Rockwell Automation System Design for the Control of Electrical Noise - Manual (Page 41)

Publication GMC-RM001A-EN-P — July 2001
Chapter
4
Shielding Wires, Cables, and Components
Chapter Objectives This chapter describes how using shielded cable or steel shields can
reduce electrical noise coupling. This chapter covers the following
topics:
• Understanding the shielding concept
• Ferrite sleeves
• Mixing categories
Understanding the
Shielding Concept You can avoid many of the problems caused by noise by shielding
sources and victims (along with their associated wiring) with the use
of shielded cable or a supplementary steel shield.
If sources and victims cannot be sufficiently segregated it may be
possible to prevent noise coupling by shielding as shown in the figure
below.
Figure 4.1
Wire segregation vs. shield
Dirty Zone Clean Zone
Minimum segregation is
150 mm (6.0 in.) within a panel
Grounded steel shield
allows minimal segregation
distance.