Mitsubishi Electric EHST17D-YM9D Service Manual page 65

Pressure sensor
4.5
2.5
0.5
2.5 5 PRESSURE
(MPa)
Thermistors
<Thermistor Characteristics Charts>
• Room temperature thermistor (TH1)
• Liquid refrigerant temperature thermistor (TH2)
• Flow water temperature thermistor (THW1)
• Return water temperature thermistor (THW2)
• DHW tank temperature thermistor (THW5)
• Zone1 flow water temperature thermistor (THW6)
• Zone1 return water temperature thermistor (THW7)
• Zone2 flow water temperature thermistor (THW8)
• Zone2 return water temperature thermistor (THW9)
Thermistor R0 = 15kΩ ± 3%
B constant = 3480 ± 2%
Rt = 15exp {3480 ( 273+t – 273 )}
0°C 15 kΩ
10°C 9.6 kΩ
20°C 6.3 kΩ
25°C 5.2 kΩ
30°C 4.3 kΩ
40°C 3.0 kΩ
• Boiler flow water temperature thermistor (THWB1)
• Mixing tank temperature thermistor (THW10)
Thermistor R100 = 3.3kΩ ± 2%
B constant = 3970 ± 1%
Rt = 3.3exp {3970 ( 273+t – 273 )}
0°C 162.8 kΩ
10°C 97.4 kΩ
20°C 60.3 kΩ
25°C 48.1 kΩ
30°C 38.6 kΩ
40°C 25.4 kΩ
50°C 17.1 kΩ
60°C 11.9 kΩ
70°C 8.4 kΩ
80°C 6.0 kΩ
OCH714B
Part Name
FTC CONTROLLER BOARD
CN401 WH
5 VDC
RD 1
BK
3
MICRO
Vout WH
4
PROCESSOR
1-3 : 5 V (DC)
3-4 : Output Vout (DC)
1 1
1 1
Vout (V)
4.5
2.5
0.5
Disconnect the connector then measure the resistance with a multimeter.
(At ambient temperatures of 10 to 30°C.)
Thermistor
TH1
TH2
THW1
THW2
THW5A
THW5B
THW6
THW7
THW8
THW9
THW10
THWB1
50
40
30
20
10
0
-20 -10
1000
900
800
700
600
500
400
300
200
100
0
-30 -20 -10
65
Checkpoints
2.5 5 PRESSURE
(MPa)
Normal Abnormal
4.3 - 9.5 kΩ Open or short
40 - 100 kΩ Open or short
0 10 20 30 40 50
Temperature (:)
0 10 20 30 40 50 60
Temperature (°C)
FTC CO
CN401 WH
RD
1
BK
3
Vout WH
4
1-3 : 5 V (DC)
3-4 : Output Vout (DC)
70 80