Mitsubishi MU-GA20VB, MSC-CA25VB, MUH-GA20VB, MUX-2A28VB, MSC-CB20VB Service Technical Manual

...

SPLIT-TYPE, AIR CONDITIONERS SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS FLOOR AND CEILING TYPE AIR CONDITIONERS FLOOR TYPE, HEAT PUMP AIR CONDITIONERS

Revision D:

• MXZ-5A100VA- has been added. Please void OBT06 REVISED EDITION-C.

No. OBT06

REVISED EDITION-D

SERVICE TECHNICAL GUIDE

Wireless type Models

MSC-CA•VB - · MU-GA•VB MSC-CB•VB - · MUH-GA•VB MSC-GA•VB -

Multi system type Models

· MUX-A•VB -

Wireless type Models

MS-GA•VB - · MU-GA•VB MSH-CA•VB MSH-CB•VB -

E E

MSH-GA•VB - · MUH-GA•VB MSZ-CA•VB - · MUZ-CA•VB MSZ-FA•VA - · MUZ-FA•VA -

· MUZ-FA•VAH -

MSZ-GA•VA - · MUZ-GA•VA -

· MUZ-GA•VAH -

MSZ-CB•VA -

MSZ-HA•VA - · MUZ-HA•VA MSZ-GB•VA - · MUZ-GB•VA -

Inverter-controlled multi system type Models Wireless type Models

MCF-GA•VB MCFH-GA•VB MFZ-KA•VA

- · MUCF-GA•VB -

- · MUCFH-GA•VB -

· MXZ-A•VA -

CONTENTS

1. MSC MICROPROCESSOR CONTROL················6

2. MS MICROPROCESSOR CONTROL················15

3. MSH MICROPROCESSOR CONTROL··············26

4. MSZ-CA MICROPROCESSOR CONTROL········39

5. MSZ-FA MICROPROCESSOR CONTROL ········54

6. MSZ-GA, MSZ-CB MICROPROCESSOR CONTROL ············72

7. MCF MICROPROCESSOR CONTROL············100

8. MCFH MICROPROCESSOR CONTROL·········106

9. MFZ MICROPROCESSOR CONTROL ············115

10. MSZ-HA MICROPROCESSOR CONTROL·····127

11. MSZ-GB MICROPROCESSOR CONTROL·····137

12. MXZ MICROPROCESSOR CONTROL···········150

Revision D: • MXZ-5A100VA- and MXZ-4A80VA- have been added.

E2E

Revision C: • MXZ-2A30VA- and MXZ-2A40VA- have been added. Revision B: • MSZ-CB•VA- has been added.

• MSZ-HA•VA- has been added.

• MSZ-GB•VA- has been added.

• MXZ-2A40/52VA- has been added.

Revision A: • MFZ-KA•VA - has been added.

E E

E2E

1. MSC MICROPROCESSOR CONTROL·························································6

Indoor unit models Outdoor unit models

MSC-CA20VB MSC-CB20VB MSC-GA20VB MU-GA20VB MUH-GA20VB MUX-2A28VB MSC-CA25VB MSC-CB25VB MSC-GA25VB MU-GA25VB MUH-GA25VB MUX-2A59VB MSC-CA35VB MSC-CB35VB MSC-GA35VB MU-GA35VB MUH-GA35VB MUX-3A60VB

MUX-2A70VB MUX-3A63VB MUX-4A73VB

1-1. COOL OPERATION················································································6 1-2. DRY OPERATION ··················································································7 1-3. FAN OPERATION ···················································································8 1-4. HEAT OPERATION················································································8 1-5.“I FEEL CONTROL” OPERATION·························································9 1-6. INDOOR FAN MOTOR CONTROL ······················································11 1-7. AUTO VANE OPERATION ···································································11 1-8. TIMER OPERATION·············································································12 1-9. EMERGENCY / TEST OPERATION····················································13

. OUTDOOR UNIT ACTUATOR CONTROL··········································14

2. MS MICROPROCESSOR CONTROL ·························································15

Indoor unit models Outdoor unit models

MS-GA50VB MU-GA50VB MS-GA60VB MU-GA60VB MS-GA80VB MU-GA80VB

2-1. “I FEEL CONTROL” OPERATION······················································15 2-2. COOL OPERATION··············································································18 2-3. DRY OPERATION ················································································19 2-4. FAN OPERATION ·················································································19 2-5. INDOOR FAN MOTOR CONTROL······················································19 2-6. AUTO VANE OPERATION ···································································19 2-7. TIMER OPERATION·············································································22 2-8. EMERGENCY / TEST OPERATION····················································23 2-9. EXPANSION VALVE CONTROL (LEV CONTROL) ····························24 2-

10.

FUNCTION OF SOFT START RELAY ·················································25

3. MSH MICROPROCESSOR CONTROL·······················································26

Indoor unit models Outdoor unit models

MSH-CA50VB MSH-GA50VB MUH-GA50VB MSH-CB50VB MSH-GA60VB MUH-GA60VB

MSH-GA80VB MUH-GA80VB

3-1. “I FEEL CONTROL” OPERATION······················································26 3-2. COOL OPERATION··············································································32 3-3. DRY OPERATION ················································································32 3-4. HEAT OPERATION··············································································32 3-5. INDOOR FAN MOTOR CONTROL······················································32 3-6. AUTO VANE OPERATION ···································································33 3-7. TIMER OPERATION·············································································35 3-8. EMERGENCY / TEST OPERATION····················································36 3-9. EXPANSION VALVE CONTROL (LEV CONTROL) ····························37 3-

10.

FUNCTION OF SOFT START RELAY·················································38

4. MSZ-CA MICROPROCESSOR CONTROL·················································39

Indoor unit models Outdoor unit models

MSZ-CA25VB MUZ-CA25VB MSZ-CA35VB MUZ-CA35VB

4-1. “I FEEL CONTROL” OPERATION·····················································39 4-2. AUTO CHANGE OVER ··· AUTO MODE OPERATION······················44 4-3. COOL OPERATION·············································································45 4-4. DRY OPERATION ···············································································45 4-5. HEAT OPERATION·············································································45 4-6. INDOOR FAN MOTOR CONTROL·····················································46 4-7. AUTO VANE OPERATION ··································································46 4-8. TIMER OPERATION············································································47 4-9. EMERGENCY / TEST OPERATION···················································48

10.

INVERTER SYSTEM CONTROL ························································49

11.

OPERATION FREQUENCY CONTROL OF OUTDOOR UNIT··········51

44-

12.

EXPANSION VALVE CONTROL (LEV CONTROL)···························52

5. MSZ-FA MICROPROCESSOR CONTROL ·················································54

Indoor unit models Outdoor unit models

MSZ-FA25VA MUZ-FA25VA MUZ-FA25VAH MSZ-FA35VA MUZ-FA35VA MUZ-FA35VAH

5-1. COOL OPERATION·············································································55 5-2. DRY OPERATION ···············································································56 5-3. HEAT OPERATION·············································································56 5-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION······················58 5-5. INDOOR FAN MOTOR CONTROL·····················································59 5-6. OUTDOOR FAN MOTOR CONTROL·················································59 5-7. AUTO VANE OPERATION··································································59 5-8. i-see CONTROL OPERATION····························································61 5-9. AREA SETTING ··················································································62 5-10. PLASMA DUO OPERATION ······························································64

. AUTO FRONT PANEL ········································································65

. TIMER OPERATION ···········································································65

5-13. EMERGENCY / TEST OPERATION···················································66

INVERTER SYSTEM CONTROL ························································67

14.

15.

OPERATIONAL FREQUENCY CONTROL OF OUTDOOR UNIT ·····69

16.

EXPANSION VALVE CONTROL (LEV CONTROL)···························70

6. MSZ-GA, MSZ-CB MICROPROCESSOR CONTROL ································72

Indoor unit models Outdoor unit models

MSZ-GA22VA MSZ-CB22VA MSZ-GA25VA MSZ-CB25VA MUZ-GA25VA MUZ-GA25VAH MSZ-GA35VA MSZ-CB35VA MUZ-GA35VA MUZ-GA35VAH

6-1. COOL OPERATION·············································································73 6-2. DRY OPERATION ···············································································74 6-3. HEAT OPERATION·············································································74 6-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION······················76 6-5. INDOOR FAN MOTOR CONTROL·····················································77 6-6. OUTDOOR FAN MOTOR CONTROL·················································77 6-7. AUTO VANE OPERATION··································································77 6-8. TIMER OPERATION············································································79 6-9. EMERGENCY / TEST OPERATION···················································80 6-10.

INVERTER SYSTEM CONTROL·······················································81

11.

OPERATIONAL FREQUENCY CONTROL OF OUTDOOR UNIT ·····83

66-

12.

EXPANSION VALVE CONTROL (LEV CONTROL) ···························84

Indoor unit models Outdoor unit models

MSZ-GA50VA MUZ-GA50VA MSZ-GA60VA MUZ-GA60VA MSZ-GA71VA MUZ-GA71VA

6-13. COOL OPERATION············································································86 6-14. DRY OPERATION ···············································································87

. HEAT OPERATION·············································································88

66-

. AUTO CHANGE OVER ··· AUTO MODE OPERATION ·····················90

6-17. INDOOR FAN MOTOR CONTROL·····················································90

. OUTDOOR FAN MOTOR CONTROL·················································91

66-

. AUTO VANE OPERATION··································································91

6-20. TIMER OPERATION ···········································································94

. EMERGENCY/TEST OPERATION·····················································95

66-

22.

