRING DIAGRAM
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12
REFRIGERANT SYSTEM DIAGRAM7
MU-GA50VB - E1
OUTDOOR UNIT
Refrigerant pipe [12.7(with heat insulator)
Flared connection
Flared connection
Refrigerant pipe [6.35(with heat insulator)
Stop valve
Compressor
Stop valve(with serviceport)
Outdoorheatexchanger
MU-GA60VB - E1
OUTDOOR UNIT
Refrigerant pipe [15.88(with heat insulator)
Flared connection
Flared connection
Refrigerant pipe [6.35(with heat insulator)
Stop valve Capillary tube[3.0X[1.8X500
Compressor
Stop valve(with service port) Outdoor
heatexchanger
Refrigerant flow in cooling
Muffler#100
Unit:mm
Capillary tube[3.0o[1.6o600
Muffler
Strainer#100
Muffler
OB370-1.qxp 04.10.14 1:45 PM Page 12
13
MU-GA80VB - E1
OUTDOOR UNITUnit:mm
Indoorunit
wMax. Heightdifference:
10m(MS-GA50/GA60VB)/ 15m(MS-GA80VB)
A
Refrigerant PipingMax. Length
w Height difference should be within 10m(MS-GA50/GA60VB)/ 15m(MS-GA80VB) regardless of which unit, indoor or outdoor position is high.
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 been pro-vided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.(1) GUARANTEED VOLTAGE
198 ~ 264V, 50Hz(2) AIR FLOW
Air 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: W
Indoor air wet/dry-bulb temperature difference on the left side of the chart on this page 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.
How to measure the indoor air wet-bulb/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 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
} Cooling
Wet-and dry-bulbthermometers
Wet-and dry-bulbthermometers
MU-GA50VB - MU-GA60VB - MU-GA80VB - E1E1E1
OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENTCOOL operation11 Both indoor and outdoor unit are under the same
temperature/humidity condition.Dry-bulb temperature Relative humidity(%)
20 50
25 60
30 70
OB370-1.qxp 04.10.14 1:45 PM Page 15
16
MU-GA80VB - E1
Ambient temperature(˚C)Ambient humidity(%)
18 3270(%)
230V
15 2050
2560
30 350.6
0.7
0.8
0.9
1.0
1.1
(:)6
7
8
9
10
11
Ambient temperature(˚C)Ambient humidity(%)
18 3270(%)
230V
15 2050
2560
30 3510
11
12
13
14
15
16
(:)
Out
door
low
pre
ssur
e
Out
door
uni
t cu
rren
t(A
)
(kgf/F[Gauge])(MPa[Gauge]) MU-GA80VB - E1
22 Air flow should be set at MAX.33 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])
NOTE Q : Total capacity (kW) SHF : Sensible heat factor DB : Dry-bulb temperatureSHC : Sensible heat capacity (kW) INPUT : Total power input (W) WB : Wet-bulb temperature
OB370-1.qxp 04.10.14 1:45 PM Page 22
23
TROUBLESHOOTING9
9-1. 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 first turn off the remote controller to stop the main unit, 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 the board with care NOT to apply stress on the com-
ponents.(4) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
MU-GA50VB -MU-GA60VB -MU-GA80VB - E1
E1
E1
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 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 discoloration.(4) When troubleshooting, refer to 9-2..
OB370-1.qxp 04.10.14 1:45 PM Page 23
24
Start
Indoor unit operates.Outdoor unit doesn't operate.
Indoor unit doesn't receive the signal from remote controller.
Indoor unit operates.Outdoor unitdoesn't operatenormally.
OPERATION INDICATORlamp 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".
MU-GA80VBRefer to9-4. A "Check of outdoor unit".
Refer to "Check of remote controller and receiver P.C. board".
MU-GA80VBFlash on and off at 0.5-second intervalsCause: Indoor/Outdoor unit• Mis-wiring
Refer to 9-4. C"How to checkmis-wiring (When outdoor unit doesn't work)".
3-time flash Cause:Indoor unit• Trouble of indoor fan motor
Check room temperature thermistor and indoor coil thermis-tor.Refer to "Test point diagram and voltage".
Refer to"Check of indoor fan motor".
