Transformer Compatibility: 208/480 work for 220/440 mill?

mariner3302

mariner3302

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I have a mill that is wired for 440v, 3 phase at the power box. I have 220v, 1 phase. If I had this Transformer and a VFD to convert up to 3 phase, would I be able to wire it up to the mills power box and it would produce the voltage necessary? I wouldn't have to replace the 2 speed motor on the mill, convert a new motor, etc...

Please educate me!
 
The guy selling this says it turns 208v to 480v but isn't this tag saying it makes 480v into 208v?
1590773132563.png
 
So you want to reverse feed the transformer? You can do that but 208 not 240.
Then feed a VFD 480Vac?
 
Well, no, what I read from that data tag is that the transformer takes 480v and then turns into into 208v. His add says the opposite. I was hoping to find one that actually does 220v stepping up to 440v semi-locally and without the price tag...that and a VFD would make replacing my motor unnecessary because it can't be changed to 220v.

To this point, a motor swap has become the easiest and least expensive route. I have a thread in the Gorton section where we discuss it. This question was more general so figured I'd put it up here to limit the magic smoke escaping my brain housing group.

I'm still unclear on a couple things like if a motor is rated for 1800rpm, can it be run up to 3600 with a VFD?
 
What mill/motor is it? It is possible to internally rewire (not rewind!) most motors for lower volt operation. Its a bit of a fiddle, but means you can use a common 220v vfd.

I did this to my bridgeport pancake motor which was high volt only, it works beautifully:


I very much take the "you see a mousetrap. I see free cheese and a ******* challenge" approach to these things :D

I went through the same process of wondering if I can transform the input to or output of a VFD. In the end, fiddling with a few wires in the motor was cheap and quite painless.
 
That sounds like something I will try. It will give me a much needed learning curve and the worse that happens is I smoke the motor.. In that case, I am exactly where I am now. Now to start researching! I called the motor manufacturer and the said that couldn't help me with, well, anything actually. I took It to different motor shops, no help. So this will be a great learning experience.
 
Fantastic, I'll help as much as I can! As far as I know, my method is unique - certainly within the realms of what's been posted online. 400 something volts two speed is exactly the same as my motor was wired, so I'm certain you'll be able to achieve the same. Post some pics of what wires you've got coming out of the motor and we'll take it from there :)
 
I'm on it! I built everything from scratch on this flight simulator, a scale replica of a F-14B Tomcat front office, except the actual seat so let's do this lol
 

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Nice work!

The video is crammed with my thoughts and scribbles, but you'll find various drawings and diagrams in the doobly-do down below. Hopefully it'll save you reinventing the wheel! Once I understood the winding scheme that was used, tracing wires and soldering the tails back together in a different arrangement was trivial. With luck, your motor uses the same winding scheme. I'll post up my drawings here too for future reference.
 
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