The Siemens 3RT1024-3BB44-3MA0 is a SIRIUS power contactor in size S0, rated for switching motor loads up to 7.5 kW at 400 V AC-3. The 24 VDC coil draws 5.4 W both closing and holding, so the coil supply sees a steady load once picked.
Snaps onto a 35 mm DIN rail per DIN EN 50022 or screws directly to a backplate — 45 mm wide, 85 mm tall, 150 mm deep, with 6 mm side clearance required for adjacent units.
Ratings that matter for the panel
AC-3 motor switching at 400 V delivers 7.5 kW; at 690 V the same 7.5 kW applies, meaning the contactor is current-limited above 400 V. AC-4 at 400 V handles 12.5 A for reversing or inching duty. The auxiliary contact block carries two instantaneous contacts rated 10 A at 24 V, 6 A at 230 V, 3 A at 400 V — enough for a PLC feedback loop or a holding circuit. Pollution degree 3 and IP20 on the front (IP00 at the terminals) suit it for standard control cabinets where conductive dust or occasional condensation is expected.