Daikin VRV IV-S RXTQ-TAVJU Series, Service Manual

Page: 202 / 272

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