The Siemens SIDAC 4EU2521-0AS00-0A is a 3-phase output reactor — a line choke placed between a variable-frequency drive and the motor to limit dv/dt, reduce capacitive coupling currents, and protect the motor windings from reflected-wave voltage spikes on long cable runs. It's rated for a 7.4 kHz switching frequency, which means it's matched to modern IGBT drives running carrier frequencies in that range; the 0.8 mH inductance (0.0008 H) and 60 A maximum current define the motor load it can handle.
The 60 A maximum current (Ithmax 1) is the thermal continuous rating — this reactor can carry 60 A indefinitely at its 40 °C ambient. The detailed spec line gives 54 A at 460 V, 50/60 Hz, which is the real-world motor current for a 460 V drive application. The 7.4 kHz switching frequency rating is critical: if your drive's carrier frequency is set higher than that, the core saturates and the reactor loses its filtering effectiveness. The 0.8 mH inductance and 5.68 % impedance (Uk) are the values that govern the voltage drop and the reflected-wave attenuation — this is a standard-duty output reactor, not a heavy-duty dv/dt filter.
Thermal and insulation class
Rated ambient temperature is 40 °C. The insulation system is Class H per IEC 60085 — that's 180 °C hot-spot capability, which gives generous headroom for overloads and high-ambient installations. Total power loss splits between the coil (160 W) and the iron core (130 W), so at full load this reactor dumps about 290 W of heat into the enclosure. That matters for panel cooling calculations.
Width 0.22 m, height 0.21 m, depth 0.16 m. Free cable endings for main circuit connection.