The Siemens 3RA2145-4MB47-1AK6 is a combination motor starter from the SIRIUS 3RA21 series, panel-mounted, Size 3, rated for the 80-100 A range. It integrates a contactor and overload relay into a single unit, so it handles both switching and motor protection in one panel footprint — one less device to wire and one less SKU on the shelf.
What the 80-100 A rating means in practice
The 80-100 A range on a Size 3 SIRIUS combination starter covers motor full-load currents in that band. The integrated overload relay sets the trip point within that window.
Panel-mounted, Size 3 footprint. The combo starter bolts directly to a backplate or sub-panel — no DIN rail required. That saves rail space but means the mounting hole pattern and cutout need to be in the panel drawing before fabrication. Verify the physical envelope against your enclosure depth; the contactor and overload stack is taller than a bare contactor.