Radiation Fin Thermistor Abnormality - Daikin VRV IV-S RXTQ-TAVJU Series Service Manual

Troubleshooting by Error Code

4.37 Radiation Fin Thermistor Abnormality

P4
Error Code
Applicable
All outdoor units
Models
Method of Error Resistance of the following thermistor is detected when the compressor is not operating.
Detection (1) Radiation fin thermistor
(2) PCB circuit thermistor
Error Decision
When the resistance value of thermistor becomes a value equivalent to open circuited or short
circuited status
Conditions
∗ Error is not decided while the unit operation is continued.
Supposed
Causes
Troubleshooting
CHECK 11
189
P4
will be displayed by pressing the inspection button.
Defective radiation fin temperature thermistor
Defective PCB
Defective inverter compressor
Defective fan motor
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Measure resistance value of
the radiation fin thermistor.
CHECK 11
Is the thermistor
resistance value normal?
The
compressor's insulation
resistance is less than
100 kΩ.
The fan
motor's insulation resistance
is less than 1 MΩ.
Does the error
recur when the
power supply turns
ON?
Refer to page 231.
* Disconnect the connector (X111A) from the radiation
fin thermistor, and then check the thermistor.
NO
YES
YES
NO
YES
NO
YES
NO
SiUS331604E
Replace the outdoor
main PCB (A1P).
Replace the
compressor (M1C).
Replace the fan motor.
Replace the outdoor
main PCB (A1P).
Continue the operation.
Service Diagnosis