Hi

After reading the VFD manual, it seems that there are many fault sensing modes in the Hunayang VFD's.

Taking that into consideration. If for example an older motor has weaker insulation , then the VFD would, in theory , detect a phase drawing more current due to insulation breakdown in a winding, and the VFD would switch itself off . Or , a leakage to earth , it would switch itself off also .

So in many respects the VFD's are safer to use than a "normal" non-VFD system .

Mike