Omron S8AS User manual

S8AS
Smart Power Supply
USER'S MANUAL
Cat. No. Z269-E1-05

S8AS Smart Power Supply
User’s Manual
Revised September 2013

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About this Manual:
This manual describes the installation and operation of the S8AS Smart Power Supply and includes
the sections described below.
Please read this manual carefully and be sure you understand the information provided before
attempting to install or operate the S8AS Smart Power Supply. Be sure to read the precautions pro-
vided in the following section.
Precautions provides general precautions for using the S8AS Smart Power Supply and related
devices.
Section 1 introduces the features and functions of the S8AS Smart Power Supply and concepts
related to its operation.
Section 2 identifies the S8AS Smart Power Supply’s components, provides specifications, and
describes the basic functions.
Section 3 describes how to install and wire the S8AS Smart Power Supply.
Section 4 describes how to set the S8AS’s various parameters.
Section 5 describes how to connect the branch outputs and test operation.
Section 6 describes how to use S8AS communications.
Section 7 provides information on troubleshooting problems that may occur with the S8AS Smart
Power Supply.
The appendices provide a glossary of terms related to the S8AS and flowcharts of S8AS key opera-
tions.
! W ARNING Failure to read and understand the information provided in this manual may result in per-
sonal injury or death, damage to the Product, or Product failure. Please read each section
in its entirety and be sure you understand the information provided in the section and
related sections before attempting any of the procedures or operations given.

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TABLE OF CONTENTS
SECTION 1
Features and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1-1 Overview of Features and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1-2 S8AS Operating Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
1-3 Table of Basic Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1-4 S8AS Operating Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
SECTION 2
Specifications and Functions . . . . . . . . . . . . . . . . . . . . . . . . . 15
2-1 Component Names and Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2-2 Internal Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2-3 Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2-4 Basic Function Details. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2-5 Startup Sequence Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
2-6 Shutdown Sequence Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2-7 External Tripping Input Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
SECTION 3
Installation and Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3-1 Installing the S8AS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3-2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3-3 Power Supply and Input/Output Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3-4 RS-485 Port Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
SECTION 4
Parameter Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4-1 Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4-2 Switching the Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4-3 Changing the Protection Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4-4 Switching to Setting Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
4-5 Individual Branch Output Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4-6 Shared Parameter Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
4-7 Special Settings and Communications Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
SECTION 5
Trial Operation to Actual Operation . . . . . . . . . . . . . . . . . . 77
5-1 Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5-2 Connection/Disconnection Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
5-3 Checking Sequence Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5-4 Run Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

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TABLE OF CONTENTS
SECTION 6
Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6-1 CompoWay/F Communications Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6-2 Frame Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6-3 Variable Area Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6-4 Read Controller Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102
6-5 Read Controller Attributes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
6-6 Read Controller Status. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
6-7 Echoback Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
6-8 Operation Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
6-9 Response Code List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6-10 ASCII List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
SECTION 7
Error Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
7-1 Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
7-2 Seven-segment Error Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
7-3 Clearing Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Appendices
A Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
B List of Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

