I've worked on exactly one corner-grounded delta in my career, when I was a very green apprentice. The journeyman I was with wondered why one phase was taped white-- what did I know? Well, it was the grounded conductor, of course!
This was a plant that made all those telescoping dentist mirrors and magnets that auto mechanics use. I'm sure they've moved all the production to China by now.
So, 240V phase-to-phase, 240V phase-to-ground. If you want 120V, you need a transformer.
