Harmonic filter for Altivar drives
The VW3A46125 is a passive filter designed to reduce current harmonics on Altivar variable-speed drives. It is specified for 18.5 kW / 25 hp drives in the ATV61H, ATV61W, ATV71H, and ATV71W ranges, delivering a THDI of 10 % for most variants and 5 % for the ATV61W. One filter per drive is required. Rated for a 400 V +/- 10 % three-phase supply at 50 Hz +/- 2 %, it handles 35 A on the input side and 37 A on the output side. Efficiency is 98 %, with thermal losses of 396 W at full load.
The 35 A input / 37 A output rating tells you this filter is sized for the continuous current draw of a 18.5 kW drive at 400 V. The 1.5 x nominal current overload capacity for 60 seconds covers the inrush during motor acceleration without nuisance tripping. The power factor (cos phi) varies with load: 1 at 150 % line current, 0.85 at 75 % load, and 0.99 at full load. That means the filter maintains near-unity power factor across the typical operating range, which keeps the line-side current draw close to the active power component. Ambient temperature range is 5 to 45 °C without derating; above that up to 60 °C, derate current by 3 % per °C. For a panel in a warm enclosure, factor that into the sizing — at 55 °C ambient, the effective output current drops to roughly 31.5 A.
The filter carries an IP20 rating for the body and IP55 when enclosure-mounted, so it can be installed in a cabinet or directly on the machine frame in washdown areas. Operating altitude up to 1000 m is full-rated; above that, derate 5 % per 1000 m up to 4000 m. Terminals accept 1.5 to 25 mm² on the main connections and 2.5 mm² on the auxiliary terminals. Vibration resistance per IEC 60068-2-6 covers 2 mm peak-to-peak from 5 to 13.2 Hz and 0.7 gn from 13.2 to 150 Hz, which is standard for drive-mount applications.
The Class F insulation rating means the windings can handle a 155 °C hot-spot temperature, which is standard for industrial drive filters and gives a comfortable margin above the 396 W thermal loss at full load.