Mitsubishi Electric MU-GA20VB-E1, MU-GA25VB-E1, MU-GA20VB-E2, MU-GA25VB-E2, MU-GA35VB-E1 Service Manual

HFC

utilized

R410A

SPLIT-TYPE, AIR CONDITIONERS

OUTDOOR UNIT

SERVICE MANUAL

Wireless type
Models

Revision B:

● MU-GA20VB- and MU-GA25VB -
have been added.

Please void OB386 REVISED EDITION-A.

No. OB386

REVISED EDITION-B

E2E2

MU-GA20VB­MU-GA20VB­MU-GA25VB­MU-GA25VB­MU-GA35VB-

MU-GA20VB
MU-GA25VB
MU-GA35VB

E1

E2

E1

E2

E1

Indoor unit service manual

MSC-GA• VB Series (OB385)
MSC-CA• VB Series (OB393)

CONTENTS

1. TECHNICAL CHANGES ····································2

2. PART NAMES AND FUNCTIONS······················3

3. SPECIFICATION·················································3

4. NOISE CRITERIA CURVES·······························5

5. OUTLINES AND DIMENSIONS·························6

6. WIRING DIAGRAM ············································6

7. REFRIGERANT SYSTEM DIAGRAM················7

8. PERFORMANCE CURVES································8

9. TROUBLESHOOTING······································17

10. DISASSEMBLY INSTRUCTIONS·····················20

11. PARTS LIST······················································22

12. RoHS PARTS LIST···········································24

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.

Revision A:

• 11-1. PARTS LIST has been modified. (The parts No. of BACK PANEL has been changed.)

Revision B:

• MU-GA20VB- and MU-GA25VB- have been added.

1

TECHNICAL CHANGES

MU-A07YV- ➔MU-GA20VB-

1. Indication of capacity has been changed.(BTU base ➔ kW base)

2. Unit size has been changed. (W780mm x H540mm x D255mm ➔ W800mm x H550mm x D285mm)

3. Outdoor fan motor has been changed. (RC6V20-AC ➔ RA6V21-AC)

4. Stop valve cover has been added.

5. Outdoor fan capacitor has been changed.

6. Compressor capacitor has been changed.

MU-A09YV- ➔MU-GA25VB-

1. Indication of capacity has been changed.(BTU base ➔ kW base)

2. Unit size has been changed. (W780mm x H540mm x D255mm ➔ W800mm x H550mm x D285mm)

3. Outdoor fan motor has been changed. (RC6V20-AC ➔ RA6V21-AC)

4. Stop valve cover has been added.

5. Outdoor fan capacitor has been changed.

6. Compressor capacitor has been changed.

7. Compressor has been changed. (RN099VHSHT ➔ RN092VHSHT)

MU-A12YV- ➔MU-GA35VB-

1. Indication of capacity has been changed.(BTU base ➔ kW base)

2. Unit size has been changed. (W780mm x H540mm x D255mm ➔ W800mm x H550mm x D285mm)

3. Outdoor fan motor has been changed. (RC6V33-AC ➔ RA6V33-KA)

4. Stop valve cover has been added.

5. Outdoor fan capacitor has been changed.

6. Compressor capacitor has been changed.

7. Compressor has been changed. (RN135VHSHT ➔ 5PS132DAH01)

8. Stop valve (Gas) has been changed from [12.7 to [9.52.

9. Fuse for compressor protection has been added.

E2E2

E1E1

E1E1

E1E1

MU-GA20VB- ➔MU-GA20VB­MU-GA25VB- ➔MU-GA25VB-

1. Compressor has been changed. (RN092VHST ➔ KN092VDMHC)

2. Compressor capacitor has been changed.

3. Capillary tube has been changed. ([3.0x[1.4x700 ➔ [3.0x[1.4x900)

E2E1
E2E1

2

2

Air outlet

Drain outlet

Piping

Drain hose

( )

Air inlet

back : MU-GA20VB

MU-GA25VB

back and side : MU-GA35VB

Capacity
Dehumidification
Outdoor air flow
Power outlet
Running current
Power input
Auxiliary heater
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
Fan speed
Fan speed regulator
Refrigerant filling
capacity (R410A)
Refrigeration oil (Model)

kW

R/h

K /h

A
A

W

A(kW)

%

A
A
A

W

"

"

mm

kg

dB

rpm

kg
cc

MU-GA20VB -

E1

Single phase

230V,50Hz

2.3

0.9

1,800

10

3.17
715

–
98
21

2.76

0.245

3.22

RN092VHSHT

600
C-R 3.87
C-S 6.14

RA6V21-AC

WHT-BLK 366

BLK-RED 274
800o550o285

31
45

745

1

0.60

350 (NEO22 )

MU-GA20VB -

E2

Single phase

230V,50Hz

2.3

0.9

1,800

10

3.17
715

–

98

15.5

2.76

0.245

3.22

KN092VDMHC

650

C-R 3.62
C-S 5.40

RA6V21-AC
WHT-BLK 366
BLK-RED 274

800o550o285

27
45

745

1

0.60

350 (NEO22 )

Compressor

Electrical

data

Fan

motor

Special

remarks

Capacity

Coefficient of performance(C.O.P)

Outdoor unit power supply

Outdoor model

PART NAMES AND FUNCTIONS

OUTDOOR UNIT

MU-GA20VB
MU-GA25VB
MU-GA35VB

3

NOTE: Test conditions are based on ISO 5151.

