The Siemens 4EU3631-0BJ10-0A is a 3-phase filter reactor (line choke) rated for 180 A continuous with a 200 A maximum, 0.27 mH inductance, designed for 400 V AC / 50 Hz systems. It sits between the drive and the line to smooth current ripple, limit harmonic distortion, and protect the DC bus from line transients — standard practice on any PWM drive install where the motor cable run is long or the supply is weak.
180 A rated current (200 A max) means this reactor is sized for a drive output in that range — typically a 75–90 kW motor on 400 V three-phase, depending on the drive's own continuous rating. The 0.27 mH inductance is the key number for harmonic mitigation; at 50 Hz the impedance is about 0.085 Ω, which limits the rate of rise of fault current and knocks down the 5th and 7th harmonics that cause nuisance trips on upstream breakers. IP00 open-frame means it has no enclosure — it's a bare coil and core assembly. The 0.227 m depth, 0.35 m width, and 0.321 m height define the footprint; total power loss is 701 W (560 W in the coil, 141 W in the iron core). Thermal class H insulation means the coil can run hot without degrading. The 55 °C ambient rating is the maximum air temperature around the reactor.