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Service Manual -
VMH 9/12/18/24 SU & VMH30/36S D Series
44
47
For 24K~36K:
T
est the resistance between
all
ports of U, V, W of IPM and P, N. If any result
i
s 0 or close to 0, the
IPM is defective. Otherwise, please follow the procedure below:
Check whether the power
voltage is normal.
Restart the unit when the
power supply is normal
Check that the wiring
of power wires is
correct and tight
Reconnect
Measure whether outdoor
terminal voltage is normal?
Measure whether the voltage
between L and N is normal?
Measure whether input voltage
of bridge rectifier is normal?
Measure whether the voltage
between P and N is normal.
Refer to Appendix 4.
Check that the
wiring of L and N is
correct and tight
Replace bridge rectifier
Check whether
bridge rectifier is
normal.
Reconnect
Reconnect
Check that the wiring
of bridge rectifier is
correct and tight
Check whether the
connecting wire between
main board and the IPM
board is connected tightly.
Check whether the
connecting wire of the
compressor is connected
correctly and tightly.
Reconnect
Reconnect
Replace the PFM module (if applicable)
Reconnect the
wiring
Check the wiring
of reactor or
inductor
Check if the outdoor unit
ventilation is good.
Correct ventilation issue
Check if the outdoor fan
runs properly.
Please refer to the solution of
[Fan Speed Has Been Out of
Control] malfunction. Find out
the cause and have it solved.
Check whether
reactor or inductor
is normal
Replace reactor
or inductor
Replace IPM board
Replace the outdoor
main PCB
Replace the
compressor
Is the compressor
functioning normal?
Check whether the refrigerant
system is OK.