The Siemens 4EU4551-5UA00 is a 3-phase mains choke (Netzdrossel f. FU) rated for 1120 A continuous at 500 V AC, 50/60 Hz. It is designed for the line side of a frequency converter drive to attenuate harmonics, limit inrush current, and provide some protection against line notching. The IP00 enclosure means it is an open-frame component intended for mounting inside a cabinet or panel — not for standalone outdoor or washdown duty. Thermal class H insulation (IEC 60085) allows a 40 °C ambient with a 700 W coil loss and 400 W iron core loss, so forced ventilation or adequate cabinet airflow is expected at full load.
The 1120 A rating is the maximum thermal current (Ithmax) at the rated frequency — this is the continuous current the choke can carry without exceeding its thermal class H limits at 40 °C ambient. For a drive application, size the choke so the drive's input current does not exceed this figure; a 4% relative inductive voltage drop (UK=4%) at rated current is typical for a line reactor intended to reduce harmonic distortion. The 0.000032 H (32 µH) inductance value is the per-phase inductance at rated current and frequency. The flat-type terminals are sized for high-current busbar or cable lug connections — not spring-cage or screw-clamp terminations. Verify the terminal hole pattern and busbar spacing against your panel layout before ordering.