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53 

In order to obtain appropriate operation characteristics, minimum 15 minutes or more operation time [testing 
operation (rated operation)] is required. 
1.  Method of rated operation (rated operation) 

For the models which have two buttons of “emergency operation and forced cooling operation”, press forced 
cooling button once. For the models which have only emergency operation button, press the button once for 5 
seconds and when hear “beep” sound, release the button. Then, cooling operation starts. 

2.  Checking the mal-functions of indoor / outdoor units 

1)  Any obstacles against heat release and air suction? (short circuit) 

(Forget to remove the outdoor unit cover or fallen leaves blocking the outdoor unit) 

2)  Are the indoor unit air filters clean? (obstructing heat suction) 
3)  Is the setting temperature on the remote controller correct? (is the setting temperature set at lower/higher 

than the room temperature?) 

 

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

H

eat

ex

chan

ge

r

H

eat

ex

chan

ge

r

Compressor

（

COMP）

4-way

valve

Condenser

（

COND）

Expansion

valve

Liquid side

2-way

valve

Gas side

3-way

valve

High temp
High pressure

Air

Mid temp /

High pressure

Liquid

Low
temp/
Pressure
liquid

Low temp
Low pressure

Air

Evaporator

（

EVA）

FM

Fan

Capillary tube

Indoor unit

Temp difference

Suction temp ＜Cooling＞

８

Release temp ＜Heating＞

１４

＊Measured after 15 mins with strong

fan operation

(Cooling)

Gas pressure

0.9～1.2MPa

Low temp /
Low pressure

Air

Low temp /
Low pressure

liquid

(Cooling

Heating

)

High temp /
High pressure

Air

Mid temp /
high pressure
liquid

Low temp /
Low pressure
Liquid

Low temp /
Low pressure
Air

Mid temp /

High temp

liquid

(Heating)

Gas pressure

2.2～ 3.0MPa

Release temp

Outdoor temp

Suction temp

Heat exchanger

temp

Heat exchanger

temp

High temp / high
pressure

Air

「

Indoor

「

」

Outdoor」

54 

1. Measuring 

temperature 

1)  Indoor unit suction temperature, release temperature, temperature difference, → Measure by thermometer 
2)  2-way valve pipe temperature in cooling mode is low temperature (benchmark：5 ~ 10°C), in heating mode 

is medium temperature (benchmark：25 ~ 35°C). 

3)  3-way valve pipe temperature in cooling mode is low temperature (benchmark：7 ~ 15°C) in heating mode is 

high temperature (benchmark：38 ~ 50°C). 

2.  Measuring electric current 

  Measuring electric current in operation → check by clump meter (refer to table of technical characteristic 

guideline) 

3. Meauring 

pressure 

  Measuring gas pressure → check the pressure by manifold gauge (refer to table of technical characteristic 

guideline) 

4.  Any sound from the expansion valve? 

(when starting the operation and the outdoor unit is turned on, the expansion valve is re-set, check if there is any 
edged sound or clack sound) 

Comparison with 
normal operation 

Cooling mode 

High Low 

Refrigerant 

pressure 

Excess insertion of refrigerant 

Clogged capillary, expansion valve malfunction 

Heat releasing obstruction 

Clog by moisture 

Dirty condenser, attachment of impurity 

Lack of refrigerant gas 

Compressor malfunction 

 

Operation electric 

current 

Excess insertion of refrigerant 

Lack of refrigerant gas 

Heat releasing obstruction 

Compressor malfunction 

Dirty condenser, impurity 

Mixture of air 

 (Insufficient 

evacuation) 

2-way valve 

temperature 

Excess insertion of refrigerant 

Clogged capillary, expansion valve malfunction 

Compressor malfunction 

Lack of refrigerant gas 

3-way valve 

temperature 

Lack of refrigerant gas • Compressor malfunction 

Excess insertion of refrigerant 

Clogged capillary, expansion valve malfunction 

 

 

