Siemens SIRIUS 3SK1 User manual

Manual
Industrial Controls
Safety Engineering
SIRIUS 3SK1 Safety Relays
04/2013Edition
Answers for industry.

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Industrial Controls
Safety engineering
3SK1 safety relays
Manual
04/2013
A5E02526190021A/RS-AA/01
Introduction
1
Product-specific safety
information
2
Product overview for 3SK1
3
Safety systems - General
information
4
3SK1 devices
5
System configuration
6
Circuit diagrams
7
Mounting
8
Connection
9
Configuration / operation
10
Commissioning
11
Display and diagnostics
12
Technical data
13
Dimension drawings
14
Accessories
15
Appendix
A

Siemens AG
Industry Sector
Postfach 48 48
90026 NÜRNBERG
GERMANY
Order number: 3ZX1012-0SK11-0AC0
Ⓟ 04/2013 Technical data subject to change
Copyright © Siemens AG 2013.
All rights reserved
Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
indicates that property damage can result if proper precautions are not taken.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.
Qualified Personnel
The product/system described in this documentation may be operated only by personnel qualified for the specific
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Qualified personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.
Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be complied with. The information in the relevant documentation must be observed.
Trademarks
All names identified by ® are registered trademarks of Siemens AG. The remaining trademarks in this publication
may be trademarks whose use by third parties for their own purposes could violate the rights of the owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

3SK1 safety relays
Manual, 04/2013, A5E02526190021A/RS-AA/01 5
Table of contents
1 Introduction.............................................................................................................................................. 11
1.1 User responsibility for system design and function......................................................................11
1.2 Required basic knowledge...........................................................................................................11
1.3 Validity range ...............................................................................................................................11
1.4 Definitions ....................................................................................................................................11
1.5 DataMatrix code...........................................................................................................................12
1.6 Correction sheet...........................................................................................................................13
2 Product-specific safety information .......................................................................................................... 15
2.1 General safety notes....................................................................................................................15
2.2 Safety information for hazardous areas.......................................................................................17
2.3 Intended use ................................................................................................................................17
2.4 Current information about operational safety...............................................................................18
2.5 Declaration of conformity .............................................................................................................18
3 Product overview for 3SK1 ...................................................................................................................... 19
3.1 Overview ......................................................................................................................................19
3.2 Overview of components and accessory parts............................................................................22
3.3 Functional scope of the 3SK1 basic units....................................................................................23
3.4 Introduction ..................................................................................................................................24
3.5 3SK1 system................................................................................................................................25
3.5.1 Standard.......................................................................................................................................25
3.5.1.1 Typical system configuration........................................................................................................25
3.5.2 Advanced .....................................................................................................................................26
3.5.2.1 Typical system configuration........................................................................................................26
4 Safety systems - General information...................................................................................................... 29
4.1 What is safety?.............................................................................................................................29
4.2 Safety function .............................................................................................................................29
4.3 Basic terminology.........................................................................................................................31
4.3.1 Redundancy/single-channel and two-channel.............................................................................31
4.3.2 Cross-circuit detection .................................................................................................................32
4.3.3 Enabling circuit.............................................................................................................................32
4.3.4 Signaling circuit............................................................................................................................33
4.3.5 Feedback circuit...........................................................................................................................33
4.3.6 Stop categories ............................................................................................................................33
4.3.7 Automatic start .............................................................................................................................34
4.3.8 Manual start .................................................................................................................................34

