Gree GMV-VQ680WM/C-X Service Manual page 168

Gree
2.103 "H9" Loss of Synchronization Protection for Inverter Fan
Fault display: main board of outdoor unit displays
Fault diagnosis:
If the fault code displayed on the 2-digit digital LED of the outdoor unit's main control board is H9, it
indicates the loss of synchronization protection for the inverter fan.
Possible causes:
■ Poor contact of fan's UVW cables;
■ The fan is damaged;
■ The blades are stuck (the blades are blocked or the motor shaft gets rusty);
■ The fan drive board operates improperly.
Troubleshooting:
the windings of each phase for the fan is normal
(generally less than 10 ohms)? Whether the resistance values are
equal to each other? Is grounding insulation of the phase
windings of the fan normal (generally greater
Whether blad es are stuck d ue to foreign
at the same time (for example, over-current
protection (H5), IPM module prote ction (H6),
"H9" Loss of
Synchroni zation Pro tection
for the Inverte r Fan
Whether th e U, V and W p hases
of fan wires a re conn ected pro perly?
Yes
Whether the resistance between
than 2 megohms)?
Ye
s
matters or rusting of mo tor shaft?
Yes
Have other faults occu rred
start failure (HJ))?
No
The fan dr ive boa rd is
abn ormal
GMV6 HR DC Inverter VRF Units Service Manual
No
Yes
Remove forei gn matters
Yes
Replace th e faulty fan
Yes
Replace th e fan drive board
166
Replace th e fan