SPECIFICATION

Cooling : Indoor DB27°C WB19°C
Indoor-Outdoor piping length : 5m

Outdoor DB35°C WB24°C

3

Capacity
Dehumidification
Outdoor air flow
Power outlet
Running current
Power input
Auxiliary heater
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
Fan speed
Fan speed regulator
Refrigerant filling
capacity (R410A)
Refrigeration oil (Model)

kW

R/h

K /h

A
A

W

A(kW)

%

A
A
A

W

"

"

mm

kg
dB

rpm

kg

cc

MU-GA25VB -

E2

Single phase

230V,50Hz

10

KN092VDMHC

650
C-R 3.62
C-S 5.40

RA6V21-AC
WHT-BLK 366
BLK-RED 274

800o550o285

27
45

745

1

0.60

350 (NEO22 )

2.5

1.1

1,800

3.40
775

–

99

15.5

2.99

0.245

3.23

MU-GA25VB -

E1

Single phase

230V,50Hz

10

RN092VHSHT

600
C-R 3.87
C-S 6.14

RA6V21-AC

WHT-BLK 366

BLK-RED 274
800o550o285

31
45

745

1

0.60

350 (NEO22 )

2.5

1.1

1,800

3.40
775

–
99
21

2.99

0.245

3.23

MU-GA35VB -

E1

Single phase

230V,50Hz

1.7

10

5PS132DAH01

900
C-R 2.80
C-S 5.43

RA6V33-KA
WHT-BLK 215
BLK-RED 307

800o550o285

30
49

855

1

0.70

350 (RB68A)

3.45

1,902

5.02

1,120

–
97
21

4.50

0.33

3.08

Compressor

Electrical

data

Fan

motor

Special

remarks

Capacity

Coefficient of performance(C.O.P)

Outdoor unit power supply

Outdoor model

NOTE: Test conditions are based on ISO 5151.

Cooling : Indoor DB27°C WB19°C

Outdoor DB35°C WB24°C

Indoor-Outdoor piping length : 5m

4

4

90

80

70

60

50

40

30

20

10

63 125 250 500 1000 2000 4000 8000

APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

BAND CENTER FREQUENCIES, Hz

Test conditions,

Cooling :DB35: WB24:

MU-GA35VB

COOL

FUNCTION

49

SPL(dB(A)) LINE

OUTDOOR UNIT

MICROPHONE

1m

90

80

70

60

50

40

30

20

10

63 125 250 500 1000 2000 4000 8000

APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

BAND CENTER FREQUENCIES, Hz

Test conditions,

Cooling : DB27: WB19:

MU-GA20VB
MU-GA25VB

COOL

FUNCTION

45

SPL(dB(A)) LINE

NOISE CRITERIA CURVES

5

5

C2

C1

WHT

POWER SUPPLY

~/N 230V 50Hz

CIRCUIT
BREAKER

BLU

BRN

WHT

RED

BLU

WHT

BLK

RED

12V

TO INDOOR

UNIT

CONNECTING

WHT

BLK

DSAR

52C

TB2

2

1

C

R

S

GRN/YLW

PE

N

L

BRN

TB1

COM

52C

NO

MC

1

3
2

BLK

RED

WHT

MF

SYMBOL

TB2
52C

SYMBOL

MC
MF

TB1

SYMBOL

C1
C2

DSAR

NAME

NAME NAME
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER

COMPRESSOR(INNER PROTECTOR)

TERMINAL BLOCK
COMPRESSOR CONTACTOR

OUTDOOR FAN MOTOR(INNER FUSE)
TERMINAL BLOCK

OUTLINES AND DIMENSIONS

MU-GA20VB MU-GA25VB MU-GA35VB

OUTDOOR UNIT

344.5

285

550

44

Air in

(MU-GA35VB)

2 holes 10X21

22.3

Handle

280

10

400

Air in

Air out

150

302.5
500 Bolt pitch for installation

Drain hole [42

40

17.5

164.5

69

800

installation

Bolt pitch for

23

99.5
Service port

REQUIRED SPACE

100mm or more

304~325

Service panel

Liquid refrigerant pipe joint
Refrigerant pipe (flared) [6.35

35-

Gas refrigerant pipe joint
Refrigerant pipe (flared) [9.52

170.5

ore

or m

m

200m

Open two sides of left,
right, or rear side.

