Daikin Aurora Series Service Manual page 250

Troubleshooting by Error Code
2.47.2 Inverter Radiation Fin Temperature Rise Abnormality (Fan PCB)
L4
Error Code
Sub code: 06, 07, 18-21
Applicable RXLQ72-120TAYCU, RXYQ72-168TAYCU
Models
Method of Error
Fan PCB radiation fin temperature is detected by the thermistor located inside the fan PCB circuit.
Detection
Error Decision
Detected temperature exceeds a certain level.
Conditions
Supposed
Causes
Troubleshooting
237
Radiation fin plate not fixed with screws
U0 error
Defective fan PCB
High outdoor air temperature
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Check for the cooling
conditions of radiation fin
used to cool the inverter.
(1) Is the radiation fin plate
fixed with screws?
(2) Error code U0 is displayed
on the Error History
screen.
Normal?
YES
Turn ON the
power supply, and
then press the ON button.
Does the error
recur?
NO
NO
YES
SiUS341802E
Rectify troubles.
Replace the fan PCB (A5P, A6P).
Continue operation.
Field factor. Radiation fin temperature
may have risen due to high outdoor air
temperature.
Service Diagnosis