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4.3.9 Monitored start ............................................................................................................................ 35
4.3.10 Two-hand operation/synchronism............................................................................................... 36
4.3.11 Cascading ................................................................................................................................... 36
4.3.12 Startup testing ............................................................................................................................. 37
4.3.13 Connection of actuators .............................................................................................................. 37
4.3.14 Series connection of sensors...................................................................................................... 40
5 3SK1 devices........................................................................................................................................... 43
5.1 3SK1 standard ............................................................................................................................ 43
5.1.1 General information..................................................................................................................... 43
5.1.2 Applications................................................................................................................................. 43
5.1.3 3SK1111 Standard basic unit instantaneous (with relay outputs) .............................................. 44
5.1.3.1 General information..................................................................................................................... 44
5.1.3.2 Function description .................................................................................................................... 44
5.1.3.3 Design ......................................................................................................................................... 45
5.1.3.4 Terminal assignment................................................................................................................... 46
5.1.3.5 Inputs........................................................................................................................................... 46
5.1.3.6 Outputs........................................................................................................................................ 47
5.1.3.7 Display of the operating state ..................................................................................................... 47
5.1.3.8 Function setting........................................................................................................................... 47
5.1.4 3SK1112 Standard basic unit instantaneous (with solid-state outputs)...................................... 50
5.1.4.1 General information..................................................................................................................... 50
5.1.4.2 Function description .................................................................................................................... 50
5.1.4.3 Design ......................................................................................................................................... 51
5.1.4.4 Terminal assignment................................................................................................................... 52
5.1.4.5 Inputs........................................................................................................................................... 52
5.1.4.6 Outputs........................................................................................................................................ 53
5.1.4.7 Display of the operating state ..................................................................................................... 53
5.1.4.8 Function setting........................................................................................................................... 54
5.2 3SK1 Advanced .......................................................................................................................... 56
5.2.1 General information..................................................................................................................... 56
5.2.2 Applications................................................................................................................................. 56
5.2.3 General device features.............................................................................................................. 57
5.2.4 Function description .................................................................................................................... 57
5.2.5 Functions..................................................................................................................................... 58
5.2.6 3SK1121 Advanced basic unit instantaneous (with relay outputs)............................................. 60
5.2.6.1 Device features ........................................................................................................................... 60
5.2.6.2 Function description .................................................................................................................... 60
5.2.6.3 Design ......................................................................................................................................... 61
5.2.6.4 Terminal assignment................................................................................................................... 62
5.2.7 3SK1121 Advanced basic unit time-delayed (with relay outputs)............................................... 63
5.2.7.1 Device features ........................................................................................................................... 63
5.2.7.2 Design ......................................................................................................................................... 64
5.2.7.3 Terminal assignment................................................................................................................... 65
5.2.8 3SK1122 Advanced basic unit instantaneous (with solid-state outputs) .................................... 67
5.2.8.1 Device features ........................................................................................................................... 67
5.2.8.2 Design ......................................................................................................................................... 68
5.2.8.3 Terminal assignment................................................................................................................... 69
5.2.9 3SK1122 Advanced basic unit time-delayed (with solid-state outputs) ...................................... 71
5.2.9.1 Device features ........................................................................................................................... 71
5.2.9.2 Design ......................................................................................................................................... 72
5.2.9.3 Terminal assignment................................................................................................................... 73

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5.2.10 3SK1120 Advanced basic unit instantaneous (with solid-state outputs) .....................................75
5.2.10.1 Device features ............................................................................................................................75
5.2.10.2 Design..........................................................................................................................................76
5.2.10.3 Terminal assignment....................................................................................................................77
5.3 3SK1 output expansions ..............................................................................................................78
5.3.1 Applications..................................................................................................................................78
5.3.2 Function description.....................................................................................................................78
5.3.3 Display of the operating state ......................................................................................................79
5.3.4 Function setting............................................................................................................................79
5.3.5 Output expansion 3SK1211.........................................................................................................80
5.3.5.1 Device features ............................................................................................................................80
5.3.5.2 Design of 3SK1211-.B..0 .............................................................................................................81
5.3.5.3 Design of 3SK1211-.BB40...........................................................................................................82
5.3.5.4 Terminal assignment....................................................................................................................83
5.3.6 Output expansion 3SK1213.........................................................................................................84
5.3.6.1 Device features ............................................................................................................................84
5.3.6.2 Design of 3SK1213-.AB40...........................................................................................................85
5.3.6.3 Design of 3SK1213-.A.20 ............................................................................................................86
5.3.6.4 Terminal assignment....................................................................................................................86
5.4 3SK1 input expansions ................................................................................................................87
5.4.1 Input expansion 3SK1220............................................................................................................87
5.4.1.1 Device features ............................................................................................................................87
5.4.1.2 Applications..................................................................................................................................87
5.4.1.3 Design..........................................................................................................................................88
5.4.1.4 Terminal assignment....................................................................................................................88
5.4.1.5 Display of the operating state ......................................................................................................89
5.4.1.6 Function setting............................................................................................................................89
5.4.2 Power supply 3SK1230................................................................................................................91
5.4.2.1 Device features ............................................................................................................................91
5.4.2.2 Applications..................................................................................................................................91
5.4.2.3 Design..........................................................................................................................................92
5.4.2.4 Terminal assignment....................................................................................................................93
5.4.2.5 Display of the operating state ......................................................................................................93
6 System configuration ............................................................................................................................... 95
6.1 General information .....................................................................................................................95
6.1.1 General notes on the Standard system .......................................................................................95
6.1.2 General information on the Advanced system.............................................................................95
6.1.3 Maximum system configuration ...................................................................................................96
6.2 3ZY12 device connector ..............................................................................................................98
6.2.1 Device features ............................................................................................................................98
6.2.2 Applications................................................................................................................................100
6.3 System configuration rules.........................................................................................................100
7 Circuit diagrams..................................................................................................................................... 103
7.1 Internal circuit diagrams.............................................................................................................103
7.1.1 Internal circuit diagrams for 3SK1 Standard basic units............................................................103
7.1.2 Internal circuit diagrams for 3SK1 Advanced basic units ..........................................................105
7.1.3 Internal circuit diagrams for expansion units .............................................................................108
7.2 Typical circuits............................................................................................................................111

