What it is and what it does
The Siemens SIDAC 4EP4180-0DB00 is a 3-phase output reactor (output choke) rated for 42 A AC at 50 Hz, with a rated switching frequency of 7.2 kHz. It's designed to sit between a variable-frequency drive and the motor, smoothing the PWM waveform and limiting voltage spikes that can damage motor windings or cause nuisance tripping. The IP00 rating means it's an open-frame component — intended for installation inside a cabinet, not for direct exposure to dust or moisture.
Key ratings and what they mean for fit
The 42 A maximum current at 50 Hz sets the upper bound for continuous motor load; the reactor's operational current is listed at 37.8 A, which is the figure to use for thermal sizing in a continuous-duty application. The 7.2 kHz switching frequency matches common IGBT drive carrier frequencies — if your drive runs at a different carrier, the reactor still works but derating may apply. Inductance is 0.55 mH, and the short-circuit voltage is 3.14%, which gives a predictable voltage drop under load. Power loss splits between coil (46.5 W) and iron core (59.6 W), totalling about 106 W — enough to consider ventilation in a sealed enclosure. Thermal class B means the winding insulation is rated for a 130 °C hot-spot, standard for general-purpose motor circuits.
Integration and mounting
This reactor uses screw-type terminals for the main circuit — no push-in or spring-cage. The footprint is 0.26 m wide by 0.22 m tall by 0.14 m deep. At IP00, it needs to be mounted inside a panel with adequate clearance from live parts and some airflow around the core. The 3-phase connection is straightforward: line-side to the drive output, load-side to the motor cable. No auxiliary supply needed.