Earth Conductor Size Calculator


What does the term earthing conductor?

Electrical systems often have their earth conductors installed such that the outer metallic housing is the one that is connected to the ground.

In the condition of defect occurs and the supply voltage is able to reach the outside components of a piece of electrical operational equipment, the equipment must be removed from the voltage as soon as possible.

The earthing conductor that carries the fault current from an electrical source to the ground.

Earthing size calculators are used for the purpose of determining the exact earthing conductor size in (sqmm) that is essential.

Formula for calculating the size of the earthing conductor

Earth conductor size PE(Sqmm) is measured in square millimetres and is calculated as the square root of the maximum operating duration t(S) in seconds multiplied by the square of the fault current I(fault-A) and then divided by the material constant k.

As a result, the formula for determining the size of the earth conductor may be expressed as follows:

Earth conductor size PE(Sqmm) = √ (I(Fault-A)2 x t(s)) / k


I(Fault-A) – Fault Current in Amps

t(s) – Time in Seconds

k -Material (GI, Copper, Aluminium)

Click here for more Electrical Calculators