Phase Shift Across Transformers

This should sort it out for you....

https://electricalnotes.wordpress.com/2012/05/23/vector-group-of-transformer/

So long as you don’t try to parallel them your customers won’t know the difference.

A transformer connection . . . dYn just does not exist.

The only customer issue would be if a fault condition occurs in the transformer at some future time. If the Dyn0 transformer fails for any reason, the customers will have an outage or at least a grid bump as the lines are switched to the other transformers. Depending on how fast the switching works, the customer will potentially see the 11 degree phase shift as the load shifts from the zero degree shifted source to the 11 degree shifted source. This is because the transformer is essentially stand alone.

Those customers on the paralleled transformers wouldn't see a major change as the load would transfer to the paralleled transformers.

Ummm, the 11 doesn't stand for 11degrees, it represents the number of 30 degree shifts from zero going clockwise. In this case it means either 330 degrees or, as a power engineer would read it, -30 degrees, from the reference vector.

OK, so 11 "hours". Same issue.