SIRIUS S2 power contactor — what the ratings tell a buyer
The Siemens SIRIUS 3RT1036-1AV00 is a size S2 power contactor with screw-type terminals, rated 22 kW at 400 V in AC-2 duty — the category that covers slip-ring motor starting and reversing, where contactor life is governed by making and breaking at reduced current. For AC-4 duty (plugging, inching, reversing on the fly) it carries 41 A at 400 V, which is the rating that limits its use in high-cycle reversing applications. The 30 kW at 500 V and 11.4 kW at 690 V ratings expand its reach into 500 V and 690 V distribution systems, though the 690 V figure is derated relative to the 400 V AC-2 rating.
Wiring and panel integration
Stranded wire capacity is 2x (0.75... 25 mm²); solid wire accepts 2x (0.5... 1.5 mm²), 2x (0.75... 2.5 mm²), and max 2x (0.75... 4 mm²). The minimum permissible cross-section at 40 °C is 16 mm² — that is the smallest conductor size allowed for full rated current without derating. Dimensions are 55 mm wide, 112 mm high, 115 mm deep, so it occupies a standard 55 mm DIN-rail space (three modules wide on a 18 mm pitch). Side-by-side mounting is permitted, which saves panel width when grouping multiple contactors.
The rated frequency is 50 Hz, with an operating range of 0.8 to 1.1 times nominal. Coil data is given for DC control: at 24 V the coil draws 10 A (likely inrush), at 60 V it draws 2 A, at 110 V 1 A, at 220 V 0.3 A. For AC control at 230 V it draws 6 A, at 400 V 3 A. These are the coil inrush or holding currents, not the main circuit current. Maximum switching rates: AC-1 1000 cycles/h, AC-2 400 cycles/h, AC-3 800 cycles/h, AC-4 300 cycles/h.