Siemens 3RQ1000-1HB00 Coupling Relay

The Siemens 3RQ1000-1HB00 Coupling Relay is a force-guided (positively driven) safety interface housed in an industrial enclosure, designed to safely couple control signals between a controller and safety devices. It features four contacts—two normally open and two normally closed—driven by a 24 V DC coil, with screw terminals for straightforward wiring. This configuration makes it suitable as an interface/expansion module within Siemens safety ecosystems, enabling reliable isolation between logic and final control elements and allowing safe interconnection of control circuits with safety relays. The device carries SIL 2 and PL c safety classifications, reflecting its use in safety-critical applications, and is marketed under the SIRIUS 3RQ1 family as a coupling relay for safety purposes, often employed to safely couple a controller to safety relays or sensors in automated systems.