The Siemens 4EP3804-8DK00 is a 3-phase commutating choke (line reactor) designed for converter front-end duty. It carries a rated current of 23 A (25 A maximum) at 400/480 V AC, 50/60 Hz, with an inductance of 1.2 mH and a relative inductive voltage drop of 4% at the rated operating point. The part is recognized under UL/CSA and built to EN 61558-2-20, thermal class B, with screw-type terminals and IP00 protection — meaning it must be installed inside an enclosure that provides the required ingress protection.
What the Ratings Mean for Panel Fit
The 23 A rated current (25 A maximum) is the continuous thermal current at 40 °C ambient. The 30.6 A DC-rated value applies if the choke is used in a DC-link circuit — a different duty than the AC line reactor role. The 1.2 mH inductance with 4% voltage drop is sized for typical 6-pulse converter harmonics; a lower-drop choke (2%) would give less line distortion filtering, a higher-drop (5% or more) increases losses and voltage sag. The 54.3 W coil loss plus 16.6 W iron-core loss means about 71 W total heat to dissipate inside the panel — factor that into cabinet ventilation or forced cooling if ambient is near the 40 °C limit.
Mounting and Integration
Dimensions are 0.178 m width × 0.153 m height × 0.12 m depth. The IP00 rating means no enclosure — mount this choke inside a panel that provides at least IP2X (finger-safe) or better, depending on the installation environment. Screw-type terminals accept standard power conductors; no special lug kit required. The thermal class B insulation (130 °C) is standard for industrial reactors and compatible with most converter cabinets.