Gree GMVVQ1015WM/C-X, Service Manual

Page: 168 / 433

Gree GMV6 HR DC Inverter VRF Units Service Manual
166
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:
"H9" Loss of
Synchroni zation Pro tection
for the Inverte r Fan
The fan dr ive boa rd is
abn ormal
Yes
Replace th e fan drive board
No
Whether th e U, V and W p hases
of fan wires a re conn ected pro perly?
Yes
No
Replace th e fan
Whether the resistance between
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
than 2 megohms)?
Ye
s
Yes
Remove forei gn matters
Whether blad es are stuck d ue to foreign
matters or rusting of mo tor shaft?
Yes
Yes
Replace th e faulty fan
Have other faults occu rred
at the same time (for example, over-current
protection (H5), IPM module prote ction (H6),
start failure (HJ))?