Question

find the efficiency of a 150kva transformer at 25% full load at 0.8 p.f lag if the copper loss at full load is 1600W and iron loss is 1400W .ignore the effects of temperature rise and magnetising current​

Answer 1

Explanation:

0.8 pf : First, we will calculate the copper lost at full load. ... Example 2: In a 25 kVA, 2000/200 V transformer, the iron and full load ... (i) Efficiency of full load 0.8 pf lagging : % = = ... Example 3: A 40 kVa transformer has a core loss of 450 W, fullload copper loss of 850 W. If the power factor of the load is 0.8,

Answer 2

Answer:

25 percentage of full load(KVA2)^2 =25/100×150=37.5kva

(KVA2)^2/(KVA1)^2=(Poh2)/(Poh1)

Poh2=(37.5/150)^2×1600

=100w

percentage efficiency =37.5×10^3×0.8/((37.5×10^3×0.8)+1600+100)×100

=95.23percentage