57
Thermistor R0 = 15k
"
± 3%
B constant = 3480 ± 2%
t (
:
): R
t
=15exp{3480( 273+t – 273 )}
T (
˚
F): R
T
=15exp{3480( 273+(T– 32)/1.8 – 273 )}
10-7. HOW TO CHECK THE COMPONENTS
<Thermistor feature chart>
Low temperature thermistors
• Thermistor <Outdoor pipe> (TH3)
• Thermistor <Outdoor 2-phase pipe> (TH6)
• Thermistor <Outdoor> (TH7)
0
:
[32
˚
F] 15k
"
10
:
[50
˚
F] 9.6k
"
20
:
[68
˚
F] 6.3k
"
25
:
[77
˚
F] 5.2k
"
30
:
[86
˚
F] 4.3k
"
40
:
[104
˚
F] 3.0k
"
1
1
Thermistor R120 = 7.465k
"
± 2%
B constant = 4057 ± 2%
t (
:
): Rt =7.465exp{4057( 273+t – 393 )}
T (
˚
F): R
T
=7.465exp{4057( 273+(T– 32)/1.8 – 393 )}
1
1
20
:
[68
˚
F] 250k
"
30
:
[86
˚
F] 160k
"
40
:
[104
˚
F] 104k
"
50
:
[122
˚
F] 70k
"
60
:
[140
˚
F] 48k
"
70
:
[158
˚
F] 34k
"
80
:
[176
˚
F] 24k
"
90
:
[194
˚
F] 17.5k
"
100
:
[212
˚
F] 13.0k
"
110
:
[230
˚
F] 9.8k
"
High temperature thermistor
• Thermistor <Discharge> (TH4) <for A42>
• Thermistor <Shell> (TH32) <for A12/18/24/30/36>
0
10
20
30
40
50
-20 -10 0 10 20 30 40 50
-4 -14 32 50 68 86 104122
°F
Temperature
Resistance (k
)
500
400
300
200
100
0
25
50
75
100
120
77
122
167
212
248
°F
Temperature
Resistance (k
)
0
:
[32
˚
F] 180k
"
25
:
[77
˚
F] 50k
"
50
:
[122
˚
F] 17k
"
70
:
[158
˚
F] 8k
"
90
:
[194
˚
F] 4k
"
Thermistor R50 = 17k
"
± 2%
B constant = 4170 ± 3%
t (
:
): Rt =17exp{4170( 273+t – 323 )}
T (
˚
F): R
T
=17exp{4170( 273+(T– 32)/1.8 – 323 )}
1
1
Medium temperature thermistor
• Thermistor <Heatsink> (TH8)
200
150
100
50
0
25
50
75
100 110 125
77
122
167 212 230 257
°F
Temperature
Resistance (k
)
1
1
1
1
1
1
