What it is and where it fits
The Siemens 4EP3800-2US00 is a three-phase mains choke (line reactor) designed for variable-frequency drive input circuits. It handles 480 V AC at 50/60 Hz, rated for 45 A continuous with a 50 A maximum current. The 0.28 mH inductance and 2 % relative voltage drop smooth the drive's current draw and reduce harmonic distortion on the line side. This is an open-frame (IP00) component — no enclosure, so it mounts inside a panel with clearance for airflow. The flat-type terminals accept busbar or cable lugs; plan for a 0.178 m width and 0.153 m height footprint. Thermal class B (130 °C rise) and 40 °C ambient rating mean it derates in hotter cabinets — keep the ventilation path clear.
Electrical and thermal losses
Total power loss splits into 54 W in the coil and 19.2 W in the iron core at rated load. That 73 W of heat must be dissipated inside the panel — factor it into your thermal budget, especially if the choke shares a compartment with the drive.