Mains Choke for Variable-Frequency Drives
The Siemens 4EU2752-4UB00-0AA0 is a three-phase mains choke (Netzdrossel f. FU) designed to sit between the supply and a variable-frequency drive input. Its primary job is to reduce harmonic distortion, limit inrush current, and protect the drive's DC-link capacitors from line transients. Rated for 690 V AC at 50 Hz, it handles a continuous current of 112.5 A with a maximum of 125 A — sized for medium-power drives in industrial panels. The 4% relative inductive voltage drop (UK) at rated current is the key selection parameter: it tells you the choke will smooth the line without dropping excessive voltage under load.
IP00 means this choke is an open-frame component — no enclosure. It mounts inside a panel or cabinet where the ambient temperature stays at or below 40 °C. Thermal class H (180 °C insulation system) gives headroom for the combined 266 W total power loss (179 W coil + 87 W iron core) without derating, as long as airflow is adequate. The 0.406 mH inductance at 112.5 A is the value that governs harmonic attenuation. For a 50 Hz line, this choke typically achieves around 4% impedance — enough to meet IEEE 519-2014 harmonic limits for most drive installations without oversizing. Termination is via flat-type connectors, not ring lugs or bus bars. Verify your cable lug or bus-bar interface matches a flat pad before panel assembly.
The choke measures 0.27 m wide, 0.248 m high, and 0.208 m deep. That footprint is typical for a 125 A class line reactor — expect to allocate roughly 270 mm × 250 mm of panel floor, plus clearance for the flat-type terminals and airflow around the core. No DIN-rail mounting; it bolts directly to a backplate.