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.

E

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

E

· 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 -

E

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

EE

E

EE

E

EE

E

EE

Inverter-controlled multi system type Models Wireless type Models

MCF-GA•VB MCFH-GA•VB MFZ-KA•VA

- · MUCF-GA•VB -

- · MUCFH-GA•VB -

E

-

· MXZ-A•VA -

E

EE

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 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

1-

10

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

2

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

4-

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

5-

11

5-

12

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

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

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

5-

14.

5-

15.

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

5-

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

3

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

15

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

66-

16

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

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

18

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

66-

19

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

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

21

. 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

)

4

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-

11

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

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

(

OC316.

)

5

1

ON/OFF

FAN

TOO

WARM

TOO

COOL

VANE

MODE

ECONO COOL

STOP

START

HR.

MIN.

I FEEL

COOL

DRY

PM

CLOCK

AM

RESET

CLOCK

HEAT /FAN

/

Open the front lid.

ON/OFF

TOO COOL

PM

AM

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

6

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 :

35

30

25

20

15

10

:

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

ON

Compressor

OFF

Outdoor fan

ON

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.

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 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

7

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

ON

OFF

Indoor fan

Outdoor fan Compressor

ON

OFF

8 minutes

OFFOFF

OFF

ON

3 minutes

OFF

4 minutes

ON

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

8

Fan speed

Difference between room temperature and set temperature during operation

3 :

1.7 :

1:

(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.

9

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.

10

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.

11

(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

C

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)

12

Lighted Not lighted

PM

AM

PM

(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.

13

1-10. OUTDOOR UNIT ACTUATOR CONTROL

ACTUATOR

ON

OFF

ON

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

A

ON

ON OFF OFF

– – – –

OFF

ON OFF

– – – – – –

ON

ON OFF OFF

– – – –

B

ON

OFF

ON

OFF

– – – –

ANY UNIT ON

OFF

– –

ON

OFF

– – – –

ON

OFF

ON

OFF

– – – –

C

– – – –

ON

ON OFF OFF

OFF

– – – –

ON OFF

– – – – – –

ON

ON OFF OFF

D

– – – –

ON

OFF

ON

OFF

– – – – – –

ON

OFF

– – – –

ON

OFF

ON

OFF

ACTUATOR

ON OFF

ON

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

A

ON

OFF

– – – –

OFF

– – – – – – – –

B

– –

ON

ON OFF OFF

ANY UNIT ON

OFF

ON OFF

– –

ON

ON OFF OFF

C

– –

ON

OFF

ON

OFF

– –

ON

OFF

ON

OFF

ON

OFF

ACTUATOR

ON

OFF ON OFF

ON (CLOSE)

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

SOLENOID VALVE

MUX-2A28VB

INDOOR UNIT

MC

MF

21R

(BALANCE)

21R1

21R2

COMPRESSOR

OUTDOOR FAN MOTOR

A

ON

ON OFF OFF

ANY UNIT ON

OFF

ON

ON OFF OFF

ON OFF

– –

B

ON

OFF

ON

OFF

ON

OFF

ON

OFF

– –

ON

OFF

ACTUATOR

ON OFF ON OFF ON OFF

MUX-2A59VB

MUX-2A70VB

INDOOR UNIT

MC1

MC2

MF61

COMPRESSOR

OUTDOOR FAN MOTOR

A

ON

OFF

– –

ANY UNIT ON

OFF

B

– –

ON

OFF

MUX-3A60VB MUX-3A63VB

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

14

2

ON/OFF

FAN

TOO

WARM

TOO

COOL

VANE

MODE

ECONO COOL

STOP

START

HR.

MIN.

WIDE VANE

LONG

I FEEL

COOL

DRY

PM

CLOCK

AM

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

PM

AM

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

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.

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:

15

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

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°C

…

To lower the set temperature 1~2°C

16

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

ON

Outdoor fan

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

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

ON

OFF

(continuously at set speed)

Indoor fan

ON

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.

17

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

ON

Thermostat

Indoor fan

Outdoor fan

OFF

ON

OFF

ON

OFF

ON

OFF

ON

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”.

18

AUTO

Horizontal

12

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

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 button.

time

19

(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.

20

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

A

B C 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

(w 1)

Downward blow time

(second)

2 5 8

11 14 17

20 23

Horizontal blow time

(second)

23

20

17

14

11

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.).

21

About 100-

Horizontal AIR FLOW blowing range

61

23

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.

(c) When the power supply turns ON.

(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.

22

PROGRAM TIMER

PM

AM

PM

• 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

23

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.

24

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

RT

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

Close

(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.

25

3

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

PM

AM

TOO

COOL

PM

AM

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

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.

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:

26

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.

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”

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

27

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

ON

Outdoor fan

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

·························Med.

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

ON

OFF

(continuously at set speed)

Indoor fan

ON

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.

28

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

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

ON

Thermostat

Indoor fan

Outdoor fan

OFF

ON

OFF

ON

OFF

ON

OFF

ON

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

29

(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:

ON

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

ON

OFF

ON

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.

30

<MUH-GA80VB>

During heating operation, the outdoor fan and the compressor are controlled by the temperature of indoor coil thermistor RT12 for excess rise protection of compressor discharge pressure.

• Outdoor fan When the temperature of indoor coil thermistor RT12 goes to 55: or more, the outdoor fan is turned OFF. When the temperature of indoor coil thermistor RT12 becomes to 52: or less, the outdoor fan is turned ON.

• Compressor When the temperature of indoor coil thermistor RT12 goes to 75: or more, the compressor is turned OFF. 3 minutes after the compressor is turned OFF and if the temperature of indoor coil thermistor RT12 becomes 75: or less,

the compressor is turned ON.

NOTE : During the high pressure protection and for 10 seconds after high pressure protection, defrosting of outdoor heat

exchanger is not detected by the defrost thermistor RT61.

4. Discharge temperature protection <MUH-GA80VB>

Discharge temperature protection is as same as during COOL mode of “I FEEL CONTROL”.

5. Defrosting

Defrosting of outdoor heat exchanger is controlled by deicer P.C. board, with detection by the defrost thermistor RT61.

(1) Starting conditions of defrost

When all conditions of a) ~ c) are satisfied, the defrosting operation starts.

a) Under the heat operation, the compressor cumulative operation time exceeds 40 minutes without the defrosting opera-

tion working. b) The defrost thermistor RT61 reads -3°C or less. c) After releasing the high pressure protection 4 minutes and 15 seconds(MUH-GA50/GA60VB) / 10 seconds

(MUH-GA80VB) have elapsed.

(2) Releasing conditions of defrost

When the condition d) or e) is satisfied, the defrosting operation stops.

d) The defrost thermistor RT61 reads 3°C(MUH-GA50/GA60VB)/ 13°C(MUH-GA80VB) or more. e) The defrosting time exceeds 10 minutes.

(3) Defrosting time chart

Defrost thermistor RT61 13: or more

3: or more

(MUH-GA80VB) (MUH-GA50/GA60VB)

-3: or less Outdoor 52C

contactor(Compressor)

ON OFF

X62 (R.V. coil)

SR61 Outdoor fan

Defrost counter

Indoor fan

ON OFF

ON

Very Low

15 seconds

30 seconds

Max. 10 minutes

NOTE

30 seconds

5 seconds

OFF

Indoor vane

Horizontal Set position

NOTE: • When the indoor coil thermistor RT12 reads above 18°C, indoor fan operates at Very Low for 30 seconds.

• When the indoor coil thermistor RT12 reads 18°C or less, the indoor fan stops.

31

High

Rotational frequency

High

time

Med.

Low

3-2. 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”.

3-3. 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.

3-4. HEAT ( ) OPERATION

(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 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. (4) Indoor fan speed control, high pressure protection, defrosting, R.V. coil control are the same as HEAT mode of “I FEEL

CONTROL”.

3-5. 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 rota-

tional frequency close to the target rotational frequency. With this control, when the fan speed is switched, the rotational

frequency changes smoothly.

(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.

32

3-6. AUTO VANE OPERATION

Released

Cold Air Prevention

24: 28:

Angle 1

Horizontal vane

Set position

1. Horizontal vane

(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 button.

AUTO

12

Horizontal

34 5

Middle Downward Swing

(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 SWING is finished (including ECONO COOL). (f) When multi-standby starts or finishes.

(4) VANE AUTO ( ) mode

The microprocessor automatically determines the horizontal vane angle and operation to make the optimum room tem-

perature distribution.

