The Siemens 4EP4000-2DS00 is a 3-phase commutating choke (line reactor) designed for converter front-ends, rated at 45 A continuous with a 50 A maximum and 0.73 mH inductance per the EN 61558-2-20 standard.
Three current figures govern the selection: 45 A rated (the thermal continuous current at 40 °C ambient), 50 A maximum (the short-term overload ceiling), and 61.2 A at DC — the DC rating matters if you're using this choke on the DC bus of a regenerative drive or a battery-fed inverter, where the current is unidirectional and the core saturates differently than under AC. Power loss splits into 80 W from the coil and 33 W from the iron core, totalling 113 W dissipated as heat inside the enclosure. That's not trivial for an IP00 open-frame component — it needs free air circulation or forced ventilation in a panel to keep the thermal class B (130 °C) insulation within its rated life. The IP00 protection class means no enclosure: the choke is a bare magnetic assembly with screw terminals (accepting solid or stranded conductors).
Where it goes and what it connects to
This is a panel-mount component — 219 mm wide, 179 mm tall, 143 mm deep — designed to be bolted onto a mounting plate inside a control cabinet. The screw terminals take the incoming AC line and the converter input, so it sits between the mains supply and the drive's rectifier section. Typical deployment is on a variable-frequency drive or DC drive input to reduce harmonic current injection back onto the line and to protect the converter's diodes from high di/dt during commutation.