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

HFC

utilized

R410A

SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS

OUTDOOR UNIT

SERVICE MANUAL

Wireless type Models

Revision B:

● MUH-GA35VB - has been added. Please void OB387 REVISED EDITION-A.

E3

No. OB387

REVISED EDITION-B

MUH-GA20VBMUH-GA20VBMUH-GA25VBMUH-GA25VBMUH-GA35VBMUH-GA35VB-

MUH-GA20VB MUH-GA25VB MUH-GA35VB

E1

E2

E1

E2

E1

E3

Indoor unit service manual

MSC-GA• VB Series (OB385) MSC-CA• VB Series (OB393) MSC-CB• VB Series (OB439)

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 ············································7

7. REFRIGERANT SYSTEM DIAGRAM················8

8. PERFORMANCE CURVES································9

9. ACTUA TOR CONTROL····································19

10. SERVICE FUNCTIONS·····································20

11. TROUBLESHOOTING······································20

12. DISASSEMBLY INSTRUCTIONS·····················27

13. PARTS LIST······················································30

14. RoHS PARTS LIST···········································32

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:

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

E2E2

Revision B:

• MUH-GA35VB- has been added.

1

MUH-A07YV- ➔MUH-GA20VB-

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

2. Dimension of outdoor unit has been changed. (W780mm x H540mm x D255mm ➔ W800mm x H550mm x D285mm)

3. Stop valve cover has been added.

4. Outdoor fan motor has been changed. (RC6V20-AB ➔ RA6V21-AD)

5. Outdoor fan motor capacitor has been changed.

6. Compressor capacitor has been changed.

7. Outdoor heat exchanger has been changed. (L-BEND ➔ FLAT)

MUH-A09YV- ➔MUH-GA25VB-

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

2. Dimension of outdoor unit has been changed. (W780mm x H540mm x D255mm ➔ W800mm x H550mm x D285mm)

3. Stop valve cover has been added.

4. Outdoor fan motor has been changed. (RA6V33-FB ➔ RA6V33-KB)

5. Outdoor fan motor capacitor has been changed.

6. Compressor capacitor has been changed.

7. Outdoor heat exchanger has been changed. (2 Row ➔ 1 Row)

E3

TECHNICAL CHANGES

E1E1

MUH-A12YV- ➔MUH-GA35VB-

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

2. Dimension of outdoor unit has been changed. (W780mm x H540mm x D255mm ➔ W800mm x H550mm x D285mm)

3. Stop valve cover has been added.

4. Outdoor fan motor has been changed. (RA6V33-FB ➔ RA6V33-KB)

5. Outdoor fan motor capacitor has been changed.

6. Compressor capacitor has been changed.

7. Size of stop valve (gas) has been changed.([12.7 ➔ [9.52)

8. Outdoor heat exchanger has been changed. (2 Row ➔ 1 Row)

MUH-GA20VB- ➔MUH-GA20VB-

1. Compressor has been changed. (BN092VHST ➔ KN092VDMHC)

2. Compressor capacitor has been changed.

3. Capillary tube has been changed.

4. Refrigerant filling capacity has been changed.

5. Deicer P.C. board has been changed.

MUH-GA25VB- ➔MUH-GA25VB-

1. Compressor has been changed. (RN104VHSHT ➔ KN104VTMHC)

2. Compressor capacitor has been changed.

3. Capillary tube has been changed.

4. Refrigerant filling capacity has been changed.

5. Deicer P.C. board has been changed.

MUH-GA35VB- ➔MUH-GA35VB-

1. Outdoor heat exchanger has been changed. (1 row ➔ 2 row)

2. Refrigerant filling capacity has been changed.

3. Outdoor unit weight has been changed. (35 kg ➔ 39 kg)

E1E1

E2E1

E3E1

2

( )

Air inlet

Air outlet

Drain outlet

Piping

Drain hose

back : MUH-GA20VB back and side : MUH-GA25VB MUH-GA35VB

Drain socket

1

1

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

MUH-GA20VB -

E1

Single phase

230V,50Hz

1,800

10

—

21

0.25

RN092VHSHT

600 C-R 3.87 C-S 6.14

RA6V21-AD

WHT-BLK 366

BLK-RED 274 800o550o285

32 47

745

1

0.65

350 (NEO22)

Cooling

2.3

0.9

3.00 680

99

2.76

3.22

Heating

2.5

—

2.86 655

100

2.62

3.62

Compressor

Electrical

data

Fan

motor

Special

remarks

Capacity

Coefficient of performance (C.O.P)

Outdoor unit power supply

Function

Outdoor model

MUH-GA20VB -

E2

Single phase

230V,50Hz

1,800

10

—

15.5

0.25

KN092VDMHC

650 C-R 3.62 C-S 5.40

RA6V21-AD WHT-BLK 366 BLK-RED 274

800o550o285

29 47

745

1

0.60

350 (NEO22)

Cooling

2.3

0.9

3.00 680

99

2.76

3.22

Heating

2.5

—

2.86 655

100

2.62

3.62

PART NAMES AND FUNCTIONS

OUTDOOR UNIT

MUH-GA20VB MUH-GA25VB MUH-GA35VB

3

SPECIFICATION

ACCESSORIES

MUH-GA20VB MUH-GA25VB MUH-GA35VB

NOTE: Test conditions are based on ISO 5151.

