The Siemens SIDAC 4EU4351-0AF00-0B is a three-phase output reactor (mains choke) rated for 500 A continuous at 60 Hz line frequency, with a rated voltage of 690 V AC and an inductance of 0.18 mH. It sits between the drive output and the motor cable to limit dv/dt and reduce capacitive charging currents on long cable runs — a standard fit for variable-frequency drive installations feeding motors over 50 m of shielded cable.
That's the RMS current the choke can carry without saturating the core or exceeding the thermal limits. The 0.18 mH inductance is relatively low — sized for larger drives where a few microhenries per amp are enough to limit switching-edge ringing. The 690 V rated voltage covers 400 V and 480 V drives with margin; it also handles 600 V class systems common in North American 60 Hz installations. Total power loss sums to 1403 W (952 W coil copper loss plus 451 W iron core loss) at rated load and 45 °C ambient. That's the heat you need to extract from the enclosure — a significant thermal load that drives ventilation or derating in sealed cabinets. Class H insulation (180 °C rated) gives headroom above the 45 °C ambient, but the losses still dictate panel cooling.
Physical integration and termination
The reactor measures 0.46 m wide × 0.43 m tall × 0.26 m deep — a substantial block that needs floor or back-panel mounting, not DIN rail. Protection class IP00 means it's an open-frame component intended for inside a ventilated electrical enclosure; no washdown or dust protection. Main circuit connection is via flat connectors (bus-bar style), so plan for bolted terminations rather than ring lugs on screw terminals.