INVERTER SYSTEM CONTROL ·······················································95

23.

OPERATIONAL FREQUENCY CONTROL OF OUTDOOR UNIT ·····97

66-

24.

EXPANSION VALVE CONTROL (LEV CONTROL) ···························98

7. MCF MICROPROCESSOR CONTROL·····················································100

Indoor unit models Outdoor unit models

MCF-GA35VB MUCF-GA35VB MCF-GA50VB MUCF-GA50VB MCF-GA60VB MUCF-GA60VB

7-1. “I FEEL CONTROL” OPERATION····················································100 7-2. COOL OPERATION············································································103 7-3. DRY OPERATION ··············································································103 7-4. FAN OPERATION ···············································································103 7-5. AUTO VANE OPERATION ·································································103 7-6. TIMER OPERATION···········································································105 7-7. EMERGENCY / TEST OPERATION··················································105

8. MCFH MICROPROCESSOR CONTROL ··················································106

Indoor unit models Outdoor unit models

MCFH-GA35VB MUCFH-GA35VB MCFH-GA50VB MUCFH-GA50VB MCFH-GA60VB MUCFH-GA60VB

8-1. “I FEEL CONTROL” OPERATION····················································106 8-2. COOL OPERATION············································································110 8-3. DRY OPERATION···············································································111 8-4. HEAT OPERATION·············································································111 8-5. AUTO VANE OPERATION··································································111 8-6. TIMER OPERATION···········································································113 8-7. EMERGENCY / TEST OPERATION···················································114

9. MFZ MICROPROCESSOR CONTROL······················································115

Indoor unit models

MFZ-KA25VA MFZ-KA35VA

As for outdoor units SUZ-KA25/35/50VA.TH and SUZKA25/35VAH.TH, refer to service manual OC322.

(

MFZ-KA50VA

9-1. COOL OPERATION···········································································117 9-2. DRY OPERATION··············································································117 9-3. HEAT OPERATION············································································117 9-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION ····················119 9-5. INDOOR FAN MOTOR CONTROL···················································120 9-6. OUTDOOR FAN MOTOR CONTROL···············································120 9-7. AUTO VANE OPERATION································································120 9-8. i-save OPERATION···········································································124 9-9. TIMER OPERATION··········································································125 9-

10.

EMERGENCY / TEST OPERATION·················································126

)

10. MSZ-HA MICROPROCESSOR CONTROL·············································127

Indoor unit models Outdoor unit models

MSZ-HA25VA MUZ-HA25VA MSZ-HA35VA MUZ-HA35VA

10-1. COOL OPERATION·········································································128 10-2. DRY OPERATION ···········································································128 10-3. HEAT OPERATION·········································································129 10-4. INDOOR FAN MOTOR CONTROL·················································130 10-5. AUTO VANE OPERATION······························································131 10-6. TIMER OPERATION········································································133 10-7. EMERGENCY / TEST OPERATION···············································133 10-8. INVERTER SYSTEM CONTROL ····················································134

OPERATIONAL FREQUENCY CONTROL OF OUTDOOR UNIT

10-9

11. MSZ-GB MICROPROCESSOR CONTROL·············································137

Indoor unit models Outdoor unit models

······136

MSZ-GB50VA MUZ-GB50VA

11-1. COOL OPERATION·········································································138 11-2. DRY OPERATION············································································139 11-3. HEAT OPERATION··········································································139 11-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION··················141 11-5. INDOOR FAN MOTOR CONTROL ·················································141 11-6. OUTDOOR FAN MOTOR CONTROL ·············································142 11-7. AUT O VANE OPERATION······························································142 11-8. TIMER OPERATION········································································144 11-9. EMERGENCY / TEST OPERATION················································145 11-10.

INVERTER SYSTEM CONTROL ···················································145

11-

11.

OPERATIONAL FREQUENCY CONTROL OF OUTDOOR UNIT

11-

12.

EXPANSION VALVE CONTROL (LEV CONTROL)·······················148

······147

12. MXZ MICROPROCESSOR CONTROL···················································150

Outdoor unit models

MXZ-2A30VA MXZ-2A40VA MXZ-2A52VA MXZ-3A54VA MXZ-4A71VA MXZ-4A80VA MXZ-5A100VA

12-1. INVERTER SYSTEM CONTROL·····················································150 12-2. EXPANSION VALVE CONTROL (LEV CONTROL) ························153 12-3. OPERATIONAL FREQUENCY RANGE···········································159 12-4. HEAT DEFROSTING CONTROL·····················································160 12-5. DISCHARGE TEMPERATURE PROTECTION CONTROL·············161 12-6. REFRIGERANT RECOVERY CONTROL ON HEATING·················161 12-7. OUTDOOR FAN CONTROL·····························································161 12-8. PRE-HEAT CONTROL·····································································162 12-9. COOL OPERATION··········································································162 12-10. DRY OPERATION ············································································163 12-

. HEAT OPERATION··········································································163

As for outdoor unit MXZ-8A140VA, refer to service manual

(

OC316.

)

ON/OFF

FAN

TOO

WARM

TOO

COOL

VANE

MODE

ECONO COOL

STOP

START

HR.

MIN.

I FEEL

COOL

DRY

CLOCK

RESET

CLOCK

HEAT /FAN

Open the front lid.

ON/OFF

TOO COOL

TOO

WARM

Signal transmitting section

Operation display section

OPERATE /STOP (ON /OFF) button

TEMPERATURE buttons

OPERATION SELECT button

FAN SPEED CONTROL button

OFF-TIMER button

HR. button

MIN. button

(TIME SET button)

ON-TIMER button

RESET button

ECONO COOL button

VANE CONTROL button

CLOCK SET button

lighted not lighted

Approx. 2 : or more

Difference between target temperature and room temperature

Approx. 2 : or less

This shows that the air conditioner is operating to reach the target temperature. Please wait until the target temperature is obtained.

This shows that the room temperature is approaching the target temperature.

Operation state

Indication

Operation Indicator

Operation Indicator lamp

The operation indicator at the right side of the indoor unit indicates the operation state.

INDOOR UNIT DISPLAY SECTION

• The following indication does not depend on the shape of lamp.

MSC MICROPROCESSOR CONTROL

MSC-CA20VB MSC-CB20VB MSC-GA20VB MU-GA20VB MUH-GA20VB MUX-2A28VB MUX-3A63VB MSC-CA25VB MSC-CB25VB MSC-GA20VB MU-GA25VB MUH-GA25VB MUX-2A59VB MUX-2A70VB MSC-CA35VB MSC-CB35VB MSC-GA35VB MU-GA35VB MUH-GA35VB MUX-3A60VB MUX-4A73VB

Once the operation mode is set, the same operation mode can be repeated by simply turning OPERATE/STOP (ON/OFF) button ON. Indoor unit receives the signal with a beep tone. When the system turns off, 3-minute time delay will operate to protect system from overload and compressor will not restart for 3 minutes.

WIRELESS REMOTE CONTROLLER

1-1. COOL ( ) OPERATION

(1) Press OPERATE/STOP(ON/OFF) button. OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone. (2) Select COOL mode with OPERATION SELECT button. (3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button)to select the desired temperature.

The setting range is 16 ~ 31°C

1. Thermostat control

Thermostat is ON or OFF by difference between room temperature and set temperature

Room temperature minus set temperature : 0.3 : or more················································ON Room temperature minus set temperature : less than -0.3 :············································OFF

2. Indoor fan speed control

Indoor fan operates continuously at the set speed by FAN SPEED CONTROL button regardless of thermostat’s OFF-ON.

In Auto the fan speed is as follows.

Room temperature minus set temperature : 1.7 : or more·······························High Room temperature minus set temperature : Between 1 and 1.7 :···················Med. Room temperature minus set temperature : less than 1 :·································Low

Initial temperature difference Thermostat

Initial temperature difference

Fan speed

Difference between room temperature and set temperature during operation

Set temperature

-0.3 :

0.3 :

Difference between room temperature and set temperature during operation

3 :

1.7 :

1 :

10 15 20 25 30 35

Set temperature

Initial room temperature

Set temperature and initial room temperature in dry mode

3. Coil frost prevention

① Temperature control

When the indoor coil thermistor RT12 reads 4°C or below(MSC-CA20/CA25/CB20/CB25/GA20/GA25VB) / 0°C or below(MSC-CA35/CB35/GA35VB) for 5 minutes, the coil frost prevention mode starts.

The indoor fan operates at the set speed and the compressor stops for 5 minutes. After that, if RT12 still reads below 4°C (MSC-CA20/CA25/CB20/CB25/GA20/GA25VB) / 0°C (MSC-CA35/CB35/GA35VB), this mode is prolonged until RT12 reads over 4°C (MSC-CA20/CA25/CB20/CB25/GA20/GA25VB) / 0°C (MSCCA35/CB35/GA35VB).

