Generating a neutral for 240V corner-grounded system (so line to neutral is 120V)

[winnie]

__dan nails it, and I retract the idea.

To guarantee that the 240V divides in half evenly all the primary coils would need to couple with all of the secondary coils.

This clearly would _not_ happen with three single phase transformers banked as a 480V:240V delta:delta transformer.

The transformer in question here is a 3 phase unit with a 3 leg common core. There are multiple flux paths and some coupling between all of the coils, but I don't believe enough to give a solid neutral.

-Jon

 

[gar]

181118-2329 EST

If there were three single phase transformers and you did not need full power capability, then you could take one transformer to go from 480 to 240, then parallel the other two primaries, series the secondaries, and connect the paralleled primaries to the 240. Now you have the equivalent of a center tapped 240 secondary.

.

 

[winnie]

Continuing to mull this, it might actually work, but would really need to be tested.

Say a single primary coil is energized at 480V. The flux threading the other two legs of the core will be roughly half that threading the leg with the energized coil, giving roughly half the output voltage.

So the coupled legs might actually do a reasonable job of keeping the voltage balanced.

I simply don't know.

-Jon

 

[LarryFine]

I'm sticking with the idea of an additional small 120/240v single-phase transformer, Bob,

 

[ptonsparky]

I'm sticking with the idea of an additional small 120/240v single-phase transformer, Bob,

:thumbsup: