Siemens 3RH1921-1HA22 ai Auxiliary Contact Block

Siemens 3RH1921-1HA22 is a four-pole auxiliary contact block that mounts on Sirius size S0 motor contactors to provide two normally open and two normally closed auxiliary contacts. This top-mounted module uses screw terminals and conforms to DIN EN 50012, designed for motor contactors in the S0 size range. It features 690 V insulation and 6 kV surge withstand, with a mechanical service life of 10,000,000 switching cycles and an electrical endurance of up to 200,000 cycles (AC-15 at 230 V). The auxiliary circuit comprises two normally open and two normally closed contacts, and it supports an operating current of up to 10 A (AC-12) at voltages such as 24 V and 230 V. Wiring is straightforward thanks to the screw-terminal configuration, and the block is intended for signaling, interlocking, and feedback in control circuits without carrying main-load current.