Quote Originally Posted by Kitwn View Post
Plus the manufacturers of small machine spindles like ours would have to bring both ends of the three windings, plus a separate casing earth connection out to a seven pin plug.
Readers should also beware of some cable sizes quoted in diameter and others in cross-sectional area.
Kit
I'm pretty sure there wouldn't be any problems with commoning up the 3 earth conductors to a single pin at the spindle, it's all about balancing inter-conductor capacitance along the length of the cable, a few cm at the far end is unlikely to upset things. And the outer screen would be best connected only at the VFD end to avoid HF earth currents, so likely you could do it with a standard 4 pin plug - if you could fit the rather fat cable into said plug of course.