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

HEAT 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.

(8) Cold air prevention in HEAT operation

When any of the following conditions occurs in HEAT operation, the 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

NOTE1: If the temperature of RT12 reads from 24: to 28: at the air conditioner starting, this control works.

NOTE2: When 2 or more indoor units are operated with multi outdoor unit, even if any indoor unit turns thermostat off,

this control doesn’t work in the indoor unit.

33

COOL / DRY HEAT

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

(9) 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 (MSH-CA50/GA50/GA60VB)

• Minimum value of indoor coil thermistor (main) RT12 and indoor coil thermistor (sub) RT13 (MSH-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(w 1)

A

B C D E

F

G

H

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

15°C or less

Downward blow time

(second)

2 5 8

11 14 17

20 23

Horizontal blow time

(second)

23 20 17 14 11

8

5

2

(10) LONG MODE ( )

By pressing LONG button indoor fan speed becomes faster than setting fan speed on the remote controller, and the hor-

izontal 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.).

34

2. Vertical vane

COOL and DRY

HEAT

About 100-

About 150-

Horizontal AIR FLOW blowing range

(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 the WIDE VANE button.

23

45SWING

61

(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. (c) When the power supply turns ON.

(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 “”.

NOTE : The position of vane angle 3, angle 4 and angle 5 are different in COOL operation and HEAT operation.

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

selected.

3-7. 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.

35

EMERGENCY OPERATION switch

Press once <Cool>

Press again <Heat>

Press once again <Stop>

OPERATION INDICATOR lamp

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

Lighted Not Lighted

2. Cancel

PM

AM

PM

TIMER setting can be cancelled with the 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.

3-8. 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 / HEAT 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 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 or twice 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.

36

3-9. EXPANSION VALVE CONTROL (LEV CONTROL) <MUH-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 one : LEV is corrected in closed direction, when the discharge temperature is higher than target one : 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

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 / Heating

5 2 1 0

-1

-2

-5

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

100 pulse or more

Cooling / Heating

20 10

2 0

-2

-5

-10

Opening immediately before having stopped last time

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.

37

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

RT

2: or more and less than 3:

60 20

2 0

-2

-5

-10

Tb (:) HEAT 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

85 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

Close

(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, or is 49: or less on heat 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

3-10. FUNCTION OF SOFT START RELAY

Soft start relay will chop some starting current.

Starting current is reduced as shown in the following figures.

38

4

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

Lighted Not lighted

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

Operation Indicator

Mode

COOL mode of

"I FEEL CONTROL"

DRY mode of

"I FEEL CONTROL"

HEAT mode of

"I FEEL CONTROL"

Initial room temperature

25: or more

23: to 25:

less than 23:

ON/OFF

FAN

TOO

WARM

TOO

COOL

VANE

MODE

ECONO COOL

STOP

START

HR.

MIN.

AM PM

CLOCK

˚C

AM

RESET CLOCK

I FEEL

COOL

DRY

AUTO

HEAT

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

ON/OFF

TOO

COOL

PM

AM

TOO

WARM

Signal transmitting section

Operation display section

OPERATE /STOP

(ON /OFF) button

TEMPERATURE buttons

Indication of remote controller model is on back

MSZ-CA MICROPROCESSOR CONTROL

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

WIRELESS REMOTE CONTROLLER

INDOOR UNIT DISPLAY SECTION

Operation Indicator lamp

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

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.

4-1. “I FEEL CONTROL” ( ) OPERATION

1. Press OPERATE/STOP(ON/OFF) button on the remote controller. OPERATION INDICATOR lamp of the indoor unit will turn on with a beep tone.

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

SELECT button.

3. The operation mode is determined by the room temperature at start-up of the operation.

39

• 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:

❈1

TOO

COOL

TOO

WARM

• Under 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

Restart

COOL mode of “I FEEL CONTROL”

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 the 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 speed, the indoor unit receives the signal 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:

…

To lower the set temperature 1 ~ 2:

40

4-1-1. COOL mode of “I FEEL CONTROL”

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 : 0.3 : or more················································ON

Difference between room

temperature and set temperature during operation.

Set temperature

Room temperature minus set temperature : less than -0.3 :············································OFF

2. Indoor fan speed control

-0.3 :

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

Initial temperature difference

Fan speed

Difference between room temperature and set temperature during operation ( T)

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

ww

In case that T has been any following condition for 30 minutes, the value in the parentheses is applied.

1

:

(0 :)W

a. Fan speed is Auto Low, and T is 1 : or more. b. Fan speed is Auto Med., and T is 1.7 : or more.

3. Coil frost prevention

1 Temperature control The operational frequency of the compressor is controlled based on the temperature of the indoor coil thermistor.

Temperature of indoor coil thermistor

8°C or more

6°C to 8°C 3°C to 6°C

Lower at the rate of 3 Hz / 90 seconds

Operation frequency

Normal (variable)

Fixed

Lower at the rate of 6 Hz / 90 seconds

3°C or less

Compressor is turned OFF for 5 minutes when temperature of indoor coil thermistor continues 3°C or less for 5 minutes or more.

0.3 :

1.7

:

(0.7 :)W

3

:

(1.7 :)W

The indoor fan maintains the actual speed of the moment.

2 Time control

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

The indoor fan operates at set speed.

a. Compressor has been continuously operating. b. Indoor fan speed is Low or Med.

c. Room temperature is below 26:. 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:. However, when two of the above conditions(b and c.) are satisfied again. Time accumulation is resumed.

4. Low outside temperature operation

When the ambient temperature thermistor RT65 reads 17: or less, the operation mode moves to cool operation in low outside temperature from normal cool operation. Each outdoor actuator (compressor/ fan/ LEV) is operated in the exclusive control, which is different from one of normal cool operation. Especially fan motor doesn’t operates continuously to maintain sufficient cooling capacity. (1) Outdoor fan control

Outdoor unit (compressor) operates with outdoor fan OFF basically. But any of following conditions is satisfied, the outdoor fan turns ON for about 5 seconds. a). the defrost thermistor RT61 reads 50: or more. b). the fin temperature thermistor RT64 reads 60: or more.

(2) LEV (expansion valve) control

In normal cool operation the opening degree of expansion valve is corrected according to the discharge temperature (RT62). But in this mode it is fixed to the value corresponding to the operation frequency of compressor.

(3) Dew drop prevention

When the ambient temperature thermistor RT65 reads -13: or less, as coil frost or dew drop from indoor unit may occur, the compressor turns OFF with the outdoor fan ON for prevention of them. NOTE: This control can be released by cut of the jumper line JG on the outdoor inverter P.C. board.

Be sure to cut it since user accepts that maker can’t be responsible for coil frost or dew drop from indoor unit.

(4) Outside temperature detecting control

In this mode to detect the exact outside temperature the compressor turns OFF with the outdoor fan ON for 3 minutes once 1 hour.

41

4-1-2. 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.

Difference between room

1. Thermostat control

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

Initial temperature difference Thermostat

temperature and set temperature during operation

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

-0.3 :

0.3 :

2. Indoor fan speed control

Indoor fan operates at the set speed by FAN SPEED CONTROL button. When thermostat OFF (compressor OFF) fan speed becomes Very Low.

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

Compressor operates by temperature control and time control.

1 Set temperature is controlled to fall 2°C from initial room temperature. 2 Operational frequency of compressor during operation is fixed to 30Hz.

4. Coil frost prevention

Coil frost prevention is as same as COOL mode of “I FEEL CONTROL”. (4-1-1.3.) The indoor fan maintains the actual speed of the moment. However, when coil frost prevention works while the compressor is not operating (= indoor fan speed Very Low), it’s speed becomes the set speed.

5. Low outside temperature operation

Low outside temperature operation is as same as COOL mode of “I FEEL CONTROL”. (4-1-1.4.)

4-1-3. HEAT mode of “I FEEL CONTROL”

Difference between room temperature and set tem-

1. Thermostat control

perature during operation

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

Initial temperature difference Thermostat

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

-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.

Initial temperature difference

Set temperature minus room temperature: 2 :or more Set temperature minus room temperature:

Between 1 and 2 : ·····································

Set temperature minus room temperature: less than 1

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

:··················································

Fan speed

Med.

