Rockwell Automation System Design for the Control of Electrical Noise - Manual (Page 34)

Publication GMC-RM001A-EN-P — July 2001
3-2 Segregating Sources and Victims
Figure 3.1 shows how you can create three zones in a standard panel
or cabinet enclosure. The very-dirty items are placed in the right/front
section. The dirty items are placed behind them in the right/rear
section and the least noisy (clean) items are placed in the left/rear
section.
Figure 3.1
Relative position of noise zones on the panel
A side panel is fitted on the right to support the power cable shield
clamps and any very-dirty wires, cables, or components. This leaves
the main panel free for the clean and dirty zones.
Note: It is preferable to mount PLC and motion control equipment in a
separate cabinet away from power control equipment (motor
starters, etc.).
Ensuring CE Compliance at Build Time
Ensuring CE compliance is aided by the use of detailed physical panel
layouts, together with wiring schedules to specify precise wire routing
and zone categories. Periodic checks during installation are
recommended to achieve full CE compliance.
As an aid to the technicians wiring the panel, the use of grey
wireways for the clean zone and black wireways for the dirty zone
helps ensure proper segregation of cables. For example, this makes a
communication cable running in a dirty wireway easier to see.
Zone Classification You can classify each cable or device based on these two factors:
• How much noise does the cable/device generate/radiate?
• How sensitive is the device connected via the cable to electrical
noise?
Dirty wireway and component
mounting section
Clean wireway and component
mounting section
Main Panel or Cabinet
(top view)
Left side and front panels (if cabinet)
Right side
divider panel
Very-Dirty
cable tray and
component mounting