The SIEMENS 4EP3901-0DS00 is a commutating choke (line reactor) designed for converter applications, rated for 90A continuous current with a maximum of 100A, on a 3-phase 400V AC 50Hz system. The 0.14mH inductance limits current rise and harmonics in the DC link or input of a variable-frequency drive or rectifier. At IP00, it has no enclosure — plan for mounting inside a cabinet or panel with appropriate clearance to live parts.
The 90A rated current at 40°C ambient (thermal class B per IEC 60085) is the continuous duty figure — size your converter load so the RMS current stays at or below this. The 100A maximum is a short-term overload ceiling, not a running spec. Power loss breaks into 71W in the coil and 22W in the iron core at rated conditions — 93W total heat to manage inside the enclosure.
Dimensions are 0.219m wide × 0.179m high × 0.123m deep. Flat-type terminals for the main circuit connection — expect busbar or cable lug terminations, not spring-cage or screw-clamp. No DIN-rail clip; this is a panel-mount component. The 122.5A DC-rated value suggests it can also serve in DC-link applications, but the primary spec is AC 3-phase at 50 Hz.