GREE         U-Match 5 SERIES UNIT SERVICE MANUAL 
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3.4.22 “HC” PFC Protection 
Error display: ODU mainboard, IDU wired controller and IDU receiver light board will display HC 
Error judgment condition and method: 
After power is connected, and drive chip received IPM lead F0 that is of low level, than it is IPM module 
malfunction. System will shut down for protection. 
Possible reason: 
■Power grid voltage is abnormal. 
■Drive board PFC module is damaged. 
■Drive board IPM module’s 15V power supply is lower than 13.5V. 
■Drive board PWM signal for PFC and the corresponding element are abnormal. 
■Drive board PFC current sampling circuit element is damaged or drive  chip current sampling AD terminal is 
abnormal. 
Troubleshooting: 
HC
PFC protection
Normal protection
Check whether power grid voltage is
normal?
NO
Drive board PFC is damaged ?
YES
Replace the drive board .
YES