② Time control

When the three conditions as follows have been satisfied for 1 hour and 45 minutes, the compressor stops for 3 minutes. The indoor fan operates at the set speed. a. Compressor has been continuously operating. b. Indoor fan speed is Low or Med. c. Room temperature is below 26°C. When compressor stops, the accumulated time is cancelled. When compressor restarts, time counting starts from the beginning. Time counting also stops temporarily when the indoor fan speed becomes High or the room temperature exceeds 26°C. However, when two of the above conditions (b.and c.) are satisfied again, time accumulation is resumed.

Operation chart

Example

Compressor

OFF

Outdoor fan

Indoor fan

( continuously at set speed)

1-2. DRY ( ) OPERATION

(1) Press OPERATE/STOP(ON/OFF) button.

OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone. (2) Select DRY mode with the OPERATION SELECT button. (3) The microprocessor reads the room temperature and determines the set tem-

perature. Set temperature is as shown on the right chart.

DRY operation will not function when the room temperature is 13°C or below. (4) When DRY operation functions the fan speed is lower than COOL operation

except at (fan speed) Low.

The system for dry operation uses the same refrigerant circuit as the cooling circuit. The compressor and the indoor fan are controlled by the room temperature.

1. Thermostat control

Thermostat is ON or OFF by difference between room temperature and set temperature.

2. Indoor fan speed control

Indoor fan operates at the set speed by FAN SPEED CONTROL button. In Auto fan speed becomes Low.

3. The operation of the compressor and indoor / outdoor fan <MU-GA20/GA25/GA35VB, MUH-GA20/GA25/GA35VB, MUX-2A28/2A59/3A60/3A63/2A70/4A73VB>

Compressor operates by room temperature control and time control. Indoor fan and outdoor fan operate in the same cycle as the compressor.

• When the room temperature is 23°C or over:

When the thermostat is ON, the compressor repeats 8 minutes ON and 3 minutes OFF. When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.

• When the room temperature is under 23°C.

When the thermostat is ON, the compressor repeats 2 minutes ON and 3 minutes OFF. When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.

OFF

Initial temperature difference Thermostat

Difference between room temperature and set temperature during operation

Set temperature

-0.3 :

0.3 :

Operation time chart

Released

Cold Air Prevention

18: 22:

Fan speed Set speed

Very Low or stop

Example

Thermostat

OFF

Indoor fan

Outdoor fan Compressor

OFF

8 minutes

OFFOFF

OFF

3 minutes

OFF

4 minutes

1 minute

4. Coil frost prevention

The operation is as same as coil frost prevention during COOL operation.(Refer to 1-1.3.) However when coil frost prevention works while the indoor fan is OFF, its speed becomes set speed.

1-3. FAN ( ) OPERATION <MU-GA20/GA25/GA35VB, MUX-2A28/2A59/3A60/3A63/2A70/4A73VB>

(1) Press OPERATE/STOP(ON/OFF) button. OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone. (2) Select FAN mode with OPERATION SELECT button. (3) Select the desired fan speed. When AUTO, it becomes Low.

Only indoor fan operates. Outdoor unit does not operate.

1-4. HEAT ( ) OPERATION <MUH-GA20/GA25/GA35VB>

(1) Press OPERATE/STOP(ON/OFF) button.

OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone. (2) Select HEAT mode with the OPERATION SELECT button. (3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature.

The setting range is 16 ~ 31°C.

1. Thermostat control

Thermostat is ON or OFF by difference between room temperature and set temperature.

Initial temperature difference Thermostat Room temperature minus set temperature : less than -0.3 :··············································ON Room temperature minus set temperature : 0.3 : or more·················································OFF

Difference between room temperature and set temperature during operation

Set temperature

-0.3 :

0.3 :

2. Indoor fan speed control

(1) Indoor fan operates at the set speed by FAN SPEED CONTROL button.

In Auto the fan speed is as follows.

Set temperature minus room temperature: 1.7 :or more······················································· High Set temperature minus room temperature: Between 1 and 1.7 :··········································· Med. Set temperature minus room temperature: less than 1

(2) Cold air prevention control

1 When the compressor is not operating,

(1) if the temperature of indoor coil thermistor RT12 is 0°C or less, the fan stops. (2) if the temperature of indoor coil thermistor RT12 is more than 0°C, the fan operates at Very Low.

2 When the compressor is operating,

(1) if the temperature of RT12 is 22°C or more, the fan operates at set speed. (2) if the temperature of RT12 is less than 22°C and

(1) if the temperature of room temperature thermistor RT11 is 15°C or less, the fan stops. (2) if the temperature of room temperature thermistor RT11 is more than 15°C, the fan operates at Very Low.

NOTE : If the temperature of RT12 reads from 18°C to 22°C at the air conditioner stating and also after defrosting,

this control works.

Initial temperature difference

························································ Low

Fan speed

Difference between room temperature and set temperature during operation

3 :

1.7 :

(3) Warm air control

less than 2 minutes Low 2 minutes to 4 minutes Med. more than 4 minutes High

Mode

COOL mode of

"I FEEL CONTROL"

DRY mode of

"I FEEL CONTROL"

HEAT mode of

"I FEEL CONTROL"

Initial room temperature

MUH type

25: or more

23:or more,

less than 25: less than 23:

MU & MUX type

25: or more

more than13:,

less than 25:

When the following any conditions of 1 (a. ~ c.) and the condition of 2 are satisfied at the same time, warm air control works.

1 a.) When outdoor unit starts operating in HEAT mode.

b.) When cold air prevention has been released.

c.) When defrosting has been finished

2 When the temperature of indoor coil thermistor RT12 is less than 37°C. When warm air control works, the fan speed changes as follows to blow out warm air gradually.

Gradation of fan speed in initial

The upper limit of the fan speed in MANUAL is the set speed. The upper limit of the fan speed in AUTO is the speed decided by indoor fan speed control.(Refer to 1-4.2.(1).) When the temperature of RT12 has been 37°C or more, or when the set speed has been changed, this control is released and the fan speed is the set speed.

NOTE: As for high pressure protection, defrosting and R.V. coil control, refer to service manual for outdoor unit.

1-5. “I FEEL CONTROL” ( ) OPERATION

(1) Press OPERATE/STOP(ON/OFF) button.

OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.

(2) Select “I FEEL CONTROL”( ) mode with the OPERA-

TION SELECT button.

(3) The operation mode is determined by the initial room tem-

perature at start-up of the operation, as shown on the right table.

• Once the mode is fixed, the mode does not change by room temperature afterwards.

• Under the ON-TIMER ( ) operation, mode is determined as follows.

When the system is stopped on the remote controller and restarted within 2 hours in “I FEEL CONTROL” ( ) mode, the system operates in previous mode automatically regardless of the room temperature.

Operation time chart

Example

Previous operation

COOL mode of “I FEEL CONTROL” or COOL mode

When the system is restarted after 2 hours and more, the operation mode is determined by the room temperature at

start-up of the operation.

Operation time chart

Example

Previous operation

COOL mode of “I FEEL CONTROL”

or COOL mode

Restart

COOL mode of “I FEEL CONTROL”

Restart

COOL or DRY or HEAT mode of “I FEEL CONTROL” that determined by room temperature at start-up of the operation.

Mode

COOL mode of

"I FEEL CONTROL"

DRY mode of

"I FEEL CONTROL"

HEAT mode of

"I FEEL CONTROL"

Initial room temperature

Initial set temperature

26:

26: or more

25: or more, less than 26:

23: or more, less than25:

24:

Initial room temperature minus 2:

❈1

more than 13:,

less than 25:

26: or more

25: or more,

less than 26:

less than 23:

MU & MUX type

MUH type

(4) The initial set temperature is decided by the initial room temperature.

TOO

COOL

TOO

WARM

❈1 When the system is restarted with the remote controller, the system operates with the previous set temperature regard-

less of the room temperature at restart.

(5) TEMPERATURES buttons

In “I FEEL CONTROL” ( ) mode, set temperature is decided by the microprocessor based on the room temperature. In addition, set temperature can be controlled by TOO WARM or TOO COOL buttons when you feel too cool or too warm. Each time the TOO WARM or TOO COOL button is pressed, the indoor unit receives the signal and emits a beep tone.

• Fuzzy control

When the TOO COOL or TOO WARM button is pressed, the microprocessor changes the set temperature, considering the room temperature, the frequency of pressing TOO COOL or TOO WARM button and the user’s preference to heat or cool. So this is called “Fuzzy control”, and works only in “I FEEL CONTROL” mode. In DRY mode of “I FEEL CONTROL”, the set temperature doesn’t change.

…

To raise the set temperature 1~2 degrees(°C)

…

To lower the set temperature 1~2 degrees(°C)

1-5-1. COOL mode of “I FEEL CONTROL”

1. Thermostat control

Thermostat control is as same as COOL OPERATION.(1-1.1.)

2. Indoor fan speed control

Indoor fan speed control is as same as COOL OPERATION.(1-1.2.)

3. Coil frost prevention

Coil frost prevention is as same as COOL OPERATION.(1-1.3.)

1-5-2. DRY mode of “I FEEL CONTROL”

1. Thermostat control

Thermostat control is as same as DRY OPERATION.(1-2.1.)