Suction 

temperature 

& 

Release air 

temperature 

Temperature difference at or less than 8°C in cooling operation • • • Causes 

 

• Heat releasing obstruction 

  • Dirty condenser 

  • Attachment of impurity 

 

• Lack of refrigerant gas 

  • Excess insertion of refrigerant 

   

 

• Mixture of air 

  • Mixture of moisture 

   

 

• Clogged capillary 

  • Expansion valve malfunction 

  • Compressor malfunction 

 
◎ 

Above all are based on the condition that the installation work is properly performed (no issues in indoor / outdoor 
pipe connections, etc.) 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

55 

Inverter control, which equipped with a microcomputer in determining the most suitable operating mode as time 
passes, automatically adjusts output power for maximum comfort always. In order to achieve the suitable operating 
mode, the microcomputer maintains the set temperature by measuring the temperature of the environment and 
performing temperature shifting. The compressor at outdoor unit is operating following the frequency instructed by 
the microcomputer at indoor unit that judging the condition according to internal setting temperature and intake air 
temperature. 

Once the operation starts, remote control setting temperature will be taken as base value for temperature shifting 
processes. These shifting processes are depending on the air conditioner settings and the operation environment. 
The final shifted value will be used as internal setting temperature and it is updated continuously whenever the 
electrical power is supplied to the unit. 
 

 

  Compressor is OFF when Intake Air Temperature - Internal Setting Temperature < -2.0°C continue for 3 minutes. 

  Compressor is ON after waiting for 3 minutes, if the Intake Air Temperature - Internal Setting Temperature > 

Compressor OFF point. 

  Compressor is OFF when Intake Air Temperature - Internal Setting Temperate < -2.0°C continue for 3 minutes. 

  Compressor is ON after waiting for 3 minutes, if the Intake Air Temperature - Internal Setting Temperature > 

Compressor OFF point. 

 
 
 

56 

  Compressor is OFF when Intake Air Temperature - Internal Setting Temperate > +2.0°C. 

  Compressor is ON after waiting for 3 minutes, if the Intake Air Temperature - Internal Setting Temperature < 

Compressor OFF point. 

  This mode can be set using remote control and the operation is decided by remote control setting temperature, 

remote control operation mode and indoor intake air temperature. 

  During operation mode judgment, indoor fan motor (with speed of Lo-) is running for 30 seconds to detect the 

indoor intake air temperature. 

  Every 10 minutes, the indoor temperature is judged. 

  For the 1st judgment 

o  If indoor intake temperature - remote control setting temperature ≥ 2°C, COOL mode is decided. 
o If 

-2°C 

≤ indoor intake temperature - remote control setting temperature < 2°C, DRY mode is decided. 

o  If indoor intake temperature - remote control setting temperature < -2°C, HEAT mode is decided. 

 

 

 

  For the 2nd judgment onwards 

o  If indoor intake temperature - remote control setting temperature ≥ 3°C, if previous operate in DRY mode, 

then continue in DRY mode. otherwise COOL mode is decided. 

o If 

-2°C 

≤ indoor intake temperature - remote control setting temperature < 3°C, maintain with previous mode. 

o  If indoor intake temperature - remote control setting temperature < -2°C, HEAT mode is decided. 

 

 

A. Basic Rotation Speed (rpm) 
i. Manual Fan Speed 
[Cooling, Dry] 

  Fan motor’s number of rotation is determined according to remote control setting. 

 

Remote 

Control 

O O O O O 

Tab (rpm) 

Hi 

Me+ 

Me 

Me- 

Lo 

 
[Heating] 

  Fan motor’s number of rotation is determined according to remote control setting. 

 

Remote 

Control 

O O O O O 

Tab (rpm) 

Shi 

Me+ 

Me 

Me- 

Lo 

 
ii. Auto Fan Speed 
[Cooling, Dry] 

  According to room temperature and setting temperature, indoor fan speed is determined automatically. 

 
 
 
 
 

Cool
/Dry

Maintain

current mode

Heat

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6