Siemens

SIRIUS 3SK safety relays are the key elements of a consistent, cost-effective safety sequence. Whether you need EMERGENCY-STOP functionality, protective door monitoring, light arrays, laser scanners or the protection of presses or punches – slimline SIRIUS safety relays enable all safety applications to be implemented in the best possible way in terms of engineering and price.

The following safety-related functions are available:

  • Monitoring the safety functions of sensors
  • Monitoring the sensor leads
  • Monitoring the correct device function of the safety relay
  • Monitoring the actuators in the shutdown circuit
  • Safety-related disconnection when dangers arise

SIRIUS 3SK safety relays are approved for applications up to SIL 3 (IEC 61508/IEC 62061) or PL e (EN ISO 13849-1).

Device series

SIRIUS 3SK safety relays stand out on account of their flexibility in both parameterization and system configurations with several evaluation units. This reduces device variance, thus bringing advantages in terms of device selection and spare parts management. Optimized solutions when selecting components and reduced spare part inventory requirements are facilitated by a clearly structured component range.

SIRIUS 3SK device series

The following device series are available:

  • 3SK1 Standard basic units
  • 3SK1 Advanced basic units
  • 3SK2 basic units
  • 3SK1 output expansions
  • 3SK1 input expansions
  • Accessories

3SK1 Standard basic units

The 3SK1 Standard basic units are characterized by the following features:

  • Compact design
  • Simple operation
  • Relay and semiconductor outputs
  • Economical solution

3SK1 Advanced basic units

The 3SK1 Advanced basic units additionally offer:

  • Universal application opportunities thanks to multifunctionality
  • Time-delayed outputs
  • Expansion of inputs and outputs

3SK2 basic units

In addition, 3SK2 basic units offer:

  • Up to six fail-safe, independent shutdown functions
  • Flexible application thanks to software parameterization
  • Powerful semiconductor outputs
  • Convenient diagnostics using diagnostics display and configuration software
  • Communication via PROFINET/PROFIBUS by means of communication module

The 3SK1 and 3SK2 Standard and Advanced series are a high-quality replacement for the 3TK28 safety relays. In their narrower design, and equipped with greater functionality, they can replace every 3TK28 device. The only exceptions to this are 3TK2810 devices.

Overview of functions of the 3SK series

Type

3SK1 Standard basic units

3SK1 Advanced basic units

3SK2 basic units

22.5 mm

45 mm

Safe
relay outputs

Safe semiconductor outputs

Safe
relay outputs

Safe semiconductor outputs

Safe semiconductor outputs

Safe semiconductor outputs

Sensors

  • Mechanical

  • Single-ended

1)

  • Antivalent

  • Expandable

✓ By means of cascading

Inputs

2 x single-channel,
1 x two-channel

2 x single-channel,
1 x two-channel

2 x single-channel,
1 x two-channel

2 x single-channel,
1 x two-channel

Freely parameterizable:

10 x single-channel,
5 x two-channel

Freely parameterizable:

20 x single-channel,
10 x two-channel

Parameter

  • Start (auto/monitored)

A variety of functions can be set for each input/output by means of software parameterization.

  • Sensor connection 2 x single channel,
    1 x two-channel

✓ Using wiring

  • Cross-circuit detection

✓ Using wiring

  • Start test ON/OFF

  • Monitoring of two-hand operator panels acc. to EN 574

  • Safety shutdown/pressure-sensitive mat

Safe outputs

  • Instantaneous

Parameterizable

Parameterizable

  • Time-delayed

Parameterizable

Parameterizable

  • Can be expanded using safe relay outputs

✓ Using wiring

✓ Using wiring

  • independent

4)

5)

  • Device connectors

Options

  • External memory module

  • Display on device

  • External diagnostic module can be connected

Control supply voltage

  • 24 V DC

2)

  • 110 … 240 AC/DC

6)

3)

3)

✓ Available

— Not available

1) 24 V basic units only.

2) 24 V AC/DC.

3) Possible using 3SK1230 power supply via device connector.

4) Up to four independent safe outputs, two of which via device connector.

5) Up to six independent safe outputs, two of which via device connector.

6) Possible using 3SK1230 power supply by means of wiring.

