Allen-Bradley Compact 1769-IR6, User Manual

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Publication 1769-UM005A-EN-P
Installation and Wiring 3-9
Shield Grounding
•
Use Belden shielded, twisted-pair wire to ensure proper operation
and high immunity to electrical noise. Refer to the following table and
the RTD Wiring Considerations below.
•
Under normal conditions, the drain wire and shield junction should be
connected to earth ground, via a panel or DIN rail mounting screw at
the 1769-IR6 module end.
•
Keep shield connection to ground as short as possible.
•
If noise persists for a device, try grounding the opposite end of the
cable. (You can only ground one end at a time.)
•
Refer to Industrial Automation Wiring and Grounding Guidelines ,
Allen-Bradley publication 1770-4.1, for additional information.
RTD Wiring Considerations
Since the operating principle of the RTD module is based on the
measurement of resistance, take special care when selecting your input
cable. For 2-wire or 3-wire configurations, select a cable that has a
consistent impedance throughout its entire length. See Cable
Specifications on page A-4.
Configuration
Recommended Cable
(1)
2-wire Belden™ 9501 or equivalent
3-wire
less than 30.48 m (100ft.) Belden™ 9533 or equivalent
3-wire
greater than 30.48 m (100 ft.) or high humidity conditions Belden™ 83503 or equivalent
(1) For additional information, see page A-4.
IMPORTANT
The RTD module requires three wires to compensate for
lead resistance error. We recommend that you do not use
2-wire RTDs if long cable runs are required, as it reduces
the accuracy of the system. However, if a two-wire
configuration is required, reduce the effect of the lead
wire resistance by using a lower gauge wire for the cable
(for example, use AWG #16 instead of AWG #24). The
module’s terminal block accepts two AWG #14 gauge
wires.
AB PLCs