Rockwell Automation 1797-Series ControlNet Ex Media Plannng Installation Manual - Manual (Page 36)

Publication CNET-IN003A-EN-P - January 2006
2-14 Plan a ControlNet Ex Media System
General Wiring Guidelines
Follow these guidelines with regard to noise coupling. Following
intrinsic safety requirements should prevent most or all of these
situations from occurring. These guidelines are provided as a general
reference for wiring.
•
If wiring must cross power feed lines, it should do so at right
angles.
•
Route wiring at least 1.5 m (5 ft) from high-voltage enclosures,
or sources of rf/microwave radiation.
•
If the conductor is in a metal wireway or conduit, each section
of that wireway or conduit must be bonded to each adjacent
section so that it has electrical continuity along its entire length,
and must be bonded to the enclosure at the entry point.
For more information on general wiring guidelines, see the
Industrial Automation Wiring and Grounding Guidelines, publication
1770-4.1.
Wire External to Enclosures
Cables that run outside protective enclosures are relatively long.
To minimize cross-talk from nearby cables, you should maintain
maximum separation between the ControlNet Ex cable and other
potential noise conductors. Route your cable following these
guidelines:
Wire Inside Enclosures
Cable sections that run inside protective equipment enclosures are
relatively short. As with wiring external to enclosures, you should
maintain maximum separation between your ControlNet Ex cable and
Category-1 conductors.
Cable in a Contiguous
Metallic Wireway or
Conduit?
Route Your
Cable At Least From Noise Sources of This Strength
Yes 0.08 m (3 in.) Category-1 conductors of less than 20A
0.15 m (6 in.) ac power lines of 20A or more, up to 100 KVA
0.3 m (12 in.) ac power lines greater than 100 KVA
No 0.15 m (6 in.) Category-1 conductors of less than 20A
0.3 m (12 in.) ac power lines of 20A or more, up to 100 KVA
0.6 m (24 in.) ac power lines greater than 100 KVA