innovair Inverter FLEX24 DEV24H2R18, Service Manual

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3.4.2 “E3” Compressor Low-pressure Protection, Refrigerant Shortage
Protection, Refrigerant Recovery Mode
Error display: ODU mainboard LED displayer
Error judgment condition and method:
It is judged through the action of low pressure switch. If the low pressure switch is cut off, it is judged that low
pressure is too low and the system stops operation for protection.
Possible reason ：
Cut-off valve of ODU is not fully opened;
Low pressure sensor is abnormal;
Outdoor or indoor fan is not working properly;
IDU filter or air duct is blocked (cooling mode);
Ambient temperature is too low;
Refrigerant charging amount is insufficient;
System pipeline is blocked;
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SERVICE MANUAL