Just an interesting observation: There are different ways to interpret and answer the original question. You take the angle of "this is the conductors we have, so if we keep those, what kind of delta fits that." I take the angle of "ok a delta, well erase the secondary stuff you have there and here are the options..." (as I did in post #6). Im am not saying one way of addressing the question is more right or wrong, just noting the difference. Similarly with the transformer designation in the drawing, I gave the OP words more weight and took into account that the drawing was not say drawn up in autocad. Others treated the drawing as gospel. Again, I am not saying one reading of the OP is more correct, just interesting to see how different people analyze and interpret things.
Regarding transformer designations, I'll retract the "industry standard" comment. I guess I dont really know if there actually is a specific "industry standard" in terms of the use of the words "delta" and "3-wire". I did do some digging though. I looked at a website that sells used transformers and they have photos of the data plates on almost every one.
http://www.philipsbrothers.com/. About half of the delta primary padmounts just had a single voltage on the data plate. The other half had the voltage and the word delta. Of course they all had the phasor diagram on the dataplate. All of them said the voltage and the word delta in the verbal description. I didnt see any use of the term "3-wire"
Just today I came across an example of why I like to see the word "delta"/ 1.33 MW PV project plan set. Drawn/stamped by an EE. Also had third party review. Transformer shown as 12.47-480 volt, but its a wye-wye. You cant assume everything will denote a transformer correctly.
