The Siemens SIRIUS 3RT1034-1BB44-0AA2 is a Size S2 power contactor rated for switching motor loads up to 18.5 kW at 500 V (AC-3) and 10 kW at 690 V (AC-3). Screw-type terminals on the main circuit accept solid conductors up to 2x (0.75... 4 mm²) and stranded up to 2x (0.75... 25 mm²). Front-side protection is IP20 (finger-safe), while the terminal area is IP00 — panel builders must ensure the wiring compartment is within an enclosure or guarded against accidental contact.
Switching performance and duty-cycle limits
AC-3 motor switching is rated at 1 000 operations per hour maximum; AC-1 resistive loads allow 1 200 ops/h. For demanding reversing or inching applications (AC-4), the limit drops to 250 ops/h. Mechanical endurance is 10 million cycles typical. DC switching capability covers common control voltages: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. Rated for pollution degree 3 (industrial environments with conductive or dry non-conductive pollution).
As a SIRIUS series product, it carries the usual Siemens compliance documentation package (CE, UKCA, EAC, and UL/CSA certifications available on request).
Dimensions: 55 mm wide, 139 mm high, 179 mm deep — fits standard S2 contactor footprint. Screw-type terminals for the main circuit accept solid conductors 2x (0.5... 1.5 mm²), 2x (0.75... 2.5 mm²), max. 2x (0.75... 4 mm²); stranded conductors 2x (0.75... 25 mm²); solid or stranded 2x (0.75... 16 mm²). Minimum permissible cross-section at 40 °C is 16 mm². The coil is 24 VDC rated. For DC switching, verify the free-wheel diode polarity on any inductive load downstream — the contactor's own coil suppression is built in, but external loads need their own flyback protection.