| Phase conductor cross-section (S) | Minimum protective conductor (copper) | |-----------------------------------|----------------------------------------| | S ≤ 16 mm² | S (same as phase) | | 16 < S ≤ 35 mm² | 16 mm² | | S > 35 mm² | S/2 |
| Overcurrent device rating (A) | Min copper EGC size (AWG / mm²) | |-------------------------------|----------------------------------| | 15 | 14 AWG (2.1 mm²) | | 20 | 12 AWG (3.3 mm²) | | 30 | 10 AWG (5.3 mm²) | | 40–50 | 10 AWG | | 60 | 10 AWG | | 100 | 8 AWG (8.4 mm²) | | 200 | 6 AWG (13.3 mm²) | | 400 | 3 AWG (26.7 mm²) | earth cable sizes