Siemens 3RH6122-1BB40 SIRIUS Contactor Relay 24V DC 2NO+2NC

The Siemens 3RH6122-1BB40 (3RH6122-1BB40) is a compact SIRIUS auxiliary contactor relay engineered for switching control circuits, interlocking systems, and signaling applications across industrial automation environments. Operating within the Siemens SIRIUS family of low-voltage control gear, this unit features a 24 V DC rated control supply voltage and provides a reliable contact configuration consisting of two normally open (2 NO) and two normally closed (2 NC) contacts. The device is built with robust screw terminals for secure electrical connections and easy wiring in motor control centers, control cabinets, and power distribution assemblies. As an essential switching component, the relay reliably interfaces programmable logic controllers (PLCs), safety circuits, and industrial controllers with downstream contactors, solenoids, or signaling indicators. Its size S00 design allows for DIN rail snap-on mounting or standard screw fixing, facilitating seamless integration and rapid maintenance inside modern machine control panels. The unit delivers dependable galvanic isolation and high switching reliability under demanding operating conditions. Typical applications include manufacturing machinery, packaging equipment, material handling systems, pump control panels, and process automation installations.