Rockwell Automation 1772-LV,D17726.6.1 A and I MNL MINI-PLC-2/15 PROCESSO - Manual (Page 28)

Assembly and Installation
Chapter 3
3Ć8
Grounding is an important safety measure in electrical installations. With solid
state control systems, grounding has added value because it helps to reduce the
effects of noise due to electromagnetic noise interference (EMI).
Allen-Bradley Programmable Controller components and their enclosures must
be properly grounded. All applicable Codes and Ordinances should be observed
when wiring the Controller.
The grounding path for the Controller components and their enclosures should
be provided through a grounding electrode conductor to earth ground, the
grounding electrode system. In this document, earth ground is defined as the
central ground for all electrical equipment and AC power within any facility.
All ground connections must be permanent and continuous to provide a
low-impedance path to earth ground for induced noise current and/or fault
currents.
An authoritative source for grounding requirements is the National Electrical
Code published by the National Fire Protection Association of Boston,
Massachusetts. Article 250 of the Code provides such data as the size and types
of conductors and methods of safely grounding electrical components. Local
Codes and Ordinances dictate which grounding method is permissible. See
Publication 1770-980 for a discussion of general grounding and field wiring
practices.
General Grounding
Information