Earth Cable Size Selection Chart 【2026】

While the chart provides a solid rule of thumb for 95% of residential and commercial projects, always verify the values. A cable might be thermally capable, but if the resistance is too high, the breaker won't trip in time.

| | Duration of Fault (s) | Earth Cable Size (mm²) | | --- | --- | --- | | Up to 1,000 | 0.2 - 0.5 | 10 - 16 | | 1,000 - 5,000 | 0.2 - 1.0 | 16 - 35 | | 5,000 - 10,000 | 0.5 - 2.0 | 35 - 50 | | 10,000 - 20,000 | 1.0 - 3.0 | 50 - 95 |