Harmonic filter for ATV drives — what the ratings mean
The VW3A46126 is a passive harmonic filter sized for 44 A input / 45 A output at 400 V 50 Hz, designed to clamp current distortion on the line side of Schneider Altivar drives. It brings THDI down to 5 % when paired with an 18.5 kW / 25 hp ATV650, ATV630, ATV950, or ATV930 drive, and to 10 % with 22 kW / 30 hp ATV61H, ATV71H, ATV61W, or ATV71W units. That 5 % figure means the filter keeps harmonic content well inside IEC 61000-3-2 and IEC 61000-3-12 limits — critical for sites that need to pass a utility power-quality survey or comply with G5/4 engineering recommendation.
Power factor and efficiency — the real load-side behavior
Power factor correction is load-dependent: the filter delivers cos phi of 1 at 150 % of line current, 0.99 at 100 %, and 0.85 at 75 %. That 0.85 at partial load is the figure to watch if your drive spends most of its cycle below full current — a VFD running a conveyor at 70 % speed will see less reactive compensation than one at full bore. Efficiency sits at 98 %, with 482 W of thermal losses to vent. The filter can handle 1.5 x nominal current for 60 seconds, enough to ride through a motor start or a brief overload without saturating the magnetics.
Mounting and environment — panel integration notes
Rated IP20 as standard, IP55 when enclosure-mounted — so it lives inside a panel unless you provide the outer enclosure. Terminal blocks accept 1.5 to 25 mm² on the main power connections and 2.5 mm² on the control terminals. Ambient temperature range is 5 to 45 °C without derating; above that, derate 3 % per °C up to 60 °C. Altitude derating kicks in above 1000 m at 5 % per 1000 m. Vibration resistance follows IEC 60068-2-6 at 2 mm peak-to-peak from 5 to 13.2 Hz and 0.7 gn from 13.2 to 150 Hz — standard for industrial panel mounting.