What it is and where it lands
The Siemens SIRIUS 3RT1034-1AP00-1AA0 is an S2-frame power contactor for switching motor loads in control panels. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, and its 55 mm width means it takes three standard module slots on the rail — plan your panel fill accordingly.
Motor-duty ratings that decide the fit
The AC-3 rating (motor starting, breaking under load) is 18.5 kW at 500 V and 10 kW at 690 V — that covers most 20–25 hp induction motors on 480 V systems. AC-2 at 400 V is 15 kW for slip-ring or wound-rotor motors. AC-4 at 400 V is 29 A for reversing or inching duty where the contactor breaks full stall current. If your application cycles hard, the maximum switching rate at AC-3 is 1,000 operations per hour; at AC-4 it drops to 250 per hour.
Auxiliary contact capacity
The built-in auxiliary contacts handle 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — enough to drive a PLC input or a small relay directly. At 110 V it's 1 A, at 220 V it's 0.3 A. No separate aux block needed for basic feedback.
Environment and wiring
Rated for pollution degree 3 (industrial environment, conductive pollution). Operating temperature -25 to +60 °C; storage range -55 to +80 °C. Main circuit terminals are screw-type, accepting 2x (0.75...25 mm²) stranded or 2x (0.5...4 mm²) solid. Side-by-side mounting is allowed with no derating gap — useful when packing contactors tight on a DIN rail.