The 4EU4551-0AB00-0B is a three-phase mains choke (Netzdrossel f. FU) designed for the input side of a frequency converter. It sits between the supply and the drive rectifier to smooth current, limit harmonics, and reduce the stress on the DC-link capacitors. Rated 140 A continuous at 500 V AC, 50 Hz, with an inductance of 1.7 mH and a relative inductive voltage drop of 18.6% at rated current. This is an open-frame (IP00) component — no enclosure, no touch protection. It mounts into a panel or cabinet where the surrounding switchgear provides the physical guard. The flat-type terminals accept busbar or cable lugs; expect to land the power conductors with ring or fork terminals sized for the 140 A circuit.
The 140 A rating is the thermal maximum continuous current (Ithmax) at 50 °C ambient. That is the number you match to the drive's input current, not the motor's full-load amps — the choke sees the rectified line current, which can be higher than the motor FLA depending on the drive topology and load profile. Class H insulation (180 °C thermal class per IEC 60085) gives headroom for overloads and elevated cabinet temperatures without derating prematurely. The 18.6% voltage drop at rated current is the impedance contribution at line frequency. For most variable-frequency drive applications, a choke with 3–5% impedance is typical; this 18.6% figure is unusually high, meaning the choke will drop significant voltage under load. Verify that the drive's DC-link can tolerate the reduced input voltage — especially on 400 V nominal systems where the 500 V rating leaves less headroom. If the line voltage sags, the choke's drop may push the DC bus below the drive's undervoltage threshold.
Dimensions: 460 mm wide, 435 mm high, 293 mm deep. That is a substantial footprint — plan for a mounting plate area roughly 460 × 435 mm, with clearance above and below for the flat-type terminal connections. The IP00 rating means no drip shield or dust cover; locate it away from washdown zones or condensation paths inside the enclosure.