What this reactor does on the line
The Siemens SIDAC 4EU3931-0AR80-0A is a 3-phase filter reactor rated for 262 A continuous with a maximum of 291 A, sized for a 525 V AC, 50 Hz line. The 4 % relative throttling factor and 0.0002 H inductance shape the impedance to attenuate harmonics and limit inrush current on the downstream drive or capacitor bank. The 175 kvar reactive power rating tells you the bank it's paired with — match this to the filter bank's total kvar, not the motor load. Thermal class H (180 °C) insulation at 40 °C ambient means it sheds 690 W of heat into the enclosure. That's a non-trivial thermal load — plan for forced ventilation or a derated panel fill. The IP00 rating means no enclosure; it's a panel-mount component that needs a cabinet for touch-safe installation. Main circuit connections are flat-type or screw terminals, so busbar or cable lugs are the expected interface. The 0.229 m depth, 0.41 m width, and 0.385 m height footprint is substantial — verify the backpanel real estate before committing the layout.
Resonant frequency and harmonic trap
The resonant frequency is 250 Hz — that's the 5th harmonic on a 50 Hz fundamental. This reactor is tuned to trap the 5th harmonic (250 Hz), which is the dominant harmonic from 6-pulse rectifiers in drives. If your line has significant 7th or 11th harmonics, this reactor alone won't cancel them; you'd need a broader detuned filter or a multi-stage trap.