what is the pf of transformer?

We know transformer itself is not a load. But does it have a pf of its own? What is the range of pf from no load to full load?

2 Answers

  • Gone
    Lv 6
    7 years ago
    Favorite Answer

    With no load, the power factor of a transformer is very low, but it not zero. The current always has a real component because of power losses in the transformer. The copper losses go down in proportion to current squared, but the iron losses are not influenced by load.


    Considering the power factor from no-load to full-load, the power factor approaches zero at no-load and approaches the power factor of the load as the load increases. The difference between the power factor measured at the primary vs. secondary is determined by the transformer loss watts and magnetizing volt-amperes vs. the load watts and volt-amperes.

    • Login to reply the answers
  • Rick
    Lv 7
    7 years ago

    A transformer has a magnetizing inductance. The RMS current though this inductance is between 10 and 20% of the rated current and lags the input voltage by 90 degrees. At no load the PF is 0. At other load conditions, it depends on the load current.

    • Login to reply the answers
Still have questions? Get your answers by asking now.