The Siemens 3RT1026-1BM44-1AA0 is a SIRIUS power contactor in the S0 frame, designed for switching motor loads and resistive circuits in industrial control panels. It mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 50022, so it drops into any standard panel without extra bracketry. Rated 11 kW at 400 V in AC-2 duty (slip-ring motors, soft-start applications) and 11 kW at both 500 V and 690 V, this contactor handles the common European motor voltages. The AC-4 rating of 15.5 A at 400 V covers inching and plugging duty where high inrush current is expected. For resistive loads (AC-12), it carries 10 A continuously. The screw-type main terminals accept up to 10 mm² stranded or 4 mm² solid conductors, with dual-wire capability for daisy-chaining.
Coordination and Protection
Type 2 coordination (no damage to the contactor after a short-circuit) requires a 35 A gL/gG fuse. Type 1 coordination (contactor may need replacement but the circuit is cleared) allows up to 100 A gL/gG. This matters when you're specifying upstream protection for a motor branch circuit. Pollution degree 3 rating means it's suited for industrial environments with conductive dust or occasional condensation — no need for a sealed enclosure in a typical panel.
Dimensions and Environment
At 45 mm wide, 85 mm tall, and 150 mm deep, the S0 frame fits in compact panel layouts. Side-by-side mounting is allowed with a 6 mm gap to adjacent devices for heat dissipation. Operating temperature range is -25 to +60 °C, and the front face carries IP20 finger protection. The terminal area is IP00 — safe inside an enclosure but not touch-safe open. Maximum operating altitude is 2000 m without derating, covering most installations.