What this contactor is and where it fits
The Siemens SIRIUS 3RT1034-1AL20-ZX95 is a size S2 power contactor built for motor switching in control panels. It mounts on 35 mm DIN rail per DIN EN 50022, using either screw-clamp or snap-on fastening. The 55 mm width and 112 mm height keep it compact for dense panel layouts. Rated for AC-2 duty at 15 kW on a 400 V 50/60 Hz supply, this contactor handles wound-rotor motors or other loads where the inrush is moderate but the switching frequency is regular. The AC-2 rating is the one that governs real motor life here — not the higher AC-3 figure, because AC-2 accounts for the longer arcing time of slip-ring motors.
Terminal wiring and auxiliary contact capacity
Main circuit terminals accept solid conductors from 2x 0.5 mm² up to max 2x 4 mm², and stranded up to 2x 25 mm². The screw-type terminals are rated IP00 at the connection point, while the front face carries IP20 for basic finger-safe touch protection inside the enclosure. The built-in auxiliary contacts are rated for 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, but verify the load type against the AC/DC curve if switching an inductive load like a contactor coil.
Environmental limits and switching endurance
Operates from -25 °C to +60 °C ambient, with storage range from -55 °C to +80 °C. Pollution degree 3 means it tolerates conductive dust and condensation typical of industrial panels without conformal coating. Side-by-side mounting is permitted, so you can pack contactors without derating for heat buildup. Mechanical life is rated at 10 million operations typical. Switching frequency limits: 1200 cycles/hour at AC-1 (resistive), 1000 at AC-3 (squirrel-cage motor), 750 at AC-2, and 250 at AC-4 (plugging/inching). For a takt-time line running 10-second cycles, AC-3 stays well under the 1000/h ceiling — holds takt time without margin concerns.