COMFORT-AIRE B-SVH24SA-1 Service Manual page 48

9.3.10 Inverter compressor drive error diagnosis and solution (P4)
Error Code
Malfunction conditions
Possible causes
Troubleshooting:
Check if the wiring between
main PCB and compressor
connected well?
Yes
Check the reactor or
inductor. Is it normal?
Yes
Check if the IPM installed correctly.
Yes
IPM continuity check. Check if the
IPM terminal resistance values are
uniform.
Yes
Check if the outdoor fan runs
properly or the outdoor unit
ventilation is good.
Yes
Check if the compressor resistance
values are uniform .
Yes
Replace the outdoor main PCB if the
main PCB and IPM are separate.
P4
An abnormal inverter compressor drive is detected by a special
detection circuit, including communication signal detection,
voltage detection, compressor rotation speed signal detection
and so on.
Wiring error
●
IPM malfunction
●
Outdoor fan assembly faulty
●
Compressor malfunction
●
Outdoor PCB faulty
●
No
No
No
No
No
No
Service Manual - SVH 09/12/18/24 Series
Correct the connection or
replace the wires and
connectors.
Replace the reactor
or inductor
Correct the installation,
tighten the screws and
apply silicon grease.
Replace the IPM board or replace
the main PCB if the IPM board and
main PCB are integrated together.
Please refer to the solution of 【Fan
Speed Has Been Out Of Control】
malfunction
Replace the compressor.
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