Gree GMV5 Series Service Manual page 174

GMV5 DC INVERTER VRF UNITS SERVICE MANUAL
(6) Low voltage protection for the DC bus of the variable-frequency fan's drive board (ODU fault HL)
HL
Elevate the voltage to
Check if the voltage of the Yes
380V.
input power cable is lower
than 320V
No
Check if the terminal
CN503 and CN504
Check if the terminal CN503 and
No
on the fan's drive
CN504 on the fan's drive board
board are connected.
are connected.
Yes
The fan's drive board is
faulty and needs to be
replaced.
Complete
(7) Variable-frequency fan starting failure (ODU fault HJ)
HJ
No
Reconnect it properly.
Check if the fan's UVW
cable is connected properly.
Yes
Replace the fan's drive
board to see if the fault is
solved.
No
The fan is faulty and needs
to be replaced.
Complete
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