Service Manual

SiUS181631EA Troubleshooting for Outdoor Unit
Troubleshooting 251
7.23 Radiation Fin Thermistor Abnormality
Error Code
P4
Method of Error
Detection
Resistance of radiation fin thermistor is detected when the compressor is not operating.
Error Decision
Conditions
When the resistance value of thermistor becomes a value equivalent to open or short circuited
status
★
Malfunction is not decided while the unit operation is continued.
P4
is displayed by pressing the inspection button.
Supposed
Causes

Defective radiation fin thermistor (FINTH)

Defective main PCB (A1P)
Troubleshooting
Refer to Thermistor Resistance/Temperature Characteristics table 2 on page 268.
Disconnect the lead wires
from the compressor, and
then check the compressor
for the insulation resistance.
Remove and insert the
connector for the radiation
fin thermistor X111A.
Turn
ON the power
supply, and then check
whether or not the
malfunction
recurs.
The
insulation
resistance is low. (not
more than 100
kΩ)
Is the
resistance of the
radiation fin thermistor
normal?
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Completed.
(R22104)
Replace the compressor.
YES
Replace the main PCB
(A1P).
NO
NO
Replace the radiation fin
thermistor.
NO
YES
YES
Power OFF
Power ON