Mitsubishi Electric PUHZ-P100VHA2 Service Manual page 72

11-7. HOW TO CHECK THE COMPONENTS
<Thermistor feature chart>
Low temperature thermistors
• Thermistor <Outdoor pipe>, <Liquid> (TH3)
• Thermistor <Outdoor 2-Phase Pipe>, <2-Phase Pipe> (TH6)
• Thermistor <Outdoor>, <Ambient> (TH7)
Thermistor R0 = 15k' ± 3%
B constant = 3480 ± 2%
1
=15exp{3480( 273+t – 273 )}
R
t
0: 15k' 30:
10: 9.6k' 40:
20: 6.3k'
25: 5.2k'
Medium temperature thermistor
• Thermistor <Heat Sink> (TH8) (VHA2
Thermistor R50 = 17k' ± 2%
B constant = 4150 ± 3%
1
=17exp{4150( 273+t – 323 )}
R
t
0: 180k'
25: 50k'
50: 17k'
70: 8k'
90: 4k'
High temperature thermistor
• Thermistor <Discharge> (TH4) : VHA2, VHA2
• Thermistor <Comp. Surface> (TH32) : VHA3R2, VHA3R3, VHA4,
Thermistor R120 = 7.465k' ± 2%
B constant = 4057 ± 2%
1
=7.465exp{4057( 273+t – 393 )}
R
t
20: 250k' 70:
30: 160k' 80:
40: 104k' 90:
50: 70k' 100: 13.0k'
60: 48k' 110:
OCH415F
1
4.3k'
3.0k'
/ VHA3(R1) / YHA2)
(1)
1
, VHA3, VHA3R1
1
YHA, YHAR1, YHAR2, YHA2
1
34k'
24k'
17.5k'
9.8k'
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
72
Temperature ( )
25 50 75 100
Temperature ( )
50 75 100
25
Temperature ( )
125
120