Trusted Advisors Providing Solutions That Best Fit Your Needs

Sydney ● Melbourne
Phone: +61 2 4272 1899

Low Harmonic Solutions

Mitigating harmonics to optimise the performance of your connected devices

An important part of iOpen’s value proposition is being able to provide complete solutions for the variable speed drive market. When installing any variable speed drive, you need to consider its effect on the power network and the conditions of which it is installed.
Long motor cables, harmonics, EMC/RFI, screened motor cables, bearing currents, transients and so on. iOpen offer a comprehensive range of solutions to cover all these conditions and more.

Want to know more?


Supply side reactors are often used to reduce harmonic effects, motor side reactors are often used to allow for longer cable runs and improve motor efficiency.

Passive filters

Passive or tuned filters is the first and low-cost step to targeted harmonic mitigation. Dv/Dt and sine wave filters facilitate long motor cables and improved motor efficiencies.

Active filters

In large and multiple VSD installations active harmonic filters come in to their own in both cost effectiveness and overall efficiency in minimising supply harmonics.

Sine wave filters

  • Recommended when cable length from VSD to motor exceeds 100m
  • 500 Volt, 50/60 Hz, 40°C
  • Rated from 4 Amps to 480 Amps
  • Reduces voltage peaks due to long motor cables & protects motor insulation
  • Reduces leakage currents due to the capacity of the motor cable
  • Enables the use of longer motor cables without nuisance trips
  • Reduces bearing currents and noise inside motor due to switching frequency

LLC passive harmonic filters

  • Harmonic reduction to <5% THDi to IEC61439 standard
  • Ambient temperature range -25 to +45°C
  • Estimated voltage drop 2% at full power
  • Low load control option available, to disconnect capacitors at partial load
  • Top or bottom cable entry options
  • Very simple to install & commission, no CTs needed

Combine an active harmonic filter and a variable speed drive in one package

iOpen’s engineered drive solutions combine a VSD with the Circutor AFQm active harmonic filter which continuously regulates harmonic currents at any load.

Interested? Click here for a quote.