The Siemens 4EU2522-2BA00-0AA0 is a 3-phase commutating choke (also called a line reactor or commutation reactor) designed for converter drives. It sits on the AC line side of a variable-frequency drive or DC drive converter to limit current rise rates, reduce harmonic distortion, and protect the converter's semiconductor switches from commutation notches. Rated for 400V AC at 50Hz, it handles a maximum AC current of 140A and a continuous rated AC current of 126A. The DC-rated current is 171.5A, reflecting the DC-link application in some converter topologies.
The 0.15mH inductance (150 µH) at 140A AC maximum and 126A rated AC current defines the choke's impedance at 50Hz. The 4% relative inductive voltage drop means at rated current and frequency, the choke drops 4% of the line voltage — a standard figure for drive input reactors that provides effective harmonic mitigation without excessive voltage sag. Thermal class H per IEC 60085 means the winding insulation withstands 180°C hot-spot temperature, critical for continuous duty in a panel with limited airflow. The total power loss is 190W (135W coil + 55W iron core), which must be considered in the enclosure's thermal budget — this choke runs hot in a sealed cabinet.
Dimensions are 0.225m wide × 0.21m high × 0.16m deep. Main circuit connections use flat-type terminals, typical for bus-bar or cable-lug termination in power circuits. Ambient temperature rating is 40°C; derate current if ambient exceeds that. This is a panel-mount component, not DIN-rail snap-on — plan for bolt-down mounting with clearance around the magnetic core for heat dissipation.