Three phase full load current

[derill03]

Hello All,

I am an electrical engineer and ive recently been studying high power distribution, which i never studied in school. Can anyone check what ive done here and let me know if it is correct or how to better approach it.

Questions

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 L-L and 14.4kV L-NEU?

Relevant equations

Full load current = VA / 1.73*Primary Voltage

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

Thanks everyone for your time.
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

 

[charlie b]

Actually, you have it right, both in your interpretation of that strange set of numbers and letters, and in your math. The answer to your question is that you use the line-to-line voltage for the calculation. So the 11.56 amps answer is the right one.

Welcome to the forum.

 

[Iron_Ben]

What Charlie said. As a crosscheck, consider each winding. They all see 167 kva at full load, and the voltage impressed across each is 14.4 kv. Then, 167 kva/14.4 kv = 11.6 amps.

 

[derill03]

Thank You All.