Gree U-Match 5 Series - “PL” Bus Low-Voltage Protection; “PH” Bus High-Voltage Protection

GREE U-Match 5 SERIES UNIT SERVICE MANUAL
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3.4.34 “PL” Bus Low-Voltage Protection
Error display: ODU mainboard, IDU wired controller and IDU receiver light board will display PL
Error judgment condition and method:
When compressor is running and there is no other malfunction, if busbar voltage is lower than the set value
for low voltage protection, then it can be judged that bus low-voltage protection occurs. System will shut down for
protection.
Possible reason:
■Voltage of power grid is abnormal.
■Drive board busbar voltage sampling circuit element is damaged or drive board busbar voltage sampling AD
terminal is abnormal.
Troubleshooting：
PL Bus low-voltage protection
Grid voltage is normal or not ?
Normal
protection
Replace the dr ive
board.
YES
NO
3.4.35 “PH” Bus High-Voltage Protection
Error display: ODU mainboard, IDU wired controller and IDU receiver light board will display PH
Error judgment condition and method:
If there is no other malfunction and the busbar voltage is higher than the set value for high voltage protection,
then it can be judged that bus high-voltage protection occurs. System will shut down for protection.
Possible reason:
■Voltage of power grid is abnormal.
■Drive board busbar voltage sampling circuit element is damaged or drive board busbar voltage sampling AD
terminal is abnormal.