What it is and what it does
The Siemens SIDAC 4EP3700-5MS00 is a 3-phase filter reactor rated for 7.89 A continuous (8.77 A maximum) at 400 V AC, 50 Hz. It provides a 5.67 % relative throttling factor, meaning it drops about 5.67 % of line voltage across the reactor at rated current — the standard impedance for smoothing harmonics and limiting inrush on capacitor banks or VFD inputs. The 0.0061 H inductance and 210 Hz resonant frequency place it in the typical range for detuned reactor banks tuned to the 5th harmonic (≈210 Hz).
Where it goes and how it mounts
IP00 means no enclosure — it's an open-frame component intended for installation inside a panel or cabinet where the environment is clean and dry. Mounting dimensions: 0.178 m wide × 0.153 m tall × 0.105 m deep. Connections are screw-type terminals and tab terminals on the main circuit, per EN 61558-2-20. Thermal class B insulation (130 °C rise) means it can run hot in a closed cabinet as long as ambient stays at or below 40 °C.