Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers - Manual (Page 40)

Publication 1785-UM012D-EN-P - July 2005
3-4 Placing System Hardware
Laying Out Your Cable
Raceway The raceway layout of a system reflects where the different types of I/O
modules are placed in I/O chassis. Therefore, you should determine
I/O-module placement prior to any layout and routing of wires. When
planning your I/O-module placement, however, segregate the modules based
on the conductor categories published for each I/O module so that you can
follow these guidelines. These guidelines coincide with the guidelines for “the
installation of electrical equipment to minimize electrical noise inputs to
controllers from external sources” in IEEE standard 518-1982.
To plan a raceway layout, do the following:
• categorize conductor cables
• route conductor cables
Categorize Conductors
Segregate all wires and cables into categories as described in the Industrial
Automation Wiring and Grounding Guidelines, publication 1770-4.1. See the
installation data for each I/O module that you are using for information about
its classification.
Route Conductors
To guard against coupling noise from one conductor to another, follow the
general guidelines for routing cables described in the Industrial Automation
Wiring and Grounding Guidelines, publication 1770-4.1. You should follow
the safe grounding and wiring practices called out in the National Electrical
Code (NEC, published by the National Fire Protection Association, in Quincy,
Massachusetts), and local electrical codes.