As both Jon and GoldDigger point out - the "classic" use of a Wye: Delta transformer is backfeeding a Delta: Wye when that's all you have. I consider this a mistake for the reasons they point out.
I still had a test transformer in the shop today and backfed it to see what current was on the neutral when connected to X0. This is a typical 30 kVA 480D to 208Y step down. You can see in the pic below that the neutral is drawing 18+ amps when I power on. There is no load present on the 480D windings - just the idle magnetizing current on the Wye side. I did measure the incoming 3 legs to N just to get a feel for what kind of balance the POCO was giving me right then. It was 123.5 /124.5 / 122.9.
View attachment 2558204
If the incoming voltage imbalance ever gets excessive you will have large neutral currents on that wire - which is typically
NOT protected with an over-current device!
I recall seeing somewhere on the Mike Holt Forum a thread where a bond of the X0 to chassis ground (when backfed) caused enough current to flow in the ground path to melt the conduit or flex feeding the unit.
In my (admittedly) limited experience, I would think the bulk of grounded Wye Primary applications are on POCO distribution systems?