The Siemens SIDAC 4EU3921-0BH00-0A is a 3-phase output reactor rated for 80 A maximum continuous current and a switching frequency of 8 kHz, with an inductance of 0.3 mH. It sits between the VFD output and the motor cable to limit the rate of voltage rise (dV/dt) and reduce reflected-wave peaks on long cable runs — a common cause of motor winding insulation stress in PWM drives. Rated for a 400 V AC system and a 40 °C ambient, with Class H insulation (180 °C thermal class per IEC 60085).
For a BOM freeze or last-time-buy planning, confirm fit with the current VFD output rating and cable length — the 80 A / 8 kHz / 0.3 mH parameters are the key selection criteria.
Dimensions are 0.41 m wide, 0.38 m high, and 0.22 m deep — a substantial block that needs panel space and structural support. Main circuit connections use flat-type terminals, typical for bolted bus-bar or cable-lug termination. Not a DIN-rail snap-on; it bolts directly to a mounting plate.