Rockwell Automation Allen-Bradley 1794-IA8 User manual

Installation Instructions
FLEX I/O AC Digital Input Modules
Catalog numbers 1794-IA8, 1794-IA8I, 1794-IA16
Table of Contents
Topic Page
Important User Information 2
Environment and Enclosure 3
Preventing Electrostatic Discharge 3
North American Hazardous Location Approval 4
Installing Your AC Digital Input Module 6
Configuring Your AC Input Module 14
Specifications 16

2FLEX I/O AC Digital Input Modules
Publication 1794-IN102C-EN-P - July 2015
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.rockwellautomation.com/literature/) 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, when necessary, 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, and recognize the consequences.
SHOCK HAZARD: Labels may be on or inside the equipment (for example, drive or
motor) to alert people that dangerous voltage may be present.
BURN HAZARD: Labels may be on or inside the equipment (for example, drive or
motor) to alert people that surfaces may reach dangerous temperatures.
IMPORTANT Identifies information that is critical for successful application and understanding of
the product.

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Publication 1794-IN102C-EN-P - July 2015
Environment and Enclosure
Preventing Electrostatic Discharge
ATTENTION: 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 m (6562 ft) 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.
In addition to this publication, see:
• Industrial Automation Wiring and Grounding Guidelines, Rockwell
Automation publication 1770-4.1, for additional installation requirements.
• NEMA Standard 250 and IEC 60529, as applicable, for explanations of the
degrees of protection provided by different types of enclosure.
ATTENTION: 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.

4FLEX I/O AC Digital Input Modules
Publication 1794-IN102C-EN-P - July 2015
North American Hazardous Location Approval
The following modules are North American Hazardous Location approved: 1794-IA8,
1794-IA8I, 1794-IA16.
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.

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Publication 1794-IN102C-EN-P - July 2015
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.
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.

6FLEX I/O AC Digital Input Modules
Publication 1794-IN102C-EN-P - July 2015
Installing Your AC Digital Input Module
The module mounts on a 1794 terminal base.
1. Rotate the keyswitch (1) on the terminal base (2) clockwise to position 8 as
required for this type of module.
2. Make certain the flexbus connector (3) is pushed all the way to the left to connect
with the neighboring terminal base/adapter. You cannot install the module
unless the connector is fully extended.
Description Description
1 Keyswitch 5 Alignment bar
2 Terminal base 6 Groove
3 Flexbus connector 7 Latching mechanism
4 Module
ATTENTION: During mounting of all devices, be sure that all debris (metal
chips, wire strands, etc.) is kept from falling into the module. Debris that falls
into the module could cause damage on power up.
1
2
3
45
6
7

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Publication 1794-IN102C-EN-P - July 2015
3. Make sure the pins on the bottom of the module are straight so they will align
properly with the connector in the terminal base.
4. Position the module (4) with its alignment bar (5) aligned with the groove (6) on
the terminal base.
5. Press firmly and evenly to seat the module in the terminal base unit. The module
is seated when the latching mechanism (7) is locked into the module.
Connecting Wiring for the 1794-IA8
1. For 1794-TB2, 1794-TB3, or 1794-TB3S – Connect individual input wiring to
even numbered terminals on the 0-15 row (A) as indicated in the Wiring
Connections for 1794-IA8 table.
For 1794-TBN – Connect individual input wiring to numbered terminals on the
16-33 row (B) as indicated in the Wiring Connections for 1794-IA8 table.
2. For 1794-TB2 – Connect the associated 120V AC power lead (L1) of the input
device to the corresponding odd numbered terminals on the 0-15 row A for each
input as indicated in the Wiring Connections for 1794-IA8 table. (The odd
numbered terminals on row A are internally connected to 120VAC L1.)
For 1794-TB3 or 1794-TB3S – Connect the associated 120V AC power lead
(L1) of the input device to the corresponding odd numbered terminals on the
34-51 row (C) or to the corresponding terminal on row (C) for each input as
indicated in the Wiring Connections for 1794-IA8 table. (The odd numbered
terminals on row (A) and the terminals of row (C) are internally connected to
120V AC power L1.)
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.