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Terms and Conditions Agreement
Read and understand this Manual
Please read and understand this catalog before purchasing the products. Please consult your OMRON
representative if you have any questions or comments.
Warranty, Limitations of Liability
Warranties
●Exclusive Warranty Omron’s exclusive warranty is that the Products will be free from defects in
materials and workmanship for a period of twelve months from the date of
sale by Omron (or such other period expressed in writing by Omron). Omron
disclaims all other warranties, express or implied.
●Limitations OMRON MAKES NO WARRANTY OR REPRESENTATION, EXPRESS OR
IMPLIED, ABOUT NON-INFRINGEMENT, MERCHANTABILITY OR FIT-
NESS FOR A PARTICULAR PURPOSE OF THE PRODUCTS. BUYER
ACKNOWLEDGES THAT IT ALONE HAS DETERMINED THAT THE PROD-
UCTS WILL SUITABLY MEET THE REQUIREMENTS OF THEIR INTENDED
USE.
Omron further disclaims all warranties and responsibility of any type for claims
or expenses based on infringement by the Products or otherwise of any intel-
lectual property right.
●Buyer Remedy Omron’s sole obligation hereunder shall be, at Omron’s election, to (i) replace
(in the form originally shipped with Buyer responsible for labor charges for
removal or replacement thereof) the non-complying Product, (ii) repair the
non-complying Product, or (iii) repay or credit Buyer an amount equal to the
purchase price of the non-complying Product; provided that in no event shall
Omron be responsible for warranty, repair, indemnity or any other claims or
expenses regarding the Products unless Omron’s analysis confirms that the
Products were properly handled, stored, installed and maintained and not
subject to contamination, abuse, misuse or inappropriate modification. Return
of any Products by Buyer must be approved in writing by Omron before ship-
ment. Omron Companies shall not be liable for the suitability or unsuitability or
the results from the use of Products in combination with any electrical or elec-
tronic components, circuits, system assemblies or any other materials or sub-
stances or environments. Any advice, recommendations or information given
orally or in writing, are not to be construed as an amendment or addition to
the above warranty.
See http://www.omron.com/global/ or contact your Omron representative for
published information.
Limitation on
Liability; Etc OMRON COMPANIES SHALL NOT BE LIABLE FOR SPECIAL, INDIRECT,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES, LOSS OF PROFITS OR
PRODUCTION OR COMMERCIAL LOSS IN ANY WAY CONNECTED WITH
THE PRODUCTS, WHETHER SUCH CLAIM IS BASED IN CONTRACT,
WARRANTY, NEGLIGENCE OR STRICT LIABILITY.

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Further, in no event shall liability of Omron Companies exceed the individual
price of the Product on which liability is asserted.
Application Considerations
Suitability of Use Omron Companies shall not be responsible for conformity with any standards,
codes or regulations which apply to the combination of the Product in the
Buyer’s application or use of the Product. At Buyer’s request, Omron will pro-
vide applicable third party certification documents identifying ratings and limi-
tations of use which apply to the Product. This information by itself is not
sufficient for a complete determination of the suitability of the Product in com-
bination with the end product, machine, system, or other application or use.
Buyer shall be solely responsible for determining appropriateness of the par-
ticular Product with respect to Buyer’s application, product or system. Buyer
shall take application responsibility in all cases.
NEVER USE THE PRODUCT FOR AN APPLICATION INVOLVING SERIOUS
RISK TO LIFE OR PROPERTY WITHOUT ENSURING THAT THE SYSTEM
AS A WHOLE HAS BEEN DESIGNED TO ADDRESS THE RISKS, AND
THAT THE OMRON PRODUCT(S) IS PROPERLY RATED AND INSTALLED
FOR THE INTENDED USE WITHIN THE OVERALL EQUIPMENT OR SYS-
TEM.
Programmable
Products Omron Companies shall not be responsible for the user’s programming of a
programmable Product, or any consequence thereof.
Disclaimers
Performance Data Data presented in Omron Company websites, catalogs and other materials is
provided as a guide for the user in determining suitability and does not consti-
tute a warranty. It may represent the result of Omron’s test conditions, and the
user must correlate it to actual application requirements. Actual performance
is subject to the Omron’s Warranty and Limitations of Liability.
Change in
Specifications Product specifications and accessories may be changed at any time based on
improvements and other reasons. It is our practice to change part numbers
when published ratings or features are changed, or when significant construc-
tion changes are made. However, some specifications of the Product may be
changed without any notice. When in doubt, special part numbers may be
assigned to fix or establish key specifications for your application. Please con-
sult with your Omron’s representative at any time to confirm actual specifica-
tions of purchased Product.
Errors and Omissions Information presented by Omron Companies has been checked and is
believed to be accurate; however, no responsibility is assumed for clerical,
typographical or proofreading errors or omissions.

