Problem 4 In power system Figure 3 the maximum short circuit

Problem 4 In power system Figure 3, the maximum short circuits, nominal load currents and CT ratios of each relay are shown. The normal inverse over current relay with instantaneous unit is used in this system. mtiemaae inatoed protection arrangement. b) Determine the time and current setting of all inverse units

Solution

(CT) is a type of instrument transformer specially designed for protection and measuring purpose, it will operate by the current whenever it exceeds the set value. The C.T converts the 1000A/5A. In the secondary more tappings we will take depend upon the measurement. then Electrons will flow in the closed path only. So the secondary will short circuited.