Changing Yd1 to Yd11

This LinkedIn "Transformers Forum" question asked the following:

Dear all, Is it possible to change the vector group of a transformer by changing the phase sequence of supply?

Kevin Newman proposed a solution that just involves swapping two line connections on the HV and two line connections on the LV - nice trick!!

Here is the explanation presented as 2 slides - before and after: Yd1 to Yd11.pdf