Check; Thermistor Resistance Check - Daikin FTXM-K Series Service Manual

Check

5. Check

5.1

Thermistor Resistance Check

Check No.01 Disconnect the connectors of the thermistors from the PCB, and measure the resistance of
each thermistor using a multimeter.
97
The data is for reference purpose only.
Thermistor temperature (°C)
–20
–15
–10
–5
0
5
10
15
20
25
30
35
40
45
50
Room temperature thermistor
of 20/25 class models
(kΩ)
50
25
0
–15 15
0
When the room temperature thermistor is soldered 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 a PCB, remove the
thermistor and measure the resistance.
Resistance (kΩ)
Room temperature thermistor
of 20/25 class models
73.4
57.0
44.7
35.3
28.2
22.6
18.3
14.8
12.1
10.0
8.2
6.9
5.8
4.9
4.1
(R25°C = 10 kΩ, B = 3435 K)
(kΩ)
150
100
50
–15
30 45 (˚C)
Resistance range
Other thermistors
197.8
148.2
112.1
85.60
65.93
51.14
39.99
31.52
25.02
20.00
16.10
13.04
10.62
8.707
7.176
(R25°C = 20 kΩ, B = 3950 K)
Other thermistors
0 15 30 45
Room temperature
thermistor
Multimeter
Multimeter
(R21542)
Service Diagnosis
SiBE041434E
(˚C)
(R11952)
(R20505)