I bought one of the 'cheap' Huanyang VFDs on Ebay some months back in preparation of me using this for Thor as a Spindle speed control mechanism. I did not buy the spindle at the time but had a 3 Phase Vacuum Pump motor I wanted to turn with it. I did get the motor to turn but it always ran hot which might be explained below.

The unit is a 4KW 5HP 380V unit which can take both single and three phase input.

Yesterday, I tried to use this unit to power a friend's new (secondhand) kneemill. We had some success but I later realised that the issues we were having were voltage related. I measured the output at 50HZ and saw no more than around 260V out. I checked the settings, I think parameter PD005 is max voltage, and this was set to 415V. I reduced it to 380V.

When the unit was running, it was reporting 380V although I was measuring 250V (on average).

What I now assume is that it will only make 380V if it has a suitable three phase incoming power. I had believed before this, that I would convert 220V single phase to 380V three phase with this unit. Should I be able to? Did I miss something? I believe the reason the pump motor ran hot was low voltage means higher current = heat.

Thanks