Zone
Zone
APPENDIX A
VCB-X Controller Field Technical Guide
86
Copeland
®
Discharge Thermistor Temperature Sensor Testing
Thermistor Sensor Testing Instructions
Use the resistance column to check the thermistor sensor while
disconnected from the controllers (not powered).
Use the voltage column to check sensors while connected to powered
controllers. Read voltage with meter set on DC volts. Place the “-”
(minus) lead on GND terminal and the “+” (plus) lead on the sensor
input terminal being investigated.
If the voltage is above 4.98 VDC, then the sensor or wiring is “open.”
If the voltage is less than 0.38 VDC, then the sensor or wiring is
shorted.
Copeland
®
Discharge Thermistor
Temperature Sensor Testing
The following sensor voltage and resistance table is provided to aid
in checking sensors that appear to be operating incorrectly. Many
system operating problems can be traced to incorrect sensor wiring.
Be sure all sensors are wired per the wiring diagrams in this manual.
If the sensors still do not appear to be operating or reading correctly,
check voltage and/or resistance to con
fi
rm that the sensor is operating
correctly per the table. Please follow the notes and instructions the
appear after the chart when checking sensors.
Discharge Thermistor Temperature/
Resistance
Temp
(ºF)
Temp
(ºC)
Resistance
(K Ohms)
Voltage @
Input (VDC)
-40
-40
2889.60
4.98
-31
-35
2087.22
4.97
-22
-30
1522.20
4.96
-13
-25
1121.44
4.95
-4
-20
834.72
4.94
5
-15
627.28
4.92
14
-10
475.74
4.89
23
-5
363.99
4.86
32
0
280.82
4.82
41
5
218.41
4.77
50
10
171.17
4.72
59
15
135.14
4.65
68
20
107.44
4.57
77
25
86.00
4.47
86
30
69.28
4.36
95
35
56.16
4.24
104
40
45.81
4.10
113
45
37.58
3.94
122
50
30.99
3.77
131
55
25.68
3.59
140
60
21.40
3.40
149
65
17.91
3.20
158
70
15.07
3.00
167
75
12.73
2.80
176
80
10.79
2.59
185
85
9.20
2.39
Table 9: Discharge Thermistor Temperature/
Resistance
Discharge Thermistor Temperature/
Resistance
Temp
(ºF)
Temp
(ºC)
Resistance
(K Ohms)
Voltage @
Input (VDC)
194
90
7.87
2.19
203
95
6.77
2.01
212
100
5.85
1.84
221
105
5.09
1.68
230
110
4.45
1.53
239
115
3.87
1.39
248
120
3.35
1.25
257
125
2.92
1.12
266
130
2.58
1.02
275
135
2.28
0.92
284
140
2.02
0.83
293
145
1.80
0.76
302
150
1.59
0.68
311
155
1.39
0.61
320
160
1.25
0.55
329
165
1.12
0.50
338
170
1.01
0.45
347
175
0.92
0.42
356
180
0.83
0.38
Table 9, cont.: Discharge Thermistor Temperature/
Resistance
Содержание OE335-26B-VCBX-A
Страница 115: ...NOTES VCB X Controller Field Technical Guide 115...