The VW3A4621 is a passive input filter from the Altivar accessory range, designed to reduce current harmonics drawn by a variable-speed drive. It is rated 6 A continuous at 400 V, 50 Hz, three-phase, and delivers a THDI of 10 % for most Altivar 61/71 H and P drives up to 3 kW, and 5 % for the Altivar 61 W series in the same power band.
Rated 6 A at 400 V, the filter is sized for drives up to 3 kW (4 hp) at 400 V three-phase. The THDI figures — 10 % for standard Altivar 61/71 H and P drives, 5 % for the Altivar 61 W compact series — tell you the residual harmonic content after filtering; a lower THDI means cleaner line current, which matters for installations with sensitive upstream equipment or utility harmonic limits. Efficiency is 98 %, so the filter dissipates roughly 2 % of the drive's input power as heat — negligible for panel thermal budgeting at this power level. The filter's cos phi varies with load: 0.99 at full load (100 % line current), 0.85 at 75 % load, and 1.0 at 150 % overload. That means power-factor correction is strongest near the drive's rated operating point; at partial load the filter still improves power factor but not to unity. Maximum current is 1.5 times nominal — the filter can handle short-term overloads without saturating, which aligns with typical drive acceleration profiles.
Deployment context
The terminal accepts up to 16 mm² conductors, which is adequate for the 6 A rating with headroom. One filter per drive is required; it mounts upstream of the drive's line input. Operating temperature range is 5 to 40 °C without derating; above 40 °C up to 55 °C, derate current by 3 % per °C. Above 1000 m altitude, derate 5 % per additional 1000 m.