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16.4.17 F90 (Power Factor Correction Protection)
Malfunction Decision Conditions
During startup and operation of cooling, when Power Factor Correction (PFC) protection circuitry at the outdoor
unit main PCB senses abnormal high DC voltage level.
Malfunction Caused
DC voltage peak due to power supply surge.
DC voltage peak due to compressor windings not uniform.
Faulty outdoor PCB.
Troubleshooting
When abnormality indication starts again
For safety reason and to prevent
component breakdown, always
switch off the power before remove
and connect the component.
NO
YES
YES
Check the compressor winding resistance:
Turn off the power supply and disconnect the harness U, V
and W.
Measure the winding resistance between U-V, V-W and W-U
Replace the outdoor unit PCB.
Check the supply voltage
Supply voltage as specified?
Operate the system. Verify PFC abnormality by measuring DC
voltage between P (+) and N (-) terminal at IPM of the outdoor
unit PCB.
Is the DC voltage between P (+) and N (-) terminal normal
between 285 ~ 315 Vdc?
Are the compressor’s winding resistance (U-V, V-W, W-U)
NO
YES
(~285 Vdc)
NO
Defect in PFC circuitry
Replace the compressor
Correct the power supply
Replace the outdoor unit PCB
