SIRIUS 3SK1 safety relays

SIRIUS 3SK safety relays are the key elements of a consistent, cost-effective safety chain. 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 62061) or PL e (ISO 13849-1).

Device series

SIRIUS 3SK device series

SIRIUS 3SK safety relays stand out due to their flexibility for both parameterization and system designs 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. Simple device connectors are used for connecting most components. This considerably reduces the wiring effort and avoids possible errors.

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 also offer:

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

3SK2 basic units

3SK2 basic units also offer:

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

All three basic device series can be supplemented with output expansions. These provide further fail-safe, potential-free relay contacts for controlling actuators. In addition, the 3RM1 Failsafe fail-safe motor starters can also be integrated into the 3SK system (see SIRIUS 3RM1 motor starters).

In the 3SK1 Advanced and 3SK2 device series, the output expansions are connected by means of device connectors, in the 3SK1 Standard series by means of wiring.

For the 3SK1 Advanced device series, there is also the possibility of supplementing the basic devices with input extensions. Here too, the connection is made via device connectors. This means that no individual basic devices need to be interconnected if more than one sensor is required in the safety application.

Since the 3SK1 Advanced device series comprises devices with 24 V DC operational voltage, a power supply is also available.

The 3SK2 device series can optionally be connected with a communications module via PROFINET to a control system, e.g. for diagnostics.

It is also possible to connect a diagnostics module to the 3SK2 system. This can be mounted in the control cabinet door, for example, and displays errors and diagnostics as well as configuration data quickly and clearly.

The 3SK1 Standard and Advanced and 3SK2 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 exception to this are the 3TK2810 devices.

The force-guided 3RQ1 coupling relays can be used as output expansion for 3SK up to SIL 3/PL e. Connection is also possible with device connectors (see SIRIUS 3RQ1 coupling relays).

System overview

Overview of functions of the 3SK series

✓ Available

— Not available

¹⁾ 24 V basic units only.

²⁾ Up to four independent safe outputs, two of which via device connector.

³⁾ Up to six independent safe outputs, two of which via device connector.

⁴⁾ 24 V AC/DC.

⁵⁾ Possible using 3SK1230 power supply by means of wiring.

⁶⁾ Possible using 3SK1230 power supply via device connector.

Enclosure concept

Innovative enclosure concept for SIRIUS 3SK safety relays

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 chains (detect, evaluate, react). A number of functions can be set using the DIP switches on the front. 3SK112 and 3SK1112 are therefore universally applicable.

3SK2 with software

The 3SK2 safety relays are configured with the SIRIUS Safety ES software. The behavior of a 3SK2 device as well as the functioning of the individual safe outputs can thus be parameterized simply and conveniently in the logic diagram.

In addition, the configuration can be printed out for documentation purposes. The software also supports users in commissioning and troubleshooting by means of online diagnostics and the option of “forcing” signals in the logic diagram. The 3SK2 safety relays thus offer maximum flexibility and universal application options.

Note:

SIRIUS Safety ES, see Parameterization, Configuration and Visualization.

Communication

✓ Available

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.

3RQ1 coupling relays as output expansion for 3SK

The force-guided SIRIUS 3RQ1 coupling relays in a modern titanium gray industrial enclosure are available in widths of 17.5 mm and 22.5 mm and can be used as an output expansion for SIRIUS 3SK safety relays.

They have safety certification up to SIL 3/PL e according to IEC 61508/IEC 62061 or ISO 13849.

Variants with a wide-range voltage input of 24 to 240 V AC/DC and an installation depth of 90 mm, and variants with 24 V DC and an installation depth of 120 mm for use with 3SK device connectors are available.

The series consists of devices with up to five outputs and can be supplied with screw or spring-loaded terminals (push-in).

Note:

SIRIUS 3RQ1 coupling relays, see SIRIUS 3RQ1 coupling relays.

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 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. schemes

Note:

The Article No. schemes show an overview of product versions for better understanding of the logic behind the article numbers.

For your orders, please use the article numbers quoted in the selection and ordering data.

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 up to 2 000 m long allows it to be used in extensive plants

Relay outputs

• Different voltages can be switched through the floating contacts
• The relay contacts allow currents of up to 5 A at AC-15/DC-13 to be connected

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 the 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 and 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 connection 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 conducted 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

Expansion option with 3RQ1 coupling relay

SIRIUS 3SK safety relays are ideal for combining with the SIRIUS 3RQ1 coupling relays. Combinations are made by means of SIRIUS 3ZY12 device connectors or wiring.

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 keeping stocks and the considerations involved in configuration where the evaluation units to be selected are concerned.

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.

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.

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.