Can anyone help with transformer calculation please

[david7]

stuck on last question ;-(
A transformer delivers a power of 5Kw when on load, what will be its efficiency if the copper loss is then 100w and the iron loss is 75w.

Thanks in advance

David

[factor-fiction]

I know nothing about transformers but I would make ane ducated guess that the total loss is 175W which is 3.5% of 5000w; therefore the efficiency is 96.5%

[HowardKennitby]

I would do that as 5000/5175

[factor-fiction]

Maybe, but I decided it was 5000 initially because it says "...if the copper loss is THEN 100w"

[david7]

Thanks for the help, looking at my notes think the calculation is V2.I2cos squared ;-( still cant do it

[mibn2cweus]

( P out / P in ) * 100 = P efficiency %

http://nuclearpowertr...v4/css/h1011v4_56.htm

[beso]

Any formula with phase angle would require information about the power factor of the load. You don't have that. Efficiency is just the simple formula as given by others.

[david7]

Thanks for your help everyone ;-)