Rockwell Automation Publication 1719-IN001D-EN-E - November 2020 15
1719 Ex I/O Installation Instructions
Wiring
Lay the signal leads such that they are separate from the power cables. Please note that AC voltages and current spikes can induce stray voltages in neighboring lines. As
such, shielded, female single-ended patchcords should be used for EMC-tested devices.
Grounding rails can be laid separately from the shielding (see the IEC/EN 60079-14 directive). The shielding is then grounded at one point.
Field Wiring
Depending on the application, the shielding of the wiring must be grounded at one point or at both ends. If possible, avoid grounding at both ends to prevent ground loops
and ensure that the shielding is not used as a return line.
Sound results can be obtained with grounding at one end of the cable if the cable is laid on a grounded metal cable support. The metal frame in the immediate vicinity of the
conductor ensures that only small areas are exposed to the field, so that interference is largely reduced.
Digital inputs are normally controlled by NAMUR proximity switches with a low-impedance signal. In this case, interfering signals have a far lower impact than in circuits
containing open switches that do not have an additional resistor circuit. For this reason, do not connect digital inputs to exposed wiring.
The analog signals of resistive sensors or thermocouples are particularly susceptible to interference. Measuring transmitters have built-in filters to reduce this
interference. The filters can be switched on if fluctuations in the measuring signal cannot be reduced sufficiently by other means.
Eliminating Interference
The following measures can improve performance.
1. Fit line filters in power supply lines.
2. Fit surge protection filters in signal leads.
3. Change to galvanically isolated circuits.
Additional Resources
You can view or download publications at rok.auto/literature. To order paper copies of technical documentation, contact your local Allen-Bradley distributor or Rockwell
Automation sales representative.
WARNING: Risk of explosion
Observe the specifications for installation as set out in IEC/EN 60079-14.
For example, potential equalization ensures that the maximum resistance between different system components is 1 Ω. This is the basis for calculating
the required cable cross-section, depending on the distance between the system components.
Resource Description
1719 Ex I/O User Manual, publication 1719-UM001
Provides information on using the 1719 Ex I/O modules, backplanes, and accessories.
1719 Ex I/O Technical Data, publication 1719-TD001
Provides specifications, wiring diagrams, and module block diagrams for 1719 Ex I/O.
1719 Certification Bulletin, publication 1719-CT001
Provides 1719 Ex I/O certification information and links to control drawings.
Industrial Automation Wiring and Grounding Guidelines, publication 1770-4.1
Provides general guidelines for installing a Rockwell Automation industrial system.
Product Certifications website, rok.auto/certifications
Provides declarations of conformity, certificates, and other certification details.
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