Earth Cable Size Selection Chart Access

For Steel Wire Armoured (SWA) cables, the armour is often used as the earth conductor (CPC). However, you must verify if the armour resistance meets the required earth loop impedance. In many cases for larger cables, the armour is sufficient, but for smaller cables, a separate earth core might be added internally.

Choosing the correct earth cable size isn’t just a matter of following code; it’s the difference between a safe electrical system and a fire hazard. If a fault occurs, the earth wire (or Circuit Protective Conductor) must be beefy enough to carry the full fault current back to the source long enough for the breaker to trip, without melting in the process. earth cable size selection chart