Century B-VMH36SD-1 Service Manual page 46

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