2. Indoor fan speed control

Indoor fan speed control is as same as DRY OPERATION.(1-2.2.)

3. The operation of the compressor and indoor/outdoor fan

The operation of the compressor and indoor/outdoor fan is as same as DRY OPERATION.(1-2.3.)

4. Coil frost prevention

Coil frost prevention is as same as DRY OPERATION.(1-2.4.)

1-5-3. HEAT mode of “I FEEL CONTROL” <MUH-GA20/GA25/GA35VB>

1. Thermostat control

Thermostat control is as same as HEAT OPERATION.(1-4.1.)

2. Indoor fan speed control

Indoor fan speed control is as same as HEAT OPERATION.(1-4.2.)

NOTE: As for high pressure protection, defrosting and R.V. coil control, refer to service manual for outdoor unit.

1-6. INDOOR FAN MOTOR CONTROL

(1) Rotational frequency feedback control

The indoor fan motor is equipped with a rotational frequency sensor, and outputs signal to the microprocessor to feedback the rotational frequency. Comparing the current rotational frequency with the target rotational frequency (High,Med.,Low), the microprocessor controls SR141 and adjusts fan motor electric current to make the current rotational frequency close to the target rotational frequency. With this control, when the fan speed is switched, the rotational frequency changes smoothly.

High High

Med.

Low

(2) Fan motor lock-up protection

When the rotational frequency feedback signal is not output for 12 seconds, (or when the microprocessor cannot detect the signal for 12 seconds) the fan motor is regarded locked-up. Then the electric current to the fan motor is shut off. 3 minutes later, the electric current is applied to the fan motor again. During the fan motor lock-up, the OPERATION INDICATOR lamp flashes on and off to show the fan motor abnormality.

1-7. AUTO VANE OPERATION

(1) Vane motor drive

These models are equipped with a stepping motor for the horizontal vane. The rotating direction, speed, and angle of the motor are controlled by pulse signals (approx. 12V) transmitted from indoor microprocessor.

(2) The horizontal vane angle and mode change as follows by pressing the VANE CONTROL button.

(3) Positioning

The vane presses the vane stopper once to confirm the standard position and then set to the desired angle. Confirming of standard position is performed in case of follows. (a) When the OPERATE/STOP(ON/OFF) button is pressed. (b) When the vane control is changed from AUTO to MANUAL. (c) When the SWING is finished. (d) When the test run starts. (e) When the power supply turns ON.

(4) VANE AUTO ( ) mode

The microprocessor automatically determines the vane angle to make the optimum room temperature distribution.

COOL and DRY operation

Vane angle is fixed to Angle 1.

(5) Dew prevention

During COOL or DRY operation at Vane Angle 4 or 5 when the cumulative operation time of compressor exceeds 1 hour, the vane angle automatically changes to Angle 1 for dew prevention.

(6) SWING MODE ( )

By selecting SWING mode with the VANE CONTROLbutton, the horizontal vane swings vertically. The remote controller displays “”.

FAN operation

<MU-GA20/GA25/GA35VB, MUX-A28/2A59/3A60/3A63/2A70/4A73VB>

HEAT operation

<MUH-GA20/GA25/GA35VB>

Vane angle is fixed to Angle 4.

(7) Cold air prevention in HEAT operation

Set position Angle 1

Released

Cold air prevention

24:

28:

When any of the following conditions occurs in HEAT operation, the horizontal vane angle changes to Angle 1 automatically to prevent cold air blowing on users.

① Compressor is not operating. ➁ Defrosting is performed. ➂ Indoor coil thermistor RT12 reads 24: or below. ➃ Indoor coil thermistor RT12 temperature is raising from 24°C or below, but it does not exceed 28:.

Indoor coil thermistor RT12 temperature

NOTE : If the temperature of RT12 reads from 24°C to 28°C at the air conditioner stating , this control works.

(8) ECONO COOL ( ) operation (ECONOmical operation)

When the ECONO COOL button is pressed in COOL mode, set temperature is automatically set 2°C higher. Also the horizontal vane swings in various cycle according to the temperature of indoor heat exchanger(RT12). SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher, the air conditioner can keep comfort. As a result, energy can be saved. ECONO COOL operation is cancelled when the ECONO COOL button is pressed once again or VANE CONTROL button is pressed or operation mode is changed.

NOTE : ECONO COOL operation does not work in COOL mode of “I FEEL CONTROL”.

In swing operation of ECONO COOL operation mode, the initial air flow direction is adjusted to “Horizontal”. According to the temperature of indoor coil thermistor RT12 at starting of this operation, next downward blow time is decided. Then when the downward blow has been finished, next upward blow time is decided. For initial 10 min. the swing operation is performed in table G~H for quick cooling. Also, after 10 min. when the difference of set temperature and room temperature is more than 2 degrees, the swing operation is performed in table D~H for more cooling. The air conditioner repeats the swing operation in various cycle as follows.

<MUH-GA20/GA25/GA35VB>

Horizontal vane

Temperature of indoor

coil thermistor RT12

A B

D E F

G H

15°C or less 15°C to 17°C 17°C to 18°C

18°C to 20°C

20°C to 21°C 21°C to 22°C 22°C to 24°C

more than 24°C

Downward blow time

(sec.)

2 5 8

11 14 17

20 23

Horizontal blow time

(sec.)

23 20 17 14 11

8 5 2

1-8. TIMER OPERATION

1. How to set the timer

(1) Press OPERATE/STOP(ON/OFF) button to start the air conditioner. (2) Check that the current time is set correctly. NOTE : Timer operation will not work without setting the current time. Initially “AM0:00” blinks at the current time display

of TIME MONITOR, so set the current time correctly with CLOCK SET button.

(3) Press ON or OFF TIMER buttons to select the operation.

“” button... AUTO START operation (ON timer) “” button... AUTO STOP operation (OFF timer)

Lighted Not lighted

(4) Press HR. and MIN. button to set the timer. Time setting is 10-minute units.

HR. and MIN. button will work when “” or “” mark is flashing. These marks disappear in 1 minute. After setting ON timer, check that OPERATION INDICATOR lamp of the indoor unit lights.

NOTE1 : Be sure to place the remote controller at the position where its signal can reach the air conditioner even during

TIMER operation, or the set time may deviate within the range of about 10 minutes.

NOTE2 : Reset the timer in the following cases, or the set time may deviate and other malfunctions may occur.

• Apower failure occurs.

• The circuit breaker functions.

2. Cancel

TIMER setting can be cancelled with ON or OFF TIMER buttons. (“” or “”) To cancel ON timer, press “” button.

To cancel OFF timer, press “” button. TIMER is cancelled and the display of set time disappears.

PROGRAM TIMER

• OFF timer and ON timer can be used in combination.

• “” and “ ” display shows the order of OFF timer and ON timer operation.

(Example 1) The current time is 8:00 PM.

The unit turns off at 11:00 PM, and on at 6:00 AM.

(Example 2) The current time is 11:00 AM.

The unit turns on at 5:00 PM, and off at 9:00 PM.

NOTE : TIMER setting will be cancelled by power failure or breaker functioning.

1-9. EMERGENCY / TEST OPERATION

In case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the front of the indoor unit. Emergency operation is available when the remote controller is missing, has failed or the batteries of remote controller run down. The unit will start and OPERATION INDICATOR lamp will light. The first 30 minutes of operation is the test run operation. This operation is for servicing. The indoor fan speed runs at High speed and the system is in continuous operation. (The thermostat is ON.) After 30 minutes of test run operation, the system shifts to EMERGENCY COOL [/ HEAT<MUH-GA20/GA25/GA35VB>] MODE with a set temperature of 24°C. The fan speed shifts to Med. speed. The coil frost prevention works even in emergency operation [, and defrosting<MUH-GA20/GA25/GA35VB> too].

In the test run or emergency operation, the horizontal vane operates in VANE AUTO ( ) mode. Emergency operation continues until EMERGENCY OPERATION switch is pressed once again (MU-GA20/GA25/GA35VB, MUX-2A28/2A59/3A60/3A63/2A70/4A73VB)/once or twice (MUH-GA20/GA25/GA35VB) or the unit receives any signal from the remote controller.

In case of latter, normal operation will start.

NOTE : Do not press EMERGENCY OPERATION switch during normal operation.

• The following indication does not depend on the shape of lamp.

Press once <Cool>

OPERATION INDICATOR lamp

EMERGENCY OPERATION switch

Press again <Heat> Press once again <Stop>

w Heat is available only in MUH-GA20/GA25/GA35VB.

