1/01 UDC3300 Limit Controller Product Manual 99
9.4 Recommended Wiring Practices, Continued
Additional rules
Please observe these additional rules for wire bundling:
• For distances over five (5) feet, and when shielding is recommended,
use a separate metal tray or conduit for each bundle. Where conduits or
trays are not practical, use twisted wires with a metal overbraid and
provide physical separation of at least one foot.
• Tray covers must be in continuous contact with the side rails of the
trays.
• When unlike signal levels must cross, either in trays or conduits, they
should cross at a 90-degree angle and at a maximum spacing. Where it
is not possible to provide spacing, a grounded steel barrier or grid
should be placed between the unlike levels at the crossover points.
• Trays containing low level wiring should have solid bottoms and sides.
Tray covers must be used for complete shielding. Tray cover contact
with side rails must be positive and continuous to avoid high reluctance
air gaps, which impair shielding. Trays for low level cables should be
metal and solidly grounded.
• Wires containing low level signals should not be routed near any of the
following:
– Contactors
– Motors
– Generators
– Radio transmitters
– Wires carrying high current that is being switched on and off.
• Use a 12-gage (or heavier) insulated stranded wire for the ground
connection. Attach it firmly to a proven good earth ground such as a
metal stake driven into the ground.
• All shields should be grounded at one end only — preferably the
instrument end.
To Next Page
Loading...
