Daikin Sensira Series, Service Manual

Page: 120 / 172

2 | Components
Service manual
120
FTXF20~71A + FTXF20~25B + FTXF20~42C + ATXF20~71A + ATXF20~42C
+ RXF20~71A + RXF20~60B + RXF20~42C + ARXF20~71A + ARXF20~42C
Split Sensira R32
ESIE18-12E – 2021.02
▪
E.g. R1T thermistor:
▪ Measured temperature with contact thermometer: 23.1°C,
▪
Resistance value determined through temperature (using the thermistor
table A):
Resistance at 23°C: 21.85 kΩ,
Resistance at 24°C: 20.90 kΩ,
▪ Disconnect connector and measure resistance between S90 pin 1‑2:
Measured resistance: 21.86 kΩ,
▪ Measured resistance value is inside the range. R1T thermistor passes the
check.
INFORMATION
All thermistors have a resistance tolerance of 3%.
INFORMATION
In most cases, the user interface allows to monitor the thermistors.
If the measured resistance value matches the resistance determined through the
measured temperature, but the temperature for the corresponding thermistor is
NOT correct on the user interface display, replace the applicable PCB.
INFORMATION
See the overview of the thermistors at the start of the procedure and the "5.2 Wiring
diagram" [
4
142] to determine if the specific thermistor is either:
▪
Directly connected to the PCB
▪
Connected to an intermediate connector which is connected to the PCB
For thermistors directly connected to the PCB
Does the measured resistance of the
thermistor match with the
temperature determined resistance? Action
Yes Thermistor is OK. Return to the
troubleshooting of the specific error
and continue with the next procedure.
No Replace the specific thermistor, see
"Repair procedures" [
4
121].
For thermistors connected to an intermediate connector
Does the measured resistance of the
thermistor match with the
temperature determined resistance? Action
Yes Thermistor is OK. Return to the
troubleshooting of the specific error
and continue with the next procedure.
No Continue with the next step.
8 Disconnect the thermistor from the intermediate connector and measure the
resistance of the thermistor (between the appropriate pins of the connector).