Lots of Delta vs Wye connection questions?

[BP-Revo]

Ok, I understand that Delta and Wye have some sort of relationship to the number 1.73, as in one provides that many times more (or less) KV than the other.

What I don't understand is which one is which compared to the ratings that we are given on the Lehner Motors.

Are the Lehner KV values rated in Delta or Wye? And please specify the differences between Delta and Wye.

Any help appreciated (this is driving me nuts - keep doing research but all the stuff gives me so much electro-babble my mind can't process any of it).