I recently installed a VFD to reduce the speed of my pump, however, occasionally the configuration will stop pumping liquid through the system. The pump is a three phase 60 Hz and this issue has happened when running the system at 13 Hz and 40 Hz. Any thoughts?

  • $\begingroup$ Reducing the power too much? $\endgroup$
    – Solar Mike
    Jun 4, 2018 at 5:29
  • 1
    $\begingroup$ What does your pump curve look like? It may explain the situation. $\endgroup$
    – Mark
    Jun 4, 2018 at 6:45
  • $\begingroup$ delivered head ist a function of square of rpm, so I'd excpect quite low head at 13Hz - what does the system curve look like? Have you talked to the VFD supplier for troubleshooting? $\endgroup$
    – mart
    Jun 4, 2018 at 8:34

1 Answer 1


may be its not getting the enough rotating flux , as you know V/F ratio needs to be maintained constant for motor to run at low speeds... may be your VFD is not providing the appropriate ratio of Votlage to Freq so that its gets right rotating flux...


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