The VFD I purchased is the Hitachi L100, capable of 10 Amps output at 240V. The input may be either single phase or 3 phase power. This gives me flexibility for the final installation. Many VFD's force another derating when used with single phase input, but not this one. The list of features is very long... modern VFD's are microprocessor controlled, and you can control acceleration, deceleration, braking, discrete speed levels, all sorts of cool functionality. It will output 360Hz, so it can be used with some HF 3phase motors, or the stock motor itself can be overdriven (go FASTER) with loss of some torque.
For now, I am going to mount the entire unit next to the mill head on an aluminum bracket. Ultimately, I can create a simple remote control keyset with a rheostat, or it can be controlled with a computer.
I went with the much larger 3HP VFD rather than a 1.5HP unit just to have the safety overhead on the current rating.
The display output can be set for current, frequency, or a user-defined scale which corresponds in a linear fashion with the frequency output. I'll probably set the latter up for a tach display.
Later today I'll power it up before going to the trouble of mounting it in detail, just to verify that it'll do what I want.
Stay tuned!
