Siemens launches force-guided coupling relays for safety-related applications
5 May 2021
The Sirius 3RQ1 series completes Siemens Smart Infrastructure’s portfolio of coupling relays for electrical systems in industry and infrastructure. With wide-range supply voltage from 24 to 240V AC/DC, the new force-guided devices are designed for universal use. They are certified up to Safety Integrity Level (SIL) 3 and Performance Level (PL) e and approved for very high safety requirements. Among other things, coupling relays are used to amplify or multiply signals to and from controllers. The Sirius 3RQ1 coupling relays can also switch electrical loads directly. Thanks to their force-guided operation in accordance with IEC 60947-5-1 (IEC 61810-3), the devices offer maximum safety for people and systems. They are particularly well suited for use in railroad and signaling applications as well as in elevators and industrial production facilities, making it possible to safely control brakes and doors, for example, and to switch traffic lights, conveyor belts or packaging machines.
“Force-guided” means that the integrated contacts of the coupling relays are mechanically connected to each other. Therefore, normally open (NO) and normally closed (NC) contacts can never be closed at the same time. This allows for fast and precise diagnostics when monitoring the force-guided feedback contact: an opening failure is detected immediately, and faulty switching is avoided.
The coupling relays offer additional safety as an output expansion of the Sirius 3SK series safety relays using a device connector. This reliably prevents wiring errors and protects against electrical accidents and damage during assembly. At the same time, the new relays save valuable time when building control panels.
Thanks to removable screw-type or spring-type (push-in) terminals, installers can wire the coupling relays while standing. This allows the devices to be replaced quickly, eliminating the need to recheck the wiring.
Sirius 3RQ1 coupling relays have functional safety certification up to SIL 3 / PL e (IEC 61508 / ISO 13849) as well as approvals for shipbuilding and railroad applications. In addition, they comply with all common international standards, including CE, UL/CSA, EAC, and CCC.
For more information on Sirius coupling relays, see
For more information on Siemens Smart Infrastructure, see
Siemens Smart Infrastructure (SI) is shaping the market for intelligent, adaptive infrastructure for today and the future. It addresses the pressing challenges of urbanization and climate change by connecting energy systems, buildings and industries. SI provides customers with a comprehensive end-to-end portfolio from a single source – with products, systems, solutions and services from the point of power generation all the way to consumption. With an increasingly digitalized ecosystem, it helps customers thrive and communities progress while contributing toward protecting the planet. SI creates environments that care. Siemens Smart Infrastructure has its global headquarters in Zug, Switzerland. As of September 30, 2020, the business had around 69,600 employees worldwide.
Siemens AG (Berlin and Munich) is a global technology powerhouse that has stood for engineering excellence, innovation, quality, reliability and internationality for more than 170 years. Active around the world, the company focuses on intelligent infrastructure for buildings and distributed energy systems and on automation and digitalization in the process and manufacturing industries. Siemens brings together the digital and physical worlds to benefit customers and society. Through Mobility, a leading supplier of intelligent mobility solutions for rail and road transport, Siemens is helping to shape the world market for passenger and freight services. Via its majority stake in the publicly listed company Siemens Healthineers, Siemens is also a world-leading supplier of medical technology and digital health services. In addition, Siemens holds a minority stake in Siemens Energy, a global leader in the transmission and generation of electrical power that has been listed on the stock exchange since September 28, 2020.
In fiscal 2020, which ended on September 30, 2020, the Siemens Group generated revenue of €57.1 billion and net income of €4.2 billion. As of September 30, 2020, the company had around 293,000 employees worldwide. Further information is available on the Internet at www.siemens.com.