Thank you both for the replies
Why would the VFD not work?
I repair a lot of Pentair pool automation boards, and this inverter came in a box containing some damaged items so I'm just assuming there's an issue with it - there's a chance it's fine.
No. Neither with light bulbs, nor with actual motorwinding-star-connection (has to be always left isolated). This is also true for line-powered "star-loads", if they are symmetrical of course.
Thank you for clearing that up for me!
and Terry thanks for that diagram... I was interested in making my own filter but wasn't super confident (not sure why?). I should have just built one and checked it with a signal generator and a scope first (although my 1054z has a 1M input impedance vs the Fluke's 10M). +1 for class-x caps!