Gree GMV5E Series Service Manual page 238

GREE
2.2.4.140 "UE" auto charging of refrigerant is invalid
Error display: ODU mainboard, IDU wired controller and IDU receive light board will
display
Error judgment condition and method:
When outdoor ambient temperature exceeds the temperature range of auto charging of refrigerant
(normal temperature range is 0~40 °C ), the unit will report this error.
Possible reason：——
Troubleshooting:
Cancel auto charging of refrigerant and change to manual charging of refrigerant.
2.2.4.141 Poor cooling and heating performances
Error judgment condition and method:
1. When electronic expansion valve is opened to 2000PLS in cooling operation of IDU and IDU coil
outlet pipe temperature is 5 °C higher than inlet pipe temperature;
2. When electronic expansion valve is opened to 2PLS in heating operation of IDU and IDU coil
outlet pipe temperature is 12 ° C lower than saturated temperature corresponding to high
pressure;
Possible reason:
■ODU cut-off valve is opened to the max flow without following the requirement.
■System pipeline is blocked.
■Operation environment exceeds the range.
■Flow organization design is not good.
■Refrigerant charging amount is insufficient.
GMV5E DC INVERTER VRF UNITS SERVICE MANUAL
234