Dv/dt filter for Altivar 68 drives
The VW3A68551 is a dv/dt output filter designed for the Altivar 68 drive series, rated 170 A continuous for 400-500 VAC three-phase motor circuits. It clamps the voltage rise rate to 6000 V/µs max at those line voltages, which protects motor winding insulation on long cable runs — especially critical with IGBT drives that can otherwise produce steep voltage edges that stress turn-to-turn insulation.
The 6000 V/µs dv/dt limit applies at 400-500 VAC — above that voltage the margin narrows. Maximum motor cable length is 500 m unshielded or 300 m shielded at 2.5 kHz switching frequency; exceed that and reflected wave overvoltage may still damage the motor even with the filter in place. Maximum drive output frequency is 100 Hz, so this filter suits standard induction motors (50/60 Hz base speed) and some high-speed applications, but not spindle drives running above 100 Hz. Ambient temperature derating starts above 50 °C: 1.5 % per °C up to 60 °C.
Dimensions are 380 mm wide × 325 mm high × 235 mm deep. Electrical connection is via copper bar with M10 bolts, sized for the 170 A current path. Plan for busbar or large-gauge cable terminations; no spring-clamp or screw terminals here.