4-time flash Cause:Indoor unit• Trouble of indoor unit control system
Replace the indoor electronic control P.C. board.
1. Check indoor / outdoor connecting wire.2. Refer to "Check of indoor electronic control P.C. board".
Outdoor unit doesn't stop even if indoor unit stops.
MU-GA50/GA60VBCheck of wiring diagram of outdoor unit on page 10.MU-GA80VBRefer to 9-4. B "Check of outdoor unit".
As for indoor unit, refer to service manual OB369.
MU-GA80VB6-time flash Cause: Outdoor unit• Trouble of thermistor in outdoor unit
MU-GA80VB7-time flash Cause: Outdoor unit• Trouble of outdoor control system
Refer to 9-4. E"Check of outdoor thermistor".
Replace the deicer P.C. board.
MU-GA80VB10-time flash Cause: Outdoor unit• Trouble of low discharge temperature protection
Refer to 9-4. D "Check of LEV".
9-2. Instruction of troubleshooting
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25
9-3. Trouble criterion of main parts
MU-GA50VB - MU-GA60VB - MU-GA80VB - E1E1E1
Part name FigureCheck method and criterion
Measure the resistance between the terminals with a tester.(Part temperature –10˚C ~ 40˚C)Compressor
(MC)INNER PROTECTOR160i 5: OPEN 90i10: CLOSE
NormalMU-GA50VB
Terminal
C – RC – S
1.59 " ~ 1.95 "2.65 " ~ 3.24 "
MU-GA60VB0.71 " ~ 0.87 "1.45 " ~ 1.77 "
MU-GA80VB0.56 " ~ 0.71 "1.43 " ~ 1.76 "
Abnormal
Open orshort-circuit
LEV(Expansion valve)MU-GA80VB
Color of lead wireWHT – REDRED – ORNYLW – BRNBRN – BLU
Abnormal
Open orshort-circuit
Normal
41.0 " ~ 49.0 "
Measure the resistance with a tester.(Part temperature : –10˚C ~ 40˚C)
Measure the resistance with a tester.(Part temperature –10˚C ~ 40˚C)
Discharge temperaturethermistor(RT62)MU-GA80VB
Ambient temperature thermistor(RT63)MU-GA80VB
Measure the resistance with a tester. Before measurement, hold the thermistor with your hands to warm it up.(Part temperature 0˚C ~ 40˚C)
Normal120 k" ~ 800k"
AbnormalOpen or short-circuit
Normal5 k" ~ 60 k"
AbnormalOpen or short-circuit
w Reference value
MU-GA50VB MU-GA60VB MU-GA80VB
Measure the resistance between the terminals with a tester.(Part temperature –10˚C ~ 40˚C)
Color oflead wire
WHT – BLKBLK – REDBLK – YLWYLW – RED
Open orshort-circuit
70.4 " ~ 85.5 " 73.6 " ~ 89.3 "
––
63 " ~ 77 "79 " ~ 96 "
––
55 " ~ 68 "–
49 " ~ 61 "22 " ~ 29 "
Normal Abnormal
Outdoor fan motor(MF)INNER PROTECTOR
MU-GA50VBMU-GA60VB 130i 5: OPEN( 83i15: CLOSEw)
MU-GA80VB 135i 5: OPEN( 87i15: CLOSEw)
REDORN WHTYLWBLK
MAIN
AUX.1AUX.2
C
P
P ~
BLKR
MAINAUX.
RED
S
CWHT
MAIN
AUX.
BLK
MU-GA50VB/GA60VB
MU-GA80VBRED WHTORN
P
LEV
WHT6
RED1
ORN4
YLW
5
BR
N2
BLU
3
:INNER PROTECTORP
OB370-1.qxp 04.10.14 1:45 PM Page 25
26
Check of outdoor unit
Compressor and/or outdoor fan motor doesn’t operate.
MU-GA80VB
Is there 230V AC to between L-N on the outdoor terminal block?
No Check the outdoor power supply and connection of wiring.
Yes
Compressor does not operate.
Yes
3minutes after the power supply turns ON, is there 230V AC between A1-A2 on the compressor contactor (52C)?
Operate the unit in COOL mode by pressing the EMERGENCY OPERATION switch.
