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14.4.16 F90 (Power Factor Correction Protection)
Malfunction Decision Conditions
• During startup and operation of cooling and heating, 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
YES
When abnormality indication starts again
Su
ecified?
YES
(~28Vdc)
Correct the power supply
Is the DC voltage between P (+) and N (-) terminal normal
between 285~315Vdc)?
Check the su
e
Operate the system. Verify PFC abnormality by measuring DC
voltage between P (+) and N (-) terminal at the outdoor unit PCB.
Check the compressor winding resistance:
• Turn off the power supply and disconnect the harness U, V
and W .
• Measure the windin
Replace the compressor
NO
• Defect in PFC circuitry
• Replace the outdoor unit PCB
NO
NO
YES
• Replace the outdoor unit PCB.
For safety reason and to prevent
component breakdown, always
switch off the power before remove
and connect the component.