Question

Find out the all day efficiency for 100 KVA ,50 hz transformer having 400 watt core loss and 600 watt full load copper loss for following condition
a) full load unity pf for 6 hrs
b) half load 0.75 lagging pf for 8 hrs
c) 1/5th of full liad 0.85 pf for 8 hrs.
d) no load for 2 hrs.​

Answer 1

Explanation:

Then the efficiency of transformer can be written as : Where, x2Pcufl = copper loss(Pcu) at any loading x% of full load