# Homework Help: Transformers connected in wye-delta

1. May 31, 2010

### a_hargy

1. The problem statement, all variables and given/known data
Three single phase transformers rated 100kVA, 13.2kV/2.4KV are connected in wye-delta on a 3-phase, 18kV line.

I need to find the maximum load that can be connected to the transformer bank and the outgoing line voltage.

2. Relevant equations

3. The attempt at a solution
I am completely stuck, so far I've got:
Voltage across primary is 2.4kV therefore voltage across secondary is 13.2kV
Es=13.2$$\sqrt{3}$$=22.86kV?

Any help would be greatly appreciated.

2. May 31, 2010

### Phrak

This can't be right can it? Do you have a 2.4KV transformer connected to an 18KV line?

3. May 31, 2010

### a_hargy

I'm not 100% sure if that's what the question is implying as I'm completely stuck on it.
Thanks for the quick reply though.

4. May 31, 2010

### Phrak

Well, I don't know how 3 phase transformers are voltage rated, as I haven't studied them. However, if the voltage of a Delta is measured from phase to phase and voltage of a Wye is measured neutral to any phase, then you don't use the factor of sqrt(3).