What it is and where it fits
The Siemens SIRIUS 3RT1015-2KB41-ZW98 is a size S00 power contactor with a 24 VDC coil, spring-loaded terminals for the main current circuit, and an integrated varistor surge suppressor. It mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 50022 — the standard DIN-rail footprint you expect in a control panel.
Key ratings — what they mean for the fit
Rated operational current at AC-2 duty at 400 V is 3 kW (motor load), and at AC-4 at 400 V it carries 6.5 A — that is the reversing / inching duty cycle, so if your application does frequent jogging, this is the rating that governs contact life, not the AC-3 number. The DC coil draws 2.3 W closing and 2.3 W holding, which is a continuous-duty coil; no extra hold-in resistor needed. The spring-loaded terminals accept 2x (0.25... 2.5 mm²) solid or stranded, or 2x (24... 14) AWG — strip length is standard, no special ferruling required for the spring cage.
Panel integration notes
Width is 45 mm, height 60 mm, depth 73 mm — that 73 mm depth is the dimension from the DIN-rail mounting surface to the front of the contactor, so verify your enclosure depth allows for wiring clearance plus the 6 mm spacing at the side for side-by-side mounting (allowed per the spec). IP20 on the front and at the terminals means it is protected against finger contact but not washdown — keep it inside the panel, not in a wet area. Pollution degree 3, so it is rated for industrial atmospheres with conductive dust or occasional condensation.