Check
SiSG121917E
169
Part 6 Service Diagnosis
Note
8. Check
8.1 Thermistor Resistance Check
Check No.01
Measure the resistance of each thermistor using multimeter.
The resistance values are defined by below table.
If the measured resistance value does not match the listed value, the thermistor must be
replaced.
Disconnect the connector of thermistor ASSY from the PCB to measure the resistance
between the pins using multimeter.
To check the thermistor soldered on a PCB, disconnect the PCB from other PCB/parts, and
measure the resistance between the both ends of soldered thermistor.
R6000517
R6000518
When replacing the defective thermistor(s), replace the thermistor as ASSY.
M
u
ltimeter
Resistance range
Thermistor ASSY
Soldered thermistor
M
u
ltimeter
Thermistor
temperature (°C)
Type A
Type B
R(25°C) = 20 kΩ
B = 3950 K
R(25°C) = 10 kΩ
B = 3435 K
–20
197.8
73.4
–15
148.2
57.0
–10
112.1
44.7
–5
85.60
35.3
0
65.93
28.2
5
51.14
22.6
10
39.99
18.3
15
31.52
14.8
20
25.02
12.1
25
20.00
10.0
30
16.10
8.2
35
13.04
6.9
40
10.62
5.8
45
8.707
4.9
50
7.176
4.1
Thermistor
Resistance
Type
B value
R(25°C)
Indoor Unit
Room temperature thermistor (R1T)
B
3435 K
10 kΩ
Indoor heat exchanger thermistor (R2T)
A
3950 K
20 kΩ
Outdoor Unit
Outdoor temperature thermistor (R1T)
A
3950 K
20 kΩ
Outdoor heat exchanger thermistor (R2T)
A
3950 K
20 kΩ
Discharge pipe thermistor (R3T)
A
3950 K
20 kΩ
Liquid pipe thermistor
A
3950 K
20 kΩ
Gas pipe thermistor
A
3950 K
20 kΩ
R(25°C) = 10 k
Ω
, B = 3435 K
(°C)
50
25
0
–15
0
15
30
45
(k
Ω
)
R(25°C) = 20 k
Ω
, B = 3950 K
(°C)
(k
Ω
)
–15
0
15
30
45
150
100
50