Parameter assignment

3SK112 and 3SK1112 with DIP switch

The 3SK112 and 3SK1112 safety relays are configurable safety relays. They are used as evaluation units for typical safety sequences (detect, evaluate, respond). A number of functions can be set using the DIP switches on the front. Thus the 3SK112 and 3SK1112 can be used universally.

DIP switch No.

OFF

ON

Schematic

1

Autostart sensor input

Monitored start sensor input

 

2

Without cross-circuit detection

With cross-circuit detection

3

2 x single-channel sensor connection

1 x two-channel sensor connection

4

With start test

Without start test

3SK2 with software

3SK2 safety relays are configured using the SIRIUS Safety ES software. This means that the response of a 3SK2 unit, as well as the function of the individual safe outputs, can be parameterized easily and conveniently in the logic diagram.

In addition, the configuration can be printed out for documentation purposes. The software also supports the user during commissioning and troubleshooting by means of online diagnostics and the option of being able to “force” signals in the logic plan. Through this, 3SK2 safety relays are able to offer maximum flexibility and universal application options.

Note:

SIRIUS Safety ES, see Parameterization, Configuration and Visualization.

Communication
   

3SK2112,
22.5 mm

3SK2122,
45 mm

PROFINET

PROFIBUS

✓ Possible

Enclosure concept

Innovative enclosure concept for SIRIUS 3SK safety relays

Optimum connection with device connectors

System configuration example

In the case of 3SK1 Advanced basic units or 3SK2 basic units, the 3ZY12 device connectors allow safety functions involving several sensors and actuators to be constructed very quickly.

Seamlessly integrated safety right through to the main circuit

Problem-free integration of functional safety into the main circuit through the simple combination of 3RM1 and 3SK1 devices

Functional safety in the main circuit needs to be both simple and flexible

The unique compatibility of hybrid 3RM1 fail-safe motor starters and 3SK safety relays means that integrated functional safety right through to the main circuit is no longer a problem.

Their compact design allows the motor starters to be installed to the right of the safety relay in a simple manner, just like an output expansion. The wiring of the safety-related signals to the relay can be performed simply, quickly and in an error-free manner using the device connector.

The ergonomically designed enclosure with removable terminals and terminal labeling in the hinged cover allows for the cables to be conveniently diagonally mounted from the front. Either screw-type or spring-loaded terminals with push-in technology are available.

Highlights

  • Fail-safe disconnection of motors up to 3 kW
  • Problem-free combination of fail-safe motor starters and safety relays
  • End-to-end system, simple setup using device connectors
  • Ergonomic enclosure

Note:

SIRIUS 3RM1 motor starters, see Load Feeders and Motor Starters.

Article No. scheme

Product versions

Article number

3SK1 safety relays

3SK1

Device version

Basic unit

1

Expansion unit

2

Device variants

3SK11: Standard; 3SK12: Output expansion

1

3SK11: Advanced; 3SK12; input expansion

2

Type of outputs

Relay outputs

1

Semiconductor outputs

2

Power outputs

3

Connection type

Screw terminal

1

Spring-loaded terminals (push-in)

2

Control circuit/actuation

3SK11: 3 enabling circuits

A

3SK11: 2 enabling circuits

B

3SK11: 4 enabling circuits

C

Type of control supply voltage

3SK1213: 24 V AC, 50/60 Hz

B

0

3SK1: 24 V AC/DC, 50/60 Hz

B

3

3SK1: 24 V DC

B

4

3SK1213: 115 V AC, 50/60 Hz

J

2

3SK1213: 230 V AC, 50/60 Hz

L

2

3SK1: 110 … 240 AC/DC; 50/60 Hz

W

2

Time delay

None

0

0.05 … 3 s

1

0.5 … 30 s

2

5 … 300 s

4

Example

3SK1

1

1

1

1

A

B

3

0

Product versions

Article number

3SK2 safety relays

3SK2

1

2

A

A

1

0

Device variants

10 F-DI, 2 F-DQ, width 22.5 mm

1

20 F-DI, 4 F-DQ, width 45 mm

2

Connection type

Screw terminal

1

Spring-loaded terminals (push-in)

2

Example

3SK2

1

1

2

1

A

A

1

0

Product versions

Article number

Interface modules

3SK2

5

1

1

F

A

1

0

Connection type

Screw terminal

1

Spring-loaded terminal

2

Example

3SK2

5

1

1

1

F

A

1

0

Note:

The article number schemes show an overview of product versions for better understanding of the logic behind the article numbers.

