How To Check The Components; Low Temperature Thermistors; Medium Temperature Thermistor; High Temperature Thermistor - Mitsubishi Electric PUMY-P112VKM1 Service Manual

8-8. HOW TO CHECK THE COMPONENTS

<Thermistor feature chart>

Low temperature thermistors

• Thermistor <HIC pipe> (TH2)
• Thermistor <Outdoor liquid pipe> (TH3)
• Thermistor <Suction pipe> (TH6)
• Thermistor <Ambient> (TH7)
Thermistor R0 = 15 k" ± 3 %
B constant = 3480 ± 2 %
1
R =15exp{3480( –
t
273+t 273
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 = 4170 ± 3 %
1
R =17exp{4170( –
t
273+t
0: 180 k"
25: 50 k"
50: 17 k"
70: 8 k"
90: 4 k"

High temperature thermistor

• Thermistor <Compressor> (TH4)
Thermistor R120 = 7.465 k" ± 2 %
B constant = 4057 ± 2 %
1
R =7.465exp{4057(
t
273+t
20: 250 k" 70:
30: 160 k" 80:
40: 104 k" 90:
50: 70 k" 100:
60: 48 k" 110:
<HIGH PRESSURE SENSOR>
Vout (V)
4.5
2.5
0.5
2.5 5
PRESSURE
(MPa)
OCH576
1
)}
4.3 k"
3.0 k"
(Only YKM)
1
)}
323
1
– )}
393
34 k"
24 k"
17.5 k"
13.0 k"
9.8 k"
OUTDOOR MULTI CONTROLLER
CIRCUIT BOARD
5 V DC
3
WHT
2
BLU
Vout MICRO
PROCESSOR
1
BLK
GND
63HS
3-1 : 5 V (DC)
2-1 : Output Vout (DC)
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
<LOW PRESSURE SENSOR>
Vout (V)
3.5
2.5
0.5
0.85 1.7
PRESSURE
(MPa)
117
Temperature (:)
25 50 75 100 110 125 :
Temperature
25 50 75 100 120
Temperature (:)
OUTDOOR MULTI CONTROLLER
CIRCUIT BOARD
5 V DC
3
RED
2
WHT
MICRO
Vout
PROCESSOR
1
BLK
GND
63LS
3-1 : 5 V (DC)
2-1 : Output Vout (DC)