Rockwell Automation 1794-IF2XOF2IXT FLEX XT I/O Isolated Input Analog Module User Manual
European hazardous location approval
 
Publication 1794-IN129B-EN-P - April 2009
Installation Instructions
FLEX XT I/O Isolated Input Analog Module
Cat. No. 1794-IF4IXT, 1794-OF4IXT, 1794-IF2XOF2IXT
European Hazardous Location Approval
Important User Information
Solid state equipment has operational characteristics differing from those of electromechanical 
equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid State 
utomation sales office or online at
describes some important differences between solid state
equipment and hard-wired electromechanical devices. Because of this difference, and also because 
of the wide variety of uses for solid state equipment, all persons responsible for applying this 
equipment must satisfy themselves that each intended application of this equipment is acceptable.
In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential 
damages resulting from the use or application of this equipment.
The examples and diagrams in this manual are included solely for illustrative purposes. Because of 
the many variables and requirements associated with any particular installation, Rockwell 
Automation, Inc. cannot assume responsibility or liability for actual use based on the examples and 
diagrams.
No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, 
circuits, equipment, or software described in this manual.
Reproduction of the contents of this manual, in whole or in part, without written permission of 
Rockwell Automation, Inc., is prohibited.
Throughout this manual we use notes to make you aware of safety considerations.
WARNING
Identifies information about practices or circumstances that can cause an 
explosion in a hazardous environment, which may lead to personal injury or 
death, property damage, or economic loss.
ATTENTION
Identifies information about practices or circumstances that can lead to 
personal injury or death, property damage, or economic loss. Attentions help 
you:
•
identify a hazard
•
avoid a hazard
•
recognize the consequence
IMPORTANT
Identifies information that is critical for successful application and 
understanding of the product.
ATTENTION
Environment and Enclosure
This equipment is intended for use in a Pollution Degree 2 industrial 
environment, in overvoltage Category II applications (as defined in IEC 
60664-1), at altitudes up to 2000 m (6562 ft) without derating.
This equipment is considered Group 1, Class A industrial equipment according 
to IEC/CISPR 11. Without appropriate precautions, there may be difficulties 
with electromagnetic compatibility in residential and other environments due 
to conducted and radiated disturbances.
This equipment is supplied as open-type equipment. It must be mounted within 
an enclosure that is suitably designed for those specific environmental 
conditions that will be present and appropriately designed to prevent personal 
injury resulting from accessibility to live parts. The enclosure must have 
suitable flame-retardant properties to prevent or minimize the spread of flame, 
complying with a flame spread rating of 5VA, V2, V1, V0 (or equivalent) if 
non-metallic. The interior of the enclosure must be accessible only by the use 
of a tool. Subsequent sections of this publication may contain additional 
information regarding specific enclosure type ratings that are required to 
comply with certain product safety certifications.
In addition to this publication, see:
•
Industrial Automation Wiring and Grounding Guidelines, for additional 
installation requirements, Allen-Bradley publication 
.
•
NEMA Standards 250 and IEC 60529, as applicable, for explanations of 
the degrees of protection provided by different types of enclosure.
WARNING
If you insert or remove the module while backplane power is on, an electrical 
arc can occur. This could cause an explosion in hazardous location installations.
Be sure that power is removed or the area is nonhazardous before proceeding.
WARNING
If you connect or disconnect wiring while the field side power is on, an 
electrical arc can occur. This could cause an explosion in hazardous location 
installations. Be sure that power is removed or the area is nonhazardous 
before proceeding.
ATTENTION
FLEX I/O is grounded through the DIN rail to chassis ground. Use zinc plated 
yellow-chromate steel DIN rail to assure proper grounding. The use of other DIN 
rail materials (for example, aluminum or plastic) that can corrode, oxidize, or are 
poor conductors, can result in improper or intermittent grounding. Secure DIN 
rail to mounting surface approximately every 200 mm (7.8 in.) and use 
end-anchors appropriately. 
ATTENTION
Prevent Electrostatic Discharge
This equipment is sensitive to electrostatic discharge, which can cause internal 
damage and affect normal operation. Follow these guidelines when you handle 
this equipment:
•
Touch a grounded object to discharge potential static.
•
Wear an approved grounding wriststrap.
•
Do not touch connectors or pins on component boards.
•
Do not touch circuit components inside the equipment.
•
Use a static-safe workstation, if available.
•
Store the equipment in appropriate static-safe packaging when not in 
use.
ATTENTION
Personnel responsible for the application of safety-related programmable 
electronic systems (PES) shall be aware of the safety requirements in the 
application of the system and shall be trained in using the system.
ATTENTION
To comply with the CE Low Voltage Directive (LVD), all connections to this 
equipment must be powered from a source compliant with the following:
Safety Extra Low Voltage (SELV) or Protected Extra Low Voltage (PELV).
ATTENTION
Do not remove or replace a Terminal Base unit while power is applied. 
Interruption of the backplane can result in unintentional operation or machine 
motion.
European Zone 2 Certification (The following applies when the product bears the Ex 
or EEx Marking)
This equipment is intended for use in potentially explosive atmospheres as defined by European 
Union Directive 94/9/EC and has been found to comply with the Essential Health and Safety 
Requirements relating to the design and construction of Category 3 equipment intended for use 
in potentially explosive atmospheres, given in Annex II to this Directive.
Compliance with the Essential Health and Safety Requirements has been assured by compliance 
with EN 60079-15 and EN 60079-0.
WARNING
Observe the following additional Zone 2 certification requirements.
•
This equipment is not resistant to sunlight or other sources of UV
radiation.
•
This equipment must be installed in an enclosure providing at least IP54
protection when applied in Zone 2 environments.
•
This equipment shall be used within its specified ratings defined by
Allen-Bradley.
•
Provision shall be made to prevent the rated voltage from being
exceeded by transient disturbances of more than 40% when applied in 
Zone 2 environments.
•
Secure any external connections that mate to this equipment by using
screws, sliding latches, threaded connectors, or other means provided 
with this product.
•
Do not disconnect equipment unless power has been removed or the
area is known to be nonhazardous.