The Siemens 4EU2721-0AA20-0AA0 is a 3-phase commutating choke designed for converter applications. It carries a rated current of 324 A (max 360 A) at 470 V AC, 50 Hz, with an inductance of 35 µH. The relative inductive voltage drop is 1.47% at the rated measurement level — this tells you how much voltage the choke absorbs under load, which matters for sizing the downstream converter's DC-link voltage margin.
This is an IP00 open-frame component — no enclosure, no washdown rating. It mounts inside a converter cabinet or drive panel, with flat-type terminals for the main circuit connection. The dimensions are 0.27 m wide × 0.248 m high × 0.187 m deep, so plan for a panel footprint that accommodates that volume and allows airflow for the 180 W coil loss plus 60 W iron core loss (240 W total heat to dissipate).