Industrial 3RH1131-2KB40 Three Pole Contactor

Siemens 3RH1131-2KB40 is a SIRIUS coupling relay designed to interconnect control circuits, offering 3 normally open contacts and 1 normally closed contact in the compact size S00 package for auxiliary switching tasks. It uses a 24 V DC coil, with a coil operating range of 0.7 to 1.25 times Us (roughly 16.8–30 V DC), and is suited for controlling devices that do not require heavy power switching. The unit is rated for insulation up to 690 V and is built for up to 60 °C ambient temperatures, with a safe operating environment up to 2,000 m above sea level; it weighs about 0.256 kg and includes features such as a varistor insert and spring-loaded terminals for robust wiring. Typical contact ratings align with AC-15 at 24 V DC, up to several amperes, making it appropriate for PLC outputs, signaling circuits, and interlocking applications rather than primary motor loads. With 30,000,000 mechanical cycles, the relay is designed for high-cycle signaling tasks in industrial control panels. Note that 3RH1131-2KB40 is a phased-out model in Siemens’ lineup, with the recommended successor being 3RH2131-2LB40 for new designs. This model is part of Siemens’ compact auxiliary contactor family and is often specified where compact, relay-based signaling interfaces are required in control circuits.