Transformer Primary and secondary currents

AI Thread Summary
For a single-phase transformer rated at 120kVA, with primary voltage of 2000V and 1000 primary turns, the secondary turns are calculated to be 50 using the formula Vp/Vs = Np/Ns. The primary current is determined by dividing the power rating by the primary voltage, resulting in 60A. To find the secondary current, the relationship Vp/Vs = Ip/Is is incorrectly applied; instead, the correct approach confirms that if the transformer is 100% efficient, the power supplied equals the power delivered. The secondary current is then calculated to be 3A based on the primary current. Overall, the calculations need verification, particularly the application of the current transformation equation.
jitznerd
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Homework Statement



A single phase transformer has the following rating : 120kVA. 2000v/100v, 60 Hz with
1000 primary turns.

Determine:

a.Secondary turns
b.The rated primary and secondary currents

Homework Equations



Vp/Vs = Np/Ns

The Attempt at a Solution



a. I have used the Vp/Vs = Np/Ns to work out secondary turns
1000 x 100/2000 which gave me 50 secondary turns.

b. I arent sure if I have gone about this the right way and just wanted to check.

I divided the 120000VA by the primary voltage of 2000 to give me 60A. Is this correct to do this.
Then with my 60A I put that into the Vp/Vs = Ip/Is which gave me 3A as secondary current.

Could someone please tell me if this is correct thanks
 
Physics news on Phys.org
Vp/Vs = Ip/Is is not the correct equation... have another look at it.
If the transformer is 100% efficient then power supplied = power delivered.
 
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