Rockwell Automation 1747-ACNR15 ControlNet Adapter Module User Manual - Manual (Page 100)

Publication 1747-UM003A-EN-P
B-8 Understanding Your SLC 500/1746 Control System
Preventing Excessive Heat
For most applications, normal convection cooling keeps the adapter
components within the specified operating range of 0° to +60° C (+32° to
+140° F). Proper spacing of components within the enclosure is usually
sufficient for heat dissipation.
In some applications, a substantial amount of heat is produced by other
equipment inside or outside the enclosure. In this case, place blower fans inside
the enclosure to assist in air circulation and to reduce “hot spots” near the
adapter.
Additional cooling provisions might be necessary when high ambient
temperatures are encountered.
Wiring Layout
Careful wire routing within the enclosure helps to cut down electrical noise
between I/O lines. Follow these rules for routing your wires:
•
Route incoming power to the power supply by a separate path from wiring
to I/O devices. Where paths must cross, their intersection should be
perpendicular.
•
If wiring ducts are used, allow for at least 5 cm (2 in.) between I/O wiring
ducts and the adapter. If the terminal strips are used for I/O wiring,
allow for at least 5 cm (2 in.) between the terminal strips and the
adapter.
•
Limit the cable length for the TTL input module to 15 m (50 ft.) per point
and 3 m (10 ft.) per point for the TTL output module. Use low power
dc I/O wiring even though it is less tolerant to electrical noise.
IMPORTANT
Do not bring in unfiltered outside air. It may introduce
harmful contaminants of dirt that could cause improper
operation or damage to components. In extreme cases, you
may need to use air conditioning to protect against heat
build-up within the enclosure.
IMPORTANT
Do not run signal or communications wiring and power
wiring in the same conduit.