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■Precaution Classifications
The following conventions are used to indicate and classify precautions in this
manual.
Always heed the information provided with them. Failure to heed precautions
can result in injury to people or damage to property.
■Cautions
Safety Precautions
CAUTION Indicates a potentially hazardous situation which, if not
avoided, may result in minor or moderate injury or in
property damage.
CAUTION
Minor electric shock, fire, or Product failure may occasionally
occur. Do not disassemble, modify, or repair the Product or touch
interior of the Product.
Minor burns may occasionally occur. Do not touch the Product
during power is being supplied or immediately after power is
turned OFF.
Minor injury may occasionally occur due to electrical shock. Do
not touch the terminals while power is being supplied. Also, be
sure to close the terminal cover after wiring the terminals.
Fire may occasionally occur. Tighten terminal screws to the
specified torque.
Minor electric shock, fire, or Product failure may occasionally
occur. Do not allow any pieces of metal or conductors or any
clippings or cuttings resulting from installation work to enter the
Product.
A maximum voltage of 370 V may be generated internally when
power is supplied.
This voltage will remain for 30 s even after the power supply has
been turned OFF.

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The S8AS Smart Power Supply combines the highly reliable S8VS Switch Mode Power Supply with the S8M
Digital Multicircuit Protector into a single unit to reduce both wiring and space requirements. The built-in digital
circuit protector uses semiconductor relays to close and trip circuits, and does not contain any contact
switching mechanisms, as normal circuit protectors do.
Observe the following precautions when introducing the S8AS into or using the S8AS in any system.
■Installation and Storage Environment
1. Store the Product at an ambient temperature of –25 to 65°C and relative humidity of 25% to 90%.
2. To maintain performance of the maintenance forecast monitor, make sure the following conditions are
satisfied for long-term storage.
• For storage exceeding three months, keep the Product at a temperature of –20°C to 30°C and a
humidity of 25% to 70%.
3. Internal parts may occasionally be deteriorated or damaged. Do not use the Product in conditions
exceeding the derating curve (in portion (1) of the derating curve on page xiv).
4. Internal parts may possibly be damaged. Do not use a current that exceeds the rated total output current.
If temporary peak currents occur repetitively, design the system so that the peak currents do not exceed
the rated total output current.
5. The surrounding air temperature to comply with UL508 and UL60950-1 is 25°C.
6. Use the Product where the relative humidity is 25% to 85%.
7. Do not use the Product where it would be subjected to direct sunlight.
8. Do not use the Product where it would be subjected to the possibility of penetration of liquid, foreign
substance, or corrosive gas.
9. Do not use the Product where it would be subjected to shock or vibration. A device such as a contact
breaker may be a vibration source. Set the Product as far as possible from possible sources of shock or
vibration. Additionally, install a PFP-M End Plate on each end of the Product after mounting it to a DIN
Rail.
10. Use a DIN Rail made of steel. If an aluminum DIN Rail is used, vibration or shock may cause the
formation of metal dust due to abrasion of the aluminum.
11. Poor heat dissipation may deteriorate or damage internal parts. Do not loosen the screws on the side of
the Product.
12. If the Product is used in an area with excessive electronic noise, be sure to separate the Product as far as
possible from the noise sources.
13. Cutoff performance is guaranteed according to the ambient operating temperature. Use the Product within
the derating range. Refer to the Derating Curve on page xiv.
14. Poor heat dissipation resulting from improper installation conditions may occasionally deteriorate or
damage internal parts and also cause the maintenance forecast monitor function to not operate properly.
Do not use any mounting orientation other than a standard one.
15. Do not connect a battery or other backup power supply to the output of the Product.
16. To comply with UL standards, insert a fast-breaking, UL-approved fuse rated at 20 A into each input line.
17. Although some inverters have an output frequency of 50/60 Hz, they may cause internal temperatures to
rise, possibly resulting in burning, if they are connected as the power source for the S8AS. Do not use the
output from an inverter as the power source for the S8AS.
Precautions for Safe Use
Standard Mounting Face-up Mounting

