The Siemens 4EU4521-1AC00 is a three-phase commutating choke (line reactor) designed for converter applications. It smooths current ripple and limits di/dt on the DC link or input side of a variable-speed drive, reducing harmonics and protecting the converter semiconductors. Rated for 1000 A continuous at 460 V AC, 0–50 Hz, with an inductivity of 0.033 mH and a 4% relative inductive voltage drop at rated current. That 4% drop is typical for a commutating choke — it provides enough impedance to limit fault current without excessive voltage sag under load.
Thermal and enclosure reality
IP00 means no enclosure — this is an open-frame component for installation inside a cabinet. Combined coil losses of 501 W and iron-core losses of 280 W total nearly 800 W of heat that must be ventilated out of the panel. Thermal class H (180 °C insulation) allows high hotspot temperatures, but the panel designer must still account for the heat rise. Dimensions are 0.460 m wide × 0.435 m high × 0.293 m deep — a substantial footprint. Flat-type terminals on the main circuit mean bolted bus-bar or cable-lug connections, not quick-connects. Verify the gland-plate clearance before panel layout.