PE Power Sample Problem 5

A three-phase 2MVA 13.8kV/480V oil-filled service entrance transformer is fed by a local electrical utility which can be assumed as an infinite bus. Transformer impedance is Z = 5%. Calculate symmetrical fault current due to three-phase short circuit at transformer’s secondary windings.
(A) 2.4kA
(B) 3.6kA
(C) 48.1kA
(D) 8.3kA

Wasim Asghar – P.E, P.ENG, M.ENG

Licensed Professional Engineer in Texas (PE), Florida (PE) and Ontario (P. Eng) with consulting experience in design, commissioning and plant engineering for clients in Energy, Mining and Infrastructure.