Mitsubishi Electric PUMY-P200YKM2 Technical & Service Manual page 101

8-8. HOW TO CHECK THE COMPONENTS
<Thermistor feature chart>
Low temperature thermistors
• Thermistor <HIC pipe> (TH2)
• Thermistor <Outdoor liquid pipe> (TH3)
• Thermistor <Suction pipe> (TH6)
• Thermistor <Ambient> (TH7)
Thermistor R0 = 15 kΩ ± 3 %
B constant = 3480 ± 2 %
1
=15exp{3480(
R
t
273+t
0°C 15 kΩ 30°C
10°C 9.6 kΩ 40°C
20°C 6.3 kΩ
25°C 5.2 kΩ
Medium temperature thermistor
• Thermistor <Heat sink> (TH8)
Thermistor R50 = 17 kΩ ± 2 %
B constant = 4150 ± 3 %
1
=17exp{4150(
R
t
273+t
0°C 180 kΩ
25°C 50 kΩ
50°C 17 kΩ
70°C 8 kΩ
90°C 4 kΩ
High temperature thermistor
• Thermistor <Compressor> (TH4)
Thermistor R120 = 7.465 kΩ ± 2 %
B constant = 4057 ± 2 %
=7.465exp{4057(
R
t
273+t
20°C 250 kΩ 70°C
30°C 160 kΩ 80°C
40°C 104 kΩ 90°C
50°C 70 kΩ 100°C
60°C 48 kΩ 110°C
OCH675D
1
– )}
273
4.3 kΩ
3.0 kΩ
1
– )}
323
1 1
– )}
393
34 kΩ
24 kΩ
17.5 kΩ
13.0 kΩ
9.8 kΩ
50
40
30
20
10
0
-20 -10 0 10 20 30 40 50
200
150
100
50
0
500
400
300
200
100
0
101
Temperature (:)
25 50 75 100 110 125
Temperature (:)
50 75 100 120
25
Temperature (:)