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 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. Optimized solutions when selecting components are facilitated by a clearly structured component range:

• 3SK1 Standard basic units
• 3SK1 Advanced basic units
• 3SK2 basic units
• 3SK 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 trip functions
• Flexible application thanks to software parameterization
• Powerful semiconductor outputs
• Convenient diagnostics using diagnostics display and configuration software

In the case of 3SK1 Advanced basic units or 3SK2 basic units, the 3ZY12 device connector allows safety functions involving several sensors and actuators to be set up very quickly.

System configuration example with 3SK1121

The 3SK1 Standard and Advanced and 3SK2 ranges are high-quality replacements for 3TK28 safety relays. In their narrow design, and equipped with greater functionality, they can replace any 3TK28 device. The only exceptions to this are 3TK2810 devices.

Note:

For converting from 3TK28 to 3SK, seehttp://www.siemens.com/sirius/conversion-tool.

Overview of functions of the 3SK series

? 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 4 independent safe outputs, two of which via device connector.

⁵⁾ Up to 6 independent safe outputs, two of which via device connector.

Parameter assignment

3SK112 and 3SK1112 with DIP switches

The 3SK112 and 3SK1112 safety relays are configurable safety relays. They are used as evaluation units for typical safety chains (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	Circuit diagram
1	Autostart sensor input	Monitored start sensor input
2	Without cross-circuit monitoring	With cross-circuit monitoring
3	2 x single-channel sensor connection	1 x 2-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:

For more information on SIRIUS Safety ES, see “Parameterization, Configuration and Visualization for SIRIUS".

Innovative enclosure concept for SIRIUS 3SK safety relays

Can be expanded by adding the 3RM1 motor starter

With previous safety relay and motor feeder configurations, a huge amount of wiring was required to monitor motor feeders in safety applications.

Conventional system configuration

Through the integration of SIRIUS 3RM1 motor starters into the SIRIUS 3SK safety relay system family, this wiring has been minimized for the first time.

Motor starters up to 3 kW can be easily integrated into the safety relay system using SIRIUS 3ZY12 device connectors, without the need for additional wiring between the evaluation unit and the motor starter.

3SK1 and 3RM1 system design

Article No. scheme

3SK1

3SK2

Note:

The article No. scheme is presented here merely for information purposes and for better understanding of the logic behind the article numbers.