Stuart, I'm not saying the VFD's are bad, they do look like a good idea in some cases. But to run a whole shop from one is not an option like it is with a single converter.
I understand how you "switch" with the VFD, in reality you "control" all aspects of the motor start, stop, and reverse with the VFD.
But if you had a forward/reverse drum switch on your Bridgeport you couldn't use it between the VFD and the motor, that's all I was trying to say.
Or take my B&S #2 milling machine for example it has 4 different motors, a VF drive as a converter would be impractical, as I would need 4. Even then the spindle motor is switched by the clutch and brake lever on the column, I'd have to do something different there, might not need to use it at all?
Just saying there are a number of options to get three phase power, (or an approximation of it) depending on the use some ways are better than others.
Grigg
