GMV5 D.C INVERTER MULTI VRF SERVICE MANUAL
193
(13) Analyzing of faults in the variable-frequency fan drive's control system
1) Communication failure between the fan's drive board and control board (outdoor fault C3)
2) Faults in the IPM temperature sensor of the fan's drive board (ODU fault H7), current detection
circuit (ODU fault HC) and out-of-step protection (ODU fault H9)
Check if the fault is solved
after turning on the system
for three times
The fan's drive board is
faulty and needs to be
replaced.
Check if the control board
and fan's drive board are
power on.
Check if the fan's drive board and
compressor's drive board are well
connected to each other using the
communication cable.
Check if the dial
switch of the fan's
drive board is correct.
The fan's drive board
is faulty and needs to
be replaced.
Replace the control board if its
LED is off; replace the drive board
if its LED is off.
If not, reconnect them. If the cable
is not conducting, replace the
cable.
Switch the dial switch of the drive
board to 00 in a signal-fan system.
For a double-fan system, switch one
to 00 and the other one to 01.