Mitsubishi Electric MUH-GA50VB-E1 User manual

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. SERVICE FUNCTIONS ····································25
10. TROUBLESHOOTING······································25
11. DISASSEMBLY INSTRUCTIONS·····················35
12. PARTS LIST······················································39
13. RoHS PARTS LIST···········································46
Wireless type
Models
MUH-GA50VB -
MUH-GA50VB -
MUH-GA60VB -
MUH-GA80VB - E1
E1
E2
E1
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
MUH-GA50VB
NOTE:
This service manual describes technical data of 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.
HFC
utilized
R410A
OUTDOOR UNIT No. OB368
REVISED EDITION-B
Please void OB368 REVISED EDITION-A.
Revision:B
• MUH-GA50VB- has been added.
E2
Indoor unit service manual
MSH-GA•VB Series (OB367)
OB368B-1.qxp 07.5.21 8:06 PM Page 1

2
Refrigerating
oil
Refrigerant
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-11
w2 :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.
TECHNICAL CHANGES
1
MUH-A18WV - ➔MUH-GA50VB -
1. Oil separator has been removed.
2. Model name has been changed.
Indication of capacity has been changed. (BTU➔kW)
MUH-A24WV - ➔MUH-GA60VB -
MUH-A30WV - ➔MUH-GA80VB -
1. Model name has been changed.
Indication of capacity has been changed. (BTU➔kW)
MUH-GA50VB - ➔MUH-GA50VB -
1. Outdoor heat exchanger has been changed. (1 row ➔2 row)
2. Outdoor fan motor has been changed.
3. Oil separator has been added.
E2E1
E1E1
E1E1
E1E1
Revision:A
•RoHS PARTS LIST has been added.
Revision:B
•MUH-GA50VB- has been added.
E2
OB368B-1.qxp 07.5.21 8:06 PM Page 2

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 refrigeration 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
refrigeration oil of the upper layer to flow back to the
compressor.
Since refrigerant and refrigeration oil are compatible each,
refrigeration oil backs to the compressor through the lower
position oil back hole.
Compressor
Suction muffler
Oil back hole
Refrigeration oil
Refrigerant
Compressor
Suction muffler
Oil back hole
Refrigeration oil /Refrigerant
Compressor
-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
Saturated liquid pressure
(:)
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 R410Awith 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 gauge
Vacuum pump
adapter
Electronic scale for
refrigerant 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 refrigerant
The 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.
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4
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 nut
Flaring work for R410A pipe differs from that for R22 pipe.
For details of flaring work, refer to Installation manual “FLARING WORK”.
3.Refrigerantion oil
Apply 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 charge
For 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 the
outdoor 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 piping
1Specifications
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.
