Siemens SIRIUS S2 Power Contactor — 3RT1036-1AL20-ZW97
The Siemens SIRIUS S2 power contactor 3RT1036-1AL20-ZW97 is a current-production, screw-terminal contactor rated for motor switching at 22 kW in AC-2 duty at 400 V, and 30 kW at 500 V AC-3.
The 22 kW at AC-2 400 V rating means this contactor is sized for slip-ring motor starting or other moderate-duty motor loads where the contacts close and open under some load. For standard squirrel-cage motors (AC-3), it handles 30 kW at 500 V. The AC-1 resistive rating isn't directly stated, but the AC-3 figure gives you the real-world motor-switching capacity. The auxiliary contact block is rated 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — these numbers govern the control-circuit side, not the main power path. That covers most panel wiring up to about 6 AWG stranded. The terminals are rated for pollution degree 3, so they tolerate conductive dust and condensation in industrial enclosures without derating.
Side-by-side mounting is allowed without derating, which saves rail space in dense panels. The -25 °C lower limit means it's fine for unheated indoor enclosures in most climates, but not for deep-freeze or outdoor arctic installations without additional enclosure heating.