Low

Difference between room temperature and set temperature during operation

2 :

1 :

1.7 :

4 :

(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 40°C or more, the fan operates at set speed. (2) if the temperature of RT12 is less than 40°C and

(1) if heating operation starts after defrosting, the fan stops. (2) if the temperature of room temperature thermistor RT11 is 15°C or less, the fan stops. (3) if the temperature of room temperature thermistor RT11 is more than 15°C, the fan operates at Very Low.

NOTE : When 3 minutes have passed since the compressor started operation, this control is released regardless of the

temperature of RT12.

42

Compressor

OFF

ON

Fan

Very Low

Set speed

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

(3) Warm air control

When the following conditions of a) ~ b) are satisfied, warm air control works. a) when cold air prevention has been released after the compressor started operation b) when defrosting has been finished

When warm air control works, the fan speed changes from Low as follows to blow out warm air gradually. When every 2 minutes have passed

(1) if the temperature of RT12 is 22°C or more, the indoor fan speed is up by 1 step. (2) if the temperature of RT12 is 18°C to 22°C, the indoor fan speed is continued with the present speed. (3) if the temperature of RT12 is less than 18°C, the indoor fan speed is down by 1 step.

Gradation of fan speed in initial (example)

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. 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.

(4) Flow soft control

When the thermostat (compressor) is off, the indoor fan operates as follows.

NOTE : When the thermostat(compressor) turns ON, the fan will operate

at set speed. But until cold air prevention and warm air control is released, the fan speed follow them.

3. High pressure protection

In HEAT operation the indoor coil thermistor detects the temperature of the indoor heat exchanger. The compressor operational frequency is controlled to prevent the condensing pressure from increasing excessively.

4. Overload starting

When the room temperature thermistor RT11 reads 18°C or more, the compressor runs with its maximum frequency regulated for 10 minutes after the start-up.

5. Defrosting

(1) Starting conditions of defrosting

When the following conditions a) ~ c) are satisfied, the defrosting starts. a) The defrost thermistor reads -3°C or less. b) The cumulative operation time of the compressor has reached any of the set valuesw (40, 45, 55, 65, 75, 85, 95, 105,

115, 125 minutes). c) More than 5 minutes have passed since the start-up of the compressor. w Set value of compressor operation time(hereinafter referred to as defrost interval)

This is decided by the temperature of defrost thermistor and ambient temperature thermistor, the previous defrosting

time. For example, the first defrost interval is 40 minutes long, and the second is 45 minutes long. The third and sub-

sequent intervals are set to be longer, and less frequent, depending on defrosting time.

The third and subsequent defrost intervals follow any of the three patterns …5 or 10 to 20 minutes longer, the same,

or 5 or 10 to 20 minutes shorter compared with the previous defrost interval … with the longest 125 minutes and the

shortest 40 minutes.

(2) Releasing conditions of defrosting

Defrosting is released when any of the following conditions is satisfied: a) The defrost thermistor continues to read 5°C or more for 10 seconds. b) Defrosting time has exceeded 10 minutes. c) Any other mode than HEAT mode is set during defrosting.

43

Time chart of defrosting in HEAT mode (reverse type)

set position

set speed

set position

set speed

Indoor fan

Compressor normal

Outdoor fan

R.V. coil

(21S4)

OFF (COOL)

OFF

Maximum frequency

horizontal

Horizontal vane

Very Low (temperature of indoor coil thermistor > 18:)

30

seconds

30

seconds

30

seconds

5 seconds 5 seconds

40

seconds

OFF

ON (HEAT)

ON ON

ON (HEAT)

4-2. AUTO CHANGE OVER ··· AUTO MODE OPERATION

1. Mode selection

Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.

(1) Initial mode

At first indoor unit operates only indoor fan with outdoor unit OFF for 3 minutes to detect present room temperature. Following the conditions below, operation mode is selected.

1 If the room temperature thermistor RT11 reads more than set temperature, COOL mode is selected. 2 If the room temperature thermistor RT11 reads set temperature or less, HEAT mode is selected.

(2) Mode change

In case of the following conditions the operation mode is changed. 1 COOL mode changes to HEAT mode when 15 minutes have passed with the room temperature 2 degrees below the

set temperature.

2 HEAT mode changes to COOL mode when 15 minutes have passed with the room temperature 2 degrees above the

set temperature. In the other cases than the above conditions, the present operation mode is continued. NOTE1: Mode selection is performed when multi standby (refer to NOTE2) is released and the unit starts operation with

ON-timer.

NOTE2: If two or more indoor units are operating in multi system, there might be a case that the indoor unit, which is

operating in AUTO ( ), cannot change over the other operating mode (COOL HEAT) and becomes a state of standby.

(3) Indoor fan control/ Vane control

As the indoor fan speed and the horizontal vane position depend on the selected operation mode, when the operation mode changes over, they change to the exclusive ones.

44

35

30

25

20

15

10

:

10 15 20 25 30 35

Set temperature

Initial room temperature

Set temperature and initial room temperature in dry mode

:

4-3. 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 control is as same as COOL mode of “I FEEL CONTROL”.(4-1-1.1.)

2. Indoor fan speed control

Indoor fan speed control is as same as COOL mode of “I FEEL CONTROL”.(4-1-1.2.)

3. Coil frost prevention

Coil frost prevention is as same as COOL mode of “I FEEL CONTROL”.(4-1-1.3.)

4. Low outside temperature operation

Low outside temperature operation is as same as COOL mode of “I FEEL CONTROL”.(4-1-1.4.)

4-4. 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 temperature and determines

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

(4) DRY operation will not function when the room temperature is

13°C or below.

1. Thermostat control

Thermostat control is as same as DRY mode of “I FEEL CONTROL”.(4-1-2.1.)

2. Indoor fan speed control

Indoor fan speed control is as same as DRY mode of “I FEEL

CONTROL”.(4-1-2.2.)

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

The operation of the compressor and indoor/outdoor fan is as

same as DRY mode of “I FEEL CONTROL”.(4-1-2.3.)

4. Coil frost prevention

Coil frost prevention is as same as DRY mode of “I FEEL CONTROL”.(4-1-2.4.)

5. Low outside temperature operation

Low outside temperature operation is as same as DRY mode of “I FEEL CONTROL”.(4-1-2.5.)

4-5. HEAT ( ) OPERATION

(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 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 control is as same as HEAT mode of “I FEEL CONTROL”.(4-1-3.1.)

2. Indoor fan speed control

Indoor fan speed control is as same as HEAT mode of “I FEEL CONTROL”.(4-1-3.2.)

3. High pressure protection

High pressure protection is as same as HEAT mode of “I FEEL CONTROL”.(4-1-3.3.)

4. Overload starting

Overload starting is as same as HEAT mode of “I FEEL CONTROL”.(4-1-3.4.)

5. Defrosting

Defrosting is as same as HEAT mode of “I FEEL CONTROL”.(4-1-3.5.)

45

High

Med.

Low

High

Rotational frequency

time

4-6. 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.

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.

4-7. 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 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 SWING is finished (including ECONO COOL). (f) When multi-standby starts or finishes.

(4) VANE AUTO ( ) mode

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

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

(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 with the vane angle at Angle 4 or 5 when the compressor cumulative operation time exceeds 1 hour, the vane angle automatically changes to Angle 1 for dew prevention.

HEAT operation Vane angle is fixed to Angle 4.

46

Horizontal vane

Set position Angle 1

38:18:

Released

Cold Air Prevention

(7) SWING MODE ( )

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

(8) Cold air prevention in HEAT operation.

When any of the following conditions occurs in HEAT operation, the 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 18: or below. ➃ Indoor coil thermistor RT12 temperature is raising from 18°C or below, but it does not exceed 38:.

Indoor coil thermistor RT12 temperature

NOTE1: If the temperature of RT12 reads from 18: to 38: at the air conditioner starting, this control works. NOTE2: When 2 or more indoor units are operated with multi outdoor unit, even if any indoor unit turns thermostat off,

this control doesn’t work in the indoor unit.

(9) 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(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 ECONO COOL button is pressed once again or VANE CONTROL button is pressed or change to other operation mode.

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

<SWING operation> 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 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 indoor

coil thermistor RT12

A B C 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

4-8. 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 / OFF TIMER buttons to select the operation.

“

ON-TIMER

“

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.

” button ... AUTO START operation (ON timer)

” button... AUTO STOP operation (OFF timer)

Downward blow time

(second)

2 5

8 11 14 17 20 23

47

Horizontal blow time

(second)

23 20 17 14 11

8 5 2

EMERGENCY OPERATION switch

Press once <Cool>

Press again <Heat>

Press once again <Stop>

OPERATION INDICATOR lamp

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

Lighted Not Lighted

PM

AM

PM

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.

