Siemens 3RT1936 1ES00 3RH1921 1HA22 Contactor

Siemens Sirius 3RT1936-1ES00 is a three-pole motor-contactor designed for AC-3 duty and capable of switching up to 40 A at voltages up to 460 V AC. It ships with the 3RH1921-1HA22 auxiliary contact block, a snap-on add-on that provides two normally open and two normally closed auxiliary contacts for enhanced control, feedback, and interlocking. The auxiliary block is compatible with Sirius sizes S0–S3 contactors and uses screw-terminal connections for reliable wiring. It offers insulation voltage up to 690 V, surge resistance rated at 6 kV, and IP20 protection on the front, making it suitable for control-circuit environments with moderate dust or condensation. Mechanical life is typically about 10,000,000 switching cycles, with electrical endurance around 200,000 cycles at AC-15, supporting frequent start/stop sequences in automated systems. This combination is commonly used to control small-to-mid-size motors in pumps, fans, conveyors, and related equipment, delivering compact, integrated motor-control functionality with added signaling capability while adhering to standard mounting and wiring practices for Siemens motor-control panels.