The Siemens 4EU4521-0BR10-0B is a 3-phase commutating choke (line reactor) for converter front-ends, rated 800 A continuous at 690 V AC, 60 Hz. The 79 µH inductance with a 6 % relative inductive voltage drop shapes the current waveform and limits di/dt on the converter's input — essential for reducing harmonic distortion and protecting the DC-link capacitors in variable-speed drive and rectifier applications.
The 6 % impedance is the standard value for most drive input reactors.
This part carries a mature lifecycle status.