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7.2.1 Sensor wiring ............................................................................................................................ 111
7.2.2 Typical circuits........................................................................................................................... 113
8 Mounting................................................................................................................................................ 123
8.1 Warning notices ........................................................................................................................ 123
8.2 Terminal coding......................................................................................................................... 124
8.3 Mounting the devices on a level surface................................................................................... 125
8.4 Disassembling devices from a level surface............................................................................. 127
8.5 Mounting the 22.5 mm/17.5 mm device on a standard mounting rail....................................... 129
8.6 Mounting the 90 mm devices on a standard mounting rail ....................................................... 130
8.7 Removing devices from a standard mounting rail..................................................................... 131
8.8 Mounting 22.5 mm/17.5 mm devices with device connectors on a standard mounting rail ..... 132
8.9 Removing 22.5 mm/17.5 mm devices with device connectors from a standard mounting
rail.............................................................................................................................................. 135
8.10 Mounting 90 mm devices with device connectors on a standard mounting rail........................ 138
8.11 Removing 90 mm devices with device connectors from a standard mounting rail................... 141
8.12 Mounting 22.5 mm/17.5 mm devices with device connectors on the wall................................ 144
8.13 Removing 22.5 mm/17.5 mm devices with device connectors from the wall ........................... 148
8.14 Mounting 90 mm devices with device connectors on the wall .................................................. 151
8.15 Removing 90 mm devices with device connectors from wall.................................................... 155
8.16 Mounting the sealable cover ..................................................................................................... 158
9 Connection ............................................................................................................................................ 159
9.1 22.5 mm/17.5 mm devices........................................................................................................ 159
9.1.1 Terminal assignment................................................................................................................. 159
9.1.2 Connection data for terminals ................................................................................................... 161
9.1.3 Connecting the screw-type terminals........................................................................................ 162
9.1.4 Disconnecting the screw-type terminals ...................................................................................163
9.1.5 Connecting the push-in terminals ............................................................................................. 164
9.1.6 Disconnecting the push-in terminals ......................................................................................... 166
9.1.7 Attaching the terminals.............................................................................................................. 167
9.1.8 Disconnecting............................................................................................................................ 168
9.2 Devices 90 mm ......................................................................................................................... 170
9.2.1 Opening the terminal cover....................................................................................................... 170
9.2.2 Connection data for terminals ................................................................................................... 171
9.2.3 Connecting terminals ................................................................................................................ 172
9.2.4 Mounting terminals.................................................................................................................... 174
9.2.5 Disconnecting............................................................................................................................ 175
9.3 Device replacement .................................................................................................................. 177
10 Configuration / operation........................................................................................................................ 179
10.1 Procedure for configuration....................................................................................................... 179
10.2 Explanation of the device's functions........................................................................................ 180