For your order, please use the article numbers specified in the selection and ordering data.

Benefits

General
  • Approved for all safety applications because of its compliance with the highest safety requirements (SIL 3 and PL e)
  • Universally usable thanks to adjustable parameters
  • Usable worldwide thanks to globally valid certificates
  • Compact SIRIUS design
  • Device connectors with standard rail mounting for flexible connectability and expandability
  • Removable terminals for greater plant availability
  • Yellow terminal covers clearly identify the device as a safety component.
  • Sensor cable length up to 2 000 m allows it to be used in plants covering large areas
Relay outputs
  • Different voltages can be switched through the floating contacts
  • Currents up to 5 A can be switched with relay contacts (AC-15/DC-13)
Semiconductor outputs
  • Wear-free
  • Suitable for operation in frequently switching applications
  • Insensitive to vibrations and dirt
  • Good electrical endurance
Power outputs (3SK1213 output expansion)
  • Different voltages can be switched through the floating contacts
  • With the power relay contacts currents up to 10 A AC-15/6 A DC-13 can be switched.
  • High mechanical and electrical endurance
  • Protective separation between safe outputs and electronics
Can be expanded by adding the 3RM1 motor starter

SIRIUS 3SK safety relays are ideal for combining with SIRIUS 3RM1 motor starters.

Combinations are made by means of SIRIUS 3ZY12 device connectors (in combination with 3SK1 Advanced/3SK2) or conventional wiring (for all 3SK1 und 3SK2 basic units).

This makes collective shutdown very easy in assemblies. The wiring, and ultimately the shutting down of the control supply voltage for the expansion components in EMERGENCY-STOP situations, is performed via the device connector. There is no further need for complex looping of the connecting cables between the safety relay and the motor starters.

The 3RM1 motor starter combines the benefits of semiconductor technology and relay technology. This combination is also known as hybrid technology.

The hybrid technology in the motor starter is characterized by the following features:

  • The inrush current in the case of motorized loads is routed briefly via the semiconductors. Advantages include protection of the relay contacts and a long service life due to low wear.
  • The uninterrupted current is conducted via relay contacts. Advantages include lower heat losses compared with the semiconductor.
  • Shutdown is implemented again via the semiconductor. The contacts are only slightly exposed to arcs, and this results in a longer service life.
  • Integrated overload protection

Note:

SIRIUS 3RM1 motor starters, see Load Feeders and Motor Starters.

3ZY12 device connectors

Using 3ZY12 device connectors to combine devices reduces the time required to configure and wire the components. At the same time errors are avoided during wiring, and this considerably reduces the testing required for the fully-assembled application.

Configuration and stock keeping

Variable setting options by means of DIP switches or software, a wide voltage range (3SK1111) and a special power supply unit (3SK1 only) reduce the cost of spare parts storage and simplify the considerations during configuration with regard to the evaluation units to be selected.

Communication

The 3SK2 safety relays can be easily integrated in the overall application via PROFINET or PROFIBUS using optionally available interface modules.

This provides the following advantages:

  • Exchange of signals and information with the plant controller
  • Read-out and visualization of diagnostics information of the safety relay via the controller supports troubleshooting and reduces plant downtimes
  • Access with the Safety ES engineering software via the fieldbus for parameterization, commissioning and diagnostics
Simulation

The SIRIUS Sim simulation tool for 3SK2 can be used to quickly and easily test configurations that have been created without real devices. The configurations thus created can then be loaded directly into the real devices. Time and costs for engineering are thus reduced.

Note:

SIRIUS Sim 3SK2, see 3SK2 basic units or https://support.industry.siemens.com/cs/ww/en/view/109763750.

Application

SIRIUS 3SK1 safety relays

SIRIUS 3SK1 safety relays are used mainly in autonomous safety applications which are not connected to a safety-related bus system. Their function here is to evaluate the sensors and the safety-related shutdown of hazards. They also check and monitor the sensors, actuators and safety-oriented functions of the safety relay.

SIRIUS 3SK2 safety relays

SIRIUS 3SK2 safety relays are used primarily in autonomous, more complex safety applications for which the functional scope of the 3SK1 devices is no longer sufficient, such as in the implementation of independent shutdown functions or integration into higher-level control systems for diagnostics via fieldbus. Their function here is to evaluate the sensors and the safety-related shutdown of hazards. They also check and monitor the sensors, actuators and safety-oriented functions of the safety relay.