Cooling : Indoor DB27°C WB19°C Heating : Indoor DB20°C Indoor-Outdoor piping length : 5m

Outdoor DB35°C WB24°C Outdoor DB 7°C/WB 6°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

MUH-GA25VB

-

E2

Single phase

230V,50Hz

1,902

10

—

19

0.33

KN104VTMHC

700 C-R 3.62 C-S 5.40

RA6V33-KB WHT-BLK 215 BLK-RED 307

800o550o285

30 49

855

1

0.65

350 (NEO22)

Cooling

2.65

1.1

3.43 785

100

3.10

3.23

Heating

3.0

—

3.43 785

100

3.10

3.66

Compressor

Electrical

data

Fan

motor

Special

remarks

Capacity

Coefficient of performance (C.O.P)

Outdoor unit power supply

Function

Outdoor model

MUH-GA25VB

-

E1

Single phase

230V,50Hz

1,902

10

—

22

0.33

RN104VHSHT

700 C-R 3.40 C-S 4.56

RA6V33-KB WHT-BLK 215 BLK-RED 307

800o550o285

32 49

855

1

0.80

350 (NEO22)

Cooling

2.65

1.1

3.43 785

100

3.10

3.23

Heating

3.0

—

3.43 785

100

3.10

3.66

MUH-GA35VB

-

E1

Single phase

230V,50Hz

1,902

10

—

27

0.33

RN135VHSHT

900 C-R 2.79 C-S 3.36

RA6V33-KB WHT-BLK 215 BLK-RED 307

800o550o285

35 49

855

1

0.80

620 (NEO22)

Cooling

3.5

1.7

4.65

1,050

98

4.32

3.21

Heating

3.7

—

4.34 980

98

4.01

3.63

MUH-GA35VB

-

E3

Single phase

230V,50Hz

1,902

10

—

27

0.33

RN135VHSHT

900 C-R 2.79 C-S 3.36

RA6V33-KB WHT-BLK 215 BLK-RED 307

800o550o285

39 49

855

1

1.05

620 (NEO22)

Cooling

3.5

1.7

4.65

1,050

98

4.32

3.21

Heating

3.7

—

4.34 980

98

4.01

3.63

NOTE: Test conditions are based on ISO 5151.

Cooling : Indoor DB27°C WB19°C Heating : Indoor DB20°C Indoor-Outdoor piping length : 5m

Outdoor DB35°C WB24°C Outdoor DB 7°C/WB 6°C

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:

Heating :DB 7: WB 6:

MUH-GA25VB MUH-GA35VB

COOLING

FUNCTION

49

HEATING

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 :DB35: WB24: Heating :DB 7: WB 6:

MUH-GA20VB

COOLING

FUNCTION

47

HEATING

SPL(dB

(A)) LINE

4

NOISE CRITERIA CURVES

5

10

69

800

302.5 500 Bolt pitch for installation

150

22.3

Handle

550

280

164.5

99.5

170.5

23

Service panel

Service port

285

344.5

44

400

Air in

Air out

Air in

17.5

Bolt pitch for

installation

304~325

40

Liquid refrigerant pipe joint Refrigerant pipe (flared) [6.35

Gas refrigerant pipe joint Refrigerant pipe (flared) [9.52

43-

35-

2 holes 10X21

(MUH-GA25

/GA35VB)

REQUIRED SPACE

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

350mm or more

200mm or more

100mm or more

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

Drain hole [42

OUTLINES AND DIMENSIONS

MUH-GA20VB MUH-GA25VB MUH-GA35VB

OUTDOOR UNIT

Unit: mm

6

SYMBOL

T61

TB1,TB2

21S4

52C

SYMBOL

MF

NR61

RT61

SR61,SR62

SYMBOL

C1

C65

DSAR

F61

MC

NAME

NAME NAME COMPRESSOR CAPACITOR OUTDOOR FAN CAPACITOR SURGE ABSORBER FUSE(T2AL250V) COMPRESSOR(INNER PROTECTOR)

VARISTOR DEFROST THERMISTOR SOLID STATE RELAY

TRANSFORMER TERMINAL BLOCK R.V. COIL COMPRESSOR CONTACTOR

OUTDOOR FAN MOTOR (INNER FUSE)

TAB20

PE

N

3

TB2

N

L

TB1

BRN

321

CN711

CN730

BLU

NR61

RT61

21S4

CN661

C65

123

SR61

SR62

CN721

T61

WHT

C

MC

S

R

RED BLK

C1

F61

BRN

DSAR

CIRCUIT BREAKER

BLU

POWER SUPPLY

~/N 230V 50Hz

12V

TO INDOOR

UNIT

CONNECTING

RED

BLK

GRN/YLW

3

52C

4

BLK

WHT

RED

MF

WIRING DIAGRAM

MUH-GA20VB MUH-GA25VB MUH-GA35VB

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

7

REFRIGERANT SYSTEM DIAGRAM

MUH-GA20VB MUH-GA25VB MUH-GA35VB-

OUTDOOR UNIT

Refrigerant pipe [ 9.52

(with heat insulator)

