Service manual 
35 
 
 
11. Electronic  function 
11.1. Display  board 
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22
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4
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6
 
11.1.1. AUTO indicator 
This indicator illuminates when the air conditioner is in AUTO operation. 
11.1.2. TIMER indicator 
This indicator illuminates when TIMER is set ON/OFF. 
11.1.3. PRE.-DEF. Indicator  (For Cooling & Heating models only) 
This indicator illuminates when the air conditioner starts defrosting automatically or when the warm 
air control feature is activated in heating mode. 
11.1.4. TEMPERATURE indicator 
Usually it displays the temperature settings. When change the setting temperature, this indicator 
begins to flash, and stops 20 seconds later.   
It displays the room temperature when the air conditioner is in FAN only operation.   
When the unit stops operation, it returns to original factory settings. 
Displays the malfunction code or protection code. 
11.1.5. OPERATION indicator   
This indicator flashes after power is on and illuminates when the unit is in operation. 
11.1.6. FREQUENCY indicator 
This indicator appears only when the compressor is in operation and indicates the current operating 
frequency. 
11.2. Protection 
11.2.1. 3 minutes delay at restart for compressor. 
11.2.2. Temperature  protection of compressor top, compressor stops when the temp. of top of 
compressor is more than 115℃, compressor runs when the temp. of top of compressor is less than 
100℃.   
11.2.3. Voltage protection, unit stop when the voltage is more than 260V and less than 175V. 
11.2.4. Inverter module Protection, Inverter module Protection itself has a protection function against 
current, voltage and temperature. 
11.2.5. Sensor protection at open circuit and breaking disconnection 
11.2.6. Fan Speed is out of control. When Indoor Fan Speed is too high(higher than 2100RPM)or too 
low(lower than 300RPM), the unit stops and LED displays failure information and can’t return  to 
normal operation automatically. 
11.2.7. Cross Zero signal error warning. If there is no Cross Zero signals in 4 minutes, the unit stops 
and LED displays failure information and can’t return to normal operation automatically. 
 
11.3. Fan-only  mode 
Fan speed is high/mid/low/ Auto 
11.4. Cooling  mode 
11.4.1. The 4-way valve is closed at cooling mode.   
11.4.2. The action of the compressor and the outdoor fan: 
 Condition 
T=Indoor Temp. 
Compressor Outdoor fan 
T> Ts+1  On  On Room temp. up 
T<Ts+1 Off Off 
T> Ts  On  On Room temp. down 
T<Ts Off Off