Technical specifications

Article number

 

3SK1111-.AB30 3SK1211-.BB00 3SK1211-.BB40

3SK1111-.AW20
3SK1121
3SK1211-.BW20

3SK1112

3SK1120

3SK1122

3SK1213

3SK1220

Width x Height x Depth

22.5 × 100 × 121.6

22.5 × 100 × 91.6

17.5 × 100 × 121.6

22.5 × 100 × 121.6

90 × 100 × 121.6

17.5 × 100 × 121.6

General technical data:

Ambient temperature

  • ● during operation

°C

-25 … +60

  • ● during storage

°C

-40 … +80

Installation altitude at height above sea level maximum

m

2 000

Air pressure acc. to SN 31205

kPa

90 … 106

Shock resistance

10g / 11 ms

5 g / 10 ms

10g / 11 ms

Vibration resistance acc. to IEC 60068-2-6

5 … 500 Hz: 0.75 mm

Protection class IP of the enclosure

IP20

Protection against electrical shock

finger-safe

Insulation voltage rated value

V

300

50

300

50

Surge voltage resistance rated value

V

4 000

800

4 000

800

Safety Integrity Level (SIL) acc. to IEC 61508

3

Performance level (PL) acc. to EN ISO 13849-1

e

T1 value for proof test interval or service life acc. to IEC 61508

y

20

EMC emitted interference

IEC 60947-5-1, IEC 61000

IEC 60947-5-1, Class A

IEC 60947-5-1, IEC 61000

IEC 60947-5-1, Class A

Certificate of suitability

  • ● UL approval

Yes

  • ● TÜV (German technical inspectorate) certificate

Yes

Article number

 

3SK1111
3SK1121-.AB40
3SK1211

3SK1112
3SK1122

3SK1120

3SK1121.CB4.

3SK1213

Switching capacity current of the NO contacts of the relay outputs

  • ● at AC-15 at 230 V

A

5

3

10

  • ● at DC-13 at 24 V

A

5

3

6

Switching capacity current of semiconductor outputs at DC-13 at 24 V

A

2

0.5

Article number

 

3SK1111-.AB30
3SK1211

3SK1111-.AW20

3SK1112
3SK1220

3SK1120
3SK1122-.AB40

3SK1121-.AB40

3SK1121-.CB4.

3SK1122-.CB4.

3SK1213

PFHD with high demand rate acc. to EN 62061

1/h

0.0000000017

0.0000000015

0.000000001

0.0000000013

0.0000000025

0.0000000037

0.0000000015

0.000000001

PFDavg with low demand rate acc. to IEC 61508

0.000001

0.000007

0.000001

Article number

 

3SK2112-.AA10

3SK2122-.AA10

Width x Height x Depth

22.5 × 100 × 124.5

45 × 100 × 124.5

General technical data:

Ambient temperature

  • ● during operation

°C

-25 … +60

  • ● during storage

°C

-40 … +80

Installation altitude at height above sea level maximum

m

2 000

Air pressure acc. to SN 31205

kPa

90 … 106

Shock resistance

15g / 11 ms

Vibration resistance acc. to IEC 60068-2-6

5 … 500 Hz: 0.75 mm

Protection class IP of the enclosure

IP20

Protection against electrical shock

finger-safe

Insulation voltage rated value

V

50

Surge voltage resistance rated value

V

800

Safety Integrity Level (SIL) acc. to IEC 61508

3

Performance level (PL) acc. to EN ISO 13849-1

e

T1 value for proof test interval or service life acc. to IEC 61508

y

20

EMC emitted interference acc. to IEC 60947-1

class A

Certificate of suitability

  • ● UL approval

Yes

  • ● TÜV (German technical inspectorate) certificate

Yes

Switching capacity current of semiconductor outputs at DC-13 at 24 V

A

4

PFHD with high demand rate acc. to EN 62061

1/h

0.00000001

0.000000012

PFDavg with low demand rate acc. to IEC 61508

0.000015

0.000018

Modular Safety System
Modular Safety System
Safety Relays
Safety Relays
3RM1 fail-safe motor starters
3RM1 fail-safe motor starters
Safety Switch
Safety Switch
Emergency-stop pushbutton
Emergency-stop pushbutton
Signalling Columns
Signalling Columns

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