Siemens 3RH1122-2BB40 Electromechanical Control Relay

Siemens 3RH1122-2BB40 is a 24 V DC coil electromechanical control relay in the S00 frame size, designed for control circuits that require two normally open and two normally closed contacts. This Siemens relay uses spring-type terminals for quick, reliable connections and is rated for an insulation voltage of up to 690 V and an operating front IP20 protection class. The device supports a pollution degree 3 environment and is suitable for installation up to 2,000 meters above sea level. The coil energizes at 24 V DC, and the contact arrangement provides two NO and two NC contacts to implement both signaling and interlocking functions in control panels. With a mechanical life specification up to 30,000,000 switching cycles and an impulse voltage resistance of 6 kV, it is built for rugged duty in automation environments. It also withstands shocks of 10 g for 5 ms and 5 g for 10 ms, and operates over an ambient temperature range of -25 to +60 °C (with storage and transport ranges broader). Typical applications include logic interlock, sequencing, and signaling tasks in machine control and panel assemblies where compact, 24 V DC control relays are needed.