|
Size
of Largest Service-Entrance Conductor, CU Wire [see 310-15(b)] |
Size of Grounding Electrode Conductor (GEC), CU Wire* |
| 2 or smaller | 8 |
| 1 or 1/0 | 6 |
| 2/0 or 3/0 | 4 |
| Over 3/0 thru 350 kcmil | 2 |
| Over 350 kcmil thru 600 kcmil | 1/0 |
| Over 600 kcmil thru 1100 kcmil | 2/0 |
| Over 1100 kcmil | 3/0 |
Notes:
1. Ref: NEC, Table 250-66.
2. * Where connected to a
concrete-encased electrode system,
NEC 250-50(c)- UFER, the GEC need not be more than No.
4 copper wire.