Gree GMV-VQ680WM/C-X Service Manual page 213

Gree
2.165 "U3" Power Phase-Sequence Protection
Fault display: main board of outdoor unit, wired controller of indoor unit and receiver of indoor unit
display
Fault diagnosis:
Check the three-phase power of the unit. If the power is connected incorrectly, thereby causing
phase loss or reverse phase, the unit generates a fault.
Possible causes:
■ The power is connected wrongly or phase loss or reverse phase occurs
■ Abnormal detection circuit
Troubleshooting:
"U3" Power Pha se-
Seq uence Protection
three-pha se power supply is
connected prope rly?
The detection circuit may
ope rate impro perly
2.166 "U4" Refrigerant Loss Protection
Fault display: main board of outdoor unit, wired controller of indoor unit and receiver of indoor unit
display
Fault diagnosis:
Check the high pressure and the low pressure of the unit by the pressure sensor. If the
temperatures corresponding to the high pressure and the low pressure of the unit are below the ambient
temperature for over 5, the unit will not start operation for safety purpose.
Possible causes:
■ Insufficient refrigerant in the unit;
■ The pipes leak.
Troubleshooting:
Whether th e
No
GMV6 HR DC Inverter VRF Units Service Manual
Yes
Replace th e main control
211
boa rd