The Siemens SIDAC 4EU2531-5AC80-0A is a 3-phase output reactor rated for a maximum current of 80 A and a switching frequency of 5 kHz. It is designed to sit between a variable-frequency drive and the motor, smoothing the PWM waveform to reduce voltage spikes, motor bearing currents, and reflected-wave damage on long cable runs. The 0.1 mH inductance and 21.8 % impedance are sized for a 400 V AC line, so the reactor limits the rate of voltage rise (dV/dt) that can cause premature motor insulation failure — especially on runs over 50 m or with older motor windings.
The reactor is an open-chassis unit rated IP00, so it requires enclosure mounting — typically inside the drive cabinet or a dedicated junction box. Dimensions are 0.22 m wide by 0.21 m tall by 0.16 m deep, which fits a standard 600 mm wide panel backplate with room for cable entry. Connections are flat-type terminals, common on larger Siemens reactors; expect M8 or M10 bus-bar lugs rather than screw-clamp blocks. The 240 W total power loss (140 W coil + 100 W iron core,) must be vented — forced airflow or a cabinet fan is advisable if the drive is already near its thermal budget.
The reactor is wound to thermal Class H per IEC 60085, rated for a 40 °C ambient. Class H insulation (180 °C hot-spot) gives a generous thermal margin for continuous full-load operation inside a warm cabinet — useful when the drive is running at rated current and the enclosure ambient climbs. The 5 kHz switching frequency matches most modern IGBT-based drives; if your drive runs a higher carrier frequency (8–16 kHz), the reactor still works but core losses will increase, so check the temperature rise at your specific PWM pattern.