Rockwell Automation 1769-IR6 Compact I/O 1769-IR6 RTD/Resistance Input Module - Manual (Page 36)

36 Rockwell Automation Publication 1769-UM005B-EN-P - March 2012
Chapter 3 Installation and Wiring
Field Wiring Connections System Wiring Guidelines
Consider the following when wiring your system:
General
· This product is intended to be mounted to a well-grounded mounting
surface such as a metal panel. Additional grounding connections from
the module’s mounting tabs or DIN rail (if used) are not required unless
the mounting surface cannot be grounded.
· Channels are isolated from one another by ±10V DC maximum.
· Route field wiring away from any other wiring and as far as possible
from sources of electrical noise, such as motors, transformers,
contactors, and AC devices. As a general rule, allow at least 15.2 cm
(6 in.) of separation for every 120V of power.
· Routing field wiring in a grounded conduit can reduce electrical noise.
· If field wiring must cross AC or power cables, ensure that they cross at
right angles.
· To ensure optimum accuracy, limit overall cable impedance by keeping
your cable as short as possible. Locate the I/O system as close to your
sensors or actuators as your application will permit.
· Tighten terminal screws with care. Excessive tightening can strip a
screw.
Shield Grounding
· Use Belden shielded, twisted-pair wire to ensure proper operation and
high immunity to electrical noise. Refer to the following table and the
RTD Wiring Considerations below.
· Under normal conditions, the drain wire and shield junction should be
connected to earth ground, via a panel or DIN rail mounting screw at
the 1769-IR6 module end.
· Keep shield connection to ground as short as possible.
· If noise persists for a device, try grounding the opposite end of the
cable. (You can only ground one end at a time.)
· Refer to Industrial Automation Wiring and Grounding Guidelines,
publication
1770-4.1 , for additional information.
Configuration Recommended Cable
2-wire Belden 9501 or equivalent
3-wire
less than 30.48 m (100 ft) Belden 9533 or equivalent
3-wire
greater than 30.48 m (100 ft) or high humidity conditions Belden 83503 or equivalent