Check; Thermistor Resistance Check - Daikin 2MXS40H2V1B Service Manual

SiBE121123_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 a tester.
The relationship between normal temperature and resistance is shown in the table and the
graphs below.
Service Diagnosis
Thermistor temperature (°C)
–20
–15
–10
–5
0
5
10
15
20
25
30
35
40
45
50
Room temperature thermistor
for FTX and ATX series
(kΩ)
50
25
0
–15 15 30
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 FTX and ATX 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)
Other thermistors
(kΩ)
150
100
50
–15
45 (˚C) 0
Tester
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)
15 30 45 (˚C)
(R11952)
Room temperature
thermistor
Tester
(R17417)
(R18296)

Check

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