Rockwell Automation System Design for the Control of Electrical Noise - Manual (Page 45)

Publication GMC-RM001A-EN-P — July 2001
Shielding Wires, Cables, and Components 4-5
In Figure 4.5 the cable is locally shielded to cross another zone. Each
shield is grounded at each boundary and the cable is run close to the
panel. The outer shield A is a thick walled steel conduit.
Figure 4.5
Very-dirty cable in clean zone
The principle works both ways. In Figure 4.6 the clean cable passes
through a very-dirty zone.
Figure 4.6
Clean cable in very-dirty zone
A
Minimum 150 mm (6.0 in.) segregation
Dirty Zone Dirty Zone
Dirty Zone
Very-Dirty Zone Very-Dirty Zone
EMC
filter to drive
Motor power
cable
24V dc I/O
cable
Clean
Zone
A
Dirty Zone
Dirty Zone Dirty Zone Clean Zone Clean Zone
24V dc I/O
cable
Very-Dirty
Zone
Analog device
cable
Encoder
cable
Minimum 150 mm (6.0 in.) segregation