Siemens launches force-guided coupling relays for safety-related applications


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. 

Due 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.

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