NFD mains filters are three-phase line filters designed specifically for the DKC drive controller power connection to reduce conducted interference on the incoming supply in 50–60 Hz systems.
The NFD range supports AC line voltages up to 480 V (+10%) and is offered in multiple rated line-current classes (with maximum continuous current specified at 45 °C) to match different drive power levels. These filters are built to protection category IP10 and are specified for operation from DC up to 60 Hz (at 40 °C), with defined thermal derating at elevated ambient temperature and an overload capability of 1.5× rated current for 1 minute per hour. Electrical and safety requirements include permanently bonding the protective conductor to the filter before startup, using a protective earth conductor cross section of at least 10 mm² due to the filter’s discharge current, and ensuring low-impedance mounting by removing paint at mounting points and using tooth-lock hardware. The series also defines performance-limiting behaviors and insulation limits, including reduced attenuation under high-current saturation conditions and specified dielectric test voltages between line/neutral and protective earth.
