What it is and where it fits
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.
What the ratings mean for the buyer
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. The 2% relative inductive voltage drop (at rated current, voltage, and frequency) is the impedance the choke presents; it's typical for commutating duties where you want enough inductance to smooth commutation notches without excessive voltage drop under load. 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. That's modest for a 90A choke, but at IP00 the heat goes straight into the cabinet air; factor it into your thermal budget.
Mounting and integration
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.