SIRIUS S2 power contactor — panel fit and motor duty
The Siemens 3RT1034-1AL20-ZW97 is a SIRIUS power contactor in size S2, designed for switching motor loads in control panels. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022, and the front face carries an IP20 rating — fine for enclosed panel use, though the terminal area is IP00, so keep live parts behind a gland plate or cover. Rated for AC-3 duty at 50/60 Hz, it handles 18.5 kW at 500 V and 10 kW at 690 V — enough for a mid-size pump or conveyor motor. The AC-2 rating at 400 V is 15 kW, so if you're switching slip-ring or wound-rotor motors, that's the curve to watch. Switching frequency tops out at 1 000 cycles/hour in AC-3, 750 in AC-2, and 250 in AC-4 — the AC-4 number matters if you're doing plugging or inching duty.
Terminal wiring and aux contact capacity
Main circuit terminals accept solid wire from 0.5 mm² up to 4 mm² (max 2x) and stranded up to 25 mm² (2x). That's generous for an S2 frame — you can land a 4 mm² solid ring tongue or a 16 mm² stranded ferrule without adapters. The aux contact block (integrated or add-on) is rated 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — typical for control-circuit isolation. Side-by-side mounting is allowed (no derating gap needed), which helps when you're packing multiple contactors into a tight DIN-rail row. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C — the storage figure is for handling, not running; don't let the panel ambient exceed 60 °C.