Struggling please help

[daws124]

A 230v single phase double wound transformer has an output of 20A at 110v

Determine the

kVA rating....
Primary current...
Transformation ratio...

Please explain my brain is mush! Thank you.

 

[derek]

Forget 41 amps as primary current. Your turns ratio is correct but the other 2 are wrong. Reconsider power equals volts multiplied by amps. Power in equals power out in this simple case.

 

[daws124]

Dam ha! So basically it's 110x20=2,200 so 2.2kVA?? So if that's right? The primary current would be 1000x 2.2kva/230v...?? My head is going to pop! This is helping thank you

 

[derek]

Looks like you've got it

 

[daws124]

Superb so just to make sure the primary current would be 9.565 so would I write that as 9.6A! Getting there slowly

 

[Richard Burns]

A 230v single phase double wound transformer has an output of 20A at 110v

Determine the

kVA rating....
Primary current...
Transformation ratio...

Please explain my brain is mush! Thank you.

Well done you have put the effort into it and (with some assistance) have got the answers!

kVA is the power and for a 100% efficient system is (volts/1000) * amps
therefore kVA is (110/1000)*20 = 2.2 kVA

Using Archy's equation rearranged Primary current, Ip, is (Is*Vs)/Vp = 110*20/230 = 9.56A

Turns ratio is Vp/Vs =230/110 = 2.09

Done