Rockwell Automation 1769-PA2 User manual

Installation Instructions
Compact I/O Expansion Power Supplies
Catalog Numbers 1769-PA2, 1769-PB2, 1769-PA4,
1769-PB4
About the Power Supplies
Compact I/O power supplies provide 120/240V AC and 24V DC power to modules, which
can be placed to the left or the right side of the 1769 power supply. As many as eight I/O
modules can be placed on each side of the power supply.
Topic Page
Important User Information 2
Environment and Enclosure 3
North American Hazardous Location Approval 4
Install Safety Circuits 4
European Hazardous Location Approval 5
Before You Begin 6
Assemble the System 9
Mount an I/O Expansion Power Supply 11
Verify Your System Power 14
Power Considerations 15
Use a Master Control Relay 17
Schematic (Using IEC Symbols) 18
Schematic (Using ANSI/CSA Symbols) 19
Connect the Power Supplies 19
Connect Field Wires 21
Replace the Fuse 24
Temperature Derating 25
Power Dissipation 28
Specifications 30
Additional Resources 35

2Compact I/O Expansion Power Supplies
Publication 1769-IN028B-EN-P - October 2008
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://literature.rockwellautomation.com) 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.
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 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.

Compact I/O Expansion Power Supplies 3
Publication 1769-IN028B-EN-P - October 2008
Environment and Enclosure
Prevent 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 meters (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 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 1770-4.1.
•NEMA Standards publication 250 and IEC publication 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.
•Store the equipment in appropriate static-safe packaging when not in use.

4Compact I/O Expansion Power Supplies
Publication 1769-IN028B-EN-P - October 2008
North American Hazardous Location Approval
Install Safety Circuits
Circuits that are installed on the machine for safety reasons, like overtravel limit switches, stop
push buttons, and interlocks, should always be hard-wired directly to the master control relay.
These devices must be wired in series so that when any one device opens, the master control
relay is de-energized, thereby removing power to the machine.
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.
WARNING 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.
AVERTISSEMENT 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 Explosion Hazard - Do not connect or disconnect connectors while circuit is live.
ATTENTION Never alter these circuits to defeat their function. Serious injury or machine damage
could result.

Compact I/O Expansion Power Supplies 5
Publication 1769-IN028B-EN-P - October 2008
European Hazardous Location Approval
1769-PB2, 1769-PB4 Only
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 •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.
•Provisions shall be made to prevent the rated voltage from being exceeded by
transient disturbances of more than 40% when applied in Zone 2 environments.
•This equipment must be used only with ATEX certified backplanes.
•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.
ATTENTION This equipment is not resistant to sunlight or other sources of UV radiation.

6Compact I/O Expansion Power Supplies
Publication 1769-IN028B-EN-P - October 2008
Before You Begin
There are some points about power distribution that you should know.
• The master control relay must be able to inhibit all machine motion by removing
power to the machine I/O devices when the relay is de-energized. We recommend
that the controller remains powered even when the master control relay is
de-energized.
• If you are using a DC power supply, interrupt the load side rather than the AC line
power. This avoids the additional delay of power supply turn-off. The DC power
supply should be powered directly from the fused secondary of the transformer.
Power to the DC input and output circuits should be connected through a set of
master control relay contacts.
Perform Periodic Tests of Master Control Relay Circuit
Any part can fail, including the switches in a master control relay circuit. The failure of one of
these switches would most likely cause an open circuit, which would be a safe power-off
failure. However, if one of these switches shorts out, it no longer provides any safety
protection. These switches should be tested periodically to assure they will stop machine
motion when needed.

Compact I/O Expansion Power Supplies 7
Publication 1769-IN028B-EN-P - October 2008
Parts Illustration of a Power Supply
The sample illustrations of a 1769-PA4 power supply let you review the various components
that comprise a power supply, which is attached to a DIN rail.
Item Description
1Bus lever (with locking function)
2a Upper panel mounting tabs
2b Lower panel mounting tabs
3Status Indicator
4Power supply door with terminal identification label
5a Movable bus connector with female pins
5b Stationary bus connector with male pins
6Nameplate label
44716
44717
44718
44719
12a
3
4
9
10
2b
11
1769-PA4
12
5b
6
5a
7a 7a
8a
8b
7b 7b

