DC choke for variable-speed drive harmonic reduction
The Schneider VW3A4504 is a DC choke designed for Altivar variable-speed drives, rated at 3.9 mH inductance and 10.7 A continuous current. It sits on the DC bus between the rectifier and inverter stages to smooth current ripple and reduce line-side current harmonics — a common retrofit on drives feeding long motor cables or serving sensitive grid connections. The 27 W thermal loss figure tells you the heat it dumps into the enclosure; at full load that's real heat to manage in a sealed panel.
The 10.7 A rated current is the DC bus current the choke is designed to carry continuously. The 3.9 mH inductance value determines the ripple attenuation — higher inductance gives better harmonic filtering but increases voltage drop (listed at 6 % maximum at rated load). The 1.65 x nominal current for 60 seconds is the overload capability; useful for drive acceleration transients but not for sustained overload. Ambient temperature derating is aggressive: above 50 °C, derate current by 2.2 % per °C, and above 1000 m altitude, derate 1 % per 100 m. At 60 °C ambient, the usable current drops to roughly 8.3 A.
IP20 rated — intended for clean, dry enclosure mounting, not washdown or outdoor exposure. Dimensions are 115 mm deep, 96 mm wide, 134 mm high. The earth terminal accepts up to 10 mm² (AWG 6); power supply terminals accept 2.5 mm² (AWG 12). Tightening torque is 1.2–1.4 N·m for the earth circuit and 0.4–0.6 N·m for the power supply terminals. Three-phase input, 50/60 Hz line frequency.