Short Circuit Current Calculator, Formula, Circuit Calculation

Short Circuit Current Calculator

Enter the values of voltage, V_(V) and resistance, R_(Ω) to determine the value of Short circuit current, I_short(A).

Short Circuit Current Formula:

Short circuit current refers to the current that flows when a circuit is completed bypassing the normal load through a low resistance path.

It is a critical parameter in electrical and electronic engineering because it determines the potential for damage and the necessary precautions in system design.

This kind of current can lead to excessive current flow in power systems, potentially causing equipment damage, fires, and other safety hazards.

In a short circuit, current flows along the path of least resistance, often bypassing the designed circuitry. This leads to a dramatic increase in current flow.

Types of Short Circuits

Bolted Fault: A bolted fault occurs when there is a direct connection with zero impedance across the conductors. This type of fault leads to the highest possible short circuit current.

Arc Fault: In an arc fault, the current flows through an arc in the air. The arc has some impedance, so the current will be less than in a bolted fault but still potentially very destructive.

Ground Fault: A ground fault occurs when one of the conductors connects to the earth or grounding system. The nature and severity depend on the grounding system’s design.

Calculations of potential short circuit currents help in selecting appropriate protective devices and designing circuit layouts that minimize risk.

Short circuit current, I_short(A) in amperes is calculated by dividing the voltage, V_(V) in volts by resistance, R_(Ω) in ohms.

Short circuit current, I_short(A) = V_(V) / R_(Ω)

I_short(A) = short circuit current in amperes, A.

V_(V) = voltage in volts, V.

R_(Ω) = resistance in ohms, Ω.

Short Circuit Current Calculation:

1. Calculate the short circuit current for a system with a voltage of 240 volts and a short circuit resistance of 0.5 ohms.

Given: V_(V) = 240V, R_(Ω) = 0.5 Ω.

Short circuit current, I_short(A) = V_(V) / R_(Ω)

I_short(A) = 240 / 0.5

I_short(A) = 480A.

2. Suppose the total short circuit current in a system is 600 amperes and the voltage is 120 volts. Calculate the total resistance of the short circuit path.

Given: V_(V) = 120V, I_short(A) = 600A.

Short circuit current, I_short(A) = V_(V) / R_(Ω)

R_(Ω) = V_(V) / I_short(A)

R_(Ω) = 120 / 600

R_(Ω) =  0.2 Ω.

Short circuit current calculation