8Compact I/O Expansion Power Supplies
Publication 1769-IN028B-EN-P - October 2008
Install an I/O Expansion Power Supply
Compact I/O Expansion Power Supplies are suitable for use in an industrial environment
when installed in accordance with these instructions. Specifically, this equipment is intended
for use in clean, dry environments (Pollution degree 2(1)) and to circuits not exceeding Over
Voltage Category II(2) (IEC 60664-1).(3)
Disconnect the Power
7a Upper tongue-and-groove slots
7b Lower tongue-and-groove slots
8a Upper DIN rail latches
8b Lower DIN rail latches
9Terminal block with finger-safe cover
10 Fuse housing cover for replaceable fuse
11 120V AC or 240V AC line input power selector switch (PA4 only)
12 Removable selector switch label (PA4 only)
(1) Pollution Degree 2 is an environment where, normally, only non-conductive pollution occurs except that occasionally a
temporary conductivity caused by condensation shall be expected.
(2) Over Voltage Category II is the load level section of the electrical distribution system. At this level transient voltages are
controlled and do not exceed the impulse voltage capability of the product’s insulation.
(3) Pollution Degree 2 and Over Voltage Category II are International Electrotechnical Commission (IEC) designations.
WARNING Remove power before removing or inserting this power supply from the 1769 I/O system.
When you remove or insert a power supply with power applied, an electrical arc may
occur. An electrical arc can cause personal injury or property damage by:
•sending an erroneous signal to your system’s field devices, causing unintended
machine motion.
•causing an explosion in a hazardous environment.
Electrical arcing causes excessive wear to contacts on both the power supply and its
mating connector. Worn contacts may create electrical resistance.
Item Description

Compact I/O Expansion Power Supplies 9
Publication 1769-IN028B-EN-P - October 2008
Assemble the System
1769 Compact I/O power supplies distribute power from either side of the power supply.
The maximum amount of current the system supports in both directions is:
• 1769-PA2, 1769-PB2: 2 amps at 5V DC; 1 amp at 24V DC.
• 1769-PA4, 1769-PB4: 4 amps at 5V DC; 2 amps at 24V DC.
The power supply can be attached to an adjacent I/O module before or after
mounting.
EXAMPLE A 2 amp at 5V DC power supply (1769-PA2, 1769-PB2) can provide 1 amp to the right side
of the power supply and 1 amp to the left. A 4 amp at 5V DC power supply (1769-PA4,
1769-PB4) can provide 2 amps to the right side of the power supply and 2 amps to the
left.
IMPORTANT The maximum amount of current that can be distributed from either side of any 1769
power supply is 2 amps at 5V DC and 1 amp at 24V DC.
This is a limit of the 1769 Compact I/O Bus.
Item Description
1 Upper and lower tongue-and-groove slots
2 Bus connectors
3 Positioning tab
4 Direction of the bus lever of the power supply to the I/O modules
5 End cap terminator
6 End cap bus terminator
21
1
3
4
5
6
44720
44721

10 Compact I/O Expansion Power Supplies
Publication 1769-IN028B-EN-P - October 2008
Follow these steps to assemble the Compact I/O system.
1. Disconnect your line power.
The power supply does not support removal or insertion of modules under power.
2. Check that the bus lever of the power supply to be installed is in the unlocked (fully
right) position.
3. Use the upper and lower tongue-and-groove slots to secure the power supply to an
I/O module.
4. Move the power supply back along the tongue-and-groove slots until the bus
connectors line up with each other.
5. Push the bus lever back slightly to clear the positioning tab.
Use your fingers or a small screwdriver.
6. To allow communication between the controller and the I/O, move the bus lever of
the power supply and its adjacent I/O modules fully to the left until it clicks.
Make sure it is locked firmly in place.
7. Attach an end cap terminator to the last I/O module in the system by using the
tongue-and-groove slots as before.
8. Lock the end cap bus terminator.
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 When attaching expansion I/O power supplies, it is very important that the bus
connectors are securely locked together to ensure proper electrical connection.
IMPORTANT A 1769-ECR or 1769-ECL right or left end cap (respectively) must be used to terminate the
end of the serial communication bus.