Can an active harmonic filter be used to protect a specific circuit or machine in a building?

AHF’s are used to mitigate harmonics in a total circuit. Let’s set up an example. A company has 5 work cells and each is producing 20 amps of harmonics. A sixth work cell is introduced, it’s a different machine and it produces 30 amps of harmonics. Some operational issues on the new sixth machine have been determined to be caused by Power Quality issues. Can an AHF be deployed to just protect the new machine?

  • If the new machine is fed from a dedicated transformer, it’s possible an AHF designed to handle at least 30 amps could be installed to mitigate harmonics on the secondary of the transformer feeding this machine.
  • If all six machines are fed by one large distribution transformer with no other isolation transformers between, then an active filter large enough to handle the entire harmonic amperage ((20 x 5) + 30 = 130 amps) must be installed.