The Schneider Altivar VW3SKLN090H400 is a 3-phase line choke rated at 90 A with 400 mH inductance, designed for variable speed drive applications to reduce current harmonics. Rated for 690V systems at 50/60 Hz, this choke handles 1.65x nominal current for 60 seconds — enough headroom for motor inrush during acceleration. Voltage drop stays at 5% maximum at rated load, so the drive sees line voltage within tolerance.
Above 45 °C up to 55 °C, derate 2% per °C. 400 mH inductance defines the impedance at line frequency — this is what attenuates the harmonic currents drawn by the drive's rectifier stage. Higher inductance gives better filtering but more voltage drop; 5% drop at rated load is typical for a line choke sized to meet IEC harmonic limits. Terminal accepts up to 6 mm² / AWG 8 wire with 0.8 to 1 N·m torque.
This line choke sits between the mains supply and a variable speed drive input. Its job is to smooth the current waveform, reduce harmonic distortion, and protect the drive's DC bus capacitors from excessive ripple current. Class F insulation handles the thermal load.