What it is and where it fits
The Siemens SIRIUS 3RT5044-1AM00 is a size S3 power contactor built for switching motor loads in industrial control panels. It mounts on 35 mm or 75 mm DIN rail via screw and snap-on fastening, and the screw-type terminals on both the main and auxiliary/control circuits mean a standard screwdriver is all you need for wiring — no special crimp tooling required. Rated insulation voltage is 1000 V, and it carries motor power ratings of 34 kW at 230 V, 59 kW at 400 V, and 102 kW at 690 V (all at 60 °C ambient). That puts it squarely in the range for medium-horsepower three-phase induction motors on 400 V or 690 V distribution.
Mounting and integration notes
The contactor measures 146 mm high, 70 mm wide, and 139 mm deep. That 70 mm width is the key panel-spacing number — it dictates how many units fit across a given DIN-rail length. Side-by-side mounting is permitted, so you can gang multiple contactors without mandatory gaps. Mounting position is flexible: the contactor can be rotated ±180° on a vertical surface and tilted forward or backward by ±22.5°. That helps when routing cables in a tight enclosure. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C. Pollution degree 3 means it's rated for the conductive-dust environments typical of industrial panels.
Terminal capacity and wiring
Main circuit terminals accept 2x (2.5 to 16 mm²) solid or stranded copper, or 2x (10 to 1/0 AWG). Minimum permissible conductor size is 35 mm² at both 40 °C and 60 °C — that's the cross-section needed to carry the rated current without exceeding terminal temperature rise. Auxiliary contacts are rated for switching: 6 A at 24 V and 230 V, 3 A at 400 V, 1 A at 110 V, 0.3 A at 220 V. The contactor accepts an auxiliary switch block extension, so you can add more signal contacts without replacing the base unit.