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17. Troubleshooting Guide 
17.1  Refrigeration Cycle System 
In order to diagnose malfunctions, make sure that there are no 
electrical problems before inspecting the refrigeration cycle. 
Such problems include insufficient insulation, problem with the 
power source, malfunction of a compressor and a fan. 
The normal outlet air temperature and pressure of the refrigeration 
cycle depends on various conditions, the standard values for them 
are shown in the table on the right. 
 
 
 
 
Value of electric
current during operation
Difference in the intake
and outlet
air temperatures
Lower than specified
Higher than specified
Cooling Mode
Heating Mode
High
Low
Low
Low
Low
Low
Gas side
pressure
Dusty condenser
preventing heat radiation
●  Measuring electric current
 during operation
●  Measuring gas side pressure
Excessive amount
of refrigerant
Inefficient compressor
Insufficient refrigerant
Insufficient refrigerant
Inefficient compressor
Clogged strainer or
expansion valve
Clogged strainer, expansion 
valve or capillary tube
Less than 8°C at the cooling mode.
Less than 14°C at the cooling mode.
More than 8°C
(15 minutes after an
operation is started.)
at cooling mode.
Above 14°C 
(15 minutes after an
operation is started.)
at heating mode  
Normal
●  Measuring the air temperature
 difference
 
 
 
 
 
 
Normal Pressure and Outlet Air Temperature (Standard)
 
Gas pressure 
MPa 
(kg/cm
2
G) 
Outlet air 
temperature 
(°C) 
Cooling Mode 0.9 ~ 1.2 (9 ~ 12)  13 ~ 17 
Heating Mode 2.0 ~ 2.7 (20 ~ 27)  32 ~ 42 
*Condition:  • Indoor fan speed = High 
• Outdoor temperature 35°C at the cooling 
                      mode and 7°C at the heating mode 
                    • Compressor operates at rated frequency