Because what they are teaching students isn't exactly real world. Wye ungrounded delta transformers are rare in the real world both for NEC electricians and poco linemen. Any engineer would discourage their use. A functioning connection yes, but rare.Thanks. Why are neutrals not used on these? I have only ever done doorbell transformers.
But you can have a grounded wye feeding the above original post, just no neutral.When was the last time an electrician hooked up a wye ungrounded delt transformer? When was the last time a line man had a primary wye ungrounded delta can?
That's why I shot my mouth off when I saw the apparently odd-ball IDs on those terminals, because in my experience this schooling often has a bunch of hypotheticals that will never, ever be applied, and as far as I'm concerned it's a waste of the student's brain-power.Because what they are teaching students isn't exactly real world....
With a few small single phase transformers I'd say that is a great teaching method.But in fairness, if they're actually letting guys build their own ganged transformers out of little single phase versions, that's actually a really neat way to teach the theory, even if the configurations are unusual.