Daikin VRV RXYQ72-384XAYCA, Service Manual

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Troubleshooting by Error Code SiUS342004EB
321 Part 6 Service Diagnosis
3.56 Inverter Radiation Fin Temperature Abnormality
3.56.1 Inverter Radiation Fin Temperature Abnormality (Inverter PCB)
Applicable
Models
All outdoor unit models
Error Code
P4
Sub code: 09-11
Method of Error
Detection
Detect the resistance of the following thermistors while the compressor is not running:

Radiation fin thermistor

Thermistor located in PCB circuit

Heat sink thermistor
Error Decision
Conditions
When the resistance of the thermistor comes to a value equivalent to open or short circuit.
Error is not decided while the unit operation is continued.
P4 will be displayed by pressing the inspection button.
Supposed
Causes

Defective radiation fin temperature thermistor

Defective inverter PCB

Defective compressor

Defective fan motor
Troubleshooting
Make meas u rement of
resistance of the radiation fin
thermistor.
Is the
resistance of the
rele v ant thermistor
normal?
The
ins u lation
resistance of the
rele v ant compressor is less
than 100 k .
The ins u lation
resistance of the rele v ant
fan motor is less than
1 M .
T u rn ON
the power s u pply.
Does the error
rec u r?
NO
YES
NO
YES
NO
YES
YES
NO
Replace the in v erter PCB
(A4P).
Replace the compressor.
Replace the fan motor
(M1F, M2F).
Replace the in v erter PCB.
Contin u e operation.
Caution
Be s u re to t u rn off the power switch b efore connecting or disconnecting
connectors, or parts may b e damaged.