Integrator's spec recap — SIRIUS 3RT1026-1AG20-1AA0
The Siemens SIRIUS 3RT1026-1AG20-1AA0 is a size S0 power contactor rated for motor switching at 11 kW on 400 V in AC-2 duty, and 15.5 A in AC-4 duty at the same voltage — so it handles both slip-ring motor starting and plugging/reversing cycles without derating the main poles. Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, occupying 45 mm of panel width — standard for S0 frame contactors in IEC panels. Screw-type terminals on the main circuit accept up to 2x 10 mm² or 1x AWG 8, with a separate solid/stranded range of 2x (0.5 to 1.5 mm²) through max 2x (0.75 to 4 mm²) for auxiliary wiring.
Coordination and protection — what the ratings mean
For Type 2 coordination (no damage to the contactor under short circuit), the specified upstream fuse is gL/gG 35 A. For Type 1 coordination (contactor may need replacement after fault), the fuse can go to 100 A gL/gG — the 35 A path is what you'd spec for minimal downtime on a motor branch. Rated operational power reaches 11 kW at both 500 V (50 Hz) and 690 V (60 Hz), so the contactor is not voltage-limited within that band — the motor full-load current determines the selection, not the voltage step. Auxiliary contact ratings: 10 A at 24 V, 6 A at 230 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V — the DC switching curve drops fast above 60 V, so verify the control voltage if running DC pilot circuits above that.
Lifecycle and sourcing reality
No official successor or replacement order code is published; this is the active variant. If you are matching a BOM line that specifies 3RT1026-1AG20-1AA0, it is the direct fit.
Panel and environmental fit
Dimensions: 85 mm high, 45 mm wide, 91 mm deep — fits S0 contactor cutouts in standard IEC enclosures. Side-by-side mounting is permitted (no derating gap needed for thermal stacking in open air). Operating temperature range: -25 °C to +60 °C. Pollution degree 3 (conductive pollution, typical for industrial control panels without climate control). Altitude limit 2 000 m without derating. Front protection IP20 (finger-safe terminals when wired); the terminal body itself is rated IP00 — so the contactor must be mounted inside an enclosure that provides the overall panel IP rating.