Check; Thermistor Resistance Check - Daikin MKS-T Series Service Manual

Check

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
 To check the thermistor soldered on a PCB, disconnect the PCB from other PCB/parts, and
Thermistor ASSY
Indoor Unit
Outdoor Unit
Note
When replacing the defective thermistor(s), replace the thermistor as ASSY.
169
between the pins using multimeter.
measure the resistance between the both ends of soldered thermistor.
Type A
Thermistor
R(25°C) = 20 kΩ
temperature (°C)
B = 3950 K
–20 197.8
–15 148.2
–10 112.1
–5 85.60
0 65.93
5 51.14
10 39.99
15 31.52
20 25.02
25 20.00
30 16.10
35 13.04
40 10.62
45 8.707
50 7.176
R(25°C) = 20 kΩ, B = 3950 K
(kΩ)
150
100
50
–15
Thermistor
Room temperature thermistor (R1T)
Indoor heat exchanger thermistor (R2T)
Outdoor temperature thermistor (R1T)
Outdoor heat exchanger thermistor (R2T)
Discharge pipe thermistor (R3T)
Liquid pipe thermistor
Gas pipe thermistor
Soldered thermistor
Multimeter
Resistance range
Type B
R(25°C) = 10 kΩ
B = 3435 K
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
(kΩ) R(25°C) = 10 kΩ, B = 3435 K
50
25
0
0 15 30 45 (°C) –15
SiSG121917E
Multimeter
0 15 30 45 (°C)
Resistance
B value
Type
B 3435 K
A 3950 K
A 3950 K
A 3950 K
A 3950 K
A 3950 K
A 3950 K
Part 6 Service Diagnosis
R6000517
R6000518
R(25°C)
10 kΩ
20 kΩ
20 kΩ
20 kΩ
20 kΩ
20 kΩ
20 kΩ