Outdoor fan motor does not operate.
No Rectify the connecting wire.
Rectify the connecting wire.
Rectify the connecting wire.
Check the compressor.Refer to page 25.
Replace the compressor contactor(52C).
Turn ON the power supply.
Yes
Is there 230V AC between 2/T1 on the compressor contactor(52C) and N on the outdoor terminal block?
Yes
Replace thedeicer P.C. board.
Replace the deicer P.C. board.
No
Yes
No Is there 230V AC between 1/L1 on the compressor contactor(52C) and N on the outdoor terminal block?
No
No
Yes
Yes Yes
Is there 230V AC between CN711 1-3 or 2-3 on the deicer P.C. board? w
Operate the unit in COOL mode by pressing the EMERGENCY OPERATION switch.
No
Check the outdoor fan motor. Refer to page 25.
Yes
Is there 230V AC CN730 1-3 on the deicer P.C. board? w
Replace the deicer P.C. board.
Replace the deicer P.C. board.
No
No
Is there 5V DC between J101 - J401 on the deicer P.C. board? w
Is there 230V AC between CN730 1-3 on the deicer P.C. board? w
+
Is there 5V DC between J101 - J401 on the deicer P.C. board? w
+
w Refer to page 29.
A
9-4. Troubleshoot flow
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27
After 30 seconds, does compressor stop?
No
Yes
Is there 230V AC between A1-A2 on the compressor contactor (52C)?
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, does outdoor fan motor stop?
Replace thedeicer P.C. board.
Yes
Ok
No
Is there 230V AC between 2/T1 on the compressor contactor (52C) and N on the outdoor terminal block?
Yes
Replace the compressor contactor (52C).
No Rectify the connecting wire.
MU-GA80VBCheck of outdoor unit
Compressor and/or outdoor fan motor doesn’t stop.
How to check mis-wiringC
1. Turn OFF the power supply (indoor/ outdoor unit) and disconnect indoor and outdoor connecting wire at the terminal block 3 of the indoor unit.
2. Short-circuit terminal block N-3 of indoor unit 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 R601on the deicer P.C. board? Refer to page 29.(By tester, the stylus is between 5 ~10V.)
As for indoor unit, refer to service manual OB369.
Start
No
NoIs 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
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 page 29.
Replace the deicer P.C. board.
Yes
Is there 5V DC between J101 + -J401 - on the deicer P.C. board?Refer to page 29.
Yes
Yes
After 3 minutes, mis-wiring is indicated(0.5-second ON, 0.5-second OFF) on OPERATION INDICATORlamp 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) Disconnect the lead wire that terminal block N-3 of the indoor unit is short-circuited.• 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.
MU-GA80VB
B
OB370-1.qxp 04.10.14 1:45 PM Page 27
28
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 resistancs of thermistor have the characteristics on page 29?
No
Yes
Does the unit operate 10 minutes or more?
Replace the deicer P.C. board.
Ok W.
W It is thought defective contact of the connector.
Turn OFF the power supply.
Discharge temperature thermistor(RT62)
Ambient temperature thermistor(RT63)
When OPERATION INDICATOR lamp flashes 6-time.Thermistors in the outdoor unit are abnormal.
E
Check of LEV (Expansion valve)D MU-GA80VB
When OPERATION INDICATOR lamp flashes 10-time.Cooling doesn't operate.
w Disconnect the connectors CN662 from the deicer P.C. board.(Check the characteristics of each thermistor.)
MU-GA80VB
Replace the LEV.
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 characterictics on page 25?
No
Yes
Yes
Yes
No
No Properly fix the LEV to the expansion valve.
Replace the deicer P.C. board.
NOTE : After check of LEV, do the undermentioned operations.
1. Turn OFF the power supply and turn ON again.
2. Press the RESET button on the remote controller.
Turn ON the power supply.1 During pressing both the OPERATION SELECT button and the TOO COOL button on the
remote controller at the same time, press the RESET button.2 First, release the RESET button. And release the other two buttons since all LCD in operation display section of the remote controller is displayed after 3 seconds.
1 During pressing both the OPERATION SELECT
button and the TOO COOL button on the
remote controller at the same time,
press the RESET button.