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■Installation and Wiring
1. Minor electric shock during operation may occasionally occur. Always attach the cover or take other
precautions so that the terminals cannot be touched directly.
Also, connect the ground completely. The ground is a protective earth (PE) terminal specified in safety
standards. If the ground is not connected completely, electric shock or malfunction may occur.
2. Minor fire may possibly occur. Ensure that input and output terminals are wired correctly.
3. Heat generated by wiring materials may cause the temperature of internal parts to increase, which may
result in deterioration of or damage to the internal parts. Select the wiring materials according to the
current that is being used.
4. Using the wiring materials, torque, and wire stripping length specified in 3-3 Power Supply and Input/
Output Wiring is recommended to prevent smoke or fire of the wire material due to an abnormal load.
5. It is conceivable that internal parts may be deteriorated or damaged. Do not repeatedly perform cutoff or
recovery operations more than necessary.
6. Do not push more than 100 N of force to the terminal block when tightening screws.
7. Be sure to tighten the lock screws on the sides of the connector after connecting any output connector.
When removing a connector, be sure the lock screws are completely loose before pulling on the
connector.
8. Be sure to remove the sheet covering the Product during installation before turning ON the power.
■Output Voltage Adjustment
1. The output voltage adjuster (V.ADJ.) may possibly become damaged. Do not apply more than the required
force.
2. Do not exceed the rated output capacity and rated total output current after adjusting the output voltage.
■Periodic Inspections
Under normal operating conditions, the Product will require several years or even more than ten years until the
maintenance forecast monitor function operates. When using the Product for an extended period of time, per-
form the following procedure periodically to confirm that the output for the maintenance forecast monitor func-
tion (LFE) is operating correctly.
a) Change to Run Mode.
b) Confirm that the (LFE) output is ON (electrical continuity between LFE and COM).
Note For details about terminal names, refer to 2-1 Component Names and Functions.

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• When the tripping alarm output operates, always remove the cause of the output first and then reset the
alarm.
• When cycling the input power supply, always remove any problems first and then turn ON the input power
supply.
■Startup Time
When the input power is turned ON to the S8AS, a hardware check, software check, and initialization process-
ing are performed before the branch outputs are turned ON. Approximately three seconds is required. When
using the S8AS with other control equipment, incorporate the startup time of the S8AS in the overall system
design.
■Installation
•Mounting Direction
Mount the S8AS to a DIN Rail using the standard mounting direction. Do not mount it in any other direction,
such as face up.
(Refer to 3-1 Installing the S8AS.)
•Mounting Space
The long-term reliability of the S8AS can be increased by installing it properly and sufficiently considering heat
dissipation.
Be sure to install the S8AS so that the air flow circulates around it, because the S8AS is designed to radiate
heat by means of natural air circulation.
■Derating Curve
The temperature range within which the S8AS can be used is restricted by the maximum current that normally
flows for the total output. This restriction is given as a derating curve.
Note
1. The ambient temperature is measured at a point 50 mm below the S8AS.
2. Use forced cooling if necessary to satisfy the derating curve.
3. For 480-W models, reduce the load to 80% or less for long-term use at an input voltage of 95 VAC or less.
■Abnormal Voltage Tripping
1. The S8AS has an abnormal voltage tripping function. All branch outputs will be cut off if the input voltage
exceeds 28.8 VDC. This function, however, does not protect loads and internal parts from high voltages in
all cases. Be sure the output voltage is within the rated range.
2. Outputs may be cut off by the abnormal voltage protection with loads that generate reverse peak electro-
motive force.
Precautions for Correct Use
Load rate (%) Total output current
Ambient temperature (°C)
120
100
80
60
40
20
0
−20 −10 0 10 20 30 40 50 60 70 80
1

