NEC 2014: Table 250.122
Min Size Equipment Grounding Conductors | ||
Rating or Setting of Automatic Overcurrent Device in Circuit Ahead of Equip, Conduit, etc., Not Exceeding (Amps) | Size (AWG or kcmil) | |
Copper | Aluminum | |
15 | 14 | 12 |
20 | 12 | 10 |
30 | 10 | 8 |
40 | 10 | 8 |
60 | 10 | 8 |
100 | 8 | 6 |
200 | 6 | 4 |
300 | 4 | 2 |
400 | 3 | 1 |
500 | 2 | 1/0 |
600 | 1 | 2/0 |
800 | 1/0 | 3/0 |
1000 | 2/0 | 4/0 |
1200 | 3/0 | 250 |
1600 | 4/0 | 350 |
2000 | 250 | 400 |
2500 | 350 | 600 |
3000 | 400 | 600 |
4000 | 500 | 750 |
5000 | 700 | 1200 |
6000 | 800 | 1200 |
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