Midea AAC-18ISCH, Service Manual

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Service manual
35
11. Electronic function
11.1. Display board
1 22
3
4
5
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