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■Abnormal Current Tripping
The S8AS has an abnormal current tripping function. A branch output will be cut off if its current exceeds a pre-
set value. Also, all branch outputs will be cut off if their total peak output current exceeds a specified value.
Note
1. Continuing operation with overcurrent may occasionally result in deterioration or destruction of internal ele-
ments.
2. Do not use the S8AS for applications in which load inrush current or overload will frequently occur.
Doing so may result in deterioration or damage to internal components.
■Maintenance Forecast Monitor Function
The accuracy of the maintenance forecast monitor function will be reduced in applications where the AC input
turns ON and OFF frequently.
■Tripping Performance
There are three methods that can be used to determine abnormal current trippings: Standard Detection,
Instantaneous Detection, and Extended Detection. (This is not possible for the S8AS-24006N/48008N.)
Refer to 2-4-2 Over-current Protection Functions for details of cutoff performance.
Note
1. When the tripping alarm output operates, always remove the cause of the output first and then reset the
alarm.
2. When using a load with a fixed-power operation, the S8AS may cause a cutoff when the power supply is
turned OFF.
3. Tolerance of current tripping alarm threshold is ±0.3 A.
4. Use Extended Detection only when using OMRON Remote I/O Terminal with short-circuit detection.
■Total Peak Output Current
The S8AS is designed to provide a temporary peak current to provide the overcurrent required to start load
devices.
The total peak output current for all branch outputs combined is given below.
If the total current exceeds any of these values, all branch outputs will be cut off according to the size of the
peak current or application time to ensure safety.
•240-W Models
Input voltage range: 200 to 240 VAC
Peak current/Peak current pulse width: 17 A max. for 2 s max.
15 A max. for 5 s max.
13 A max. for 10 s max.
12 A max. for 20 s max.
If the total output peak current exceeds even one of these conditions, all branch outputs will be shut off to
ensure safety.
•480-W Models
Input voltage range: 200 to 240 VAC
Peak current/Peak current pulse width: 27 A max. for 1 s max.
25 A max. for 2 s max.
22.5 A max. for 5 s max.
Note
1. If the input voltage range is not within the values specified above or the total output current exceeds the max-
imum peak current value, internal operation will become unstable and the branch outputs may be cut off.
2. Maintain the total current for normal operation after the load devices have started to within the rated ranges.

xvi
3. Do not allow a peak current toflow again for at least 60 seconds after a peak current has exceeded the rated
current.
■Startup Delay
The S8AS has a startup delay function that prevents cutoffs caused by inrush current at startup.
The startup delay disables the cutoff operation for 40 ms after the semiconductor relay turns ON.
To protect internal circuits, however, the relevant branch outputs will be cut off even during the startup delay
period if a current limit is exceeded within a specific time period.
Note The startup delay will not operate when a relay or other device is used for ON/OFF control on the output
side of the S8AS, so a cutoff operation may occasionally occur.
■Dielectric Strength Test
The S8AS is designed to withstand 3,000 VAC for 1 minute between the AC input terminals collectively and
the branch output, I/O signal, or communications terminals collectively. When testing, set the cutoff current for
the withstand voltage test device to 20 mA.
Note
1. The S8AS may possibly be damaged from the impulse voltage if a testing device switch is used to abruptly
apply or cut off 3000VAC. Increase the applied voltage gradually using the voltage adjustment on the testing
device.
2. When testing terminals together, always short the specified terminals so that the voltage is applied to all of
the terminals at the same time.
■Insulation Resistance Test
When testing the insulation resistance, use a DC resistance meter at 500 VDC.
Note To prevent damage, always short branch output terminals (+/–), all I/O terminals, and communications
terminals before testing.
■Output Voltage Adjustment
Default setting: Set as the rated voltage.
Adjustable range: Adjustable from –10% to +10% of the rated output voltage by using the V.ADJ. adjuster on
the front or the Power Supply. Turning the adjuster clockwise increases the output voltage, and turning it
counterclockwise decreases the output voltage.
Note
1. If the output voltage is set to less than 20 V (default setting), the undervoltage detection may be activated.
2. Do not exceed the rated output capacity and rated total output current after adjusting the output voltage.
3. The output voltage may increase beyond the allowable voltage range rated voltage +10% when the V.ADJ
adjuster is used. When adjusting the output voltage, check the output voltage of the power supply to make
sure that the load is not damaged.
■No Output Voltage
The internal circuit’s overcurrent protection or overvoltage protection may operate. Alternatively, the latch
protection circuit may operate if there is a lightning surge or other large voltage applied to the input.
Contact your OMRON representative if there is still no output voltage after checking the following two points:
• Checking Overcurrent Protection
Check whether the load is in an overcurrent or short-circuited state. Remove the wires to the load before
checking.
• Checking Overvoltage Protection and Latching Protection
Turn the power supply OFF and leave it OFF for at least 3 minutes, then turn it ON again.

