Understanding 25GNDY/14.4kV Notation for Three Phase Transformer Banks

[Derill03]

Homework Statement

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What is the maximum full-load primary current that you could safely design for a three phase 500 kVA transformer bank to provide if it has a high-voltage winding of 25GndY/14.4 kV?

What does the notation 25GNDY/14.4kV really mean? Is it 25kV three phase and 14.4kV single phase?

Homework Equations

Full load current = VA / 1.73*Primary Voltage


3. Attempt at solution

Full load current = 500kVA / (1.73*25kV) = 11.56A *Assuming 25kV for primary voltage

Full load current = 500kVA / (1.73*14.4kV) = 20.07A *Assuming 14.4kV for primary voltage

 

[NascentOxygen]

A google search does turn up uses of the GndY notation, but I haven't been able to figure it out its meaning.

Do you have the textbook's answer to this question?