The Siemens 4EP3805-3BK00 is a 3-phase commutating choke (line reactor) designed for converter input circuits. Rated for 400 V AC at 13 A continuous, it handles peaks up to 14.5 A. The 3.05 mH inductance and 6% relative inductive voltage drop smooth current ripple and limit di/dt on the converter's input — critical for protecting the DC-link capacitors and reducing harmonic injection back to the line.
What the ratings mean for fit
The 13 A rated current (14.5 A maximum) is the thermal continuous current at 40 °C ambient, thermal class B. This means the choke can carry its rated load indefinitely without exceeding the insulation temperature limit — no derating needed at 40 °C, but above that you'll need to reduce current per the insulation class curve. The 6% impedance (relative inductive voltage drop) is typical for input line reactors; it limits fault current and reduces harmonics enough to meet most drive-system recommendations without excessive voltage drop at full load. IP00 means no enclosure — the choke is an open-frame component intended for mounting inside a panel or cabinet. The screw-type terminals accept standard power wiring; plan for adequate clearance to grounded metalwork per IEC 61558-2-20.
Where this class is used
Commutating chokes (line reactors) sit between the AC supply and a variable-frequency drive, servo drive, or DC converter input. They attenuate voltage notches, limit inrush current, and reduce harmonic distortion — particularly important on weak grids or when multiple drives share a common bus. The 0... 50 Hz operating frequency covers standard 50 Hz line applications; at 50 Hz the 3.05 mH inductance delivers the stated 6% drop.