Mitsubishi MXZ-4C36NAHZ - Page 114

114
8-7. HOW TO CHECK THE COMPONENTS
<Thermistor characteristic Graph>
Low temperature thermistors
• Thermistor <HIC pipe> (TH2)
• Thermistor <Outdoor liquid pipe> (TH3)
• Thermistor <Suction pipe> (TH6)
• Thermistor <Ambient> (TH7)
Thermistor R0 = 15 k" ± 3 %
B constant = 3480 ± 2 %
R
t =15exp{3480(
273+t
–
273
)}
1
1
Thermistor R120 = 7.465 k" ± 2 %
B constant = 4057 ± 2 %
R
t =7.465exp{4057(
273+t
–
393
)}
1
1
High temperature thermistor
• Thermistor <Compressor> (TH4)
0
10
20
30
40
50
−20 −10 0 10 20 30 40 50
Temperature
Resistance (k")
:
−4 −14 32 50 68 86 104122
°F
500
400
300
200
100
0
25
50 75 100 120
Temperature
Resistance (k")
:
77
122 167 212 248
ºF
32˚F [0:] 180 k"
77˚F [25:] 50 k"
122˚F [50:] 17 k"
158˚F [70:] 8 k"
194˚F [90:] 4 k"
Thermistor R50 = 17 k" ± 2 %
B constant = 4170 ± 3 %
R
t =17exp{4170(
273+t
–
323
)}
1
1
Medium temperature thermistor
• Thermistor <Heat sink> (TH8)
200
150
100
50
0
25 50 75 100 110 125 :
Temperature
Resistance (k")
77 122 167 212 230 257 ºF
32˚F [0:] 15 kΩ
50˚F [10:] 9.6 kΩ
68˚F [20:] 6.3 kΩ
77˚F [25:] 5.2 kΩ
86˚F [30:] 4.3 kΩ
104˚F [40:] 3.0 kΩ
68˚F [20:] 250 kΩ
86˚F [30:] 160 kΩ
104˚F [40:] 104 kΩ
122˚F [50:] 70 kΩ
140˚F [60:] 48 kΩ
158˚F [70:] 34 kΩ
176˚F [80:] 24 kΩ
194˚F [90:] 17.5 kΩ
212˚F [100:] 13.0 kΩ
230˚F [110:] 9.8 kΩ
OCH573C