Troubleshooting – WattMaster WM-WCC3-TGD-01B User Manual
Page 800
VAV/Zone Controller Technical Guide
Operator Interface
32
Troubleshooting
Thermistor Sensor Testing Instructions
1.) Use the resistance column to check the thermistor sensor while
disconnected from the controllers (not powered).
2.) 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 5.08 VDC, then the sensor or wiring is “open.”
If the voltage is less than 0.05 VDC, the sensor or wiring is shorted.
Table 6: Temperature/Resistance for Type III 10K
Ohm Thermistor Sensors
Temperature – Resistance – Voltage for
Type III 10 K Ohm Thermistor Sensors
Temp
(ºF)
Resistance
(Ohms)
Voltage @ Input
(VDC)
-10
93333
4.620
-5
80531
4.550
0
69822
4.474
5
60552
4.390
10
52500
4.297
15
45902
4.200
20
40147
4.095
25
35165
3.982
30
30805
3.862
35
27140
3.737
40
23874
3.605
45
21094
3.470
50
18655
3.330
52
17799
3.275
54
16956
3.217
56
16164
3.160
58
15385
3.100
60
14681
3.042
62
14014
2.985
64
13382
2.927
66
12758
2.867
68
12191
2.810
69
11906
2.780
70
11652
2.752
71
11379
2.722
72
11136
2.695
73
10878
2.665
Temperature – Resistance – Voltage for
Type III 10 K Ohm Thermistor Sensors
Temp
(ºF)
Resistance
(Ohms)
Voltage @ Input
(VDC)
74
10625
2.635
75
10398
2.607
76
10158
2.577
78
9711
2.520
80
9302
2.465
82
8893
2.407
84
8514
2.352
86
8153
2.297
88
7805
2.242
90
7472
2.187
95
6716
2.055
100
6047
1.927
105
5453
1.805
110
4923
1.687
115
4449
1.575
120
4030
1.469
125
3656
1.369
130
3317
1.274
135
3015
1.185
140
2743
1.101
145
2502
1.024
150
2288
0.952
Table 6, cont.: Temperature/Resistance for Type III
10K Ohm Thermistor Sensors