The Siemens 4EP3400-0AK00 is a 3-phase mains choke (Netzdrossel) rated for 400 V AC at 50 Hz, with a rated current of 6.3 A and a maximum of 7 A. Its 2.5 mH inductance limits harmonic currents and reduces voltage notching on the line side of a variable-frequency drive or rectifier. The relative inductive voltage drop is 2.4% at the rated operating point, which keeps the DC-link voltage within expected margins for a standard 400 V three-phase supply. The IP00 rating means it is open-frame — no enclosure protection against dust or moisture — so it must be installed inside a cabinet that provides the required system IP rating. Ambient temperature is rated at 50 °C, with thermal class B insulation per IEC 60085. Total power loss is the sum of coil loss (20.8 W) and iron-core loss (6.95 W), so roughly 28 W of heat must be dissipated inside the enclosure. That figure drives the cabinet ventilation or cooling requirement, not the load current alone.
Key electrical ratings and their meaning for selection
The 6.3 A rated current (7 A maximum) is the continuous RMS current the choke can carry at 50 °C ambient without exceeding thermal class B limits. The 2.4% relative inductive voltage drop means that at rated current the choke drops about 9.6 V line-to-line (2.4% of 400 V). That is a typical value for a line reactor sized to protect a drive's input rectifier without collapsing the DC bus under load. The 2.5 mH inductance per phase is the value that determines the attenuation of harmonic currents at the switching frequency. For a 50 Hz line, this choke presents an impedance of about 0.785 Ω per phase at 50 Hz, rising proportionally with frequency to suppress higher-order harmonics from a 6-pulse rectifier.