2 First, release the RESET button.
And release the other two buttons since all LCD
in operation display section of the remote controller
is displayed after 3 seconds.
AMPMCLOCK
C̊
AMPM
OB370-1.qxp 04.10.14 1:45 PM Page 28
29
MU-GA80VB -Outdoor deicer P.C. board
E1
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 temper-ature thermistor(RT62)(Refer to page 28.)
CN662 3-4Ambient temperaturethermistor (RT63)(Refer to page 28.)
LEVconnector(CN724)
Fan motorconnector(CN711)
Varistor(NR61)
CN7301-3230V AC}
(Refer to page 26 or 27.)
}
R601 10V DC(Refer to page 27.)
(Refer to page 26 or27.)
J101
J401
+
9-5. Test point diagram and voltage
OB370-1.qxp 04.10.14 1:45 PM Page 29
30
DISASSEMBLY INSTRUCTIONS10
(1) Slide the sleeve and check if there is a locking lever or not. (2) The terminal with this connector is a terminal with lock mechanism
1Slide the sleeve.2Pull the terminal while pushing the locking lever.
1Hold the sleeve, and pull out the terminal slowly.
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>
Connector
Sleeve
Locking lever
OPERATING PROCEDURE PHOTOS
1. Removing the cabinet(1) Remove the screws of the cabinet.(2) Hold the down of the cabinet on the both side and remove
the cabinet.
10-1. MU-GA50VB -OUTDOOR UNIT
E1
Photo 1
Photo 2
Screws ofthe cabinet
Screwsof thecabinet
Servicepanel
2. Removing the electrical parts(1) Remove the service panel and the cabinet.(2) Remove the following parts.
3. Removing the outdoor fan motor(1) Remove the cabinet. (Refer to 1.)(2) Disconnect the connector and remove the hooked lead
wire from the fan motor.(3) Remove the propeller nut and remove the propeller.(4) Remove 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 glass terminal of the com-
pressor.(6) Recover gas from the refrigerant circuit.(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.
NOTE● Before using a burner, reclaim gas from the pipes until the
pressure gauge shows 0 kg/cm2 (MPa).● Use the burner under the condition that gas can be recovered
even when the inner pressure rises by heat.
Photo 5
Compressor
Dischargepipe
Suctionpipe
Compressor set nuts
Photo 4 Hook
PropellerPropeller nut Soundproof felt
OPERATING PROCEDURE
OB370-2.qxp 04.10.14 1:46 PM Page 31
32
OPERATING PROCEDURE PHOTOS
1. Removing the cabinet(1) Remove the screws of the cabinet.(2) Hold the bottom of the cabinet on the both side to remove
the cabinet.
10-2. MU-GA60VB -OUTDOOR UNIT
E1
Photo 1
Photo 3
Photo 2
Screws
Screws
Servicepanel
2. Removing the electrical parts(1) Remove the cabinet . (Refer to 1.)(2) Remove the following parts.
3. Removing the outdoor fan motor(1) Remove the cabinet. (Refer to 1.)(2) Disconnect the connector and remove the hocked lead
wire from the fan motor. (3) Remove the propeller nut and remove the propeller.(4) Remove the screws fixing the fan motor.(5) Remove the outdoor 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 the lead wires from the glass terminal of the
compressor.(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 5
Compressor
Compressor set nuts
Photo 4
OPERATING PROCEDURE
Dischargepipe
Suctionpipe
Propeller nut
Hook
Propeller
OB370-2.qxp 04.10.14 1:46 PM Page 33
34
10-3. MU-GA80VB -OUTDOOR UNIT
E1
OPERATING PROCEDURE PHOTOS
1.Removing the cabinet(1) Remove the screws 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 Screws of the
relay panel
Terminalblocks
OB370-2.qxp 04.10.14 1:46 PM Page 34
35
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 the outdoor fan motor
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 (0MPa).(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 set nuts
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36
PARTS LIST11
MU-GA50VB -MU-GA60VB -11-1. OUTDOOR UNIT
STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS
E1
E1
1
17
1213
11
16
4 5 6
10
9
8
2
3
7
1920
1415
22 21
18
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MU-GA50VB -MU-GA60VB -11-1. OUTDOOR UNIT
STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS