Re: [CAD_CAM_EDM_DRO] Re: U.S. 220 vs Euro 220

info.host@... wrote:

> What is Star and Open Delta (?Wye?)? Do you remember where abouts it was
> that uses 440V raw in the house? I'm off to get my multimeter. `.^)

Star is a winding where there is a neutral connection for all three phase
windings. This is sometimes also called '4-wire', as there is a 4th wire,
the neutral. Delta has no neutral connection, each phase winding goes from
line to line. Open delta is a scheme to provide 3-phase power step-down
from high voltage mains with 2 single phase transformers, instead of
3 single phase transformers or one transformer with all 3 phases on it.
For heavy motor loads or very imbalanced loads, open delta will not give
the same phase balance as a true 3-phase transformer, but for moderate
loads it works fine. The advantage is where pole-mounted transformers
are used, it is much easier to put two small thransformers on the pole than
3 small ones or one great big, 3-phase monster. Also, one transformer
can be added to the existing transformer to get 3-phase power at the lowest
incremental cost.

Oh, star and wye are synonyms.

Jon