What this contactor is and what it does
The Siemens SIRIUS 3RT1026-3XG28-0MV0-ZW97 is a Size S0 power contactor with screw-type terminals on the main circuit and an integrated RC surge suppressor across the coil. It's rated 11 kW at AC-2 duty at 400 V, and 15.5 A at AC-4 at 400 V — so it handles both standard motor starting (AC-2) and the higher-stress reversing or plugging duty (AC-4) up to that current. The RC suppressor is built in, meaning you don't need to add an external snubber for inductive load switching; it's already on the contactor.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. The S0 frame is 45 mm wide, 88 mm tall, 140 mm deep — a standard footprint that fits alongside other S0 accessories and overload relays in a control panel. Side-by-side mounting is allowed, so you can gang multiple contactors without extra spacing. Pollution degree 3 means it's rated for industrial environments where conductive dust or condensation may occur.
Ratings and what they mean for your load
The AC-2 rating at 400 V is 11 kW — that's the motor starting duty for slip-ring motors or wound-rotor applications. The AC-4 rating at 400 V is 15.5 A, covering reversing, inching, or plugging service where the contactor makes and breaks full load current. For resistive loads (AC-12), the maximum operating current is 10 A. The auxiliary contacts are rated for 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — typical for control circuit feedback. The integrated RC suppressor is designed for 50/60 Hz coils, with the coil operating range from 0.8 to 1.1 times rated voltage at 50 Hz, and 0.85 to 1.1 at 60 Hz.