Daikin FTX25JVEA9 Service Manual page 303

Troubleshooting - Outdoor Unit Related
3.3.27 Overvoltage, Low Voltage
U2
Outdoor Unit
Indication
Method of Power supply system error is detected using the voltage of inverter DC unit.
Malfunction
Detection
Malfunction When, after starting the compressor, the voltage reached to below 210V over 450V before it
exceeded 320V, or to below 260V or over 450V after it exceeded 320V once.
Decision
Conditions
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Supposed
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Causes
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Troubleshooting
Check No.5
Refer to P.302
Check No.12
Refer to P.307
Check No.13
Refer to P.308
290
When a power supply system error is generated 4 times, the system shuts down.
(The 4-time counter resets itself when no outdoor unit abnormality occurs within 60-minute
cumulative time after the error generation.)
Electrolytic capacitor malfunction
PAM module malfunction
Faulty power transistor
Disconnection·Faulty connection of internal wiring
Faulty reactor
Faulty PC board
Instantaneous power failure
Mismatching with power supply of feedback control system
Be sure to turn off power switch before connect or disconnect connector,
Caution or parts damage may be occurred.
Check No. 5
Main circuit wiring
connection check
Is the input
voltage within a range of
220-240V±10%?
YES
Measure the voltage at both
ends of electrolytic capacitor
while the compressor is
operating.
Check No. 12
Electrolytic capacitor
capacity check
OK
Check No. 13
Voltage check when starting
the compressor
Does the
voltage reach to
approximately 370V within
approximately 2 seconds
after starting the
compressor?
YES
Do a long-term observation
on power supply voltage.
Supposed causes
n
Instantaneous power failure
NO
NO
Si18-201
Could be causes on site.
Replace if any abnormality.
Replace control PC board,
filter PC board if the voltage
is not within the range.
Replace active module.
As the system will not shut
down, use as it is.
Service Diagnosis
(MF046)