The Siemens SIRIUS 3RT1026-1BG44-1AA0 is a size S0 power contactor rated for 11 kW at 400 V in AC-3 duty (motor switching), with screw-type terminals and snap-on mounting onto 35 mm DIN rail per EN 50022. Rated operational current at AC-3 is 11 kW at 400 V, and the contactor also carries an AC-4 rating of 15.5 A at 400 V for reversing or inching applications. Coil hold power is 5.4 W DC; the magnet coil closes and holds at the same power draw, simplifying the control transformer sizing.
Mounting and integration
Mounts via screw or snap-on onto 35 mm standard rail per DIN EN 50022. Width is 45 mm, height 85 mm, depth 150 mm — fits standard S0 contactor footprint. Side-by-side mounting is allowed with a 6 mm clearance at the side for heat dissipation. Degree of pollution 3 rated, so it handles conductive dust and humidity in industrial panels. Front protection is IP20 (finger-safe), terminal area is IP00 — wire connections are exposed; panel builders should cover live parts per local code.
Ratings and what they mean for your load
The 11 kW at 400 V AC-3 rating means this contactor can switch a standard three-phase induction motor of that power under normal starting conditions (make and break at rated current). For resistive loads (AC-1), the thermal current is higher — the AC-12 operating current is 10 A. For DC switching, the contactor is rated 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V — useful for DC brake coils or control circuits. AC-4 rating of 15.5 A at 400 V covers plugging and inching duty where the motor is reversed or started frequently — a more demanding thermal cycle than AC-3. Short-circuit coordination: with type 1 coordination, a 100 A gL/gG fuse is permitted; with type 2, a 35 A gL/gG fuse limits damage to the contactor after a fault.