SiBE121135
Check
Service Diagnosis
325
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.
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.
The data is for reference purpose only.
Thermistor temperature (°C)
Resistance (k
Ω
)
Room temperature thermistor
for FTXS-K and CTXS-K series
Other thermistors
–20
70.3
197.8
–15
56.1
148.2
–10
44.1
112.1
–5
34.9
85.60
0
28.2
65.93
5
22.3
51.14
10
18.1
39.99
15
14.8
31.52
20
12.2
25.02
25
10.0
20.00
30
8.3
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 k
Ω
, B = 3435 K)
(R25°C = 20 k
Ω
, B = 3950 K)
Room temperature thermistor
(˚C)
50
25
0
–15
0
15
30
45
(k
Ω
)
(11952)
Other thermistors
(˚C)
(k
Ω
)
–15
0
15
30
45
150
100
50
Tester
Resistance range
(R11906)
RTH1
Tester
(R3460)
