The Siemens 3RT1034-3BW44 is a SIRIUS S2-frame power contactor rated for 18.5 kW at 400 V in AC-3 duty — the standard motor-switching category per IEC 60947-4-1 — so it handles typical three-phase induction motors up to that power without derating. Screw-type terminals on the main circuit accept 2x (0.75... 16 mm²) stranded or 2x (0.25... 2.5 mm²) solid, covering the range from control wiring to motor feeders.
For heavy-duty jogging or inching (AC-4), the contactor is rated 29 A at 400 V — that is the current it can interrupt during plugging or reversing without excessive contact wear. The AC-1 resistive rating supports 1 200 operations per hour, AC-3 at 1 000, and AC-4 at 250, so the thermal cycling limits are clear for high-duty applications. Coil control is 48 V DC, with a pick-up drop-out time of 20... 30 ms and an arcing time of 10... 15 ms.
RoHS compliance date is 05/01/2012, indicating the part meets the EU directive from that date forward.