Sinusoidal Filters

Output filters – also called motor filters because they are installed upstream of the motor – are critical components in electrical engineering. They serve to minimize unwanted noise and harmonic distortion in electrical systems. They help improve the efficiency and service life of motors and other electrical devices. By filtering out this noise, motor filters ensure stable operation, reduce energy loss, and protect sensitive components from damage.

For proper and trouble-free operation!

Produktbild SFAF2-400

SFAF2-400

High performance sinusoidal output filters

  • Current ratings from 2.5 A up to 600 A
  • Rated voltage 400 V (also 500 V / 690 V available)
  • Recommended for frequency inverter operation with long motor cables
  • Generates sinusoidal output voltage
  • VFD-operation with unshielded motor cable is possible
  • Reduction of the motor noise and eddy current losses
  • Protects motor windings and bearings
  • Reduction of the dV/dt values (spikes)
  • Reduction of high-frequency leakage currents
  • Improves the EMC (reduced emissions of interference)
  • UL approved insulation material
  • Also available as 4-line sinusoidal filter

Produktbild SFAF2-500

SFAF2-500

High performance sinusoidal output filters

  • Current ratings from 200 A up to 1200 A
  • Rated voltage 500 V (also 690 V available)
  • Recommended for frequency inverter operation with long motor cables
  • Generates sinusoidal output voltage
  • VFD-operation with unshielded motor cable is possible
  • Reduces motor noise
  • Protects motor windings and bearings
  • Reduces the dV/dt values (spikes)
  • Reduction of high-frequency leakage currents
  • Improves the EMC (reduced emissions of interference)
  • UL approved insulation material
  • Also available as 4-line sinusoidal filter

Produktbild SFAF3-400

SFAF3-400

High performance sinusoidal output filters – uk reduced

  • Current ratings from 2.5 A up to 610 A
  • Rated voltage 400 V (also 500 V / 690 V available)
  • Recommended for frequency inverter operation with long motor cables
  • Generates sinusoidal output voltage
  • VFD-operation with unshielded motor cable is possible
  • Reduces motor noise
  • Protects motor windings and bearings
  • Reduces the dV/dt values (spikes)
  • Reduction of high-frequency leakage currents
  • Improves the EMC (reduced emissions of interference)
  • UL approved insulation material
  • Also available as 4-line sinusoidal filter

Produktbild SFAF4-400

SFAF4-400

High performance 4-line sinusoidal output filters

  • Current ratings from 2 A up to 180 A
  • Rated voltage 400 V (also 690 V available)
  • Recommended for frequency inverter operation with long motor cables
  • Generates sinusoidal output voltage
  • VFD-operation with unshielded motor cable is possible
  • Reduces motor noise
  • Protects motor windings and bearings
  • Reduces the dV/dt values (spikes)
  • Reduction of high-frequency leakage currents
  • Improves the EMC (reduced emissions of interference)
  • UL approved insulation material
  • Reduction of pulse current relative to earth
File Size
Data_Sheets » EMC » Sinusoidal_Filters
EPA_Sinusoidal-output-filters_SFAF4-400_data-sheet.pdf2.95 M

Use of sinusoidal filters on the frequency inverter output

Sinusoidal filters are connected between inverter output and motor. Especially with long motor cables sinusoidal filters should be used to reduce parasitic leckage currents due to capacities of the motor cable. With a suitable dimensioning of the LC filter, the pulse-width modulated (PWM) inverter output voltage is converted into a sinusoidal voltage.

Not only emissions on the motor cables are significantly attenuated, but also the voltage peaks which are caused by the inverter switching frequency. In addition to improved EMC the motor is spared thus achieving a reliable and durable performance.