Wall
thickness
Outside diameter
Pipe 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
Electronic scale for refrigerant charging
Outdoor unit
Refrigerant gas
cylinder
operating valve
Refrigerant gas cylinder
for 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)
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5
PART NAMES AND FUNCTIONS
2
Drainage hose
Piping
Air inlet Air inlet
Air outlet
Drain outlet
(back and side)
Air outlet
(back and side)
ACCESSORIES
MUH-GA50VB
1
2
Drain socket
Drain cap {33
Drain cap {16
1
2
—
1
2
1
MUH-GA50VB MUH-GA60VB
MUH-GA80VB
MUH-GA60VB MUH-GA80VB
OB368B-1.qxp 07.5.21 8:06 PM Page 5

6
WHT-BLK 71.2
BLK-RED 89.3
WHT-BLK 79.5
BLK-RED 83.0
Outdoor model
Function
Power supply
Capacity
Dehumidification
Air flow(High)
Power outlet
Running current
Power input
Power factor
Starting current
Compressor motor current
Fan motor current
Model
Output
Winding
resistance(at 20:)
Model
Winding
resistance(at 20:)
Dimensions WOHOD
Weight
Sound level(High)
Fan speed(High)
Fan speed regulator
Refrigerant filling
capacity(R410A)
Refrigeration oil (Model)
Thermistor RT61(at 0:)
kW
r/h
K/h
A
A
W
%
A
A
A
W
"
"
mm
kg
dB
rpm
kg
cc
k"
MUH-GA50VB
Single phase
230V, 50Hz
2,196
15
37
0.39
RN196VHSHT
1,300
C-R 1.80
C-S 3.00
RA6V50-PA
RA6V60-MA
850o605o290
47
52
828
1
1.80
520 (NEO22)
33.18
Cooling
5.0
2.5
7.93
1,720
94
7.54
2.81
Heating
5.2
—
7.23
1,550
93
6.84
3.23
MUH-GA60VB
Single phase
230V, 50Hz
2,760
25
74
0.58
NN29VBAHT
1,900
C-R 0.80
C-S 1.64
RA6V85-DA
WHT-BLK 68.8
BLK-RED 93.1
840o850o330
74
53
730
1
2.35
1,200 (NEO22)
33.18
Cooling
6.3
3.2
10.39
2,350
98
9.81
2.61
Heating
7.2
—
10.70
2,420
98
10.12
2.90
Electrical data
Compressor
Fan motor
Special remarks
Coefficient of performance(C.O.P)
Capacity
E1
E1
E2
E2
SPECIFICATION
3
NOTE: Test conditions are based on ISO5151.
Cooling : Indoor DB27°C WB19°C Heating : Indoor DB20°C WB 15.5°C
Outdoor DB35°C WB(24°C) Outdoor DB 7°C WB 6°C
Indoor-Outdoor piping length : 5m
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7
Outdoor model
Function
Power supply
Capacity
Dehumidification
Air flow(High/Low)
Power outlet
Running current
Power input
Power factor
Starting current
Compressor motor current
Fan motor current
Model
Output
Winding
resistance(at 20:)
Model
Winding
resistance(at 20:)
Dimensions WOHOD
Weight
Sound level(High/Low)
Fan speed(High/Low)
Fan speed regulator
Refrigerant filling
capacity(R410A)
Refrigeration oil (Model)
Thermistor RT61(at 0:)
Thermistor RT62(at 25:)
Thermistor RT63(at 0:)
kW
R/h
K/h
A
A
W
%
A
A
A
W
"
"
mm
kg
dB
rpm
kg
cc
k"
k"
k"
MUH-GA80VB
Single phase
230V, 50Hz
25
90
0.57
NN37VAAHT
2,500
C-R 0.64
C-S 1.63
RA6V75-AD
WHT-BLK 62.8 BLK-YLW 55.9
YLW-RED 26.0
840o850o330
77
55/53
805/435
2
2.40
1,300 (NEO 22)
33.18
231.44
33.18
Cooling
8.5
4.6
2,940/1,470
14.42
3,191
96
13.85
2.61
Heating
9.4
—
2,940/1,470
15.19
3,361
96
14.62
2.74
Electrical data
Compressor
Fan motor
Special remarks
Coefficient of performance(C.O.P)
Capacity
NOTE: Test conditions are based on ISO5151.