1-10. OUTDOOR UNIT ACTUATOR CONTROL

ACTUATOR

OFF

OFF ON OFF ON (OPEN) OFF (CLOSE) ON (OPEN) OFF (CLOSE) ON (OPEN) OFF (CLOSE) ON (OPEN) OFF (CLOSE)

ON (CLOSE)

OFF (OPEN)

ON (CLOSE)

OFF (OPEN)

SOLENOID VALVE

MUX-4A73VB

INDOOR UNIT

MC1

MC2

MF61

21R1

21R2

21R3

21R4

21RA

(BALANCE)

21RB

(BALANCE)

COMPRESSOR

OUTDOOR FAN MOTOR

ON OFF OFF

– – – –

OFF

ON OFF

– – – – – –

ON OFF OFF

– – – –

OFF

– – – –

ANY UNIT ON

OFF

– –

OFF

– – – –

OFF

– – – –

ON OFF OFF

OFF

– – – –

ON OFF

– – – – – –

ON OFF OFF

– – – –

OFF

– – – – – –

OFF

– – – –

OFF

ACTUATOR

ON OFF

OFF ON

OFF ON (OPEN) OFF (CLOSE) ON (OPEN) OFF (CLOSE)

ON (CLOSE)

OFF (OPEN)

SOLENOID VALVE

INDOOR UNIT

MC1

MC2

MF61

21R3

21R4

21RB

COMPRESSOR

OUTDOOR FAN MOTOR

OFF

– – – –

OFF

– – – – – – – –

– –

ON OFF OFF

ANY UNIT ON

OFF

ON OFF

– –

ON OFF OFF

– –

OFF

– –

OFF

ACTUATOR

OFF ON OFF

ON (CLOSE)

OFF (OPEN) ON (OPEN) OFF (CLOSE) ON (OPEN) OFF (CLOSE)

SOLENOID VALVE

MUX-2A28VB

INDOOR UNIT

21R

(BALANCE)

21R1

21R2

COMPRESSOR

OUTDOOR FAN MOTOR

ON OFF OFF

ANY UNIT ON

OFF

ON OFF OFF

ON OFF

– –

OFF

– –

OFF

ACTUATOR

ON OFF ON OFF ON OFF

MUX-2A59VB

MUX-2A70VB

INDOOR UNIT

MC1

MC2

MF61

COMPRESSOR

OUTDOOR FAN MOTOR

OFF

– –

ANY UNIT ON

OFF

– –

OFF

MUX-3A60VB MUX-3A63VB

“–” means that the indoor unit is not related to the control of actuator.

ON/OFF

FAN

TOO

WARM

TOO

COOL

VANE

MODE

ECONO COOL

STOP

START

HR.

MIN.

WIDE VANE

LONG

I FEEL

COOL

DRY

CLOCK

RESET CLOCK

OPERATION SELECT button

FAN SPEED CONTROL button

OFF-TIMER button

HR. button

MIN. button

(TIME SET button)

ON-TIMER button

RESET button

ECONO COOL button

VANE button

(Horizontal vane button)

CLOCK SET button

LONG button

WIDE VANE button

(Vertical vane button)

ON/OFF

TOO COOL

TOO

WARM

FAN

Signal transmitting section

Operation display section

OPERATE/ STOP (ON/ OFF) button

TEMPERATURE buttons

Lighted

Not lighted

Approx. 2 : or more

Difference between target temperature and room temperature

Approx. 2 : or less

This shows that the air conditioner is operating to reach the target temperature. Please wait until the target temperature is obtained.

This shows that the room temperature is approaching the target temperature.

Operation state

Indication

Operation Indicator

Operation Indicator lamp

The operation indicator at the right side of the indoor unit indicates the operation state.

INDOOR UNIT DISPLAY SECTION

• The following indication applies regardless of shape of the indicator.

MS MICROPROCESSOR CONTROL

MS-GA50VB MU-GA50VB MS-GA60VB MU-GA60VB MS-GA80VB MU-GA80VB

WIRELESS REMOTE CONTROLLER

2-1. “I FEEL CONTROL” ( ) OPERATION

(1) Press OPERATE/STOP (ON/OFF) button on the remote

controller. OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.

(2) Select “I FEEL CONTROL” mode with OPERATION

SELECT button.

(3) The operation mode is determined by the room tempera-

ture at start-up of the operation.

Initial room temperature

25: or more

more than 13:,

less than 25:

Mode

COOL mode of

"I FEEL CONTROL"

DRY mode of

"I FEEL CONTROL"

• Once the mode is fixed, the mode does not change by room temperature afterwards.

Model

COOL mode of

"I FEEL CONTROL"

DRY mode of

"I FEEL CONTROL"

Initial room temperature Initial set temperature

26: or more

25: to 26:

more than 13:, less than 25:

24:

Initial room temperature minus 2: Initial room temperature minus 2:

❈1

TOO

COOL

TOO

WARM

• Under the ON-TIMER ( ) operation, mode is determined as follows.

When the system is stopped on the remote controller, and restarted within 2 hours in “I FEEL CONTROL” ( ) mode, the system operates in previous mode automatically regardless of the room temperature.

Operation timer chart

Example

Previous operation

COOL mode of “I FEEL CONTROL”

Restart

COOL mode of “I FEEL CONTROL”

or COOL mode

When the system is restarted after 2 hours and more, the operation mode is determined by the room temperature at start-up of the operation.

Operation timer chart

Example

Previous operation

COOL mode of

“I FEEL CONTROL”

or COOL mode

Restart

COOL or DRY mode of “I FEEL CONTROL” that determined by room temperature at start-up of the operation.

(4) The initial set temperature is decided by the initial room temperature.

❈1 When the system is restarted with the remote controller, the system operates with the previous set temperature regard-

less of room temperature at restart. The set temperature is calculated by the previous set temperature.

(5) TEMPERATURE buttons

• Fuzzy control

…

To raise the set temperature 1~2°C

…

To lower the set temperature 1~2°C

2-1-1. COOL mode of “I FEEL CONTROL”

Difference between room temperature and set temperature during operation

1°C 1.7°C

3°C

Outdoor fan speed

20: 22:

High

Ambient temperature thermistor RT63 temperature

Low

1. Indoor fan speed control

Indoor fan operates at the set speed by FAN SPEED CONTROL button. In AUTO the fan speed is as follows.

Initial temperature difference Fan Speed Room temperature minus set temperature : 1.7 °Cor more Room temperature minus set temperature : Between 1 and 1.7 Room temperature minus set temperature : less than 1

2. Coil frost prevention

① Temperature control

When the indoor coil thermistor RT12 reads 3°C or below(MS-GA50VB) /1°C or below(MS-GA60VB)/ RT12 or RT13 reads -1°C or below (MS-GA80VB), the coil frost prevention mode starts immediately. However, the coil frost prevention doesn’t work for 5 minutes since the compressor has started. The indoor fan operates at the set speed and the compressor stops for 5 minutes. After that, if RT12 still reads below 3°C(MS-GA50VB)/ 1°C(MS-GA60VB)/ RT12 or RT13 still reads below-1°C (MS-GA80VB) this mode prolonged until the RT12 reads over 3°C(MS-GA50VB)/ 1°C(MS-GA60VB) / RT12 or RT13 still

reads over-1°C(MS-GA80VB).

② Time control

When the three conditions as follows have been satisfied for 1 hour and 45 minutes, compressor stops for 3 minutes. a. Compressor has been continuously operating. b. Indoor fan speed is Low or Med. c. Room temperature is below 26°C. When compressor stops, the accumulated time is cancelled and when compressor restarts, time counting starts from the beginning. Time counting also stops temporarily when the indoor fan speed becomes High or the room temperature exceeds 26°C. However, when two of the above conditions (b.and c.) are satisfied again. Time accumulation is resumed.

Operation chart

Example

Compressor

OFF

Outdoor fan

···································High °C························Med.

°C····································Low

OFF

(continuously at set speed)

Indoor fan

3. Outdoor fan speed control <MU-GA80VB>

Outdoor fan speed is controlled according to the temperature of ambient temperature thermistor RT63. Outdoor fan Low operation : When the outside temperature decreases to 20°C or less.

Until the outside temperature goes to 22°C.

Outdoor fan High operation : Until the outside temperature decreases to 20°C or less.

When the outside temperature goes to 22°C.

NOTE : When indoor fan speed is Low except FAN operation mode and the outside temperature is 30: or less, the

outdoor fan operates at Low. Outdoor fan Low operation is cancelled according to the following conditions(1 or 2):

1 When the operation is not changed and the outside temperature goes to 33: or more. 2 When the operation is changed. (Change to FAN operation mode / Change of the indoor fan speed)

4. Discharge temperature protection <MU-GA80VB>

The compressor is controlled by the temperature of discharge temperature thermistor RT62 for excess rise protection of compressor discharge pressure.

• Compressor When the temperature of discharge temperature thermistor RT62 goes to 120: or more, the compressor is turned OFF.

After 3 minutes since the compressor has been turned OFF, if the temperature of discharge temperature thermistor RT62 becomes 100: or less, the compressor is turned ON.

2-1-2. DRY mode of “I FEEL CONTROL”

The system for dry operation uses the same refrigerant circuit as the cooling circuit. The compressor and the indoor fan are controlled by the room temperature. By such controls, indoor flow amounts will be reduced in order to lower humidity without much room temperature decrease.

1. Indoor fan speed control

Indoor fan operates at the set speed by FAN SPEED CONTROL button. However, in AUTO fan operation, fan speed becomes Low.

2. The operation of the compressor and indoor/ outdoor fan

Compressor operates by room temperature control and time control. Set temperature is controlled to fall 2°C from initial room temperature. Indoor fan and outdoor fan operate in the same cycle as the compressor.

