Mitsubishi Electric PUHZ-W50VHA Service Manual page 64

9-5. HOW TO CHECK THE COMPONENTS
<Thermistor feature chart>
Low temperature thermistors
• Thermistor <Liquid> (TH3)
• Thermistor <Plate Hex liquid> (TH6)
• Thermistor <Ambient> (TH7)
• Thermistor <Suction> (TH33 for HW112,140)
Thermistor R0 = 15 k" ± 3%
B constant = 3480 ± 2%
1
=15exp{3480( 273+t – 273 )}
R
t
0: 15 kΩ 30:
10: 9.6 kΩ 40:
20: 6.3 kΩ
25: 5.2 kΩ
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 kΩ
25: 50 kΩ
50: 17 kΩ
70: 8 kΩ
90: 4 kΩ
High temperature thermistors
• Thermistor <Discharge> (TH4)
• Thermistor <Comp. surface> (TH33 for W50VHA(R1–R3), W85VHAR1)
• Thermistor <Comp. surface> (TH34 for HW
Thermistor R120 = 7.465k" ± 2%
B constant = 4057 ± 2%
1
=7.465exp{4057( 273+t – 393 )}
R
t
20: 250 kΩ 70:
30: 160 kΩ 80:
40: 104 kΩ 90: 17.5 kΩ
50: 70 kΩ 100: 13.0 kΩ
60: 48 kΩ 110: 9.8 kΩ
OCH439M
1
4.3 kΩ
3.0 kΩ
1
HA2R3–R7)
•
1
34 kΩ
24 kΩ
50
40
30
20
10
0
-20 -10 0 10 20 30 40 50
Temperature (:)
200
150
100
50
0
25
Temperature (:)
500
400
300
200
100
0
25
64
50 75 100 125
50 75 100 120
Temperature (:)