What it is and what it does
The Siemens 4EP3905-0AK00 is a three-phase commutating choke (line reactor) designed for converter input or output circuits. It carries a rated current of 180 A with a maximum of 200 A at 400 V AC, 50 Hz. The 0.03 mH inductance provides a 0.5% relative inductive voltage drop at rated conditions — sized to limit di/dt and reduce harmonic stress on the converter's semiconductors without dropping excessive line voltage. Rated for a 40 °C ambient with Class B insulation (130 °C hot-spot per IEC 60085), the choke dissipates 69 W in the coil and 13 W in the iron core at full load — total 82 W of heat to vent inside the enclosure. IP00 means no ingress protection; it must be mounted inside a cabinet with proper clearance and airflow.
Where it goes — panel and circuit fit
Dimensions are 0.219 m wide, 0.179 m tall, and 0.123 m deep. The main circuit connects via flat-type terminals (flat connector) — expect busbar or large-gauge ring-tongue lugs, not spring-cage or screw-clamp. Verify the terminal spacing against your existing busbar layout before panel layout. This is a three-phase device; the 0.5% impedance is low enough that it won't cause significant voltage drop under normal load, but it will limit fault-current rise rate. Typical placement is between the line supply and the converter input (or between the converter output and the motor, depending on the drive topology). IP00 means no integral cooling fan — the cabinet's forced-air or natural convection must handle the 82 W heat load.