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Manual, 04/2013, A5E02526190021A/RS-AA/01 9
10.3 Modes ........................................................................................................................................183
10.4 Response times .........................................................................................................................184
10.4.1 Response times .........................................................................................................................184
11 Commissioning ...................................................................................................................................... 185
12 Display and diagnostics ......................................................................................................................... 187
12.1 LED display................................................................................................................................187
12.2 Power-up....................................................................................................................................189
12.3 Error statuses.............................................................................................................................189
12.4 Diagnostics.................................................................................................................................189
13 Technical data ....................................................................................................................................... 193
13.1 General technical data ...............................................................................................................193
13.2 Basic units..................................................................................................................................197
13.2.1 Standard.....................................................................................................................................197
13.2.1.1 Technical data for 3SK1111 Standard relay basic unit..............................................................197
13.2.1.2 Technical data for 3SK1112 Standard solid-state basic unit .....................................................202
13.2.2 Advanced ...................................................................................................................................206
13.2.2.1 Technical data for 3SK1120 Advanced solid-state basic unit....................................................206
13.2.2.2 Technical data for 3SK1121 Advanced relay instantaneous basic unit.....................................210
13.2.2.3 Technical data for 3SK1121 Advanced relay time-delayed basic unit.......................................214
13.2.2.4 Technical data for 3SK1122 Advanced solid-state instantaneous basic unit ............................219
13.2.2.5 Technical data for 3SK1122 Advanced solid-state time-delayed basic unit..............................223
13.3 Expansion modules....................................................................................................................228
13.3.1 Output expansions .....................................................................................................................228
13.3.1.1 Technical data for output expansion 3SK1211..........................................................................228
13.3.1.2 Technical data for output expansion 3SK1213..........................................................................233
13.3.2 Input expansions........................................................................................................................237
13.3.2.1 Technical data for input expansion 3SK1220 ............................................................................237
13.3.2.2 Technical data for power supply unit 3SK1230 .........................................................................241
14 Dimension drawings .............................................................................................................................. 243
14.1 Dimension drawings for 3SK1 devices ......................................................................................243
14.2 Dimension drawings for 3SK1 device connector .......................................................................251
15 Accessories ........................................................................................................................................... 257
A Appendix................................................................................................................................................ 259
A.1 Correction sheet.........................................................................................................................259

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3SK1 safety relays
10 Manual, 04/2013, A5E02526190021A/RS-AA/01

3SK1 safety relays
Manual, 04/2013, A5E02526190021A/RS-AA/01 11
Introduction 1
1.1 User responsibility for system design and function
The products described here were developed to perform safety-related functions as part of
an overall installation or machine.
A complete, safety-related system is generally equipped with sensors, evaluation units, and
signaling units, and uses reliable shutdown concepts.
It is the responsibility of the manufacturer of a system or machine to ensure that the product
functions properly.
Siemens AG, its regional offices, and associated companies (hereinafter referred to as
"Siemens") cannot guarantee all the properties of an entire plant, system or machine that
has not been designed by Siemens.
Nor can Siemens assume liability for recommendations that appear or are implied in the
following description. No new guarantee, warranty, or liability claims beyond the scope of the
Siemens general terms of supply are to be derived or inferred from the following description.
1.2 Required basic knowledge
A general knowledge of the following areas is needed in order to understand this manual:
● Low-voltage switchgear
● Digital circuit logic
● Automation systems
● Safety systems
1.3 Validity range
The manual is valid for these safety relays SIRIUS 3SK1. It describes the components that
are valid at the time of publication.
SIEMENS reserves the right of including a Product Information for each new component,
and for each component of a later version.
1.4 Definitions
"3SK1" always applies to all variants of the SIRIUS 3SK1 safety relays.

Introduction
1.5 DataMatrix code
3SK1 safety relays
12 Manual, 04/2013, A5E02526190021A/RS-AA/01
1.5 DataMatrix code
A DataMatrix code is lasered onto the lower terminal cover of all 3SK1-series safety relays.
DataMatrix codes are standardized in ISO/IEC 16022. The DataMatrix codes on Siemens
devices use ECC200 coding for powerful error correction.
The following device information is encoded in the DataMatrix codes as a bit stream:
● MLFB
● Serial number
● MAC address, if applicable
This information is stored in the following format in the DataMatrix code:
1P MLFB + S serial number
(+ 23S MAC address)
Data identifier Net content Separator
Note
The information content is displayed without spaces.
This machine-readable information simplifies and accelerates handling of the respective
devices.
As well as fast access to the serial numbers of the respective devices for unique
identification, the DataMatrix codes simplify communication with Siemens Technical Support.
The DataMatrix codes enable in particular extremely fast and convenient access to all the
device-specific information available on an MLFB in the SIEMENS Service&Support Portal,
such as operating instructions, manuals, data sheets, FAQs, etc..
We offer the SIEMENS Industry Support App free for this purpose. This can be used on
commercially available smartphones and tablet PCs.
The SIEMENS Industry Support App is available for iOS and Android-based terminal devices
and can be accessed via the following links:
Link for Android Link for iOS

Introduction
1.6 Correction sheet
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Manual, 04/2013, A5E02526190021A/RS-AA/01 13
1.6 Correction sheet
The appendix to this manual contains a correction sheet for evaluation and feedback. Please
use it to record your suggestions for improvements, additions and corrections, and return the
sheet to us. This will help us to improve the next edition of the manual.
Thank you.

