What it is and what it does
The Siemens 4EU3622-8CA00-1BA0 is a commutating choke (line reactor) for converter drives — a 3-phase AC choke rated for 500 V operating voltage, 50 Hz, with a maximum continuous current of 630 A and a rated current of 567 A. The 0.043 mH inductance limits the rate of current rise during converter commutation, reducing harmonic distortion and protecting the DC-link capacitors and IGBTs from di/dt stress. A 4 % relative inductive voltage drop at rated current and frequency is the design target — that's the trade-off between smoothing performance and voltage sag across the choke.
Current handling and thermal class
Three current ratings define the envelope: 630 A maximum continuous (the thermal limit for sizing conductors and fusing), 567 A rated (the design operating point for the 4 % voltage drop), and a peak current of 788 A — the short-duration surge the choke must pass without saturating. At DC the rated value is 772 A, so it also handles DC-link ripple current in six-pulse rectifier circuits. Thermal class H per IEC 60085 means the insulation system withstands 180 °C hot-spot temperature — necessary when the choke sits near a converter's heat sink. The coil dissipates 280 W, the iron core 190 W, for a total 470 W of heat that must be removed from the enclosure. Ambient temperature rating is 40 °C; derate above that.