What this choke does on a drive line
The Siemens 4EP3500-0KK01 is a three-phase commutating choke — a line reactor — designed to sit between a converter (VFD) and the motor or the supply. Its job is to limit the rate of current rise (di/dt) during switching, which reduces harmonic distortion, protects the drive's IGBT modules from voltage spikes, and extends the life of the motor windings. Out here in the grease, on a conveyor drive or a pump station, a choke like this is what keeps the drive from cooking itself on a long cable run or a stiff grid. Rated for 400 V AC at 50 Hz, it carries a continuous current of 21.6 A with a maximum of 24 A. The 0.35 mH inductance gives a relative inductive voltage drop of 1.14% at rated current and frequency — that's the percentage of line voltage the choke eats up, so you size it into the motor voltage budget. Thermal class F insulation means it's good for a 155 °C hot-spot, and the 40 °C ambient rating is the standard cabinet temperature. IP00 means it's an open-frame component — mount it inside a panel, not out in the weather. Termination is free cable endings — bare conductor ends — so you land it directly into a terminal block or a drive's power terminals. No connector, no lug kit. The footprint is 148 mm wide, 139 mm tall, and 68 mm deep; plan for that in your panel layout.