Daikin FTXS50K2V1B - Check; Thermistor Resistance Check

SiBE121123_A Check
Service Diagnosis 206
8. Check
8.1 Thermistor Resistance Check
Check No.01 Disconnect the connectors of the thermistors from the PCB, and measure the resistance of
each thermistor using a tester.
The relationship between normal temperature and resistance is shown in the table and the
graphs below.

When the room temperature thermistor is directly mounted on a PCB, remove the PCB from
the control PCB to measure the resistance.

When the connector of indoor heat exchanger thermistor is soldered on the PCB, remove
the thermistor and measure the resistance.
Thermistor temperature (°C)
Resistance (kΩ)
Room temperature thermistor
for FTX and ATX series
Other thermistors
–20 73.4 197.8
–15 57.0 148.2
–10 44.7 112.1
–5 35.3 85.60
0 28.2 65.93
5 22.6 51.14
10 18.3 39.99
15 14.8 31.52
20 12.1 25.02
25 10.0 20.00
30 8.2 16.10
35 6.9 13.04
40 5.8 10.62
45 4.9 8.707
50 4.1 7.176
(R25°C = 10 kΩ, B = 3435 K) (R25°C = 20 kΩ, B = 3950 K)
(R11952)
Other thermistorsRoom temperature thermistor
for FTX and ATX series
(˚C)(˚C)
50
25
0
–15
0
15 30
45
(kΩ)
(kΩ)
–15
0
15 30
45
150
100
50
Tester
(R17417)
Room temperature
thermistor
Tester
Resistance range
(R18296)