How To Check The Components; Low Temperature Thermistors; Medium Temperature Thermistor; High Temperature Thermistor - Mitsubishi Electric PUZ-ZM35VKA Service Manual

10-7. HOW TO CHECK THE COMPONENTS

<Thermistor feature chart>

Low temperature thermistors

• Thermistor <Liquid> (TH3)
• Thermistor <2-phase pipe> (TH6)
• Thermistor <Ambient> (TH7)
Thermistor R0 = 15 k" ± 3%
B constant = 3480 ± 2%
1
–
R =15exp{3480(
t
273+t
0: 15 k" 30:
10: 9.6 k" 40:
20: 6.3 k"
25: 5.2 k"

Medium temperature thermistor

• Thermistor <Heat sink> (TH8)
Thermistor R50 = 17 k" ± 2%
B constant = 4150 ± 3%
1
=17exp{4150( 273+t – 323 )}
R
t
0: 180 k"
25: 50 k"
50: 17 k"
70: 8 k"
90: 4 k"

High temperature thermistor

• Thermistor <Discharge> (TH4)
• Thermistor <Comp. surface> (TH33)
Thermistor R120 = 7.465 k" ± 2%
B constant = 4057 ± 2%
1
=7.465exp{4057( 273+t – 393 )}
R
t
20: 250 k" 70:
30: 160 k" 80:
40: 104 k" 90: 17.5 k"
50: 70 k" 100: 13.0 k"
60: 48 k" 110: 9.8 k"
OCH653
1
)}
273
4.3 k"
3.0 k"
1
1
34 k"
24 k"
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
61
Temperature (:)
25 50 75 100 125
Temperature (:)
50 75 100
25
Temperature (:)
120