Hello, I want to rewind a MOT keeping the primary at 120Vac and I want the secondary to give me 630Vac and I want to know what is the maximum gauge that I can use to have enough winding to fit in the core, the size of the central core of the E is of 32*68.5mm and the available window removing the secondary and the shunt is less than 40mm high and 16mm wide. I don't mind overheating and that's because I'll use it for less than a minute every time I turn it on.

 

It would be far easier to take windings off the secondary than to wind an entirely new one. you don’t say how much current you need, so it is hard to evaluate.

 

It is that it is difficult take windings off the secondary , there is a kind of varnish or epoxy glued and well insulated and the bad thing is aluminum and that is fragile, as far as current I don't know, I measured the secondary wire and It seems that it is aluminum 28 awg approx 0.32-0.33mm, assuming that the secondary before it was 1200Vac and it would be half a turn, then could I buy a 24 or 22 awg copper? I found one that deals with this topic but it doesn't mention the gauge of wire I use.

with the measurement of the core that gives like 400-450W

 

It is that it is difficult take windings off the secondary , there is a kind of varnish or epoxy glued and well insulated and the bad thing is aluminum and that is fragile,

You seem to be thinking about saving the secondary wire. You cut the secondary coil and take it off in pieces then scrap it, not save it.

 

What do You need ~630-Volts for ?
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