The Siemens 4EU3921-0CA00-0A is a 3-phase commutating choke designed for converter applications, rated at 690 V AC and 50 Hz. It handles a maximum continuous current of 630 A, with a rated current of 567 A and a peak current capacity of 788 A.
Sizing and thermal class
Rated for a 40 °C ambient, the choke carries thermal class H per IEC 60085, meaning the winding insulation withstands a 180 °C hot-spot temperature — critical for sustained high-current duty in a converter cabinet where airflow may be restricted. Total power loss splits between the coil (388 W) and the iron core (176 W), so the enclosure around this choke needs to vent that 564 W of heat; a sealed panel without forced ventilation will bake the surrounding components.
Physical integration
Dimensions are 0.41 m wide by 0.385 m tall by 0.229 m deep — a substantial component that needs a dedicated mounting footprint inside the converter cabinet. Main circuit connections are flat-type terminals, so the mating busbars or cable lugs must be flat-pattern compatible; no screw-clamp or ring-tongue terminals fit directly. The 0.0605 mH inductance (60.5 µH) is the value that sets the commutation notch; verify it matches the converter's design inductance requirement before substituting.