Check; Thermistor Resistance Check - Daikin Super multi NX E Series Service Manual

SiBE121135_A

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 tester.
The relationship between normal temperature and resistance is shown in the table and the
graphs below.
Service Diagnosis
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
for CTXS and FTXS20/25K
(kΩ)
50
25
0
–15 15
0
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.
Resistance (kΩ)
Room temperature thermistor
for CTXS and FTXS20/25K
series
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
45 –15
30 (˚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
45
0 15 30 (˚C)
Room temperature
Tester
thermistor
Tester
(R18296)

Check

(11952)
(R17417)
230