80
15.4.22 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
Supply voltage as specified?
YES
(~28Vdc)
Correct the power supply
Is the DC voltage between P (+) and N (-) terminal normal
between 285~315Vdc)?
Check the supply voltage
Operate the system. Verify PFC abnormality by measuring DC
voltage between P (+) and N (-) terminal at the outdoor unit PCB
Are the compressor’s winding resistance (U-V, V-W, W-U) uniform?
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 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.