What this choke does in the drive line
The Siemens 4EU3951-8UA00-0A is a three-phase mains choke (Netzdrossel f. FU) sized for variable-frequency drive input lines. It sits between the supply and the drive rectifier, smoothing current harmonics and limiting inrush. The 360 A rated current (400 A maximum) at 690 V AC and 50 Hz tells you this is a heavy line reactor — think large conveyor drives, pump stations, or compressor banks on 690 V three-phase. The 0.13 mH inductance with a 4 % relative voltage drop at rated current is the key selection figure: that drop defines how much harmonic attenuation you get versus how much voltage headroom the drive loses. At 540 W coil loss plus 190 W iron loss, the total 730 W heat dump needs panel ventilation — IP00 open-frame means it is not sealed; mount it in a clean, dry cabinet with airflow.
Ratings that govern fit
The 360 A rated current is the continuous thermal baseline at 40 °C ambient. That is the number to match against your drive's input current at full load — not the 400 A maximum, which is a short-term overload ceiling. Class H insulation per IEC 60085 means the winding can survive 180 °C hot-spot temperature; that buys you margin in a warm cabinet or under sustained harmonic load. The 4 % voltage drop is measured at rated current, voltage, and frequency — it is the impedance the choke presents to the line, and it determines both the harmonic filtering effect and the voltage sag the drive sees. Flat-type terminals for the main circuit mean bus-bar or large-lug connections, not finger-safe spring cages.
Physical integration
The dimensions are 0.41 m wide by 0.385 m tall by 0.229 m deep — about 16 × 15 × 9 inches. That is a substantial iron core; it needs a dedicated mounting plate or sub-panel, not a DIN rail. IP00 means no enclosure protection — the live terminals and core are exposed. Install it in a locked cabinet with at least the clearance specified in the Siemens manual for heat dissipation. The flat-type terminals accept bus-bar or crimp lugs; plan for torque-rated connections.