What this reactor does on the line
The Siemens SIDAC 4EP4001-3MS00 is a 3-phase filter reactor rated for 400 V AC at 50 Hz, with a rated current of 19.7 A and a maximum current of 21.9 A. Its 0.0025 H inductance and 5.67 % relative throttling factor are sized to attenuate harmonic currents and limit inrush on the line side of a variable-frequency drive or similar non-linear load. The reactor's resonant frequency is 210 Hz, and the filter bank's rated reactive power is 12 500 var. This places the trap below the 5th harmonic at 50 Hz fundamental.
The reactor measures 0.219 m wide, 0.179 m tall, and 0.143 m deep. IP00 protection means it is an open-frame component intended for enclosure installation. Thermal class B (130 °C) per IEC 60085 gives the winding insulation a 40 °C ambient rating with a 89 W power loss to dissipate inside the cabinet.
The 5.67 % impedance is a common choice for general-purpose harmonic mitigation and motor lead-length protection — enough to reduce harmonic distortion without dropping excessive voltage across the reactor under full load. Power loss of 89 W at rated load must be factored into the enclosure thermal design. In a sealed cabinet with multiple reactors or drives, that heat adds up — plan for forced ventilation or derating if ambient inside the panel exceeds 40 °C.