Dashed line on Delta Wye transformer meaning

[CasualEngineering]

What does the dashed line between the H1 pole and the center of the delta mean on this delta/wye transformer?
Does this mean that the delta is corner grounded?
The wye also has the dashed line, and I presume that is just representing the ground of X0.
Thanks in advance.

 

[LarryFine]

Welcome to the forum.

I believe the dashed line indicates a theoretical connection, not an actual conductor.

 

[synchro]

Those diagrams show relative phasing of the primary and secondary windings on a vector diagram, with the dashed lines showing the 30 degree phase shift between the H1 line voltage and X1.