Hi,
I run that exact same spindle, and have used it and used it for many thousands of hour over ten tears, simply brilliant.
I use a 750W Delta VFD.
There are a few things to think about, firstly how fast are you ramping up the spindle. The faster you ramp up the more the current. I have mine set fairly leisurely at 6 seconds.
I would suggest a fairly leisurely ramp down time to, to avoid a large voltage surge back into the VFD when decelerating.
I think the more likely cause of your issue is that you have not correctly set the V/F curve. Most VFDs are set at factory defaults of applying full voltage at 60Hz. This would be normal for
a standard induction motor. You spindle however expects full voltage at 400Hz, and some part voltage at lower frequencies. I suspect that you have not programmed that part
correctly an therefore your VFD is applying full voltage at a much lower frequency than it should resulting in much higher currents.
You need to review the settings to find which of them describe the V/F curve. I know which parameters describe that in Delta VFDs but have no idea about ATO?
A huge number of happless souls have misunderstood this, not programmed the VFD properly, hooked up their brand new spindle and blown the sh****tter out of it. Don't do it.
You are risking your brand new spindle. You have paid a premium to get a German made spindle.......why economize on the VFD?
Craig