The 3RT1034-1BB44-0AA2-ZW97 is a Siemens SIRIUS contactor rated for AC-3 duty at 15 kW / 400 V, with a 24 V DC coil. It is a 3-pole unit fitted with an S2 module carrying 2 normally-open and 2 normally-closed auxiliary contacts, terminated via screw connections. The order code includes the ZW97 suffix, which designates a multipack of 7 units — so the BOM line buys seven contactors on one order code, not one.
The AC-3 15 kW / 400 V rating is the motor-switching duty class per IEC 60947-4-1: it covers starting and switching off squirrel-cage motors under load. A contactor rated here handles the inrush and breaking current of a 15 kW motor at 400 V three-phase without welding or excessive wear. The 24 V DC coil means it pulls in on a 24 VDC control supply — common in PLC-driven panels where AC control voltage isn't available. Check that your DC supply can deliver the coil inrush; DC coils draw higher peak current than AC equivalents during pickup. The S2 module with 2NO+2NC auxiliary contacts gives you four signal-feedback or interlock circuits without adding a separate auxiliary contact block. That's enough for a basic motor starter with a run signal and a fault interlock, but if you need more than four auxiliary poles, you'll add a separate block on the left side of the contactor.
Deployment context
The screw terminals accept up to the rated conductor size for the 15 kW load — typically 4–6 mm² for the power circuit. The S2 module clips onto the front of the contactor and its terminals are clearly marked for wiring the auxiliary circuits. The multipack of 7 means you get seven identical units in one box, which simplifies kitting for a multi-starter panel or a line with several identical motor branches.