Introduction
1.6 Correction sheet
3SK1 safety relays
14 Manual, 04/2013, A5E02526190021A/RS-AA/01

3SK1 safety relays
Manual, 04/2013, A5E02526190021A/RS-AA/01 15
Product-specific safety information 2
2.1 General safety notes
Note
Recycling and disposal
Dispose of existing packing material in accordance with applicable regulations or recycle it.
The 3SK1 safety relays are able to be recycled thanks to a low-pollutant manufacturing
process. For environmentally-friendly recycling and disposal of your electronic waste, please
contact a company certified for the disposal of electronic waste.
Note
SILCL 3 to IEC 62061:2005 / PL e to ISO 13849-1:2008
The 3SK1 safety relays are designed in such a way as to allow implementation of
applications up to SILCL 3 in accordance with IEC 62061 and PL e/Kat. 4 in accordance with
EN ISO 13849-1.
Note
Safe state
The basis of the safety function is the definition of the safe state. In the case of safety relays,
this is the "OFF state", i.e. an open contact for sensors or shutdown of the actuators.
WARNING
Protection against electrically conductive contamination!
The devices must be protected against conductive contamination while taking account of
the ambient conditions. One way you can do this is to install the devices in a control cabinet
with the appropriate degree of protection.
WARNING
Safe functional extra-low voltage
The 3SK1 safety relays with a supply voltage of 24 V DC must be operated with safe
functional extra-low voltage (SELV, PELV). This means these modules must only be
subjected to a voltage of Um even in the event of a fault. The following applies for these
3SK1 safety relays: Um < 60.0 V.
You can find more detailed information about safe functional extra low voltage in the data
sheets of the power supplies to be used.

Product-specific safety information
2.1 General safety notes
3SK1 safety relays
16 Manual, 04/2013, A5E02526190021A/RS-AA/01
CAUTION
Protection against electrostatic charge
When handling and installing the 3SK1 safety relays, ensure that the components are
protected from being electrostatically charged. Changes to the system configuration and
wiring are only permissible while the supply voltage is switched off.
Connection of 3SK1 safety relays is only permissible when the power supply units (PELV
and SELV) are switched off.
CAUTION
Noise immunity / grounding
The following must be grounded in accordance with the regulations to ensure noise
immunity of the 3SK1 safety relays:
•PELV / SELV power supply units (please also note the documentation for the respective
power supply unit in this regard).
Note
Operational faults and malfunctions in communication
If the EMC Directive 2004/108/EC is not complied with when plants and devices are
installed, communication breaks may occur.
Note
Cover the 3ZY12 device connector on the left-hand side using the cover supplied with the
device termination connector.
WARNING
3SK1..1 and 3SK1..3 (devices with outputs using contacts):
In continuous operation, the key safety values apply in the case of a function test interval
(state change of the outputs) ≤ 1 year.
3SK1..2 (devices with solid-state outputs):
In continuous operation, the key safety values apply in the case of a function test interval
(state change of the outputs) ≤ 1 year.
Note
Annual function test
•Actuate the connected sensors.
•Check their effect on the safety relay and the downstream actuators.
•Activate the safety relay via the connected sensors.
•Check their effect on the safety relay and the downstream actuators.
•Defective devices must be replaced.

Product-specific safety information
2.2 Safety information for hazardous areas
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2.2 Safety information for hazardous areas
WARNING
Hazardous Voltage.
Can Cause Death, Serious Injury, or Property Damage.
Installation of the 3SK1 safety relays in hazardous areas
The components of the 3SK1 are not suitable for installation in hazardous areas.
Please contact your ATEX specialist.
2.3 Intended use
WARNING
Hazardous Voltage.
Can Cause Death, Serious Injury, or Property Damage.
Proper use of hardware products
This equipment is only allowed to be used for the applications described in the catalog and
in the technical description, and only in conjunction with non-Siemens equipment and
components recommended by Siemens.
Correct transport, storage, installation and assembly, as well as careful operation and
maintenance, are required to ensure that the product operates safely and without faults.
EU note: Commissioning is absolutely prohibited until it has been ensured that the machine
in which the component described here is to be installed complies with the stipulations of
the Directive 2006/42/EC.

