Mitsubishi Electric PUMY-P36NKMU4 Technical & Service Manual page 117

8-8. HOW TO CHECK 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 ± 1 %
1
R =15exp{3480( –
t
273+t 273
32°F [0 °C ] 15 kΩ
°C
50°F [10 ] 9.6 kΩ
°C
68°F [20 ] 6.3 kΩ
°C
77°F [25 ] 5.2 kΩ
Medium temperature thermistor
• Thermistor <Heat sink> (TH8)
Thermistor R50 = 17 kΩ ± 2 %
B constant = 4150 ± 3 %
1
R =17exp{4150( –
t
273+t 323
°C
0 180 kΩ
°C
25 50 kΩ
°C
50 17 kΩ
°C
70 8 kΩ
°C
90 4 kΩ
High temperature thermistor
• Thermistor <Compressor> (TH4)
Thermistor R120 = 7.465 kΩ ± 2 %
B constant = 4057 ± 2 %
1
R =7.465exp{4057(
t
273+t
°C
68°F [20 ] 250 kΩ
°C
86°F [30 ] 160 kΩ
104°F [40 °C ] 104 kΩ
°C
122°F [50 ] 70 kΩ
°C
140°F [60 ] 48 kΩ
OCH811A
1
)}
86°F [30 °C ] 4.3 kΩ
°C
104°F [40 ] 3.0 kΩ
1
)}
1
)}
–
393
°C
158°F [70 ]
°C
176°F [80 ]
194°F [90 °C ]
212°F [100 ]
°C
°C
230°F [110 ]
50
40
30
20
10
0
200
150
100
50
0
500
400
300
200
34 kΩ
24 kΩ
17.5 kΩ
100
13.0 kΩ
9.8 kΩ
0
117
−4 −14 32 50 68 86 104122
−20 −10 0 10 20 30 40 50
Temperature (ºF)
Temperature (:)
25 50 75 100 110 125
Temperature （℃）
122 167 212
77
50 75 100
25
Temperature (ºF)
Temperature (:)
248
120