MXZ-SM36NAMHZ Service Manual

118
OCH789
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)
32°F [0:] 15 k"
50°F [10:] 9.6 k"
68°F [20:] 6.3 k"
77°F [25:] 5.2 k"
86°F [30:] 4.3 k"
104°F [40:] 3.0 k"
Thermistor R0 = 15 k" ± 3 %
B constant = 3480 ± 1 %
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
68°F [20:] 250 k"
86°F [30:] 160 k"
104°F [40:] 104 k"
122°F [50:] 70 k"
140°F [60:] 48 k"
158°F [70:] 34 k"
176°F [80:] 24 k"
194°F [90:] 17.5 k"
212°F [100:] 13.0 k"
230°F [110:] 9.8 k"
High temperature thermistor
• Thermistor <Compressor> (TH4)
0
10
20
30
40
50
−20 −10 0 10 20 30 40 50
−4 −14 32 50 68 86 104122
Temperature (:)
Temperature (ºF)
Resistance (k")
500
400
300
200
100
0
25
50 75 100 120
77
122 167 212 248
Temperature (ºF)
Temperature (:)
Resistance (k")
0: 180 k"
25: 50 k"
50: 17 k"
70: 8 k"
90: 4 k"
Thermistor R50 = 17 k" ± 2 %
B constant = 4150 ± 3 %
R
t =17exp{4150(
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")