Harmonic filter for Altivar drives – now obsolete
The VW3A4605 is a passive harmonic filter from the Altivar accessory range, designed to reduce current harmonics on the line side of compatible variable speed drives.
The 35 A rated current sets the continuous line-side capacity. The filter can handle up to 1.5 times nominal current transiently, which covers motor inrush and acceleration peaks without saturating the core. THDI performance depends on the specific drive model: 10 % for ATV61WD18N4 and ATV61WD18N4C motors at 18.5 kW/25 hp, and 16 % for ATV61HD18N4, ATV71HD18N4, and ATV71WD18N4 at the same power rating. This means the filter brings input current distortion down to those levels from a typical 30-40 % unfiltered drive, which is relevant for installations needing to meet IEEE 519 or G5/4 harmonic limits. Power factor correction is load-dependent: the filter achieves a cos phi of 1 at 150 % of line current, 0.99 at 100 %, and 0.85 at 75 %. The near-unity figure at full load means the filter compensates reactive current effectively when the drive is running near its rated output. One filter is required per drive for the listed Altivar models. The terminal connection accepts up to 50 mm² cable, sized for the 35 A rating with margin.
Installation and environmental constraints
Operating temperature range is 5 to 40 °C without derating; above 40 °C up to 55 °C, derate current by 3 % per °C. At altitudes above 1000 m up to 4000 m, derate 5 % per 1000 m. Class F insulation (155 °C) gives thermal headroom for the filter windings under the derated conditions.