•When the room temperature is 23°C or over: When the thermostat is ON, the compressor repeats 8 minutes ON and 3 minutes OFF. When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.

•When the room temperature is under 23°C. When the thermostat is ON, the compressor repeats 2 minutes ON and 3 minutes OFF. When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.

Operation time chart

Example

Thermostat

Indoor fan

Outdoor fan

OFF

Compressor

8 minutes

3 minutes

4 minutes

1 minute

3. Coil frost prevention

• The operation is as same as coil frost prevention during COOL mode of “I FEEL CONTROL”.

• Indoor fan operates at the set speed and the compressor stops for 5 minutes, because protection(Coil frost

prevention) has the priority. However, when coil frost prevention works while the compressor is not operating, its speed becomes Low.

4. Outdoor fan speed control <MU-GA80VB>

Outdoor fan speed control is as same as one of COOL mode of “I FEEL CONTROL”.

2-2. COOL ( ) OPERATION

(1) Press OPERATE/STOP (ON/OFF) button.

OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone. (2) Select COOL mode with OPERATION SELECT button. (3) Press TEMPERATURE buttons.

(TOO WARM or TOO COOL button) to select the desired temperature.

The setting range is 16 ~ 31°C.

✻ Indoor fan continues to operate regardless of thermostat’s OFF-ON at set speed.

✻ Coil frost prevention is as same as COOL mode of “I FEEL CONTROL”.

AUTO

Horizontal

34 5

Middle Downward Swing

2-3. DRY ( ) OPERATION

(1) Press OPERATE/STOP (ON/OFF) button.

OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.

(2) Select DRY mode with OPERATION SELECT

button.

(3) The microprocessor reads the room tempera-

ture and determines the set temperature. Set temperature is as shown on the right chart. Thermostat (SET TEMP.)does not work. The other operations are same as DRY mode of “I FEEL CONTROL”.

(4) DRY operation will not function when the room

temperature is 13°C or below.

2-4. FAN ( ) OPERATION

(1) Press OPERATE/STOP(ON/OFF) button.

OPERATION INDICATOR lamp of the indoor unit turns ON with a beep tone.

(2) Select FAN mode with OPERATION

SELECT button.

(3) Select the desired fan speed. When AUTO, it

becomes Low.

Only indoor fan operates. Outdoor unit does not

operate.

2-5. INDOOR FAN MOTOR CONTROL

(1) Rotational frequency feedback control

The indoor fan motor is equipped with a rotational frequency sensor, and outputs signal to the microprocessor to feedback the rotational frequency. Comparing the current rotational frequency with the target rotational frequency (High, Med., Low), the microprocessor controls SR141 and adjusts fan motor electric current to make the current rotational frequency close to the target rotational frequency. With this control, when the fan speed is switched, the rotational frequency changes smoothly.

Rotational frequency

High

Med.

Low

(2) Fan motor lock-up protection

When the rotational frequency feedback signal has not output for 12 seconds, (or when the microprocessor cannot detect the signal for 12 seconds) the fan motor is regarded locked-up. Then the electric current to the fan motor is shut off. 3 minutes later, the electric current is applied to the fan motor again. During the fan motor lock-up, the OPERATION INDICATOR Indicator lamp flashes on and off to show the fan motor abnormality.

2-6. AUTO VANE OPERATION

1. Horizontal vane

(1) Vane motor drive

(2) The horizontal vane angle and mode change as follows by pressing the VANE button.

time

(3) Positioning

The vane presses the vane stopper once to confirm the standard position and then moves to the set angle. Confirming of standard position is performed in case of follows. (a) When the power supply turns ON. (b) When the operation starts or finishes (including timer operation). (c) When the test run starts. (d) When the vane control is changed AUTO to MANUAL(except SWING). (e) When the SWING is finished (including ECONO COOL).

(4) VANE AUTO ( ) mode

The microprocessor automatically determines the horizontal vane angle and operation to make the optimum room temperature distribution.

COOL and DRY operation Vane angle is fixed to Angle 1.

FAN operation Vane angle is fixed to Angle 4.

(5) STOP (operation OFF) and ON-TIMER standby

When the following cases occur, the horizontal vane returns to the closed position. (a) When OPERATE/STOP (ON/OFF) button is pressed (POWER OFF). (b) When the operation is stopped by the emergency operation. (c) When ON-TIMER is on standby.

(6) Dew prevention

During COOL or DRY operation at Vane Angle 4 or 5 when the compressor cumulative operation time of compressor exceeds 1 hour, the vane angle automatically changes to Angle 1 for dew prevention.

(7) SWING MODE ( )

By selecting SWING mode with VANE button, the horizontal vane swings vertically. The remote controller displays “”. SWING mode is cancelled when VANE button is pressed once again.

COOL / DRY FAN

Fan speed : Faster Solid arrow : When LONG mode is used. Dotted arrow : When LONG mode is not used.

(8) ECONO COOL ( ) operation (ECONOmical operation)

When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 2°C higher. Also the horizontal vane swings in various cycle according to the temperature of indoor heat exchanger(Tp

(w 1)).

SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher, the air conditioner can keep comfort. As a result, energy can be saved. ECONO COOL operation is cancelled when ECONO COOL button is pressed once again or VANE button is pressed or LONG button is pressed or change to other operation mode.

NOTE : ECONO COOL operation does not work in COOL mode of “I FEEL CONTROL”.

w 1 Tp : • Value of RT12 (MS-GA50/GA60VB)

• Minimum value of indoor coil thermistor (main) RT12 and indoor coil thermistor (sub) RT13 (MS-GA80VB)

In swing operation of ECONO COOL operation mode, the initial air flow direction is adjusted to “Horizontal”. According to the temperature of indoor coil thermistor Tp

(w 1) at starting of this operation, next downward blow time is

decided. Then when the downward blow has been finished, next horizontal blow time is decided. For initial 10 minutes the swing operation is performed in table G~H for quick cooling. Also, after 10 minutes when the difference of set temperature and room temperature is more than 2:, the swing operation is performed in table D~H for more cooling. The air conditioner repeats the swing operation in various cycle as follows.

Temperature of Tp

B C D E

G H

15°C or less

15°C to 17°C

17°C to 18°C

18°C to 20°C

20°C to 21°C 21°C to 22°C 22°C to 24°C

more than 24°C

(w 1)

Downward blow time

(second)

2 5 8

11 14 17

20 23

Horizontal blow time

(second)

8 5 2

(9) LONG MODE ( )

By pressing LONG button indoor fan speed becomes faster than setting fan speed on the remote controller, and the horizontal vane moves to the position for LONG mode. The remote controller displays “”. LONG mode is cancelled

when LONG button is pressed once again or VANE button is pressed or ECONO COOLbutton is pressed in COOL mode.

• In the following example, the vertical vane is set to (front.).

About 100-

Horizontal AIR FLOW blowing range

45SWING

2. Vertical vane

(1) Vane motor drive

These models are equipped with a stepping motor for the vertical vane. The rotating direction, speed, and angle of the motor are controlled by pulse signals (approx. 12V) transmitted from microprocessor.

(2) The vertical vane angle and mode change as follows by pressing WIDE VANE button.

(3) Positioning

The vane is once pressed to the vane stopper to confirm the standard position and then set to the desired angle.

Confirming of standard position is performed in case of follows.

(a) When OPERATE/STOP(ON/OFF) button is pressed (POWER ON/OFF).

(b) When SWING is started or finished.

(4) SWING MODE ( )

By selecting SWING mode with WIDE VANE button, the vertical vane swings horizontally. The remote controller displays

“”. The vane moves right and left in the width of Angle 4 repeatedly.

(5) WIDE MODE ( )

By selecting WIDE mode with WIDE VANE button, indoor fan speed becomes faster than setting fan speed on the

remote controller (W). The remote controller displays “”.

W Indoor fan speed becomes faster than setting fan speed on the remote controller even when or is

selected.

2-7. TIMER OPERATION

1. How to set the timer

(1) Press OPERATE/STOP (ON/OFF) button to start the air conditioner. (2) Check that the current time is set correctly.

NOTE : Timer operation will not work without setting the current time. Initially “AM0:00” blinks at the current time display of

TIME MONITOR, so set the current time correctly with CLOCK SET button.

(3) Press ON/OFF TIMER buttons to select the operation.

“ON-TIMER” button... AUTO START operation (ON timer) “OFF-TIMER” button... AUTO STOP operation (OFF timer)

(4) Press HR. and MIN. button to set the timer. Time setting is 10-minute units.

HR. and MIN. button will work when “” or “” mark is flashing. These marks disappear in 1 minute. After setting the ON timer, check that OPERATION INDICATOR lamp of the indoor unit lights.

NOTE1 : Be sure to place the remote controller at the position where its signal can reach the air conditioner even during

TIMER operation, or the set time may deviate within the range of about 10 minutes.

NOTE2 : Reset the timer in the following cases, or the set time may deviate and other malfunctions may occur.

• Apower failure occurs.

•The circuit breaker functions.

2. Cancel

TIMER setting can be cancelled with ON/OFF TIMER buttons. To cancel ON timer, press “ON-TIMER” button. To cancel OFF timer, press “OFF-TIMER” button. TIMER is cancelled and the display of set time disappears.

