Spectrum Controls 1756sc-OF8H Series A - Manual (Page 27)

Chapter 2: Installing And Wiring Your Module 13
• Ground the shield drain wire at only one end of the cable. The
preferred location is at the shield connections at the ControlLogix
chassis. (Refer to IEEE Std. 518, Section 6.4.2.7 or contact your
sensor manufacturer for additional details.)
• Keep all unshielded wires as short as possible.
• To limit overall cable impedance, keep input cables as short as
possible. Locate your I/O chassis as near to the sensors as your
application will permit.
• Tighten screw terminals with care. Excessive tightening can strip a
screw.
• Follow system grounding and wiring guidelines found in your
ControlLogix Installation and Operation Manual.
Preparing and Wiring
the Cables
To prepare and connect cable leads and drain wires, follow these steps:
1. At each end of the cable, strip some casing to expose individual wires.
2. Trim signal wires to 5-inch lengths beyond the cable casing. Strip
about 3/16 inch (4.76 mm) of insulation to expose the ends of the
wires.
3. At the module-end of the cables (see figure above):
- extract the drain wire and signal wires
- remove the foil shield
- bundle the input cables with a cable strap
4. Connect pairs of drain wires together, Channels 0 and 1, Channels 2
and 3, Channels 4 and 5, Channels 6 and 7. Keep drain wires as short
as possible.
5. Connect the drain wires to the grounding lug on the PLC chassis.
6. Connect the signal wires of each channel to the terminal block.
Important: Only after verifying that your connections are correct for
each channel, trim the lengths to keep them short. Avoid cutting leads
too short.
7. At the source-end of cables from voltage devices:
- remove the drain wire and foil shield
- apply shrink wrap as an option