8FLEX I/O AC Digital Input Modules
Publication 1794-IN102C-EN-P - July 2015
For 1794-TBN – Connect the associated 120V AC power lead (L1) of the input
device to the corresponding odd numbered terminal on the 34-51 row (C) for
each input as indicated in the Wiring Connections for 1794-IA8 table. (The
120V AC power terminals of row (C) are internally connected together.)
3. Connect 120V AC power (L1) to terminal 34 on the 34-51 row (C).
4. Connect 120V AC common (L2) to terminal 16 on the 16-33 row (B).
5. If daisychaining power to the next terminal base, connect a jumper from terminal
51 (+120V AC L1) on this base unit to terminal 34 on the next base unit.
6. If continuing AC common to the next base unit, connect a jumper from terminal
33 (120V common L2) on this base unit to terminal 16 on the next base unit.
Wiring Connections for 1794-IA8
1794-TB2, 1794-TB3, 1794-TB3S 1794-TBN
Input Input Terminal 120V AC Supply Input Terminal 120V AC Supply
Input 0 A-0 A-1(1)/C-35
(1) A-1, 3, 5, 7, 9, 11, 13, and 15 on the 1794-TB2, 1794-TB3, and 1794-TB3S are internally connected in the module to
120V AC L1.
B-0 C-1(2)
(2) C-1, 3, 5, 7, 9, 11, 13, and 15 on the 1794-TBN are internally connected in the module to 120V AC L1.
Input 1 A-2 A-3(1)/C-36 B-2 C-3(2)
Input 2 A-4 A-5(1)/C-37 B-4 C-5(2)
Input 3 A-6 A-7(1)/C-38 B-6 C-7(2)
Input 4 A-8 A-9(1)/C-39 B-8 C-9(2)
Input 5 A-10 A-11(1)/C-40 B-10 C-11(2)
Input 6 A-12 A-13(1)/C-41 B-12 C-13(2)
Input 7 A-14 A-15(1)/C-42 B-14 C-15(2)
A = Input terminals (Even numbered terminals 0...14)
B = Common terminals
C = Power terminals (C-34 and C-51 on 1794-TB2; C-34 to
C-51 on 1794-TB3 and 1794-TB3S)
B = Even numbered input terminals 0...14,
AC common terminals 16 and 33
C = Power terminals C-34 and C-51, and
odd numbered input terminals 1...15

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Publication 1794-IN102C-EN-P - July 2015
1794-TB2, 1794-TB3, and 1794-TB3S Terminal Base Wiring for
1794-IA8 and 1794-IA16
1794-TBN Terminal Base Wiring for 1794-IA8 and 1794-IA16
Connecting Wiring for the 1794-IA16
1. For 1794-TB3 or 1794-TB3S – Connect individual input wiring to numbered
terminals on the 0-15 row (A) as indicated in the Terminal Base Wiring for
1794-IA16 table.
For 1794-TBN – Connect individual input wiring to even numbered terminals
on the 16-33 row (B), and to the odd numbered terminals on the 34-51 row (C)
as indicated in the Terminal Base Wiring for 1794-IA16 table.
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
16
35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
34
Inputs
Commons
(1794-TB3 shown)
L2
L1 Voltage
A
B
C
L2
Connect 120V AC L1 power to terminal C-34
Connect 120V AC common L2 to terminal B-16
Use B-33 and C-51 for daisychaining to the next terminal base unit
L1
(Terminals C-35 thru C-50 not available on the 1794-TB2.)
16 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15 51
33
34
L1
L2
L1
L2
B
C
Even Numbered I/O Terminals 0 thru 14
Odd Numbered I/O Terminals 1 thru 15 (1794-TBN shown)
L1 = 120V AC - Connect to terminal C-34
L2 = 120V AC common - Connect to terminal B-16
Use B-33 and C-51 for daisychaining to the next terminal base unit

10 FLEX I/O AC Digital Input Modules
Publication 1794-IN102C-EN-P - July 2015
2. For 1794-TB3 or 1794-TB3S – Connect the associated 120V AC power lead
(L1) of the input device to the corresponding terminals on the 34-51 row (C) for
each input as indicated in the Terminal Base Wiring for 1794-IA16 table. (The
120V power terminals of row (C) are internally connected together.)
For 1794-TBN – An external terminal strip is needed to distribute 120V AC
power (L1) to each device.
3. Connect 120V AC power (L1)to terminal 34 on the 34-51 row (C).
4. Connect 120V AC common (L2) to terminal 16 on the 16-33 row (B).
5. If daisychaining power to the next terminal base, connect a jumper from terminal
51 (+120V AC L1) on this base unit to terminal 34 on the next base unit.
6. If continuing AC common to the next base unit, connect a jumper from terminal
33 (120V common L2) on this base unit to terminal 16 on the next base unit.
Terminal Base Wiring for 1794-IA16
Input Input Terminal
1794-TB3, 1794-TB3S
Input Terminal
1794-TBN
120V AC Supply (L1)(1)
Input 0 A-0 B-0 C-35
Input 1 A-1 C-1 C-36
Input 2 A-2 B-2 C-37
Input 3 A-3 C-3 C-38
Input 4 A-4 B-4 C-39
Input 5 A-5 C-5 C-40
Input 6 A-6 B-6 C-41
Input 7 A-7 C-7 C-42
Input 8 A-8 B-8 C-43
Input 9 A-9 C-9 C-44
Input 10 A-10 B-10 C-45
Input 11 A-11 C-11 C-46
Input 12 A-12 B-12 C-47
Input 13 A-13 C-13 C-48
Input 14 A-14 B-14 C-49