● A power failure occurs.

● The circuit breaker functions.

2. Cancel

TIMER setting can be cancelled with ON / OFF TIMER buttons. To cancel ON timer, press “ To cancel OFF timer, press “

ON-TIMER

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.

4-9. 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 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 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 or twice 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.

48

4-10. INVERTER SYSTEM CONTROL

POWER P.C. BOARD

Power supply

INVERTER P.C. BOARD

R64A R64B

CT

TR821

DB65

X64

L62 L63

C62A C62B C61B

DB61

L61

P

W

V

U

N

CT761

CT781

IPM

U

W

MC

V

+

Booster chopper circucuit

SYMBOL IPM C62A/C62B/C61B CT761/CT781

CT DB61 R64A, R64B

X64 DB65

TR821 L61

NAME INTELLIGENT POWER MODULE SMOOTHING CAPACITOR CURRENT TRANSFORMER

CURRENT TRANSFORMER DIODE MODULE CURRENT-LIMITING RESISTOR

RELAY DIODE MODULE

SWITCHING POWER TRANSISTOR REACTOR

FUNCTION It supplies three-phase AC power to compressor. It stabilizes the DC voltage. It measures the current of the compressor motor. It measures the value of current which is supplied to the main power supply circuit. It converts the AC voltage to DC voltage. It absorbs the rush current not to run into the main power supply circuit when the electricity turns ON. It short-circuits the resistance which restricts rush current during the normal operation after the compressor startup.

Booster chopper circuit

Function of main parts

It improves power factor. It rectifies AC and controls its voltage.

4-10-2. Outline of main power supply circuit

1. At the start of operation

Main power supply circuit is formed when X64 (Relay) is turned ON at compressor startup. To prevent rush current from running into the circuit when power supply is turned ON, R64A and R64B (Current-limitting resistor) are placed in sub circuit.

2. At normal operation

1 When AC runs into POWER P.C. board, its external noise is eliminated in the noise filter circuit. 2 After noise is eliminated from AC, it is rectified to DC by DB61 (Diode module). 3 DC voltage, to which AC has been rectified by process 2, is stabilized by C62A, C62B and C61B (Smoothing capacitor) and supplied to IPM (INTELLIGENT POWER MODULE). 4 DC voltage, which has been stabilized in process 3, is converted to three-phase AC by IPM and supplied to compressor. 5 CT761 and CT781 (Current Transformer), which are placed in the power supply circuit to compressor, are used to measure the value of phase current and locate the polar direction of rotor with algorithm. PWM (Pulse width modulation) controls impressed voltage and frequency with those information.

4-10-1. Inverter main power supply circuit

49

4. Intelligent power module

IPM consists of the following components

· IGBT (x6) : Converts DC waveform to three-phase AC waveform and outputs it.

· Drive Circuit : Drives transistors.

· Protection circuit : Protects transistors from overcurrent. Since the above components are all integrated in IPM, IPM has a merit to make the control circuit simplify and miniaturize.

5. Smoothing capacitor

C62A, C62B and C61B stabilize the DC voltage and supply it to IPM.

6. Elimination of electrical noice

Noise filter circuit, which is formed by *CMC COILS capacitors placed on the POWER P.C. board, eliminates electrical

noise of AC power that is supplied to main power supply circuit. And this circuit prevents the electrical noise generated in the inverter circuit from leaking out. *CMC COILS; Common mode choke coils

Outline of simple partial switching method

In conventional inverter models, diode module rectifies AC voltage to DC voltage, smoothing capacitor makes its DC waveform

smooth, and IPM converts its DC voltage to imitated AC voltage again in order to drive the compressor motor.

However, it has been difficult to meet IEC harmonic current emission standard by above circuit because harmonic gets generated in the input current waveform and power factor gets down. The simple partial switching method with PAM, which has been adopted this time, places and utilizes the booster chopper circuit (L61, DB65 and TR821) before rectifying AC voltage in the general passive-method converter circuit. As harmonic gets suppressed and the peak of waveform gets lower by adding booster chopper circuit as mentioned above and by synchronizing the timing of one-time switching with the zero-cross point of

waveform, the input current waveform can be improved and the requirement of IEC harmonic current emission standard can be satisfied. Since the switching times is just once by synchronizing with the zero cross point, this simple partial switching method has the feature of lower energy loss compared to active filter method. In addition, output and efficiency is enhanced by

combining with vector-controlled inverter in order to boost the voltage of power supplied to IPM.

Input current waveform without PAM Input current waveform with PAM

Due to the time of no electricity;

· Power factor gets worse.

· Harmonic gets increased.

Input voltage

Release of energy stored in L

Energized time is extended by optimization of L inductance.

Peak gets down.

Energized time is short in case L inductance is small.

No electricity runs into diode module because the voltage at both sides of smoothing capacitor is higher than input voltage.

Compulsory energizing by switching.

Input current

Owing to the increase of energized time;

· Power factor gets better.

· Harmonic gets suppressed.

3. Purpose of PAM adoption

PAM : Pulse Amplitude Modulation

PAM has been adopted for the efficiency improvement and the adaptation to IEC harmonic current emission standard.

4-10-3. Sine wave control

In these air conditioners, compressor equips brushless DC motor which doesn't have Hall element. In short, the motor is sensorless. However, it's necessary to locate the polar direction of rotor in order to drive brushless DC

motor efficiently. The general detection method of the polar direction for such a DC motor is to locate it from the voltage induced by unenergized stator.

Therefore, It is necessary to have a certain period of time in which the stator is being unenergized for the rotor position detection when the voltage of supplied power is impressed. So the motor has been driven by square wave control (the conventional motor drive system) which energizes the motor only

when the range of electrical angle is within 120_ because it is forced to be unenergized within 30_ at start & end of one heap in one waveform cycle (180_) when the voltage is impressed.

However, torque pulsation occurs at rotation in this method when the current-carrying phases are switched over to other phases in sequence. Therefore, sine wave control system is adopted for these air conditioners because it can make the phase-to-phase current waveform smoother (sine wave) in order to drive the motor more efficiently and smoothly.

50

1hour

Time

Maximum frequency

Upper limit frequency

Rated frequency or less

4-11. OPERATIONAL FREQUENCY CONTROL OF OUTDOOR UNIT

Rotor

Rotor Position Signal

Permanent magnet is embedded. Necessary

DC Motor

Excited by magnetic field of stator Unnecessary

AC Motor

4-10-4. Characteristics of sine wave control in case of brushless DC motor

● Although ordinary three-phase induction motor requires energy to excite the magnetic field of rotor, brushless DC motor

doesn't need it. So, higher efficiency and torque are provided.

● This control provides the most efficient waveform corresponding to the rotation times of compressor motor.

● The rotation can be set to higher compared to the conventional motor drive system. So, the time in which air conditioner

can be operated with energy saved is longer than conventional models. This can save annual electric consumption.

● Compared to square wave control, the torque pulsation is reduced at rotation so that the motor operates more quietly.

● Since response and efficiency of motor are enhanced in sine wave control, finer adjustment can be provided.

w In brushless DC motor, permanent magnet is embedded in the rotor. Therefore, it doesn't require energy to excite the rotor

like AC motor does. However, it's necessary to control the frequency of three-phase AC current supplied to the stator according to the polar direction of magnet embedded in the rotor so as to drive the motor efficiently. Controlling three-phase AC current frequency also means controlling the timing to switch the polarity of stator. Therefore, the polar direction of rotor needs to be detected.

4-10-5. Control Method of Rotation Times

Sine wave control makes the current transformers conduct real time detection of the value of the current running into the motor, locates the rotor position from the detected value, and decides if voltage should be impressed and if frequency should be chan ged. Compared to the conventional control and rotor position detection method, sine wave control can provide finer adjustment of the voltage of supplied power. The value of the current running into the motor is determined by each motor characteristic.

1. Outline The operational frequency is as following: First, the target operational frequency is set based on the difference between the room temperature and the set temperature. Second, the target operational frequency is regulated by discharge temperature protection, high pressure protection, electric current protection and overload protection and also by the maximum/minimum frequency.

