Thermistor System Fault - Daikin E Series Service Manual

SiBE04-624

2.11 Thermistor System Fault

C4, C9
Remote
Controller Display
Method of Thermistor fault is detected based on the temperature determined by each thermistor
Malfunction
Detection
Malfunction When power is supplied and the input of thermistor is 4.96 V or more or 0.04 V or less
* (for reference)
Decision
In case of 120 Ω (equivalent to 212°C) or less or 1860 kΩ (equivalent to –50°C) or more
Conditions
Supposed
Causes
Troubleshooting
Chart
Check No.2
Refer to P.202
C4
C9
Service Diagnosis
Improper connector connection
Defective thermistor
Defective PCB for indoor unit control system
Defective PCB for indoor humidity sensor
Be sure to turn off power switch before connect or disconnect connector,
Caution or parts damage may be occurred.
Check connector for proper
connection
Is it OK?
YES
Check No. 2
Thermistor resistance check
Is it OK?
YES
: Indoor heat exchanger thermistor
: Room temperature thermistor
NO
NO
Troubleshooting
Reconnect properly.
Replace thermistor.
(Replace the humidity
sensor PCB(A4P).)
Replace control PCB
(A1P).
(R6005)
157