Gary, thank you very much for the suggestion. No I'm not dead set on using a GFI outlet. In fact I was planning on running the new breaker off the sub panel, and most likely since I think the conduits are filled I would
likely wind up pulling another conduit line over to right over the mill.
However I just looked up that part number you gave me. It's the same form factor as my existing Home Cheapot GFCI outlets, costs $35, and will drop right in to what I already have, all the while meeting code. I don't think I'll be able to run a new circuit for less than that money and amount of time it will take me. I looked up the specs on that GFI outlet, and you're right it does say VFD rated. I guess I did not realize how common the small VFDs are getting for the home market. It's nice to see such a device exists.
Has anybody else ever had this issue before? I did a ton of searching on this website and have not seen anybody report similar issues with the controller I am using. I'm surprised I'm the first one to see this and just want to make sure I'm not overlooking a bigger issue? However if it's just capacitive noise I guess it should be fine? I guess the other question will be how much current is actually leaking out of the circuit, and if upgrading to this outlet will actually work. However for the price I think I'm going to take the gamble.
I'm not the real electrical guru, but do others think this makes sense? Unlike a VFD which varies the frequency of the output voltage, my system is the exact opposite I thought? I have a rectifier circuit and I'm running everything off of straight up DC? Or is the system PWMing or something to control the DC servo motors and that's what's causing the variable frequency type effects that might be triggering nuisance trips on my GFCI?