2. Maximum/minimum frequency in each operation mode.

COOL

Applied

model

MUZ-CA25VB

MUZ-CA35VB

Minimum frequency

30

30 69

Rated frequency

57

Maximum frequency

87

84

Minimum frequency

40

30

HEAT

Rated frequency

75 98

76 98 30

Maximum frequency

w The operation frequency in COOL mode is restricted the upper limit frequency after 1 hour as shown below for dew

prevention. It is rated frequency or less.

51

DRY

30

4-12. EXPANSION VALVE CONTROL (LEV CONTROL)

(1) Outline of LEV control The LEV basic control is comprised of setting LEV opening degree to the standard opening degrees set for each opera-

tional frequency of the compressor. However, when any change in indoor/outdoor temperatures or other factors cause air conditioning load fluctuation, the LEV control also works to correct LEV opening degree based on discharge temperature (Shell temperature) of the compressor, developing the unit’s performance.

Control range from minimum 33 pulse to maximum 500 pulse. Actuating speed LEV opens 40 pulse/second and close 90 pulse/second Opening degree adjustment LEV opening degree is always adjusted in opening direction.

standard

specification

Unit OFF LEV remains at maximum opening degree (reaches maxi-

Remote controller ON LEV is positioned. (first full-closed at zero pulse and then

During 2 to 13 minutes after compressor starts LEV is fixed to standard opening degree according to opera-

(When reducing the opening degree, LEV is once overclosed, and then adjusted to the proper degree by opening.

mum opening degree approximate in 15 minutes after compressor stops)

positioned.)

tional frequency of compressor.

More than 13 minutes have passed since compressor start-up

general operation

Thermostat OFF LEV is adjusted to exclusive opening degree for thermostat

Thermostat ON LEV is controlled in the same way as that after the compres-

Defrosting in HEAT mode LEV is adjusted to open 500 pulse.

LEV opening degree is corrected to get target discharge temperature of compressor. (For discharge temperature lower than target temperature, LEV is corrected in closing direction.) (For discharge temperature higher than target temperature, LEV is corrected in opening direction.) wIt may take more than 30 minutes to reach target temperature, depending on operating conditions.

OFF.

sor has started up.

52

(2) Time chart

OFF Time

Time

ON

Operational frequency

of the compressor

Commanded to open

Standard opening degree

Opening degree is corrected according to discharge temperature.

Positioning

Air conditioner ON

Air conditioner OFF (thermostat off)

LEV opening degree

about 15 minutes 06 05 04 03 02

01

LEV opening degree

A(target discharge temperature)

B

C

D

E

F

30 50 70

Operational frequency of the compressor

90 110 130

(Hz)

(3) Control data

(a) Reference value of target discharge temperature

(COOL/HEAT :)

Applied model

MUZ-CA25VB

MUZ-CA35VB

Applied model

In COOL operation, the two indoor coil thermistors (one main and one sub) sense temperature ununiformity (super heat) at the heat exchanger, and when temperature difference have developed, the indoor coil thermistors adjust LEV opening degree to get approximate 10 degrees lower temperature than the target temperature in the table above, thus diminishing super heat.

(b) Reference value of LEV standard opening degree

A

50/46B54/53C60/58

57/45

57/53 63/59

(COOL/ HEAT pulse)

01

02

MUZ-CA25VB

MUZ-CA35VB

110/80

150/90

120/12003130/16004220/19005280/20006280/200

170/130 180/140

D

64/63

67/65

260/200

E

67/68F67/72

67/69 67/72

280/210

53

5

MSZ-FA MICROPROCESSOR CONTROL

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

WIRELESS REMOTE CONTROLLER

Signal transmitting section

Operation display section

OPERATE/STOP (ON/OFF) button

Temperature buttons

Indication of remote controller model

(This diagram shows an overall view.)

WIDE VANE button (Vertical vane button)

FAN SPEED CONTROL button

OPERATION SELECT button

ECONO COOL button

PLASMA button

AREA button

i-see button

RESET button

OFF-TIMER button

ON-TIMER button

TIME SET buttons FORWARD button BACKWARD button

CLOCK SET button

VANE CONTROL button (Horizontal vane button)

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.

54

5-1. COOL ( ) OPERATION

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

POWER 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

Difference between room

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 : -1.0 : or more··············································ON Room temperature minus set temperature : less than -1.0 :············································OFF

2. Indoor fan speed control

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

Initial temperature difference

Fan speed

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

3. Coil frost prevention

Temperature control When indoor coil thermistor detects following temperature for 90 seconds, operational frequency of compressor is controlled according to the following table.

temperature and set temperature during operation.

Difference between room temperature and set temperature during operation

Set temperature

-1.0 :

-0.7 :

3 :

1.7 :

1 :

Temperature of indoor coil thermistor

10°C or more

Operation frequency

Normal (variable)

8°C to 10°C Raise 6 Hz

6°C to 8°C 3°C to 6°C

Fixed

Lower 3Hz Lower 6Hz

3°C or less

when temperature of indoor coil thermistor continues 3°C or less

Compressor is turned OFF for 5 minutes

for 5 minutes or more.

The indoor fan maintains the actual speed of the moment.

4. Low outside temperature operation

If the outside temperature falls to 18°C or less during operation in COOL mode, the unit enters the low outside temperature operation mode.

<Operation> (1) If the unit enters the low outside temperature operation mode, the outside fan rotation speed gets slow down. (2) Even when the unit is in the "thermostat-off" status under the low outside temperature operation mode, the outside fan

rotation does not stop.

(3) In this mode to detect the exact outside temperature the compressor turns OFF with the outdoor fan ON for 3 minutes

once 1 hour; if the outside temperature rises over 18°C, the unit goes back to the normal COOL mode, and if the outside temperature is still 18°C or less, the unit stays in the low outside temperature operation mode.

(4) Dew drop prevention

When the ambient temperature thermistor RT65 reads -12: or less, as coil frost or dew drop from indoor unit may occur, the compressor turns OFF with the outdoor fan ON for prevention of them.

WOther protections work as well as in the normal COOL mode.

55

5-2. DRY ( ) OPERATION

35

30

25

20

15

10

:

10 15 20 25 30 35

Set temperature

Initial room temperature

Set temperature and initial room temperature in dry mode

:

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

POWER 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 temperature and determines

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

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. Thermostat control

Thermostat is ON or OFF by difference between room temperature and set temperature. Room temperature minus set temperature : -1.0 : or more················································ON

Room temperature minus set temperature : less than -1.0 :··············································OFF

2. Indoor fan speed control

Indoor fan operates at the set speed by FAN SPEED CONTROL button. When thermostat OFF (compressor OFF) fan speed becomes Very Low.

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 : Room temperature minus set temperature : less than 1 : ········································Low

3. Coil frost prevention

Coil frost prevention is as same as COOL mode. (5-1.3.) The indoor fan maintains the actual speed of the moment.

4. Low outside temperature operation

Low outside temperature operation is as same as COOL mode. (5-1.4.)

5-3. HEAT ( ) OPERATION

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

POWER lamp of the indoor unit turns on with a beep tone. (2) Select HEAT 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 : less than 2.0 :···············································ON Room temperature minus set temperature : 2.0 : or more·················································OFF

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: 2 :or more Set temperature minus room temperature: Set temperature minus room temperature: less than 0.2

(2) Cold air prevention control

1 When the compressor is not operating,

(1) if the temperature of room temperature thermistor RT11 is less than 19°C, the fan stops.

(2) if the temperature of room temperature thermistor RT11 is 19°C or more and

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

2 When the compressor is operating,

(1) if the temperature of RT12 is 40°C or more, the fan operates at set speed. (2) if the temperature of RT12 is less than 40°C and

(1) if heating operation starts after defrosting, the fan stops. (2) if the temperature of room temperature thermistor RT11 is 19°C or less, the fan stops. (3) if the temperature of room temperature thermistor RT11 is more than 19°C, the fan operates at Very Low.

NOTE : When 3 minutes have passed since the compressor started operation, this control is released regardless of the

temperature of RT11 and RT12.

Initial temperature difference Thermostat

Initial temperature difference

··································

Fan speed

Med.

Initial temperature difference Thermostat

Initial temperature difference

Fan speed

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

Between 0.2 and 2 : ·································

:··············································

Med. Low

56

Difference between room temperature and set temperature during operation

Set temperature

-1.0 :

-0.7 :

Difference between room temperature and set temperature during operation

2.5 :

1.7 :

1 :

Difference between room temperature and set temperature during operation

Set temperature

1.7 :

2.0 :

Difference between room temperature and set temperature during operation

2 :

4 :

0.2 :

1.7 :

3. High pressure protection

In HEAT operation the indoor coil thermistor detects the temperature of the indoor heat exchanger. The compressor operational frequency is controlled to prevent the condensing pressure from increasing excessively.