PROGRAM TIMER

• OFF timer and ON timer can be used in combination.

• “” and “” display shows the order of OFF timer and ON timer operation.

(Example 1) The current time is 8:00 PM.

The unit turns off at 11:00 PM, and on at 6:00 AM.

(Example 2) The current time is 11:00 AM.

The unit turns on at 5:00 PM, and off at 9:00 PM.

NOTE : TIMER setting will be cancelled by power failure or breaker functioning.

2-8. EMERGENCY / TEST OPERATION

In case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the front of the indoor unit. Emergency operation is available when the remote controller is missing, has failed or the batteries of remote controller run down. The unit will start and OPERATION INDICATOR lamp will light. The first 30 minutes of operation is the test run operation. This operation is for servicing. The indoor fan speed runs at High speed and the system is in continuous operation. (The thermostat is ON.) After 30 minutes of test run operation, the system shifts to EMERGENCY COOL MODE with a set temperature of 24°C. The fan speed shifts to Med. speed. The coil frost prevention works even in emergency operation.

In the test run or emergency operation, the horizontal vane operates in VANE AUTO ( ) mode. Emergency operation continues until EMERGENCY OPERATION switch is pressed again or the unit receives any signal from the remote controller. In case of latter, normal operation will start.

NOTE : Do not press EMERGENCY OPERATION switch during normal operation.

• The following indication applies regardless of shape of the indicator.

OPERATION INDICATOR lamp

Press once <Cool>

Press again <Stop>

EMERGENCY OPERATION switch

Lighted Not Lighted

Rank

Ta (:) more than Tb+10 Tb+5 to Tb+10 Tb+2 to Tb+5 Tb-2 to Tb+2 Tb-5 to Tb-2 Tb-10 to Tb-5 less than Tb-10

100 pulse or less

Cooling

5 2 1 0

-1

-2

-5

NOTE : Discharge temperature : Ta, Target discharge temperature : Tb

100 pulse or more

Cooling

20 10

2 0

-2

-5

-10

Opening immediately before having stopped last time

2-9. EXPANSION VALVE CONTROL (LEV CONTROL) <MU-GA80VB>

Controlled range

Basic specification

Minimum : 54 pulse, Maximum : 500 pulse

Drive speed

30 ~ 90 pulse / second

Opening set

The setting is always in opening direction. (To close the LEV, it is closed to the pulse smaller than the one which is set finally. Then the LEV is opened to the final setting pulse.)

Stop of indoor unit

Opening in stop : 150 pulse ➔ LEV opening is set to becomes 500 pulse after 3 minutes passed.

Remote controller ON

LEV positioning (LEV is closed completely at once)

Power ON (Breaker ON)

LEV is positioned. However, afterwards, LEV is not positioned at the first remote controller ON.

Approximate for 2 minutes since compressor has started.

Opening is set by the initial opening. (Initial opening is set according to each operation modes and outer temperature conditions.)

From approximate 2 minutes to approximate 13 minutes (for 11 minutes) since compressor has started.

Opening is set by standard opening. (Standard opening is set according to each operation modes and outer temperature conditions.)

After 13 minutes passed since compressor has started.

LEV opening is corrected to be once every 2 minutes so that discharge temperature becomes the target discharge temperature. (When the discharge temperature is lower than target : LEV is corrected in closed direction, when the discharge temperature is higher than target : LEV is corrected in opening direction.)

At thermostat OFF

Opening in stop : 150 pulse ➔ LEV is set to the initial opening after about 3 minutes passed.

At thermostat ON

Same as the starting of compressor operation

At remote controller OFF

Opening in stop : 150 pulse ➔ LEV is set so that the opening is opened completely at the speed of 4 pulse every 5 seconds in opening after about 3 minutes passed.

General operation

LEV (Expansion valve) is controlled by “Thermostat ON” commands given from the unit.

(1) LEV opening correction by discharge temperature

The LEV opening is corrected according to the temperature difference between target discharge temperature (Tb) and

actual discharge temperature (Ta). 1 The LEV correction is used properly for two kinds according to the LEV opening status at operation off.

2 When the temperature difference RT between indoor coil thermistor (main) RT12 and indoor coil thermistor (sub)

Ta (:)

more than Tb+10 Tb+5 to Tb+10 Tb+2 to Tb+5 Tb-2 to Tb+2 Tb-5 to Tb-2 Tb-10 to Tb-5 less than Tb-10

less than 2:

20 10

2 0

-2

-5

-10

NOTE : Discharge temperature : Ta, Target discharge temperature : Tb

3: or more

60 20

2 0

-2

-5

-10

2: or more and less than 3:

60 20

2 0

-2

-5

-10

Tb (:) COOL (Normal) COOL ( RT is less than 2:, or RT is 2:or more and less than 3:.) COOL ( RT is 3 :or more.)

NOTE : Target discharge temperature : Tb

80 70 65

Operation mode

NOTE : Opening increases and decreases to be in the target discharge temperature during operation.

Opening completely

Positioning

Power ON

Initial opening

Standard opening

Remote controller ON

➔

Operation

Thermostat OFF

Standard opening

Thermostat ON

Opening in stop

Operation

Opening in stop

Remote controller OFF

Opening completely

Remote controller ON

➔

Positioning

Standard opening

Operation

Time

LEV opening

Initial opening

Open

(Second)

(A)

WITH SOFT START RELAY

WITHOUT SOFT START RELAY

RT13 in the indoor unit is 2: or more for a fixed time at cool or dry operation, the target discharge temperature is changed. After the temperature is changed, when temperature difference RT is 3: or more, the target temperature

is changed again. The LEV opening is controlled based on the changed target discharge temperature and the temperature difference RT.

The target discharge temperature (Tb) is set according to the operation mode or the unit status as follows.

NOTE : When the discharge temperature (Ta) is 50: or less on the cool operation LEV opening is set in 54 pulse.

When this state continues for 20 minutes, the compressor is stopped and restarts in 3 minutes. When the compressor is stopped, the indoor unit indicates the abnormality of refrigerant system and stops. (OPERATION INDICATOR lamp is 10-time flashing on and off.)

(2) LEV time chart

2-10. FUNCTION OF SOFT START RELAY

Soft start relay will chop some starting current. Starting current is reduced as shown in the following figures.

Lighted

Not lighted

Approx. 2 : or more

Difference between target temperature and room temperature

Approx. 2 : or less

This shows that the air conditioner is operating to reach the target temperature. Please wait until the target temperature is obtained.

This shows that the room temperature is approaching the target temperature.

Operation state

Indication

Operation Indicator

Operation Indicator lamp

The operation indicator at the right side of the indoor unit indicates the operation state.

INDOOR UNIT DISPLAY SECTION

• The following indication applies regardless of shape of the indicator.

MSH MICROPROCESSOR CONTROL

MSH-CA50VB MSH-GA50VB MUH-GA50VB MSH-CB50VB MSH-GA60VB MUH-GA60VB

MSH-GA80VB MUH-GA80VB

WIRELESS REMOTE CONTROLLER

Signal transmitting section

Operation display section

OPERATE /STOP (ON /OFF) button

VANE button

(Horizontal vane button)

OPERATION SELECT button

ECONO COOL button

WIDE VANE button

(Vertical vane button)

RESET button

ON/OFF

I FEEL

COOL

VANE

DRY

HEAT

MODE

WIDE VANE

ECONO COOL

LONG

RESET CLOCK

TOO

WARM

TOO

WARM

FAN

CLOCK

TOO

COOL

TOO

COOL

FAN SPEED CONTROL button

STOP

START

HR.

MIN.

TEMPERATURE buttons

OFF-TIMER button

ON-TIMER button

HR. button

MIN. button

(TIME SET button) CLOCK SET button

LONG button

3-1. “I FEEL CONTROL” ( ) OPERATION

(1) Press OPERATE/STOP (ON/OFF) button on the remote

controller. OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.

(2) Select “I FEEL CONTROL” mode with OPERATION

SELECT button.

(3) The operation mode is determined by the room tempera-

ture at start-up of the operation.

Initial room temperature

25: or more

23:to 25:

less than 23:

Mode

COOL mode of

"I FEEL CONTROL"

DRY mode of

"I FEEL CONTROL"

HEAT mode of

"I FEEL CONTROL"

• Once the mode is fixed, the mode does not change by room temperature afterwards.

Model

COOL mode of

"I FEEL CONTROL"

DRY mode of

"I FEEL CONTROL"

HEAT mode of

"I FEEL CONTROL"

Initial room temperature Initial set temperature

26:

26: or more

25: to 26:

less than 23:

23: to 25:

24:

Initial room temperature minus 2: Initial room temperature minus 2:

❈1

TOO

COOL

TOO

WARM

• Under ON-TIMER ( ) operation, mode is determined as follows.

Operation time chart

Example Previous operation

COOL mode of “I FEEL CONTROL”

Restart

COOL mode of “I FEEL CONTROL”

or COOL mode

When the system is restarted after 2 hours and more, the operation mode is determined by the room temperature at start-up of the operation.

Operation time chart

Example

Previous operation

COOL mode of “I FEEL CONTROL”

or COOL mode

Restart

COOL or DRY or

HEAT mode of “I FEEL CONTROL” that determined by room temperature at start-up of the operation.

