Service manual

SiUS28-902_a Troubleshooting by Indication on the Remote Controller
Troubleshooting 116
3.25 “J6” Outdoor Unit: Malfunction of Thermistor (R4T) for
Outdoor Unit Heat Exchanger
Remote
Controller
Display
J6
Applicable
Models
RZQ18~30PVJU
Method of
Malfunction
Detection
Malfunction is detected from the temperature detected by the heat exchanger thermistor.
Malfunction
Decision
Conditions
When a short circuit or an open circuit in the heat exchange thermistor is detected.
Supposed
Causes
 Defect of thermistor (R4T) for outdoor unit heat exchanger
 Defect of outdoor unit P.C.B. (A1P)
Troubleshooting
Refer to Thermistor Resistance / Temperature Characteristics table on P.166
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts could be damaged.
Resistance
is normal when
measured after
disconnecting the thermistor
(R4T) from the outdoor
unit P.C.B.
(3.5kΩ~
360kΩ)
Replace the outdoor unit P.C.B.
(A1P).
Connect the thermistor and turn
on again.
NO
NO
Replace the thermistor (R4T).
YES
YES
Connector
is connected to outdoor
unit P.C.B.
(A1P).