4. Overload starting

When the room temperature thermistor RT11 reads 18°C or more, the compressor runs with its maximum frequency regulated for 10 minutes after the start-up.

5. Defrosting

(1) Starting conditions of defrosting

When the following conditions a) ~ c) are satisfied, the defrosting starts. a) The defrost thermistor reads -3°C or less. b) The cumulative operation time of the compressor has reached any of the set valuesw (30, 35, 40, 45, 55, 65, 75, 85,

95, 105, 115, 125, 150 minutes). c) More than 5 minutes have passed since the start-up of the compressor. w Set value of compressor operation time(hereinafter referred to as defrost interval)

This is decided by the temperature of defrost thermistor and ambient temperature thermistor, the previous defrosting

time. For example, the first defrost interval is 40 minutes long, and the second is 45 minutes long. The third and sub-

sequent intervals are set to be longer, and less frequent, depending on defrosting time.

The third and subsequent defrost intervals follow any of the three patterns …5 or 10 to 20 minutes longer, the same,

or 5 or 10 to 20 minutes shorter compared with the previous defrost interval … with the longest 150 minutes and the

shortest 30 minutes.

(2) Releasing conditions of defrosting

Defrosting is released when any of the following conditions is satisfied: a) The defrost thermistor continues to read 5°C or more (MUZ-FA25VA) / 8°C or more (MUZ-FA25VAH) / 10°C or more

(MUZ-FA35VA) / 13°Cw1or 10°Cw2or more (MUZ-FA35VAH) for 30 seconds.

w1 13°C (Serial No: ~6002550) w2 10°C (Serial No: 6002551~)

b) Defrosting time has exceeded 10 minutes. c) Any other mode than HEAT mode is set during defrosting.

6. Defrost heater (MUZ-FA25/ FA35VAH)

(1) Starting conditions

When all of the following conditions a) ~ d) are satisfied, defrost heater turns ON to prevent ice from foaming on the base of outdoor unit. a) HEAT mode is selected. b) The ambient temperature thermistor RT65 reads 5: or less for 5 minutes continuously. (NOTE 1). c) The defrost thermistor RT61 reads -1: or less for 5 minutes continuously. d) Outdoor fan motor is turned ON.

(2) Releasing conditions

When any of the following conditions is satisfied, defrost heater turns OFF. a) Any other mode than HEAT mode is selected. (NOTE 2). b) The ambient temperature thermistor RT65 reads 8: or more for 5 minutes continuously. (NOTE 1). c) The defrost thermistor RT61 reads more than 15: for 5 minutes continuously. d) Outdoor fan motor is turned OFF.

NOTE1 : Ambient temperature thermistor RT65.

5: 8:

Defrost heater ON

OFF

NOTE2 : During defrosting operation defrost heater continues to be ON.

57

Time chart of defrosting in HEAT mode (reverse type)

set position

set speed

set position

set speed

Indoor fan

Compressor normal

Outdoor fan

R.V. coil

(21S4)

OFF (COOL)

OFF

Maximum frequency

horizontal

Horizontal vane

Very Low (temperature of indoor coil thermistor > 18:)

30

seconds

30

seconds

30

seconds

40

seconds

5 seconds 5 seconds

40

seconds

OFF

ON (HEAT)

ON ON

ON (HEAT)

5-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION

1. Mode selection

Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.

(1) Initial mode

At first indoor unit operates only indoor fan with outdoor unit OFF for 3 minutes to detect present room temperature. Following the conditions below, operation mode is selected.

1 If the room temperature thermistor RT11 reads more than set temperature, COOL mode is selected. 2 If the room temperature thermistor RT11 reads set temperature or less, HEAT mode is selected.

(2) Mode change

In case of the following conditions the operation mode is changed. 1 COOL mode changes to HEAT mode when 15 minutes have passed with the room temperature 2 degrees below the

set temperature.

2 HEAT mode changes to COOL mode when 15 minutes have passed with the room temperature 2 degrees above the

set temperature. In the other cases than the above conditions, the present operation mode is continued. NOTE1: Mode selection is performed when multi standby (refer to NOTE2) is released and the unit starts operation with

ON-timer.

NOTE2: If two or more indoor units are operating in multi system, there might be a case that the indoor unit, which is

operating in AUTO ( ), cannot change over the other operating mode (COOL HEAT) and becomes a state of standby.

(3) Indoor fan control/ Vane control

As the indoor fan speed and the horizontal vane position depend on the selected operation mode, when the operation mode changes over, they change to the exclusive ones.

58

5-5. INDOOR FAN MOTOR CONTROL

COOL

Fan speed

Up

Down

Up

Down

Mode

HEAT

Compressor frequency

MUZ-FA25 MUZ-FA35

43Hz 33Hz 43Hz 33Hz

54Hz 41Hz 54Hz 41Hz

Up

Down

Fan speed

High

Low

Compressor frequency

Min.

Max.

(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 (Super High, High, Med., Low), the microprocessor 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

Super High

High

Med.

Low

Super High

(2) Fan motor lock-up protection

time

When the rotational frequency feedback signal has not output for 12 seconds, (or when the microprocessor cannot detect the signal for 12 seconds) energizing to the fan motor is stopped. Then the microprocessor retries detection 3 times every 30 seconds. If the microprocessor still cannot detect the signal, the fan motor is regarded locked-up. When the fan motor lock-up, POWER lamp flashes on and off to show the fan motor abnormality.

5-6. OUTDOOR FAN MOTOR CONTROL

Fan speed is switched according to the compressor frequency.

5-7. AUTO VANE OPERATION

1. Horizontal vane

(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 changes as follows by pressing VANE CONTROL button.

(3) Positioning

The vane is once pressed to the vane stopper 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 operation starts or finishes (including timer operation). (b) When the test run starts. (c) When multi-standby starts or finishes.

59

(4) VANE AUTO ( ) mode

Horizontal

position

The air conditioner starts heating operation approx. 3 minutes after the vane has moved to the horizontal position.

• Sometimes the area around your feet may not warm. To warn the area around the feet, set the horizontal vane to (AUTO) or the downwardblowing position.

• When VANE CONTROL button is pressed again, the vane returns to the previously-set position and the air conditioner starts the heating operation in approx. 3minutes.

To change the air

flow direction

When to use this function?

Use this function if you don’t want the air from the indoor unit to blow directly onto your body.

• Depending on the shape of the room,the air may blow directly onto your body.

• Press VANE CONTROL button again to return the

vane to the previously-set position.

The air conditioner starts the cooling or drying operation approx. 3 minutes after the vane has moved to the horizontal position.

•

Pressing and holding VANE CONTROL

button for 2 seconds

or more causes the horizontal vane to reverse and move to horizontal position.

COOL/DRY

HEAT

NOTE:

• If you make the air flow not to blow directly onto your body by pressing VANE CONTROL button, the compressor stops for 3 minutes even during the operation of the air conditioner.

• The air conditioner operates with decreased air flow until the compressor turns on again.

(9) To change the air flow direction not to blow directly onto your body.

Horizontal

position

When VANE CONTROL button is pressed again, the vane returns to the previously-set position and the air conditioner starts the cooling or drying operation in approx. 3minutes.

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

COOL and DRY operation Vane angle is fixed to Horizontal position.

HEAT 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 with the vane angle at Angle 2 ~ 4 when the compressor cumulative operation time exceeds 1 hour, the vane angle automatically changes to Angle 1 for dew prevention.

(7) SWING MODE ( )

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

(8) Cold air prevention in HEAT operation.

When any of the following conditions occurs in HEAT operation, the vane angle changes to Horizontal position 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 39:. ⑤ For about 3 minutes after compressor starts.

NOTE : When 2 or more indoor units are operated with multi outdoor unit, even if any indoor unit turns thermostat off,

this control doesn’t work in the indoor unit.

60

(

(SWING)

1

23

45

10

) 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(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 ECONO COOL button is pressed once again or VANE CONTROL button is pressed or change to other operation mode.

<SWING operation> 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 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 indoor

coil thermistor RT12

A B C 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

(second)

2 5

8 11 14 17 20 23

Horizontal blow time

(second)

23 20 17 14 11

8 5 2

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 (approximate 12V) transmitted from microprocessor.

