Gree GWH18MC-K3DNA2G Service Manual page 57

(3) Malfunction of Overload Protection of Compressor (H3) and Discharge High-temperature Protection of Compressor (E4)
Main check point:
Whether the electronic expansion valve is connected well and whether it's damaged?
Whether the refrigerant is leaking?
Whether the overload protector is damaged?
Check flow chart:
No
Replace overload
protector
Remark:
Detection method for electronic expansion valve: There are 5 wires for the coil of electronic expansion valve and one of them are
common port (the left or the right wire) .The resistance for other terminals are all most the same (about 100Ω). You can measure
those resistance values to judge whether the electronic expansion valve is damaged or not.
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Start
Whether the overload protector is
connected?
Yes
Measure the resistance between both
ends of overload protector under
ambient temperature. Whether the
resistance <1KΩ?
Yes
Whether wire connection wire electronic
expansion valve is in good condition?
Yes
Check the coil of electronic
expansion valve. If it's
damaged, please replace it.
Is malfunction eliminated?
No
If the refrigerant is leaking,
please add refrigerant
according to Service Manual.
Is malfunction eliminated?
No
Replace main board of
outdoor unit
End
No
No
Yes
Yes
Installation and Maintenance
Service Manual
Connect wire
correctly according
to circuit diagram