I realize this is not an optimal solution, so take this as an academic question. I have a generator which only supplies 50A at 120VAC. I would like to use it to supply back up power to a house, primarily for the 120VAC outlets. I have successfully done this for some time by tying the two hots together (off-grid, of course) and supplying them with the 120VAC. Of course, all the 240VAC devices don’t work because their two hot lines are now ‘shorted together’, putting the entire house on one leg of 120VAC.
But . . . the question I have is this. I have come across a rather large, 3-phase, 2:1 step up or down transformer that I am considering using to boost the 120VAC to 240VAC to supply the whole house.
See below for the wiring diagram for this transformer.
Can you figure out a way to double the 120VAC input voltage to give me a 240VAC output with a center tap for neutral?
X is the low side and H is the high side. That is, voltage, V, into H comes out 1/2 V from the X side of the transformer.
I’m thinking that whatever I do, I’ll have to open the X winding at the area marked by yellow. Otherwise the X windings look like a short circuit with only the application of a single phase. The H side can be disconnected or so it appears.
Maybe I could just use the ‘X’ side of the transformer as follows. Open the delta of the X side at the yellow mark then apply 120VAC from X2 to X3 and then use X2 as neutral for the house and use X1, X3 as the two hot lines. There would not be isolation between the generator and the house but that does not matter. Would want to make sure to use X2 as the primary neutral and have it grounded at the generator and the house.
