Gree IWZA Service Manual page 18

2. IPM protection(H5), desynchronizing malfunction(H7), overcurrent of compressor phase current (P5) (AP1 below means
control board of outdoor unit)
Main detection points:
● Is voltage input within the normal range
● If the control board AP1 is well connected with compressor COMP? If they are loosened? If the connection sequence is correct?
● Heat exchange of unit is not good (heat exchanger is dirty and unit radiating environment is bad);
● If the system pressure is too high?
● If the refrigerant charging amount is appropriate?
● If coil resistance of compressor is normal? Is compressor coil insulating to copper pipe well?
● If the work load of unit is heavy? If radiating of unit is good?
Malfunction diagnosis process:
H5, H7 or P5 is
displayed after
turning on the unit
Measure if the voltage
input is within 180~265V
with AC voltmeter
(see fig 30)
Y
The compressor
is well connected
with mainboard
AP1?
Y
Heat exchanger is
blocked with dirt?
N
Check if system pressure
is too high?
N
Replace outdoor
mainboard AP1
66
N
Repair power supply to make
the power voltage normal
Adjust it properly
N
according to wiring
diagram 5.1
N
Clean the heat exchanger
Y
to improve its performance
N
Adjust refrigerant
Y
charging amount
Does the unit
work normally
N
Replace compressor
Restart the unit
N
Restart the unit
Restart the unit
Restart the unit
Y
Service Manual
The unit starts
Y
operation again
The unit starts
Y
operation again
The unit starts
Y
operation again
The unit starts
Y
operation again
End
Installation and Maintenance