xvii
■Startup Time
At startup, the S8AS will check hardware and software before starting the operation of branch outputs.
A time of approximately 3 seconds is required for these self-diagnostic functions.
Take this time into account when designing the system.
■External Tripping Input
Wire the polarity of the external tripping input correctly. After completing wiring, confirm that operation is cor-
rect.
■Tripping Alarm Output, Undervoltage Detection Output, Maintenance
Forecast Monitor Output, and Over-temperature Output
Photoswitch outputs: 30 VDC max., 50 mA max., residual voltage when ON: 2 V max., leakage current when
OFF: 0.1 mA max.
Wire all output signal circuits correctly. Internal current control circuits are not provided internally for output sig-
nals. Do not allow the output current to exceed 50 mA. After completing wiring, confirm that the circuits operate
correctly.
■Displaying the Output Voltage
The voltage detection function displays on the 7-segment display the voltage that is monitored at the internal
circuit after AC/DC conversion. The displayed voltage will be somewhat lower than the value at the output
terminals of the power source due to internal voltage drop. To accurately confirm the output voltage, measure
it at the branch output terminal.
■Prohibition of Parallel Connection
Do not connect branch outputs from the S8AS in parallel. Also, do not connect the branch outputs in parallel
with branch outputs of other S8AS Power Supplies.
■Supplementary Information: Conformity to IEC and EN Safety Stan-
dards
Warning: The S8AS is a Class A product. In a residential, commercial, or light industrial environment, it may
cause radio interference. The S8AS is not intended to be installed in a residential environment. In a
commercial or light industrial environment with connection to a commercial power supply, the user may be
required to take adequate measures to reduce interference.
S8AS
S8AS
S8AS
Connections cannot be made in parallel
with other branch output circuits.

xviii
■Notation in this Manual
In this manual, the S8AS Smart Power Supply is referred to as the S8AS.
■Notation of Setting Data
Setting data codes and contents are displayed in seven-segment display characters, as shown in the following
diagram.
Using this Manual
V

1
SECTION 1
Features and Functions
This section describes the features and functions of the S8AS.
1-1 Overview of Features and Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1-2 S8AS Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1-3 Table of Basic Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1-4 S8AS Operating Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2
Overview of Features and Functions Section 1-1
1-1 Overview of Features and Functions
The S8AS Smart Power Supply is a 24-VDC power supply unit with an inter-
nal digital circuit protector that incorporates the highly reliable S8VS Switch
Mode Power Supply and the S8M Digital Multicircuit Protector in one unit.
The input power supply to the S8AS is 100 to 240 VAC at 50/60 Hz. Models
are available for 240 W with 6 branch outputs or for 480 W with 8 branch out-
puts, with and without communications. Models for which parameters cannot
be changed are also available.
The S8AS provides a stable 24-VDC power supply at an output current of 3.8
A maximum.
Model Number
Legend S8AS Model Numbers
Reduced Space, Wiring, and Work
■Combination of S8VS and S8M
The space required within the control panel and the amount of wiring have
been reduced by integrating a Digital Multicircuit Protector into a Switch Mode
Power Supply.
No. Item Code Meaning
1 Output capacity 240 240 W
480 480 W
2 Number of output
branches 06 6 branch outputs
08 8 branch outputs
3 Communications /
Additional functions blank Changeable parameter settings with no com- munications
N Unchangeable parameter settings with no
communications
R Changeable parameter settings with communi-
cations (RS-485)
S8AS-@@@@@@
123
115 mm
170 mm for models with 4 branch outputs
245 mm for models with 8 branch outputs