Pardon while I digress a little here...
So, an "ungrounded" 19.9 KV Delta still has
11,489 Volts potential to ground...or???
Where does the Grounded Conductor on the subbed 7200/4160 Wye system originate, and how does it relate to the 19.9 KV lines?
How does a corner grounded Delta keep from shorting?
Sorry to be so elementary, but hey, I'm trying to learn more about it here...
Even though I should probably move this to the theory section, I still think it relates to my original question. Excuse my laziness!