if i look at the secondary and see that their is 240V between L1 and L2 will that mean i can have a primary phase voltage of 480 volts?

 

A 30:1 turns ratio would give you a secondary voltage of 1/30 of the input voltage.

 

if i look at the secondary and see that their is 240V between L1 and L2 will that mean i can have a primary phase voltage of 480 volts?

Nope, looks like the mains transformer that feeds my house. You have, as mentioned a 30:1 turns ratio. Actually the numbers are realistic.

Ron

 

Nope, looks like the mains transformer that feeds my house. You have, as mentioned a 30:1 turns ratio. Actually the numbers are realistic.

Ron

So, 480 is the best choice?

 

No, do the math, you have a 30:1 turns ratio.

Ron

 

In an ideal transformer operated within it's design limitations, the voltage ratio is the same as the turns ratio. Thus, in the 30:1 turns ratio of the transformer in the sketch, the primary voltage is 30 times 240 volts, which is 7200 volts. There, I have done the math for you. It is not complicated. Transformer impedance ratios are more complex, but we are not discussint them here.