### Ze derived from calculations to determine the Potential Short Circuit Current.

One method to determine the Potential short circuit current if you do not have a Loop Impedance Tester.

Find the volt drop of the system V1-V2 Divided by the Load gives Zs. Where V1 is the open circuit voltage,

V2 is the voltage under load and load is the amperage of the system.

IE: (V1)240 - (V2)238 = 2 divided by the Load 40Amps = 0.05 Ω.

Then PSC = System voltage (Uo) / (Zs) 240 ÷ 0.05 = 4800 Amp.

Enter different values in the boxes below and the result is automatically calculated, you can use the Tab button to move between boxes.

No load volts at the incomer

Voltage under load

Load of circuit

Can your circuit breaker handle this?