Rockwell Automation System Design for the Control of Electrical Noise - Manual (Page 30)

Publication GMC-RM001A-EN-P — July 2001
2-12 High Frequency (HF) Bonding
Figure 2.10
Extending the panel ground plane using cable tray
New Buildings
In new installations it is possible to specify that the structural steel
columns are bonded together beneath the floor. This is similar in
concept to the special floor grid shown earlier (refer to Figure 2.7),
but inferior due to the large grid squares.
The panels are bonded by a flat strip or braid to the nearest steel
column. The floor, machine structure, and panels form a large, but
relatively ill-defined ground plane.
Figure 2.11
Panel ground plane extended to the building
Zinc plated
steel main
panel
Zinc plated
steel cable tray
(wider is better)
Must be directly bonded
here and at the
machine structure
Note: A ground plane does not have to be flat.
Same
width
Multiple
fasteners
Building ground plane.
Copper strip laid into the floor
bonding columns together.
Cabinet ground plane (panel)
bonded to nearest
building steel
Steel
Column
Machine structure used as ground plane
Steel
Column