The Siemens 4EP3804-0ES00 is a 3-phase commutating choke for converter applications, rated at 400V AC and 34A AC with an inductance of 0.82 mH. It's built for line-side or DC-link duty in variable-speed drives and rectifier front-ends, where it limits di/dt and smooths commutation notches.
The 34A AC rated current and 41.6A DC rated current tell you this choke handles the continuous RMS current of a 34A AC drive input or a 41.6A DC bus. The 3.8% relative inductive voltage drop at rated current, voltage, and frequency means the choke will drop about 15.2V at 400V line — enough to soften current spikes without starving the DC bus of voltage. Thermal class B insulation allows a 130°C hot-spot limit, and the 46.9W coil loss plus 17W iron loss add up to roughly 64W total heat to vent inside the panel at 50°C ambient.
Integration notes
Mounting dimensions: 0.178m wide, 0.153m tall, 0.12m deep. Screw-type terminals accept standard lug or ring-tongue terminations — no spring-cage here. The 50Hz operating frequency is fixed; if your drive runs 60Hz, the choke still works but the voltage drop percentage shifts slightly. Plan for the 64W heat dissipation inside the enclosure — don't bury it next to a heatsink without airflow.