What it is and what it does
The Siemens SIRIUS 3RT1046-1AP00-1AA0 is a size S3 power contactor for switching motor loads in control panels. Its AC-3 rating of 55 kW at 500 V means it handles standard three-phase squirrel-cage motors up to that power — the duty class that governs real motor switching, not the higher resistive-load (AC-1) figure. The AC-2 rating of 45 kW at 400 V covers slip-ring motors or wound-rotor applications where the load current stays on during acceleration.
Mounting and integration
Mounts via screw and snap-on onto 35 mm or 75 mm DIN rail — standard for European-style panels. The 70 mm width and 146 mm height fit the S3 frame footprint; depth of 139 mm leaves room for wiring ducts in a 200 mm enclosure. Screw-type terminals on the main circuit accept stranded up to 2x (10... 50 mm²) and solid up to 2x (0.5... 1.5 mm²) with ferrules. Side-by-side mounting is permitted, so you can gang multiple contactors without spacing — saves rail length when building a motor control center.
Environmental and compliance notes
Rated for pollution degree 3, so it's suited for industrial environments with conductive dust or occasional condensation. Operating temperature range of -25 to +60 °C covers most plant-floor conditions without derating. The substance prohibition date of 05/01/2012 aligns with RoHS compliance timelines — the part is RoHS-compliant as shipped.