Stop valve (with service

Flared connection

Refrigerant pipe [6.35

(with heat insulator)

port)

Strainer #100

Stop valve

Capillary tube

[3.0x[1.4x700 (MUH-GA20VB - ) [3.0x[1.4x900 (MUH-GA20VB - ) [3.0x[1.4x1000(MUH-GA25VB - ) [3.0x[1.6x1500(MUH-GA25VB - ) [3.0x[1.4x500 (MUH-GA35VB - )

Capillary tube

[3.0x[1.4x500 (MUH-GA20VB - ) [3.0x[1.4x300 (MUH-GA20VB - , MUH-GA35VB - ) [3.0x[1.4x600 (MUH-GA25VB - ) [3.0x[1.6x750 (MUH-GA25VB - )

E1

4-way valve

Muffler

Check valve

Defrost thermistor RT61

Compressor

Unit:mm

Outdoor heat exchanger

E1 E2 E1 E2

E1

R.V. coil heating ON cooling OFF

E1

E1E2 E1 E2

MUH-GA35VB-

OUTDOOR UNIT

E3

Refrigerant pipe [ 9.52

(with heat insulator)

Flared connection

Refrigerant pipe [6.35

(with heat insulator)

Stop valve (with service port)

Strainer #100

Stop valve

4-way valve

Muffler

Check valve

Capillary tube [3.0x[1.4x400

8

Compressor

Outdoor heat exchanger

Capillary tube [3.0x[1.8x600 (2 pcs)

Capillary tube [3.0x[1.4x350

R.V. coil heating ON cooling OFF

Defrost thermistor

RT61 Refrigerant flow in cooling Refrigerant flow in heating

MAX. REFRIGERANT PIPING LENGTH

Refrigerant piping : m

Model

Max. lengthAMax. height

B

Piping size O.D : mm

Gas

Liquid

Length of connecting pipe : m Indoor unit

Outdoor unit

MUH-GA20VB MUH-GA25VB

MUH-GA35VB

20

25

10

9.52

MAX. HEIGHT DIFFERENCE

Indoor unit

Refrigerant Piping

Max. height B

Max. length

A

ADDITIONAL REFRIGERANT CHARGE(R410A : g)

Model

MUH-GA20VB -

MUH-GA25VB MUH-GA25VB -

MUH-GA35VB MUH-GA35VB -

Outdoor unit precharged

E1

E2

E1

E2 E1

E3

650 600 800 650 800

1050

7m

0

Gas 0.43

6.35 Liquid 0.5

Outdoor unit

Refrigerant piping length (one way)

10m

60

15m

160

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

20m

260

Gas 0

Liquid 0

25m

360

8

PERFORMANCE CURVES

MUH-GA20VB MUH-GA25VB MUH-GA35VB

The standard specifications apply only to the operation of the air conditioner under normal conditions, since operating condi-

tions 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 (5) Indoor intake air dry-bulb temperature : °CDB (6) Outdoor intake air wet-bulb temperature : °CWB (7) Total input : W Indoor air wet/dry-bulb temperature difference on the left side of the chart on page 10 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.

Cooling

}

Heating

}

9

MSC-GA20VB

MUH-GA20VB

MUH-GA35VB

MSC-GA35VB

MUH-GA25VB

MSC-GA25VB

8.5

7.8

7.1

6.4

5.8

5.1

10.0

9.2

8.3

7.5

6.8

6.0

11.0

10.0

9.1

8.2

7.4

6.5

20.0

18.5

16.9

15.4

13.9

12.3

10.8

9.2

19.2

17.8

16.3

14.8

13.3

11.8

10.4

8.9

MSC-GA20VB

MUH-GA20VB

MUH-GA25VB

MSC-GA25VB

MUH-GA35VB

MSC-GA35VB

24.0

22.1

20.3

18.4

16.6

14.7

12.9

11.1

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(twice) to start the EMERGENCY COOL

(HEAT) 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

Wet-and dry-bulb thermometers

8-1.CAPACITY AND THE INPUT CURVES

OUTDOOR UNIT

Wet-and dry-bulb thermometers

NOTE:The above curves are for the heating operation without any frost.

10

8-2.OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT

18 32

7

8

9

10

11

12

13

230V

15 20

50

25 6030 70(%)

35(:)

0.7

0.8

0.9

1.0

1.1

1.2

1.3

15 20

50

25 60

30 70(%)

35(:)

1

2

4

3

18 32

230V

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

18 32

230V

15 20

50

25 60

30

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 6030 70(%)

35(:)

3

4

5

6

18 32

230V

COOL operation

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

Dry-bulb temperature

20 25

Relative humidity(%)

50 60

30 70

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