What this choke does in the drive line
The Siemens 4EU4321-1BA00-0A is a commutating choke (line reactor) for a converter, rated for 3-phase AC at 690 V. That 4% drop is the design point — you size the choke so the drive's DC-link voltage sees that sag under full load. Total power loss hits 780 W (480 W coil + 300 W iron core) at the 40 °C ambient rating. That's a non-trivial heat load in a cabinet — plan for forced ventilation or derating if the enclosure runs hot. Thermal class H (180 °C insulation) gives headroom for overloads, but the IP00 enclosure means it needs a clean, dry environment; no washdown, no dust.
Physical fit and termination
Footprint is 0.46 m wide × 0.435 m tall × 0.265 m deep — a substantial block. Terminated via flat-type connectors on the main current circuit, so expect bus-bar or heavy cable lugs, not DIN-rail spring clamps. No DIN-rail mounting; this bolts into a chassis or sub-panel.