In a delta Transformer the earth is formed by connecting what?

Question

in a 33kv to 400kv delta Transformer the earth is formed by connecting what?

i`m soing some revision thanks

Answer 1

In a delta a ground is provided by using a centertap connection on one of the phase windings.   The disadvantage here is that for one phase (called the high phase) there will be a sustantially higher phase to ground voltage.

Answer 2

The delta-wye transformer converts the delta windings (with no ground wire) to wye windings (with a ground wire).