Check; Thermistor Resistance Check - Daikin 3MKS50E3V1B Service Manual

SiBE121135

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
(kΩ)
50
25
0
–15 0 15
The room temperature thermistor is directly mounted on the display PCB. Remove the
display PCB from the control PCB to measure the resistance.
When the indoor heat exchanger thermistor is soldered on the PCB, remove the thermistor
and measure the resistance.
Resistance (kΩ)
Room temperature thermistor
for FTXS-K and CTXS-K series Other thermistors
70.3
56.1
44.1
34.9
28.2
22.3
18.1
14.8
12.2
10.0
8.3
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
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 45
15 30
RTH1
Tester
Tester
(R11906)

Check

(˚C) (11952)
(R3460)
325