I see these around mine sites quite a bit. Many mine sites use 240 or 480 3 phase Delta ungrounded systems as permitted by 250.21 (A)(4). These transformers could also be used for a corner grounded Delta.
Few things are harder to put up with than the annoyance of a good example.
yes it is... 99% of the 480V running around the oil fields in western Kern Co, CA are ungrounded delta sec's. with delta primary on 12KV systems and Wye on 21KV systems
