What it is and where it fits
The Siemens 3RT1034-1AG20-ZW96 is a SIRIUS power contactor in size S2, designed for switching motor loads in control panels. It fastens via screw or snap-on mounting onto a 35 mm DIN rail per DIN EN 50022, so it integrates into a standard panel layout without special adapters. The 55 mm width and 112 mm height mean it occupies one standard modular slot, and the IP20 finger-safe front allows safe access in an open cabinet during commissioning.
What the ratings mean for your motor load
The key motor-switching ratings are 15 kW at AC-2 duty on 400 V, 18.5 kW at 500 V, and 10 kW at 690 V. AC-2 is the standard category for slip-ring motor starting and reversing — so this contactor is sized for a 15 kW motor on a 400 V line, not for high-inrush AC-3 or AC-4 duty at those same power levels. The AC-3 maximum mechanical switching rate is 1 000 operations per hour, while AC-4 drops to 250 per hour due to heavier arc stress during plugging or inching. If your application is frequent jogging or reversing, the lower AC-4 rate governs the contactor's service life.
Terminal capacity and wiring
The main circuit uses screw-type terminals. Solid wire accepts 2x (0.5... 1.5 mm²), 2x (0.75... 2.5 mm²), or max 2x (0.75... 4 mm²). Stranded wire goes up to 2x (0.75... 25 mm²).