Mitsubishi Electric MS-GF20VA-E1, MS-GF25VA-E1, MS-GF35VA-E1, MS-GF50VA - E1, MS-GF60VA - E1 Service Manual

CONTENTS

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

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

3. SPECIFICATION ················································ 4

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

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

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

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

8. SERVICE FUNCTIONS ····································· 8

9. MICROPROCESSOR CONTROL ··················· 10

10. TROUBLESHOOTING ····································· 15

11. DISASSEMBLY INSTRUCTIONS ···················· 25

SPLIT-TYPE AIR CONDITIONERS

Outdoor unit service manual
MU-GF·VA Series (OBH622)

SERVICE MANUAL

No. OBH621

INDOOR UNIT

PARTS CATALOG (OBB621)

NOTE:

RoHS compliant products have <G> mark on the spec name plate.

Models

MS-GF20VA

-

E1

MS-GF25VA

-

E1

MS-GF35VA

-

E1

2

MS-GF20VA -

E1

MS-GF25VA -

E1

MS-GF35VA -

E1

1. New model

TECHNICAL CHANGES

1

Use the specifi ed refrigerant only

Never use any refrigerant other than that specified.

Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the spec labels provided with our products.
We will not be held responsible for mechanical failure, system malfunction, unit breakdown or accidents caused by
failure to follow the instructions.

<Preparation before the repair service>

Prepare the proper tools.
Prepare the proper protectors.
Provide adequate ventilation.
After stopping the operation of the air conditioner, turn off the power-supply breaker and remove the power plug.
Discharge the capacitor before the work involving the electric parts.

<Precautions during the repair service>

Do not perform the work involving the electric parts with wet hands.
Do not pour water into the electric parts.
Do not touch the refrigerant.
Do not touch the hot or cold areas in the refrigeration cycle.
When the repair or the inspection of the circuit needs to be done without turning off the power, exercise great caution not to

touch the live parts.

OBH621

3

ACCESSORIES

PART NAMES AND FUNCTIONS

2

Model

MS-GF20VA
MS-GF25VA
MS-GF35VA

Installation plate 1
Installation plate fi xing screw 4 × 25 mm 5
Remote controller holder 1
Fixing screw for 3.5 × 16 mm (Black) 2
Battery (AAA) for remote controller 2
Wireless remote controller 1
Felt tape (For left or left-rear piping) 1

MS-GF20VA MS-GF25VA MS-GF35VA

Air filter
(Nano platinum filter)

Front panel

Air cleaning filter
(Electrostatic anti-allergy

enzyme filter, option)

Operation indicator lamp

Remote control receiving section

Emergency operation switch (E.O. SW)

Horizontal vane

Air outlet

Heat exchanger

Display section

Air inlet

Remote controller

OBH621

4

SPECIFICATION

3

Indoor model MS-GF20VA MS-GF25VA MS-GF35VA

Function Cooling

Power supply Single phase 230 V, 50 Hz

Electrical

data

Running current A

0.20 0.22

Power input W

35 43

Fan

motor

Model RC4V18-FA

Current A

0.20

0.22

Dimensions W × H × D mm 798 x 295 x 232

Weight kg

9

Special remarks

Air direction

5

Airfl ow

Super High (POWERFUL)

m3/h

558 624

High 474 558

Med. 378 396

Low 246 288

Sound level

Super High (POWERFUL)

dB (A)

40 44

High 36 40

Med. 31 33

Low 25 26

Fan speed

Super High (POWERFUL)

rpm

1,000 1,100

High 880 1,000

Med. 740 770

Low 540 610

Fan speed regulator 4

Remote controller model KM12A

NOTE: Test conditions are based on ISO 5151.
Cooling: Indoor Dry-bulb temperature 27 Wet-bulb temperature 19
Outdoor Dry-bulb temperature 35 Wet-bulb temperature 24
Indoor-Outdoor piping length: 5 m

OBH621

5

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

COOLING

FUNCTION

SPL(dB(A))

LINE

Super High

FAN SPEED

40

NC-10

OCTAVE BAND SOUND PRESSURE LEVEL, 0dB 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

COOLING

FUNCTION

SPL(dB(A))

LINE

Super High

FAN SPEED

40

NC-10

OCTAVE BAND SOUND PRESSURE LEVEL, 0dB re 0.0002 MICRO BAR

Test conditions

Cooling: Dry-bulb temperature 27 °C

Wet-bulb temperature 19 °C

INDOOR UNIT

WALL

MICROPHONE

0.8m

1m

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

COOLING

FUNCTION

SPL(dB(A))

