Mitsubishi Electric PUZ-M200YKA, Service Manual

Page: 59 / 110

59
OCH737
10-7. HOW TO CHECK THE COMPONENTS
<Thermistor feature chart>
Low temperature thermistors
• Thermistor <Liquid> (TH3)
• Thermistor <2-phase pipe> (TH6)
• Thermistor <Ambient> (TH7)
0
:
15 k
"
10
:
9.6 k
"
20
:
6.3 k
"
25
:
5.2 k
"
0
:
180 k
"
25
:
50 k
"
50
:
17 k
"
70
:
8 k
"
90
:
4 k
"
30
:
4.3 k
"
40
:
3.0 k
"
Thermistor R0 = 15 k
"
± 3%
B constant = 3480 ± 2%
R
t
=15exp{3480( 273+t – 273 )}
1
1
Thermistor R50 = 17 k
"
± 2%
B constant = 4150 ± 3%
R
t
=17exp{4150( 273+t – 323)}
1
1
Thermistor R120 = 7.465 k
"
± 2%
B constant = 4057 ± 2%
R
t
=7.465exp{4057( 273+t – 393)}
1 1
Medium temperature thermistor
• Thermistor <Heat Sink> (TH8)
20
:
250 k
"
30
:
160 k
"
40
:
104 k
"
50
:
70 k
"
60
:
48 k
"
70
:
34 k
"
80
:
24 k
"
90
:
17.5 k
"
100
:
13.0 k
"
110
:
9.8 k
"
High temperature thermistors
• Thermistor <Discharge> (TH4)
• Thermistor <Comp. Surface> (TH33)
0
10
20
30
40
50
− 20 − 10 0 10 20 30 40 50
Temperature (
:
)
Resistance (k
"
)
200
150
100
50
0
25 50 75 100 125
Temperature (
:
)
Resistance (k
"
)
500
400
300
200
100
0
25
50 75 100 120
Temperature (
:
)
Resistance (k
"
)