Rockwell Automation 1794-IRT8XT FLEX I/O Thermocouple/RTD /Millivolt Input Module User Manual - Manual (Page 29)

Publication 1794-6.5.12 - September 2011
Install Your FLEX I/O Input Module 17
Signal wiring shields can be connected to terminals 16 or 33 on row B or
terminals 40…45 on row C.
2. Connect the +V DC power lead to terminal 34 on row C, terminals
34…51.
3. Connect the -V DC common (return-) to terminal 35 on row C,
terminals 34…51.
4. If daisychaining power to the next terminal base unit, connect a jumper
from terminal 50 (+V DC) on this base unit to +V terminal on the next
terminal base unit.
5. Connect a jumper from terminal 51 (-V DC common) to the -V DC
common terminal on the next terminal base unit.
6. If using cold junction compensators, make these connections as shown
in the CJC Sensor chart below.
Identify RTD Wire Pairs
If the RTD wires are color-coded, the wires that are the same color are
connected together. If the wires are not color-coded, use an ohmmeter to
determine the pairs as explained below.
How to Connect a 4-wire RTD
If the 4-wire RTD wires are all different colors, use an ohmmeter to determine
which leads are connected together. One of the leads in each pair is the
compensation lead. Either lead of the pair can be the compensation lead.
Attach one pair to terminals L and - and the other pair to + and H.
How to Connect a 3-wire RTD
If the 3-wire RTD wires are all different colors, use an ohmmeter to determine
which leads are connected together. Either lead of the pair can be the
compensation lead. Attach one lead of the pair to terminal L and the other to
+. Attach the single lead to -.
Refer to the table, Wiring Connections for the FLEX I/O Input Module, on
page 18.
ATTENTION
Do not daisychain power or ground from this terminal base unit to any
AC or DC digital module terminal base units.