Cooling : Indoor DB27°C WB19°C Heating : Indoor DB20°C WB 15.5°C
Outdoor DB35°C WB(24°C) Outdoor DB 7°C WB 6°C
Indoor-Outdoor piping length : 5m
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8
NOISE CRITERIA CURVES
4
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 35: Wet-bulb temperature 24:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
52
SPL(dB(A)) LINE
High
FAN SPEED
Heating : Dry-bulb temperature 7: Wet-bulb temperature 6:
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
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 35: Wet-bulb temperature 24:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
53
SPL(dB(A)) LINE
High
FAN SPEED
Heating : Dry-bulb temperature 7: Wet-bulb temperature 6:
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
MUH-GA50VB MUH-GA60VB
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 35: Wet-bulb temperature 24:
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
55
SPL(dB(A)) LINE
High
FAN SPEED
Heating : Dry-bulb temperature 7: Wet-bulb temperature 6:
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
MUH-GA80VB
OUTDOOR UNIT
MICROPHONE
1m
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9
MUH-GA60VB MUH-GA80VB
OUTLINES AND DIMENSIONS
5
Unit: mm
MUH-GA50VB
100mm or more
100mm or more
100mm or more
350mm or more
500mmor more
REQUIRED SPACE
Drainage
3holes [33 Air out
Air in
Air in
Service panel
Liquid refrigerant
pipe joint
Refrigerant pipe
(flared) [6.35
Gas refrigerant
pipe joint
Refrigerant pipe
(flared) [12.7
35-
30-
30
100
161
157
74
850
500
183
20 292
605 248
35
350
50
290
310 345
20
355
90
Drainage
hole [16.2
30-
35-
155
90
198
40
515
299
66
34
51
330
360
850
430
500 80
121
840
Open as a rule
500mm or more if
the front and both
sides are open
100mm or more
200mm or more if
there are obstacles
to both sides
Open as a rule
500mm or more if the back,
both sides and top are open 350mm or more
100mm or more
Service panel
Gas refrigerant
pipe joint
Refrigerant pipe
(flared) [15.88
Liquid refrigerant
pipe joint
Refrigerant pipe
(flared) [6.35 (MUH-GA60VB)
[9.52 (MUH-GA80VB)
REQUIRED SPACE
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10
WIRING DIAGRAM
6
MUH-GA60VB
DEICER
P.C. BOARD
BLU
X52
X52 NO
COM
TAB52
BLU 52C A2
A1
T61
BLK WHT
RED
BRN
TB2
7
1
CN730
BLK WHT
CIRCUIT BREAKER CN721
352C 4
RED C2
ORN
DSAR
12V
WHT
C1
BLK
SCR
MC
RED
NR61 3
5
BLU
TB1
GRN/YLW
POWER SUPPLY
~ / N 230V 50Hz
CN661
RT61
X62 X62 1
2
321S4
BLU
BRN
BLU
BRN
SR61
F61
CN711
MF
123
21
ORN RED
34
NO
COM
TO INDOOR UNIT CONNECTING
N
3
N
L
PE
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).
3.Symbols below indicate.
: Terminal block, : Connector
SYMBOL
C1
C2
DSAR
F61
MC
MF
NR61
RT61
SR61
TB1
TB2
T61
X52
X62
21S4
52C
NAME
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER
FUSE (3.15A)
COMPRESSOR (INNER PROTECTOR)
OUTDOOR FAN MOTOR (INNER PROTECTOR)
VARISTOR
DEFROST THERMISTOR
SOLID STATE RELAY
TERMINAL BLOCK
TERMINAL BLOCK
TRANSFORMER
CONTACTOR
R. V. COIL RELAY
R. V. COIL
COMPRESSOR CONTACTOR
MUH-GA50VB
MC
CN661
3
1
2CN721
21S4 MF
SR62
SR61
TAB20
GRN/YLW
BLU
CIRCUIT BREAKER
POWER SUPPLY BLU
BRN
DSAR
BLK
BRN
RED
DEICER P.C. BOARD
4
C1
BLK
RED
3
WHT
S
C
R
CN730
RT61
BLK
2
3
1
RED
WHT
12V
TO
CONNECTING
INDOOR UNIT TB2
3
N
TB1
L
N
PE
~/N
NR61
F61
T61 C65
CN711
52C
230V 50Hz
1234
WHT
BLK RED ORN
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
C65
DSAR
F61
MC
NAME
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER
FUSE (2A)
COMPRESOR (INNER PROTECTOR)
SYMBOL
MF
NR61
RT61
SR61,SR62
T61
NAME
OUTDOOR FAN MOTOR (INNER PROTECTOR)
VARISTOR
DEFROST THERMISTOR
SOLID STATE RELAY
TRANSFORMER
SYMBOL
TB1,TB2
21S4
52C
NAME
TERMINAL BLOCK
R.V. COIL
COMPRESSOR CONTACTOR
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