1.

A capacitor-type stored-energy welder is to deliver the same heat to a single weld as a conventional welder that draws 20 kVA at 0.8 pf for 0.0625 second/weld. If C = 2000 μF, find the voltage to which it is charged.

Answer»

The energy supplied per weld in a conventional welder is

W = VA × cos φ× time = 20,000 × 0.8 × 0.0625 = 1000 J

Now, energy stored in a capacitor is (1/2) CV2

∴ W = 1/2CV2 or V = √(2W/C) = √((2 x 1000)/(2000 x 10-6)) = 1000V



Discussion

No Comment Found

Related InterviewSolutions