24
RSMV Technical Guide
TROUBLESHOOTING
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 4.88 VDC, then the sensor or wiring is
“open.” If the voltage is less than 0.05 VDC, then the sensor or
wiring is shorted.
Sensor Voltage and Resistance
The following sensor voltage and resistance table is provided to
aid in checking sensors that appear to be operating incorrectly. See
Table 5
, below. 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 confirm that the sensor is operating
correctly per the tables. Please follow the notes and instructions that
appear after the chart when checking sensors.
Table 5: 0-5V Temperature Sensor - Voltage & Resistance for Type III Sensors
Temperature – Resistance – Voltage for Type III 10 K Ohm Thermistor Sensors
Temp
(ºF)
Temp
(ºC)
Resistance
(Ohms)
Voltage @
Input (VDC)
Temp
(ºF)
Temp
(ºC)
Resistance
(Ohms)
Voltage @
Input
(VDC)
-10
-23.3
93333
4.51
72
22.2
11136
2.635
-5
-20.6
80531
4.45
73
22.8
10878
2.605
0
-17.8
69822
4.37
74
23.3
10625
2.576
5
-15
60552
4.29
75
23.9
10398
2.549
10
-12.2
52500
4.2
76
24.4
10158
2.52
15
-9.4
45902
4.1
77
25
10000
2.5
20
-6.6
40147
4.002
78
25.6
9711
2.464
25
-3.9
35165
3.891
80
26.7
9302
2.41
30
-1.1
30805
3.773
82
27.8
8893
2.354
35
1.7
27140
3.651
84
28.9
8514
2.3
40
4 4.4
23874
3.522
86
30
8153
2.246
45
7.2
21094
3.39
88
31.1
7805
2.192
50
10
18655
3.252
90
32.2
7472
2.139
52
11.1
17799
3.199
95
35
6716
2.009
54
12.2
16956
3.143
100
37.8
6047
1.884
56
13.3
16164
3.087
105
40.6
5453
1.765
58
14.4
15385
3.029
110
43.3
4923
1.65
60
15.6
14681
2.972
115
46.1
4449
1.54
62
16.7
14014
2.916
120
48.9
4030
1.436
64
17.8
13382
2.861
125
51.7
3656
1.339
66
18.9
12758
2.802
130
54.4
3317
1.246
68
20
12191
2.746
135
57.2
3015
1.159
69
20.6
11906
2.717
140
60
2743
1.077
70
21.1
11652
2.691
145
62.7
2502
1.001
71
21.7
11379
2.661
150
65.6
2288
0.931
Summary of Contents for RSMV ASM01686
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