MGVCL Exam Paper (30-07-2021 Shift 3)
A 1000 kVA ONAN cooled transformer has a load of 500 kVA throughout the day except for a period of 2 hours. What is the permissible overload for a duration of two hours. Assume the permissible load kVA as a fraction of rated kVA is 1.43.
After closing switch, Capacitor is behave as short circuit element, So, I(to) = V/R = 10/5 2 At t = infinite time capacitor is behave as open circuit, I(t) = I(to)e^(-t/Ƭ) Ƭ = time constant of circuit Ƭ = R*C = 200 μF I(t) = 5*e^(-t/(500*10^(-6)) = 5*e^(-5000t) A
1.6 inches = 1.6 inches x 1,000 mils per inch = 1,600 mils 0.25 inch = 0.25 inch x 1,000 mils per inch = 250 mils Area = 1,600 x 250 = 400,000 square mils
EXAMIANS