Gree GUD24W2/D-D(U) - Page 56

GREE DC INVERTER HEAT PUMP CONDENSING UNIT SERVICE MANUAL
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Possible reason:
■Voltage of power grid is abnormal. Voltage is too low.
■Drive board charge loop element is abnormal.
■Drive board busbar voltage sampling circuit element is damaged or drive chip busbar voltage sampling AD
terminal is abnormal.
Troubleshooting
：
PU
Charge loop error
Normal protection
Replace the drive board
Grid voltage is too low ?
YES
NO
3.4.28 “A1” Outdoor fan IPM module protection
Error display:
ODU mainboard LED displayer
Error judgment condition and method:
When 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:
■Outdoor fan 3-phase wire connection is lack of phase or phase-reversed.
■System is overloaded and outdoor fan current is too large.
■Drive board IPM module is damaged.
■Drive board IPM module’s 15V power supply is lower than 13.5V.
■Drive board 6-line PWM signal and the corresponding element are abnormal.
■Drive board outdoor fan current sampling circuit element is damaged or drive chip current sampling AD
terminal is abnormal.
■Compressor is damaged.