LINE

Super High

FAN SPEED

44

NC-10

OCTAVE BAND SOUND PRESSURE LEVEL, 0dB re 0.0002 MICRO BAR

NOISE CRITERIA CURVES

4

MS-GF20VA MS-GF25VA

MS-GF35VA

OBH621

6

Unit: mm

OUTLINES AND DIMENSIONS

5

211.5

231.5

253

21.5

155 155

80

80

225 225

3

5

232

56

69

798
785 6.5

130619

50

295

50

42

56

43

42

8

100

107

112

45

56

69

33861

212.5

254

41

42

315 84

11×26 Oblong hole

11×20 Oblong hole

Installation plate

Indoor unit

Wall hole ø65

Air in

Air out

Installation plate

Piping

Drain hose

159

19

58

MS-GF20VA MS-GF25VA MS-GF35VA

Piping

Insulation ø35 O.D
Liquid line ø7 - 0.5 m (Flared connection ø6.35)
Gas line ø9.52 - 0.43 m (Flared connection: ø9.52)

Drain hose Insulation ø28 O.D Connected part ø16 O.D

WIRING DIAGRAM

6

MS-GF20VA MS-GF25VA MS-GF35VA

OBH621

7

Unit: mm

REFRIGERANT SYSTEM DIAGRAM

7

MS-GF20VA MS-GF25VA

Indoor
heat
exchanger

Flared connection

Room temperature
thermistor
RT11

Flared connection

Refrigerant pipe 6.35
(with heat insulator)

Indoor coil
thermistor
RT12

Refrigerant flow in cooling

Refrigerant pipe 9.52
(with heat insulator)

MS-GF35VA

Indoor
heat
exchanger

Flared connection

Room temperature
thermistor
RT11

Flared connection

Refrigerant pipe 6.35
(with heat insulator)

Indoor coil
thermistor
RT12

Refrigerant flow in cooling

Refrigerant pipe 9.52
(with heat insulator)

OBH621

8

8-1. TIMER SHORT MODE

For service, the following set time can be shortened by short circuit of JPG and JPS on the electronic control P.C. board.
(Refer to 10-7.)
Set time: 3 minutes → 3 seconds (It takes 3 minutes for the compressor to start operation. However, the starting time is
shortened by short circuit of JPG and JPS.)

8-2. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION

A maximum of 4 indoor units with wireless remote controllers can be used in a room.
In this case, to operate each indoor unit individually by each remote controller, P.C. boards of remote controller must be
modified according to the number of the indoor unit.

How to modify the remote controller P.C. board

Remove batteries before modification.
The board has a print as shown below:

NOTE: For modification, take out

the batteries and press
the OPERATE/STOP (ON/
OFF) button 2 or 3 times at
first.

After modification, put back

the batteries then press the
RESET button.

J2

J1

Table 1

1 unit operation 2 units operation 3 units operation 4 units operation

No. 1 unit No modifi cation Same as at left Same as at left Same as at left

No. 2 unit — Solder J1 Same as at left Same as at left

No. 3 unit — — Solder J2 Same as at left

No. 4 unit — — — Solder both J1 and J2

How to set the remote controller exclusively for particular indoor unit

After you turn the breaker ON, the first remote controller that sends the signal to the indoor unit will be regarded as the remote
controller for the indoor unit.
The indoor unit will only accept the signal from the remote controller that has been assigned to the indoor unit once they are set.
The setting will be cancelled if the breaker is turned OFF, or the power supply is shut down.
Please conduct the above setting once again after the power has restored.

SERVICE FUNCTIONS

8

MS-GF20VA MS-GF25VA MS-GF35VA

The P.C. board has the print “J1” and “J2”. Solder “J1” and “J2” according to the number of indoor unit as shown in Table 1.
After modification, press the RESET button.

OBH621

9

8-3. AUTO RESTART FUNCTION

When the indoor unit is controlled with the remote controller, the operation mode, the set temperature, and the fan speed
are memorized by the indoor electronic control P.C. board. “AUTO RESTART FUNCTION” automatically starts operation
in the same mode just before the shutoff of the main power.

Operation

If the main power has been cut, the operation settings remain.
After the power is restored, the unit restarts automatically according to the memory.

(However, it takes at least 3 minutes

for the compressor to start running.)

How to disable “AUTO RESTART FUNCTION”

Turn off the main power for the unit.
Solder the jumper wire to JR07 on the indoor electronic control P.C. board. (Refer to 10-7.)

NOTE:

• The operation settings are memorized when 10 seconds have passed after the indoor unit was operated with the remote

controller.

• If main power is turned OFF or a power failure occurs while AUTO START/STOP timer is active, the timer setting is can-

celled.

• If the unit has been off with the remote controller before power failure, the auto restart function does not work as the

power button of the remote controller is OFF.

• To prevent breaker OFF due to the rush of starting current, systematize other home appliance not to turn ON at the same

time.

• When some air conditioners are connected to the same supply system, if they are operated before power failure, the

starting current of all the compressors may flow simultaneously at restart.

Therefore, the special counter-measures are required to prevent the main voltage-drop or the rush of the starting current

by adding to the system that allows the units to start one by one.

JR07

Indoor electronic
control P.C. board

111NCA01NC 151NC

211NC

OBH621