rpm increase ?

[joe aiello]

I have a 5 hp 3 phase 230v 3450 rpm motor from a WADKINS moulder that I like to set up as a shaper with a dedicated 3-5" cutter (1 1/4" bore) with a specified height and setbacks(once setup,no change). This is direct drive, no pulleys. I like to run this in the 7000- 9000 rpm range; can I do this with a vfd? If so, which one? -- thanks ... joe

[Zumba]

No, an inducation motor cannot be sped up to 300% rated RPM by a VFD. You will need pulleys.

Companies such as Baldor make special "VFD-ready" motors that have better insulation, but even those can only be sped up to 200%.