What it is and what it does
The Siemens 4EP3603-7DS00 is a three-phase commutating choke designed for line-side or load-side use with converters (variable-frequency drives, rectifiers). It limits current rise and reduces harmonic distortion on the AC line. Rated 400 V AC, 50 Hz, 17 A continuous, with an inductance of 1.2 mH and a relative inductive voltage drop of 2.8% at rated current, voltage, and frequency. That 2.8% figure tells you the choke's impedance at line frequency — low enough to avoid significant voltage sag under load, but high enough to smooth commutation notches.
Key ratings and what they mean for fit
The 17 A AC rating is the continuous current the choke can carry in a 50 °C ambient with thermal class B insulation. That means the winding temperature rise is limited to 80 K above ambient — standard for industrial converter duty. The DC rated current is 20.8 A, so if you're using the choke on the DC link of a drive, you have a bit more headroom. Power loss splits into 25 W in the coil and 13 W in the iron core — total 38 W at rated load. That's heat that stays in the panel; account for it in your thermal budget. IP00 means no enclosure — this is an open-frame component for cabinet mounting only, not for standalone outdoor or washdown use.
Where it goes and how it connects
Mounts inside a control cabinet on a flat panel or chassis — no DIN rail provision. Dimensions are 0.125 m wide by 0.125 m high by 0.09 m deep, so it fits a compact footprint. Connections are screw-type terminals or tab terminals, which gives you flexibility: screw terminals for permanent wiring, tabs for quick-connect or bus-bar links. The 3-phase design means it handles all three lines symmetrically; single-phase converters need a different part.