This is a "rule of thumb" based on the size of the live wire: If the live wire is , the earth wire should generally be the same size (
It was a typical Monday morning at the construction site of a new residential complex. The electrical team was busy installing the wiring and circuitry for the building. As they were connecting the earth cables, one of the apprentices, Alex, asked his senior, Jack, "Hey, Jack, why are we using such a thick earth cable? Can't we use a smaller one?" earth cable size
For typical cables up to 16mm², the general rule is simple: This is a "rule of thumb" based on
Often used for high-power appliances like electric ovens or small showers. Can't we use a smaller one
If the live wire is , the earth wire should be at least half the size ( B. The Adiabatic Equation (The Exact Method)
$$ S = \frac\sqrt1000^2 \times 0.1115 $$ $$ S = \frac\sqrt100,000115 $$ $$ S = \frac316.2115 \approx 2.75mm² $$