Mitsubishi Electric PUZ-HA24NHA1, Руководство по обслуживанию

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54
OCH750A
10-6. HOW TO CHECK THE COMPONENTS
<Thermistor feature chart>
Low temperature thermistors
• Thermistor <Liquid pipe> (TH3)
• Thermistor <2-phase pipe> (TH6)
• Thermistor <Ambient> (TH7)
• Thermistor <Suction pipe> (TH32)
32˚F [0˚C] 15 kΩ
50˚F [10˚C] 9.6 kΩ
68˚F [20˚C] 6.3 kΩ
77˚F [25˚C] 5.2 kΩ
86˚F [30˚C] 4.3 kΩ
104˚F [40˚C] 3.0 kΩ
68˚F [20˚C] 250 kΩ
86˚F [30˚C] 160 kΩ
104˚F [40˚C] 104 kΩ
122˚F [50˚C] 70 kΩ
140˚F [60˚C] 48 kΩ
158˚F [70˚C] 34kΩ
176˚F [80˚C] 24kΩ
194˚F [90˚C] 17.5kΩ
212˚F [100˚C] 13.0kΩ
230˚F [110˚C] 9.8kΩ
High temperature thermistors
• Thermistor <Discharge> (TH4)
• Thermistor <Comp. surface> (TH33)
0
10
20
30
40
50
-20 -10 0 10 20 30 40 50
-4 -14 32 50 68 86 104122
°C
°F
Temperature
Resistance (k
"
)
500
400
300
200
100
0
25
50 75 100 120
77
122 167 212 248
°
C
°
F
Temperature
Resistance (k
"
)
Thermistor R0 = 15 kΩ ± 3%
B constant = 3480 ± 1%
t (
:
): R
t
=15exp{3480( 273+t – 273 )}
T (˚F): R
T
=15exp{3480( 273+(T– 32)/1.8 – 273 )}
1 1
1 1
Thermistor R120 = 7.465 kΩ ± 2%
B constant = 4057 ± 2%
t (˚C): Rt =7.465exp{4057(
273+t – 393)}
T (˚F): R
T
=7.465exp{4057( 273+(T– 32)/1.8 – 393 )}
1 1
1 1
32°F [0°C] 180 kΩ
77°F [25°C] 50 kΩ
122°F [50°C] 17 kΩ
158°F [70°C] 8 kΩ
194°F [90°C] 4 kΩ
Medium temperature thermistor
• Thermistor <Heat sink> (TH8)
200
150
100
50
0
25 50 75 100 110 125
77 122 167 212 230 257
(°C)
(°F)
Temperature
Resistance (k
Ω
)
Thermistor R50 = 17 k
"
± 2%
B constant = 4150 ± 3%
t (°C): Rt =17exp{4150( 273+t – 323)}
T (°F): R
T
=17exp{4150( 273+(T– 32)/1.8 – 323 )}
1 1
1 1