What this contactor is and what it does
The Siemens SIRIUS 3RT1015-1MB41-0KT0 is a size S00 power contactor designed for switching 3-phase motor loads up to 3 kW at 400 V in AC-3 duty, or 4 kW at 690 V. The 24 VDC coil draws 1.4 W holding power, so it stays cool in a sealed panel and places minimal load on a 24 VDC supply. Screw-type terminals on both main and auxiliary circuits accept up to 4 mm² stranded or 12 AWG solid, which covers most motor branch wiring up to the contactor's rating.
Mounting and panel fit
Mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 50022. The 45 mm width and 57.5 mm height match the S00 footprint, and side-by-side mounting is supported with 6 mm clearance at the side. IP20 on the front and terminals means it's protected against finger contact but needs enclosure for washdown or dust.
Coordination and protection
For Type 2 coordination (no damage to the contactor on a short circuit), use a 20 A gL/gG fuse upstream. For Type 1 coordination (contactor may need replacement after fault), a 35 A gL/gG fuse is sufficient. The pollution degree 3 rating means it's suitable for industrial environments with conductive dust or moisture — typical for control panels in factories.