WARNING
As with all calculators check your answer!
(Iz) = current carryng capacity of the cable where it is installed. (It) = tabulated
current for a single circuit at ambient temp of 30°
(Ib) = the actual current to be carried. (In) = is the Circuit Breaker rating
in Amps.(I2) = the current at which the CB opens.
(Ca) = correction factor for Ambient temp. (Cg) = correction factor for grouping.
(Ci) = correction factor for thermal insulation.
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 click on Send, you can
use the Tab button to move between boxes.