This video was made to teach the principles behind:
How a new lathe runs on 3 phase power - like a Rotary Phase Converter
How a VFD changes your wiring set up from conventional
Why you have to change out so much wiring in a new lathe when using a VFD
How to control a VFD using Factory or Factory like controls that came on your lathe
The extra functionality a VFD provides
There are a lot of videos about making a three phase motor run with a VFD, and a few with a remote start and stop switch. What I could not find when I was learning was a video that really explained how a VFD was different from just running 3 phase power. Or how a VFD functioned different from a Rotary Phase Converter and why you needed to re-wire so much of your lathe for a VFD. For a total newbie, this high level mental picture was missing for me.
Thanks to great Members of The Hobby Machinist (mksj), and to Matt at Precision Matthews, I was able to build my mental model of how to do this and I wanted to pay that learning forward and save you all a couple of weeks of reading.
This Video is designed to give that high level overview and comparison to really give you the principles to understand the VFD. The video does walk through a specific example with a Precision Matthews PM 1440TL Lathe wired with a Hitachi WJ200-075LF VFD. In this example the full wiring set up along with all the controls and changes from the factory set up are explained.
Disclaimer: I am not a certified Electrician and the wiring diagrams shown are not certified wiring diagrams, just my own visual representation of how this works. Consult your Lathe and VFD Owners manuals and work with a certified electrician for all electrical work. Use of any of this information is completely at your own risk. Electricity can be fatal - and this is dealing with high voltage!!