Transformer secondary conductors

[jap]

If I were guessing , I'd say they back fed a standard 480v Delta primary to 120/208v Secondary 3ph Tranformer.

When they back fed it, they probably fed the secondary 208v Delta (No Neutral Connection) and are feeding a disconnect 480v Delta (No Neutral).

At least that's the picture I have in my mind.

JAP>

 

[kwired]

I doubt the 480v side is actually a corner grounded delta.

JAP>

If there is only three leads on that side of the transformer there it is either corner grounded or not grounded at all.