Product-specific safety information
2.4 Current information about operational safety
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2.4 Current information about operational safety
Important note for maintaining operational safety of your system
WARNING
Hazardous Voltage
Can Cause Death, Serious Injury, or Property Damage.
Please take note of our latest information
Systems with safety-related characteristics are subject to special operational safety
requirements on the part of the operator. The supplier is also obliged to comply with special
product monitoring measures. For this reason, we publish a special newsletter containing
information on product developments and features that are (or could be) relevant to
operation of safety-related systems. By subscribing to the appropriate newsletter, you will
ensure that you are always up-to-date and able to make changes to your system, when
necessary:
SIEMENS newsletter ()
Sign on to the following newsletter under "Products & Solutions":
•Control Components and System Engineering News
•Safety Integrated Newsletter
2.5 Declaration of conformity
The manufacturer declares that the safety components of the SIRIUS 3SK1 series in the
designs marketed by us comply with the applicable basic safety and health requirements of
the EC Directives* stated (including amendments) and that the stated standards* were
applied in their design and construction.
* You can download the complete EC Declaration of Conformity as a PDF.

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Manual, 04/2013, A5E02526190021A/RS-AA/01 19
Product overview for 3SK1 3
3.1 Overview
Overview of 3SK1 safety relays
The following tables provide an overview of the 3SK1 safety relays.
3SK1 Standard basic units
Designation Voltages MLFB
24 V AC/DC 3SK1111-xAB30 Basic unit 3SK1 Standard instantaneous (with relay outputs)
110 ... 240 V AC/DC 3SK1111-xAW20
Basic unit 3SK1 Standard instantaneous (with solid-state outputs) 24 V DC 3SK1112-xBB40
x = 1: screw terminals; x = 2: push-in terminals
3SK1 Advanced basic units
Designation Voltages MLFB
Basic unit 3SK1 Advanced instantaneous (with relay outputs) 24 V DC 3SK1121-xAB40
Basic unit 3SK1 Advanced time-delayed (with relay outputs) 24 V DC 3SK1121-xCB4y
Basic unit 3SK1 Advanced instantaneous (with solid-state outputs) 24 V DC 3SK1122-xAB40
Basic unit 3SK1 Advanced time-delayed (with solid-state outputs) 24 V DC 3SK1122-xCB4y
Basic unit 3SK1 Advanced 17.5 mm instantaneous (with solid-state
outputs)
24 V DC 3SK1120-xAB40
x = 1: screw terminals; x = 2: push-in terminals
y = 1: 0.05 ... 3 s; y = 2: 0.5 ... 30 s; y = 4: 5 ... 300 s

Product overview for 3SK1
3.1 Overview
3SK1 safety relays
20 Manual, 04/2013, A5E02526190021A/RS-AA/01
Expansion units
Designation Voltages MLFB
24 V AC 3SK1211-xBB00
24 V DC 3SK1211-xBB40
Output expansion 3SK1211
110 ... 240 V AC/DC 3SK1211-xBW20
24 V DC 3SK1213-xAB40
115 V AC 3SK1213-xAJ20
Output expansion 3SK1213
240 V AC 3SK1213-xAL20
Input expansion 3SK1220 24 V DC 3SK1220-xAB40
Power supply 3SK1230 110 ... 240 V AC/DC 3SK1230-xAW20
x = 1: screw terminals; x = 2: push-in terminals
Overview of the enabling circuits
Type and number of enabling circuits
Relay Solid-state
Advanced Instantaneous Delayed Instantaneous Delayed
Signaling
circuits
Device
connectors
3SK1121-
xAB40
3 - - - 1 ✓
3SK1121-
xCB4x
2 2 - - - ✓
3SK1122-
xAB40
- - 3 - 1 ✓
3SK1122-
xCB4x
- - 2 2 - ✓
3SK1120-
xAB40
- - 1 - - ✓
Standard
3SK1111-
xAxx0
3 - - - 1 -
3SK1112-
xBB40
- - 2 - 1 -
Output expansions
4RO
3SK1211 4 - - 1 ✓ (for 24 V DC)
3RO
3SK1213 3 - - - 1 ✓ (for 24 V DC)