The Siemens 3RT1024-1BP44 is a SIRIUS power contactor in the S0 frame size, designed for switching motor loads up to 7.5 kW at 400 V AC-3. The AC-4 rating at 400 V is 12.5 A — that's the plugging / inching duty cycle, significantly lower than the AC-3 motor-start value, so if your application reverses or jogs the load frequently, size against the AC-4 number, not the 7.5 kW headline.
The DC coil draws 5.4 W both on close and hold — no inrush spike to sag a 24 VDC supply, but the steady-state draw is continuous. Rated control voltage is 230 V. Auxiliary contact ratings: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V — use the 230 V / 6 A figure for typical pilot-duty circuits.
Short-circuit coordination
For Type 1 coordination (contactor may need replacement) the fuse can be 63 A. If the panel spec calls for Type 2, the 25 A limit is hard — don't oversize the fuse to save on spares.
Altitude limit is 2 000 m; above that, dielectric and thermal margins shrink. Pollution degree 3 — suitable for industrial atmospheres with conductive dust or occasional condensation. Dimensions: 85 mm high, 45 mm wide, 150 mm deep.