(2) The vertical vane angle and mode change as follows by pressing WIDE VANE 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 OPERATE/STOP(ON/OFF) button is pressed (POWER ON). (b) When SWING is started.

(4) SWING MODE ( )

By selecting SWING mode with WIDE VANE button, the vertical vane swings horizontally. The remote controller displays “”. Swing mode is cancelled when WIDE MODE button is pressed once again.

5-8. i-see CONTROL OPERATION

The sensors constantly measure the room and floor/wall temperatures to automatically adjust to the set temperature by estimating the temperature actually perceived by a person inside the room (“sensory temperature”).

Advantages

· The air inside the room is conditioned quickly to a comfortable condition.

· The room will not become too cold or hot even when the air conditioner is kept on for a long period.

· The air conditioner will not overcool or overheat, which means you can save on electricity.

i-see control operation is activated when i-see button is pressed with a thin stick in manual COOL or manual HEAT mode.

NOTE :

i-see control operation is activated when the remote controller is first used following replacement of the batteries or resetting of the remote controller.

i-see control operation is cancelled when i-see button is pressed with a thin stick once again.

NOTE :

If the conditioner is turned OFF without cancelling i-see control operation, i-see control operation is activated the next time the air conditioner is turned ON.

61

i-see Sensor

(1) Press OPERATE / STOP (ON/ OFF)button to start the air conditioner. (2) Press i-see button. (NOTE 1) (3) Press AREA button.

Each time the button is pressed, the area is changed in sequence:

NOTE1: AREA setting is only available during i-see control operation. NOTE2: If AREA setting is canceled, the vertical vane returns to the previously set position before AREA setting. NOTE3: The horizontal air flow direction (WIDE VANE button), including horizontal SWING, cannot be set during AREA setting.

(AUTO) (LEFT) (RIGHT) Cancel

The indoor unit delivers warm air detecting the cold area in the room.

· If AREA setting is set to AUTO in heating operation, the indoor unit automatically delivers warm air to the area where the floor/wall temperature is the lowest in the room.

· If AREA setting is set to AUTO in cooling operation, the indoor unit automatically delivers cool air to the area where the floor/wall temperature is the highest in the room.

Ex.) In heating operation

Moving of horiz

ontal air flow direction

Indoor unit

display

NOTE

· The horizontal air flow direction changes if i-see Sensor detects approx. 3; temperature difference.

· In AUTO of AREA setting, both right and left lamps are lighted when the room is evenly air-conditioned.

Indication of AREA setting

Day

Night

Warm area Cold area

Lighted Not lighted

i-see Sensor moves intermittently, measuring the floor and wall temperature.

i-see Sensor, which is installed on the right side of the air outlet of the indoor unit, is moved with the stepping motor and it

detects the floor/ wall temperature.

i-see Sensor is installed here.

Enlarged view of i-see Sensor

i-see Sensor

When AREA setting is not activated, the sensing range of i-see Sensor differs depending on the installation

·

location of the air conditioner.

Installation

position

Image of sensing

range

Direction of sensor

Refer to the description on service manual OB371 (8-4. Remote controller) for slide switch settinng.

Installed at left Installed at center Installed at right

Right Center Left

· Install the front panel correctly after being removed for maintenance or service so that the

floor/wall temperatures can be measured correctly.

5-9. AREA ( ) SETTING

62

(4) AREA setting is cancelled when the "cancel" is sellected by pressing AREA button, or when WIDE VANE button is pressed.

Indoor unit installation location and air-conditioning area

Installed at left Installed at center Installed at right

LEFT RIGHT LEFT RIGHT LEFT RIGHT

· Be sure to set the slide switch inside the remote controller to an appropriate position in accordance with the installed position of the indoor unit. If the switch is not set correctly, the air conditioner may not function properly.

(Refer to Service manual OB371 8-4.)

To air-condition mainly the left area of the room

AREA

Press AREA button to select LEFT.

Remote controller button

Remote controller display

i-see Sensor operation

Control range of horizontal air flow direction. The vertical air flow direction conforms to the setting on the remote controller. (The horizontal air flow direction is controlled in this range.)

Indoor unit display

NOTE: If the AREA setting is activated (AUTO), i-see Sensor moves in a range of 150 degrees detecting

floor/wall temperature of 3 area (left, right, center). Therefore, the detected temperatures may be different from the temperatures measured on commercial thermometers depending on the condition or temperature distribution on the floor and/or wall.

Installed at center

Installed at left

Installed at right

To air-condition the entire room The horizontal air flow direction and indoor unit display are switched according to the room temperature (floor/wall).

Press AREA button to select AUTO.

or

Operation and operating range

i-see sensor moves 30 degrees from the center in both right and left side.

To air-condition mainly the right area of the room

Press AREA button to select RIGHT.

Approx. 150 degrees

i-see Sensor turning to the left i-see Sensor operates as follows in accordance with AREAsetting made with the remote controller.

“AUTO” in AREAsetting; first turning to the LEFT for adjusting the position then.....

CENTER RIGHT CENTER LEFT CENTER......

(The sensor turns to the right, left and center.)

“RIGHT” in AREAsetting; first turning to the LEFT for adjusting the position then....

CENTER RIGHT CENTER RIGHT CENTER......

(The sensor turns to the right and center.)

“LEFT” in AREAsetting; first turning to the LEFT for adjusting the position then....

CENTER LEFT CENTER LEFT CENTER......

(The sensor turns to the left and center.)

The sensor finishes turning to one area to another for 3 seconds and it operates one area for 5 seconds.

i-see Sensor turning to the center

63

i-see Sensor turning to the right

PLASMA/WASH lamp

Blinking Not lighted

Lighted

WASH reset switch

WASH

reset

E.O.

SW

Each time this b utton is pressed, the oper ation mode of PLASMA is changed in sequence:

Cancel (The sign of PLASMA oper ation disappears .)

PLASMA/WASH lamp tur ns on in the displa y section of the indoor unit and PLASMA DEODORIZING and/or PLASMA AIR PURIFYING unit is energyz ed. Adjust the air flow to your desired speed.

(1) Press OPERATE/STOP (ON/OFF) button to start the air conditioner. (2) Press PLASMA button to set PLASMA DUO operation.

(3) PLASMA operation is cancelled when the "cancel" is selected by pressing PLASMA button. Once PLASMA operation is selected, PLASMA operation will be performed every time the air conditioner is turned on until the "Cancel" is selected with PLASMA button.

5-10. PLASMA DUO ( ) OPERATION

● Never touch the PLASMA DEODORIZING/AIR PURIFYING filter units during the operation of the air conditioner. Although the filter units are safety-conscious design, touching the units could be the cause of trouble as they discharge high voltage electricity.

PLASMA/WASH lamp

Not lighted

Lighted

Description of PLASMA DUO operation:

< function>

Both PLASMA DEODORIZING and PLASMA AIR PURIFYING operation work.

<

function>

PLASMA DEODORIZING operation cleans the air inside the room by adsorbing and decomposing the particles of odor-releasing substances and gases such as formaldehyde.

<

function>

PLASMA AIR PURIFYING operation cleans the air inside the room by absorbing the particles of cigarette smoke or allergens such as pollens and house dust.

NOTE1: Carbon monoxide released from cigarettes cannot be removed by PLASMA operation. Open the windows to let the outside air in from time to time. NOTE2: During PLASMA operation, you may smell ozone that is generated in small quantities from PLASMA DEODORIZING/AIR PURIFYING filter units. This is not a malfunction. NOTE3: You may hear a small "hissing" sound during PLASMA operation. This is the sound of plasma discharge, and not a malfunction.

When PLASMA/WASH lamp is blinking, please clean PLASMA DEODORIZING/AIR PURIFYING filter units. After cleaning of PLASMA DEODORIZING/AIR PURIFYING filter units, press WASH reset switch. A short “beep” is heard and the blinks of PLASMA/WASH lamp will be cancelled.

64

START

STOP

START

STOP

5-11. AUTO FRONT PANEL

When the unit starts operating, the front panel opens automatically to draw in air. When the unit stops operating, the front panel closes automatically.

Open

Closed

Operation and operating range of the auto front panel

The front panel fully opens 10 mm or more upper than the level line of the top end of the nozzle assembly. It takes about 13 seconds to open the front panel completely.

10 mm or more

Z-Z Side view

5-12. 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.

