The dv/dt filter plus VPL consists of two components: the dv/dt reactor and the VPL (VoltagePeakLimiter), which limits voltage peaks and returns the energy to the DC link.
dv/dt filters plus VPL must be used for motors for which the voltage endurance of the insulation system is unknown or insufficient. Standard motors of the 1LA5, 1LA6 and 1LA8 series require them only in cases where the motor has not been specially insulated for operation on a converter (see Catalog D 81.1, chapter “Motors operating with frequency converters”).
The dv/dt filters plus VPL limit the rate of voltage rise to values < 500 V/?s and the typical voltage peaks at rated line voltages to the values below (with motor cable lengths < 150 m):
< 1000 V atVline < 575 V
< 1250 V at 660 V < Vline < 690 V.
Note: The maximum permissible cable length between the dv/dt filter plus VPL and the Power Module is 5 m.