Transformer Voltage Possibilites

[JFletcher]

Based on this topic:

http://forums.mikeholt.com/showthread.php?t=182554&p=1812493#post1812493

Could one have a 120/240/480V system, using a center tapped 240V xfmr for the 120/240, and have 480V on the other 2 phases? Or even a double 'neutral' tapped 1ph 480xfmr; instead of a midpoint neutral tap, taps at 1/4 and 3/4 of the windings? You could have 480V delta with 120V from A to "neutral 1", 240V between N1 and "neutral 2" (or 240V from A to a center tap), and 120V between N2 and B. With 480V 3ph between AB, BC, and AC. If one needed just 480V single phase, but also 120V and 240V, could that be achieved with one transformer wired in a manner described above?

 

[ptonsparky]

IDR where I got it, some machine we scrapped (sp?) out, but the transformer had so many different taps I kept it just to play with some day. The day hasn't come, yet but maybe soon.

My SEWAG would be if you have the money they can build it.

 

[gar]

170303-0738 EST

You can do anything you want with isolated transformer secondaries so long as you do not exceed insulation breakdown voltages, and do not make any connections that cause circulating currents which includes that you can not have separate neutrals.

I could take two or more center tapped secondaries that are isolated in other respects and connect their center taps (neutrals) together. This does not create shorted windings.

.

 

[JFletcher]

Thank you gar and Tom.

 

[Jraef]

To paraphrase someone's signature line on here, "I can do anything you can sketch onto the back of a big enough check."

But one other issue would be keeping the 480V properly balanced. I would imagine that to be all but impossible with a scheme like this.