Honeywell HC900 - I;O Terminal Block Wiring Diagrams; Table 15 - Typical Thermocouple Resistance in Ohms Per Double Foot @ 68 Degrees F

Revision 6 HC900 Process & Safety Controller User and Installation Manual 91
21 April 2017
I/O Terminal Block Wiring Diagrams
Universal Analog Input Module Wiring
The Universal Analog Input Module has eight inputs, which can include any combination of the following
input types: RTD, TC, Ohms, Millivolt, Volt, or Milliamp. Figure 43 shows wiring examples of each of the
analog input types. An example of wiring for eight TC inputs is given in Figure 45.
Specifications for this module and for other modules are given in the Specifications section of this manual.
ATTENTION
To indicate sensor failure the Analog Input software will output a warning if
thermocouple resistance > 80 ohms. Use appropriate gauge wiring to prevent
inaccurate failure warnings.
Table 15 – Typical Thermocouple resistance in Ohms per Double Foot @ 68 degrees F
AWG No.
Diameter
inches
Type K
Type J
Type T
Type E
Type S
Pt/ PT110
Type R
Pt/ PT113
Type W5/
W26
Type W/
W26
10
0.102
0.058
0.034
0.029
0.069
0.018
0.018
0.023
0.020
12
0.081
0.091
0.054
0.046
0.109
0.028
0.029
0.037
0.031
14
0.064
0.146
0.087
0.074
0.175
0.045
0.047
0.058
0.049
16
0.051
0.230
0.137
0.117
0.276
0.071
0.073
0.092
0.078
18
0.040
0.374
0.222
0.190
0.448
0.116
0.119
0.148
0.126
20
0.032
0.586
0.357
0.298
0.707
0.185
0.190
0.235
0.200
24
0.0201
1.490
0.878
0.7526
1.78
0.464
0.478
0.594
0.560
26
0.0159
2.381
1.405
1.204
2.836
0.740
0.760
0.945
0.803
30
0.0100
5.984
3.551
3.043
7.169
1.85
1.91
2.38
2.03
Table values are shown as a reference only; actual values may vary. Consult manufacturer specifications.
Isolation
This module has eight inputs, which are isolated except for RTD current sources.
RTD Inputs
RTD inputs share current sources (two RTD inputs per source), as shown in
Figure 42, Figure 43, and Figure 44.
For example, the current source for the RTD input at channel one (terminals 1 and 2) is terminal 3 (I
RTD
1 &
2). This same current source (I
RTD
1 & 2) is also used for an RTD input at channel two (terminals 4 and 5).