Gree GWH18AC-D3DNA1B Service Manual page 53

Troubleshooting
9.2.3.5 Diagnosis of compressor synchronism (outdoor unit malfunction)
Indoor display: H7 (dual-8 display), heating indicator is off for 3S and blinks 7 times.
Main detection point:
Is the system pressure over-high?
Is the work voltage over-low?
Malfunction diagnosis process:
Synchronism after
energize the unit
and start it
N
If the stop time of
compressor is more than
3min
If the compressor wire COMP(UVW) is well
connected, the connection sequence forwards to
clockwise direction?
N
Connect
wire well
Replace
control board
AP1
Remove
Y
malfunction?
Replace
compress
finish
If the outdoor fan works normally?
Y
Y
N
Synchronism
occurred during
operation
N
Y
Y
If the radiating of unit is well?
N
If the input voltage of unit is
N
normal?
Y
If the refrigerant is too much? Y
N
Replace
control board
AP1
Remove
malfunction?
N
Replace
compressor
finish
50
Check if the fan
terminal OFAN is
connected well
Improve the radiating
of unit (clean heat
exchanger and
increase ventilation)
Start to run until the
power resume normal
voltage
Charge the
refrigerant with
service manual
Y
Replace fan
capacity C1
Replace
outdoor fan