The Siemens 4EP4003-0DS00 is a 3-phase commutating choke (Kommut.-Drossel f. Stromrichter) rated for converter applications at 400V AC, 50Hz. It handles a maximum AC current of 100A and a DC rated current of 122.5A, with a peak current capability of 125A.
The 100A AC maximum current and 90A AC rated operational current define the continuous load this choke can carry in a converter circuit without saturating the core. The 122.5A DC rated current tells you the DC-link side capability — useful when sizing for a rectifier output. The 4% voltage drop at rated current is the impedance penalty: expect a 16V drop at 400V line, which the converter's control loop must absorb. The IP00 open-frame construction means no enclosure protection — this choke mounts inside a cabinet or panel, not in a washdown or outdoor location.
Thermal and loss budget
Total power loss is 110W — 80W in the coil and 30W in the iron core — at the rated 40°C ambient. Thermal class B (130°C) per IEC 60085 means the insulation system can handle a 130°C hot-spot temperature, giving roughly 90°C rise over 40°C ambient. For panel thermal design, that 110W must be ventilated or the cabinet must be sized to keep internal ambient below 40°C.
Physical integration
Dimensions are 0.219m wide by 0.179m high by 0.143m deep. The main circuit connection uses flat-type terminals (flat connector), typical for busbar or cable-lug termination in a converter cabinet. No DIN-rail mounting — this is a bolt-down or chassis-mount component sized for the panel floor.