43-

Unit: mm

Basically open 100mm or more
without any obstruction in front
and on both sides of the unit.

100mm or more

350m

m

or m

ore

6

WIRING DIAGRAM

MU-GA20VB MU-GA25VB

OUTDOOR UNIT

NOTE: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.

/: Terminal block, : Connector

6

MU-GA35VB

PE

N

L

TB1

1

2

TB2

C1

C2

WHT

CIRCUIT
BREAKER

WHT

51C

41

BRN

F

BLU

BRN

WHT

RED

BLU

WHT

BLK

RED

POWER SUPPLY

~/N 230V 50Hz

12V

TO INDOOR

UNIT

CONNECTING

WHT

BLK

DSAR

52C

C

R

S

GRN/YLW

BRN

COM

52C

NO

MC

1

3
2

BLK

RED

WHT

MF

OUTDOOR UNIT

SYMBOL

COMPRESSOR CAPACITOR

C1

OUTDOOR FAN CAPACITOR

C2

DSAR

NOTE:1. About the indoor side electric wiring refer to the indoor unit electric wiring diagram for servicing.

7

SURGE ABSORBER

F

FUSE (T20AL250V)

2. Use copper conductors only. (For field wiring)

3. Symbols below indicate.
/: Terminal block, : Connector

REFRIGERANT SYSTEM DIAGRAM

NAME

SYMBOL

MC

MF
TB1
TB2

NAME NAME
COMPRESSOR
OUTDOOR FAN MOTOR (INNER FUSE)
TERMINAL BLOCK
TERMINAL BLOCK

MU-GA20VB
MU-GA25VB
MU-GA35VB

OUTDOOR UNIT

Flared connection

Refrigerant pipe [9.52
(with heat insulator)

Stop valve
(with service port)

SYMBOL

51C
52C

Muffler

OVERLOAD RELAY
COMPRESSOR CONTACTOR

Unit:mm

Outdoor
heat
exchanger

Refrigerant pipe [6.35
(with heat insulator)

Flared connection

Stop valve

Capillary tube

[3.0x[1.4x700 (MU-GA20VB
[3.0x[1.4x900 (MU-GA20VB
[3.0x[1.4x450 (MU-GA35VB)

7

Compressor

Strainer
#100

- , MU-GA25VB- )

- , MU-GA25VB- )

E1E1
E2E2

Refrigerant flow in cooling

Piping size O.D : mm Length of connecting pipe : m

Model

Refrigerant piping : m

Max. length

A

20

25

Max. height

B

10

Indoor unit

Gas 0.43

Liquid 0.5

Liquid

6.35

Gas

9.52

Outdoor unit

Gas 0

Liquid 0

MU-GA20VB
MU-GA25VB

MU-GA35VB

Indoor
unit

Max. Height
B

Outdoor unit

Refrigerant Piping

Max. length

A

Model

Refrigerant piping length (one way)

Outdoor unit precharged

600
700

25m

360

7m

0

10m

60

15m

160

20m

260

Calculation : Xg=20g/m x(A-7)m

MU-GA20VB
MU-GA25VB

MU-GA35VB

MAX. REFRIGERANT PIPING LENGTH

MAX. HEIGHT DIFFERENCE

ADDITIONAL REFRIGERANT CHARGE(R410A : g)

8

PERFORMANCE CURVES

MU-GA20VB MU-GA25VB MU-A35VB

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 pro­vided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.

(1) GUARANTEED VOLTAGE

198~264V

(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 next page shows the difference between the
indoor 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 difference

1. 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 air
speed 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.

Cooling

}

8

INDOOR UNIT

18 32

230V

15 20

50

25
6030 70

(%)

35(:)

0.7

0.8

0.9

1.0

1.1

1.2

1.3

7

8

9

10

11

12

13

15 20

50

25
60

30
70(%)

35(:)

1

2

4

3

18 32

230V

OUTDOOR UNIT

Wet-and dry-bulb
thermometers

Wet-and dry-bulb
thermometers

8-1.CAPACITY AND THE INPUT CURVES

9.6

8.5

7.8

7.1

6.4

5.8

5.1

MSC-GA20VB

11.0

8.8

10.0

8.0

7.2

6.5

5.7

MU-GA20VB

MU-GA25VB

MSC-GA25VB

9.1

8.2

7.4

6.5

MU-GA35VB

MSC-GA35VB

8-2.OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT
COOL operation

① Both indoor and outdoor unit are under the same temperature/humidity condition.

Dry-bulb temperature

20
25
30 70

Relative humidity(%)

50
60

➁ Air flow should be set at MAX.
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] )

(kgf/F[Gauge])(MPa[Gauge])

Outdoor low pressure

Ambient temperature(˚C) Ambient humidity(%) Ambient temperature(˚C) Ambient humidity(%)

MU-GA20VB MU-GA20VB

Outdoor unit current (A)

9