Service manual

SiUS28-902_a Troubleshooting by Indication on the Remote Controller
Troubleshooting 128
3.34 “P4” Outdoor Unit: Malfunction of Inverter Radiating Fin
Temperature Rise Sensor
Remote
Controller
Display
P4
Applicable
Models
RZQ18~30PVJU
Method of
Malfunction
Detection
Resistance of radiation fin thermistor is detected when the compressor is not operating.
Malfunction
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" will be displayed by pressing the inspection button.
Supposed
Causes
 Defect of radiator fin temperature sensor
 Defect of outdoor unit P.C.B. (A1P)
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts could be damaged.
Power OFF
Power ON
Replace the
compressor.
Replace the outdoor
unit P.C.B. (A1P).
End
YES
YES
NO
NO
Disconnect the cable from the
compressor, and then check
the compressor for the
insulation resistance.
Remove and insert the fin
thermistor connector [X111A].
The insulation
resistance is low (i.e., not
more than
100kW.)
Turn ON the
power supply, and
then check whether or not
the malfunction
recurs.