Siemens 4EU5051-1UA00 Mains Choke, 1250 A, 690 V AC, IP00

The Siemens 4EU5051-1UA00 is a mains choke (line reactor) sized for a 3-phase variable-frequency drive pulling up to 1250 A at 690 V AC. That 1250 A rating is the continuous thermal current — the choke handles full motor current without saturating, so it's the number that decides fit for the drive's input line. Inductance is 0.04 mH with a 4% voltage drop at rated current and frequency. That 4% impedance is typical for a line reactor — it limits harmonic distortion and inrush current on the drive's DC bus. The 50/60 Hz rating means it works on either supply frequency without derating. Thermal class H (180 °C winding) and a 40 °C ambient rating give headroom in a warm cabinet. The 1100 W coil loss plus 550 W iron-core loss means this choke dissipates about 1.65 kW total — plan for ventilation or forced airflow in the enclosure.