Voltage Regulation of Transformer

[Byk]

Hi everyone, I hope someone can help me solve this problem:

Tests are performed on a single-phase, 10 kVA, 2200/220 V, 60 Hz transformer with the following results are obtained for a fixed load of 3.41A at rated output voltage. The load is is a lagging pf load. Determine the voltage regulation for a load condition of 75% full load,  0.6 power factor lagging 

The answer is 4.86%

I tried to reverse the solution using formula Voltage Regulation=(Vnl-Vfl)/(Vfl)

Doing that I got that Vnl is 2306.94 which I have no idea who to get to.

Any help is greatly appreciated.

 

[Ampera18 PE]

is that all that says? It says "following results obtained" and then, no results?

 

[mxg2579]

I think there is some information missing from the problem, not sure how you’d get the voltage regulation from the OP. 

 

[Byk]

is that all that says? It says "following results obtained" and then, no results?

I think there is some information missing from the problem, not sure how you’d get the voltage regulation from the OP. 

That's all that was given. 

 

[mxg2579]

That's all that was given. 

View attachment 20200

Hmm. The 3.41A has got to be used somehow, unless that’s there as a trick. You could use that to calc the kVA of the first load, but beyond that I’m stumped as well. 
 

I think I’m going to have to sit on this one some more and see if I can think of it...

 

[Sparky Bill PE]

Wouldn't your no load voltage be your kva/amperage? 10E3/3.41 = X

and your full load voltage be 75% of that: X(.75)

Then apply your normal voltage reg formula?

 

[mxg2579]

Wouldn't your no load voltage be your kva/amperage? 10E3/3.41 = X

and your full load voltage be 75% of that: X(.75)

Then apply your normal voltage reg formula?

I don't think that would be the "no load" voltage though, because that 3.41A is said to be a "fixed load at rated voltage." Maybe it's the wording of the problem that is throwing me off.

 

[Sparky Bill PE]

I don't think that would be the "no load" voltage though, because that 3.41A is said to be a "fixed load at rated voltage." Maybe it's the wording of the problem that is throwing me off.

Regardless the answer, you're right. IT's worded like garbage. I would get so mad at spin exams and complex imaginary. It's all for nothing, any stupid worded question like this i would skip, The actual exam is like the NCEES practice exam so its worded a lot more thoroughly.