Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual User Manual
Page 31
Publication 1746-UM003A-EN-P
Installation and Wiring 2-11
There are several ways to insure that the lead values match as closely as
possible. They are as follows:
•
Keep lead resistance as small as possible and less than 25
Ω
.
•
Use quality cable that has a small tolerance impedance rating.
•
Use a heavy-gauge lead wire which has less resistance per foot.
Wiring Resistance Devices (Potentiometers) to the Module
Potentiometer wiring requires the same type of cable as that for the RTD
described in the previous subsection. Potentiometers can be connected to the
RTD module as a 2-wire connection or a 3-wire connection.
IMPORTANT
To ensure temperature or resistance value accuracy, the
resistance difference of the cable lead wires must be equal to
or less than 0.01
Ω
..