VFD question

[wally318]

Can anyone here answer a couple questions re: VFD?
From what I understand VFD is to AC what variable speed drives are to DC.
Can a VFD work with a single phase motor or just 3 ph.?

[WJH]

Can anyone here answer a couple questions re: VFD?
From what I understand VFD is to AC what variable speed drives are to DC.
Can a VFD work with a single phase motor or just 3 ph.?

VFD's vary the frequency of an AC motor to vary the speed. You must use a 3 phase motor. Some VFD's require 3 phase in. Many will accept 220 single phase in and output 3 phase. I think I have seen some accept 110 single phase in and put out 220 3 phase.

I have no hands on experience with them other than using friends machinery with them. They work very well and will be installing one shortly on a 9x49 milling machine running off a 220v generator.
I think once you experience it, there is no going back to single phase or dc motors.

[MoreOldIron4Me]

Just 3 phase, but they work great for that!

[woodcutter]

I have five Teco FM50 VFD's to allow me to run 3ph machines off single phase 220v. They not only give variable speed but soft start, braking and the switching on/off. A switch between the VFD and motor is a no-no. Very happy with them.
http://www.factorymation.com/s.nl/sc.2/category.11/.f