ON timer setting

(1) Press ON-TIMER button( ) to set ON timer.

Each time the button is pressed, ON timer mode alternates between ON and OFF.

(2) Set the time of the timer using TIME SET buttons ( and ).

Each time FORWARD button( ) is pressed, the set time increases by 10 minutes; each time BACKWARD button ( ) is pressed, the set time decreases by 10 minutes.

OFF timer setting

(1) Press OFF-TIMER button ( ) to set OFF timer.

Each time the button is pressed, OFF timer mode alternates between ON and OFF.

(2) Set the time of the timer using TIME SET buttons ( and ).

Each time FORWARD button ( ) is pressed, the set time increases by 10 minutes; each time BACKWARD ( ) button is pressed, the set time decreases by 10 minutes.

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.

65

EMERGENCY OPERATION switch

WASH

reset

E.O.

SW

Operation mode COOL HEAT Set temperature

24:

24: Fan speed Medium Medium Horizontal vane Auto Auto Vertical vane Straight Straight

The operation mode is indicated by the Operation Indicator lamp on the indoor unit as following figure.

Operation Indicator lamp

NOTE: This is the indication of EMERGENCY OPERATION mode. AREA setting is not available during EMERGENCY OPERATION.

Press again <Heat>

Press once <Cool>

Lighted Not lighted

Press once again <Stop>

PROGRAM TIMER

• The OFF timer and ON timer can be used in combination. The timer of the set time that is reached first will operate first.

• “” and “” display shows the order of the OFF timer and the 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 : If the main power is turned off or a power failure occurs while AUTO START/STOP timer is active, the timer setting is

cancelled. As these models are equipped with an auto restart function, the air conditioner starts operating with timer cancelled when power is restored.

5-13. 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 the remote controller run down. The unit will start and AREAlamp 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 in ON). After 30 minutes of test run operation, the system shifts to EMERGENCY COOL / HEAT MODE with a set temperature of 24°C. The fan speed shifts to Med.. The coil frost prevention works even in emergency operation, and defrosting 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 or twice or the unit receives any signal from the remote controller. In case of latter, normal operation will start.

NOTE1 : Do not press EMERGENCY OPERATION switch during normal operation. NOTE2 : 3 seconds after EMERGENCY OPERATION switch is pressed, the front panel starts moving forward

automatically.

66

5-14. INVERTER SYSTEM CONTROL

POWER P.C. BOARD

Power supply

INVERTER P.C. BOARD

R64A R64B

CT

TR821

DB65

X64

L62 L63

C63A C63B C63C

DB61

L61

P

W

V

U

N

CT761

CT781

IPM

U

W

MC

V

+

Booster chopper circucuit

SYMBOL IPM C63A/C63B/C63C CT761/CT781

CT DB61 R64A, R64B

X64 DB65

TR821 L61

NAME INTELLIGENT POWER MODULE SMOOTHING CAPACITOR CURRENT TRANSFORMER

CURRENT TRANSFORMER DIODE MODULE CURRENT-LIMITING RESISTOR

RELAY DIODE MODULE

SWITCHING POWER TRANSISTOR REACTOR

FUNCTION It supplies three-phase AC power to compressor. It stabilizes the DC voltage. It measures the current of the compressor motor. It measures the value of current which is supplied to the main power supply circuit. It converts the AC voltage to DC voltage. It absorbs the rush current not to run into the main power supply circuit when the electricity turns ON. It short-circuits the resistance which restricts rush current during the normal operation after the compressor startup.

Booster chopper circuit

Function of main parts

It improves power factor. It rectifies AC and controls its voltage.

5-14-2. Outline of main power supply circuit

1. At the start of operation

Main power supply circuit is formed when X64 (Relay) is turned ON at compressor startup. To prevent rush current from running into the circuit when power supply is turned ON, R64A and R64B (Current-limitting resistor) are placed in sub circuit.

2. At normal operation

1 When AC runs into POWER P.C. board, its external noise is eliminated in the noise filter circuit. 2 After noise is eliminated from AC, it is rectified to DC by DB61 (Diode module). 3 DC voltage, to which AC has been rectified by process 2, is stabilized by C63A, C63B and C63C (Smoothing capacitor) and supplied to IPM (Intelligent power module). 4 DC voltage, which has been stabilized in process 3, is converted to three-phase AC by IPM and supplied to compressor. 5 CT761 and CT781 (Current Transformer), which are placed in the power supply circuit to compressor, are used to measure the value of phase current and locate the polar direction of rotor with algorithm. PWM (Pulse width modulation) controls impressed voltage and frequency with those information.

5-14-1. Inverter main power supply circuit

67

4. Intelligent power module

IPM consists of the following components

· IGBT (x6) : Converts DC waveform to three-phase AC waveform and outputs it.

· Drive Circuit : Drives transistors.

· Protection circuit : Protects transistors from overcurrent. Since the above components are all integrated in IPM, IPM has a merit to make the control circuit simplify and miniaturize.

5. Smoothing capacitor

C63A, C63B and C63C stabilize the DC voltage and supply it to IPM.

6. Elimination of electrical noice

Noise filter circuit, which is formed by *CMC COILS capacitors placed on the POWER P.C. board, eliminates electrical

noise of AC power that is supplied to main power supply circuit. And this circuit prevents the electrical noise generated in the inverter circuit from leaking out. *CMC COILS; Common mode choke coils

Outline of simple partial switching method

In conventional inverter models, diode module rectifies AC voltage to DC voltage, smoothing capacitor makes its DC waveform

smooth, and IPM converts its DC voltage to imitated AC voltage again in order to drive the compressor motor.

However, it has been difficult to meet IEC harmonic current emission standard by above circuit because harmonic gets generated in the input current waveform and power factor gets down. The simple partial switching method with PAM, which has been adopted this time, places and utilizes the booster chopper circuit (L61, DB65 and TR821) before rectifying AC voltage in the general passive-method converter circuit. As harmonic gets suppressed and the peak of waveform gets lower by adding booster chopper circuit as mentioned above and by synchronizing the timing of one-time switching with the zero-cross point of

waveform, the input current waveform can be improved and the requirement of IEC harmonic current emission standard can be satisfied. Since the switching times is just once by synchronizing with the zero cross point, this simple partial switching method has the feature of lower energy loss compared to active filter method. In addition, output and efficiency is enhanced by

combining with vector-controlled inverter in order to boost the voltage of power supplied to IPM.

Input current waveform without PAM Input current waveform with PAM

Due to the time of no electricity;

· Power factor gets worse.

· Harmonic gets increased.

Input voltage

Release of energy stored in L

Energized time is extended by optimization of L inductance.

Peak gets down.

Energized time is short in case L inductance is small.

No electricity runs into diode module because the voltage at both sides of smoothing capacitor is higher than input voltage.

Compulsory energizing by switching.

Input current

Owing to the increase of energized time;

· Power factor gets better.

· Harmonic gets suppressed.

3. Purpose of PAM adoption

PAM : Pulse Amplitude Modulation PAM has been adopted for the efficiency improvement and the adaptation to IEC harmonic current emission standard.

Sine wave control

In these air conditioners, compressor equips brushless DC motor which doesn't have Hall element. In short, the motor is sensorless. However, it's necessary to locate the polar direction of rotor in order to drive brushless DC

motor efficiently. The general detection method of the polar direction for such a DC motor is to locate it from the voltage induced by unenergized stator.

Therefore, It is necessary to have a certain period of time in which the stator is being unenergized for the rotor position detection when the voltage of supplied power is impressed. So the motor has been driven by square wave control (the conventional motor drive system) which energizes the motor only

when the range of electrical angle is within 120_ because it is forced to be unenergized within 30_ at start & end of one heap in one waveform cycle (180_) when the voltage is impressed.

However, torque pulsation occurs at rotation in this method when the current-carrying phases are switched over to other phases in sequence. Therefore, sine wave control system is adopted for these air conditioners because it can make the phase-to-phase current waveform smoother (sine wave) in order to drive the motor more efficiently and smoothly.

68

1 hour

Time

Maximum frequency

Upper limit frequency

Rated frequency or less

5-15. OPERATIONAL FREQUENCY CONTROL OF OUTDOOR UNIT

Rotor Rotor Position Signal

Permanent magnet is embedded. Necessary

DC Motor

Excited by magnetic field of stator Unnecessary

AC Motor

5-14-3. Characteristics of sine wave control in case of brushless DC motor