(4) The initial set temperature is decided by the initial room temperature.

❈1 When the system is restarted with the remote controller, the system operates with the previous set temperature regard-

less of room temperature at restart. The set temperature is calculated by the previous set temperature.

(5) TEMPERATURE buttons

In “I FEEL CONTROL” ( ) mode, set temperature is decided by the microprocessor based on the room temperature. In addition, set temperature can be controlled by TOO WARM or TOO COOL buttons when you feel too cool or too warm. Each time TOO WARM or TOO COOL button is pressed, the indoor unit receives the signal and emits a beep tone.

• Fuzzy control

When TOO COOL or TOO WARM button is pressed, the microprocessor changes the set temperature, considering the room temperature, the frequency of pressing TOO COOL or TOO WARM button and the user’s preference to heat or cool. So this is called “Fuzzy control”, and works only in “I FEEL CONTROL” mode.

In DRY mode of “I FEEL CONTROL”, the set temperature doesn’t change.

…

To raise the set temperature 1~2°C

…

To lower the set temperature 1~2°C

3-1-1. COOL mode of “I FEEL CONTROL”

Difference between room temperature and set temperature during operation

1°C 1.7°C

3°C

Outdoor fan speed

20: 22:

High

Ambient temperature thermistor RT63 temperature

Low

1. Indoor fan speed control

Indoor fan operates at the set speed by FAN SPEED CONTROL button. In AUTO the fan speed is as follows.

Initial temperature difference Fan Speed Room temperature minus set temperature : 1.7 : or more Room temperature minus set temperature : Between 1 and 1.7 : Room temperature minus set temperature : less than 1 :

2. Coil frost prevention

① Temperature control

When the indoor coil thermistor RT12 reads 1°C or below(MSH-CA50/CB50/GA50VB) /–1°C or below(MSH-GA60VB)/ RT12 or RT13 reads 1°C or below (MSH-GA80VB), the coil frost prevention mode starts immediately. However, the coil frost prevention doesn’t work for 5 minutes since the compressor has started. The indoor fan operates at the set speed and the compressor stops for 5 minutes.

After that, if RT12 still reads below 1°C(MSH-CA50/CB50/GA50VB)/ –1°C(MSH-GA60VB)/ RT12 or RT13 still reads below 1°C (MSH-GA80VB) this mode prolonged until RT12 reads over 1°C(MSH-CA50/CB50/GA50VB)/ –1°C(MSHGA60VB) / RT12 or RT13 still reads over 1°C(MSH-GA80VB).

② Time control

When the three conditions as follows have been satisfied for 1 hour and 45 minutes, compressor stops for 3 minutes.

a. Compressor has been continuously operating.

b. Indoor fan speed is Low or Med.

c. Room temperature is below 26°C.

When compressor stops, the accumulated time is cancelled and when compressor restarts, time counting starts from the

beginning.

Time counting also stops temporarily when the indoor fan speed becomes High or the room temperature exceeds

26°C. However, when two of the above conditions (b.and c.) are satisfied again. Time accumulation is resumed.

Operation chart

Example

Compressor

OFF

Outdoor fan

····································High

·························Med.

·····································Low

OFF

(continuously at set speed)

Indoor fan

3. Outdoor fan speed control <MUH-GA80VB>

Outdoor fan speed is controlled according to the temperature of ambient temperature thermistor RT63. Outdoor fan Low operation : When the outside temperature decreases to 20°C or less.

Until the outside temperature goes to 22°C.

Outdoor fan High operation : Until the outside temperature decreases to 20°C or less.

When the outside temperature goes to 22°C.

NOTE1 : If the temperature of RT63 reads from 20: to 22: at the air conditioner starting outdoor fan speed is High. NOTE2 : When indoor fan speed is Low except HEAT operation mode and the outside temperature is 30: or less, the

outdoor fan operates at Low. Outdoor fan Low operation is cancelled according to the following conditions(1 or 2):

1 When the operation is not changed and the outside temperature goes to 33: or more. 2 When the operation is changed. (Change to HEAT operation mode / Change of the indoor fan speed)

4. Discharge temperature protection <MUH-GA80VB>

The compressor is controlled by the temperature of discharge temperature thermistor RT62 for excess rise protection of compressor discharge pressure.

• Compressor When the temperature of discharge temperature thermistor RT62 goes to 120: or more, the compressor is turned OFF.

After 3 minutes since the compressor has been turned OFF, if the temperature of discharge temperature thermistor RT62 becomes 100: or less, the compressor is turned ON.

3-1-2. DRY mode of “I FEEL CONTROL”

Difference between room temperature and set temperature during operation

1°C 1.7°C

4°C

2°C

1. Indoor fan speed control

Indoor fan operates at the set speed by FAN SPEED CONTROL button. However, in AUTO fan operation, fan speed becomes Low.

2. The operation of the compressor and indoor/ outdoor fan

Operation time chart

Example

Thermostat

Indoor fan

Outdoor fan

OFF

Compressor

3. Coil frost prevention

8 minutes

3 minutes

4 minutes

1 minute

• The operation is as same as coil frost prevention during COOL mode of “I FEEL CONTROL”.

• Indoor fan operates at the set speed and the compressor stops for 5 minutes, because protection(Coil frost

prevention) has the priority. However, when coil frost prevention works while the compressor is not operating, its speed becomes Low.

4. Outdoor fan speed control <MUH-GA80VB>

Outdoor fan speed is as same as one of COOL mode of “I FEEL CONTROL”.

3-1-3. HEAT mode of “I FEEL CONTROL”

1. Indoor fan speed control

(1) In AUTO the fan speed is as follows.

Set temperature minus room temperature: 2 : or more·························································· High Set temperature minus room temperature: Between 1 and 2 : ·············································· Med. Set temperature minus room temperature: less than 1: ························································· Low

Initial temperature difference Fan speed

(2) Cold air prevention control

Released

Cold Air Prevention

18: 22:

Fan speed Set speed Very Low or stop

High pressure protection

Released

48: 52:

Outdoor fan

OFF

55:

(MUH-GA50VB) (MUH-GA60VB) 58:

Outdoor fan speed

13: 18:

High

Ambient temperature thermistor RT63 temperature

Low

The fan runs at set speed when the indoor coil thermistor RT12 temperature exceeds 22°C. The fan operates Low when the temperature of indoor coil thermistor RT12 is below 18°C. But the fan stops when the indoor fan operates at Very Low and the room temperature is 15°C or less.

Indoor coil thermistor RT12 temperature

NOTE : If the temperature of RT12 reads from 18°C to 22°C at the air conditioner starting and also after defrosting, this

control works.

(3) Warm air control

When compressor starts in heating operation or after defrosting, the fan changes the speed due to the indoor coil thermistor RT12 temperature to blow out warm air. After releasing of cold air prevention, when the indoor coil thermistor RT12 temperature is 37°C or above, the fan speed shifts to the set speed, and when the fan speed is changed by the remote controller, the fan speed is the set speed. When the indoor coil thermistor RT12 temperature is less than 37°C, the fan speed is controlled by time as below.

<Time condition> <Indoor fan speed> less than 2 minutes························Low 2 minutes to 4 minutes···················Med. 4 minutes or more··························High

The upper limit of the fan speed is the set speed.

If the thermostat turns off, this operation changes to flow soft control.

(4) Flow soft control

After the thermostat turns off, the indoor fan operates at Very Low.

NOTE : When the thermostat turns on, the fan operates at the set speed. Due to the cold air prevention control, the fan

does not start at set speed until the indoor coil thermistor RT12 reads 22°C or more.

2. Outdoor fan speed control <MUH-GA80VB>

Outdoor fan speed is controlled according to the temperature of ambient temperature thermistor RT63. Outdoor fan Low operation : Until the outside temperature decreases to 13°C.

When the outside temperature goes to 18°C or more.

Outdoor fan High operation :When the outside temperature decreases to 13°C or less.

Until the outside temperature goes to 18°C.

3. High pressure protection <MUH-GA50/60VB>

During heating operation, the outdoor fan motor is controlled by the temperature of indoor coil thermistor RT12 for excess rise protection of compressor discharge pressure. (MUH-GA50VB) Outdoor fan OFF : 52°C

Outdoor fan ON : 48°C

(MUH-GA60VB) Outdoor fan OFF : 58°C

Outdoor fan ON : 55°C

High pressure protection chart Example

Indoor coil thermistor

RT12 temperature

(MUH-GA50VB) 52˚C (MUH-GA60VB) 58˚C

(MUH-GA50VB) 48˚C (MUH-GA60VB) 55˚C

Outdoor fan motor

OFF

Outdoor fan motor turn OFF

Outdoor fan motor turn ON

NOTE : During high pressure protection and for 4 minutes and 15 seconds after high pressure protection, defrosting of

outdoor heat exchanger is not detected by the defrost thermistor RT61.

+ 134 hidden pages

Mitsubishi MU-GA20VB, MSC-CA25VB, MUH-GA20VB, MUX-2A28VB, MSC-CB20VB Service Technical Manual

Specifications and Main Features

Frequently Asked Questions

User Manual