New buildings, New buildings -12 – Rockwell Automation System Design for the Control of Electrical Noise User Manual

Page 30

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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

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