The Siemens 4EP3800-1DS00 is a 3-phase commutating choke — a line reactor — designed to sit between a converter (VFD or DC drive) and the AC supply. Its job is to limit current rise during commutation, reduce harmonic distortion, and protect the converter's input diodes from switching transients and line notching. Rated for 31.5 A maximum continuous current (28.35 A nominal) at 500 V AC, 50 Hz, with an inductance of 0.0012 H and a relative inductive voltage drop of 4% at the rated point.
Thermal and environmental fit
Thermal class B (130 °C rise) per IEC 60085, with a 40 °C ambient rating. Copper losses run 59 W in the coil, iron losses 21.8 W — that 80.8 W total has to be shed into the panel air, so don't bury this choke in a sealed, uncooled enclosure without accounting for the heat rise. IP00 — no enclosure protection at all. The choke is a bare magnetic assembly with screw terminals for the main circuit. It needs to live inside a cabinet that provides the IP rating for the overall installation. The terminals accept screw-type connections; no special lug kit required.