Rockwell Automation 1794-IA8_IA8I_IA16 FLEX I/O ac Input Modules Installation Instructions User Manual
North american hazardous location approval
 
FLEX I/O is a trademark of Rockwell Automation
DeviceNet is a trademark of ODVA, Inc.
Publication 1794-IN102B-EN-P - June 2004
Installation Instructions
FLEX I/O ac Digital Input Modules
Cat. Nos. 1794-IA8, -IA8K, IA8I, -IA16
(Modules with a K in the last position of the catalog number are conformally 
coated to meet noxious gas requirements of ISA/ANSI-71.040 1985 Class 
G3 Environment.)
North American Hazardous Location Approval
The following input modules are North American Hazardous Location 
approved: 1794-IA8, -IA8K, -IA8I and 1794-IA16.
.
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 Controls (Publication SGI-1.1 available from your local Rockwell 
Automation sales office or online at http://www.ab.com/manuals/gi) 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.
IMPORTANT
Identifies information that is critical for successful application and 
understanding of the product.
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
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 publication 60664-1), at altitudes up to 2000
meters without derating.
This equipment is considered Group 1, Class A industrial 
equipment according to IEC/CISPR Publication 11. Without
appropriate precautions, there may be potential difficulties
ensuring electromagnetic compatibility in other environments
due to conducted as well as radiated disturbance.
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 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.
See NEMA Standards publication 250 and IEC publication 
60529, as applicable, for explanations of the degrees of
protection provided by different types of enclosure. Also, see the
appropriate sections in this publication, as well as the
Allen-Bradley publication 1770-4.1 ("Industrial Automation
Wiring and Grounding Guidelines"), for additional installation
requirements pertaining to this equipment.
WARNING
When 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 (e.g. aluminum, plastic, etc.) that
can corrode, oxidize, or are poor conductors, can result in improper or
intermittent grounding.
ATTENTION
Preventing 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.
• If available, use a static-safe workstation.
The following information applies when operating this 
equipment in hazardous locations:
Informations sur l’utilisation de cet équipement en 
environnements dangereux :
Products marked “CL I, DIV 2, GP A, B, C, D” are suitable for use 
in Class I Division 2 Groups A, B, C, D, Hazardous Locations and 
nonhazardous locations only. Each product is supplied with 
markings on the rating nameplate indicating the hazardous 
location temperature code. When combining products within a 
system, the most adverse temperature code (lowest “T” 
number) may be used to help determine the overall temperature 
code of the system. Combinations of equipment in your system 
are subject to investigation by the local Authority Having 
Jurisdiction at the time of installation.
Les produits marqués "CL I, DIV 2, GP A, B, C, D" ne 
conviennent qu’à une utilisation en environnements de Classe I 
Division 2 Groupes A, B, C, D dangereux et non dangereux. 
Chaque produit est livré avec des marquages sur sa plaque 
d’identification qui indiquent le code de température pour les 
environnements dangereux. Lorsque plusieurs produits sont 
combinés dans un système, le code de température le plus 
défavorable (code de température le plus faible) peut être 
utilisé pour déterminer le code de température global du 
système. Les combinaisons d’équipements dans le système 
sont sujettes à inspection par les autorités locales qualifiées 
au moment de l’installation.
EXPLOSION HAZARD
• Do not disconnect equipment unless
power has been removed or the area is 
known to be nonhazardous. 
• Do not disconnect connections to this
equipment unless power has been 
removed or the area is known to be 
nonhazardous. Secure any external 
connections that mate to this 
equipment by using screws, sliding 
latches, threaded connectors, or other 
means provided with this product.
• Substitution of components may
impair suitability for Class I,
Division 2.
• If this product contains batteries, they
must only be changed in an area known 
to be nonhazardous.
RISQUE D’EXPLOSION
• Couper le courant ou s’assurer que
l’environnement est classé non 
dangereux avant de débrancher 
l'équipement.
• Couper le courant ou s'assurer que
l’environnement est classé non 
dangereux avant de débrancher les 
connecteurs. Fixer tous les connecteurs 
externes reliés à cet équipement à 
l'aide de vis, loquets coulissants, 
connecteurs filetés ou autres moyens 
fournis avec ce produit.
• La substitution de composants peut
rendre cet équipement inadapté à une 
utilisation en environnement de Classe 
I, Division 2.
• S’assurer que l’environnement est
classé non dangereux avant de changer 
les piles.
WARNING
AVERTISSEMENT