I’m reading and learning about the various aftermarket spindle options, but I’ve kind of hit a stumbling block. I’ve determined that I don’t want to go bigger than a 1.5 kW spindle, as I don’t see myself using anything bigger than what an ER11 collet set can support. I don’t think I would ever need a 1/2" shank or even 3/8" shank mills.
Because I’m far from living in my forever home, and see several more moves in my future, I can’t guarantee that I will have 220V power available to run a 220V VFD. If I’m renting, its pretty rare for a landlord to allow you to modify the electrical panel to support a 220V feed. So I feel like I’m limited to 110V input for a number of years yet.
My concern is this: a 1.5 kW spindle at 110V could potentially draw 13.7 A at peak power on the output side of the VFD, which I doubt I would hit, but its possible. A standard 20 A breaker is only meant to handle 80% before tripping, which would mean it trips at 16 A. However if I add anything else in the mix on the same circuit like a vacuum, I could easily exceed the 16 A and constantly pop the breaker. I’m assuming that because I’m not stepping up the input voltage from 110, the input current would be the same, no? I believe all the VFD does is rectify the current to DC and then change it to 3 phase so that you get a frequency to run the spindle at variable speed, unless I’m wrong?
So the other option I have read would be to run a 220V VFD and spindle, but I’m not sure if the VFD will step up the voltage from 110V to 220V first, or do I need to run an external transformer before that? And if I do, the same problem regarding current draw possibly exists yes? You can’t change the laws of physics.
So can someone help illustrate what the input side current draw would be for a 110V input VFD or a 220V input VFD running off a transformer?