Grounding Conductor Size Selector
Table 250-122 Calculator by Gerald Newton
Select Rating
or setting of
Automatic Overcurrent
Device in Circuit
Ahead of Equipment, conduit, etc.
Not Exceeding (Amperes)
15 Amperes
20 Amperes
30 Amperes
40 Amperes
60 Amperes
100 Amperes
200 Amperes
300 Amperes
400 Amperes
500 Amperes
600 Amperes
800 Amperes
1000 Amperes
1200 Amperes
1600 Amperes
2000 Amperes
2500 Amperes
3000 Amperes
4000 Amperes
5000 Amperes
6000 Amperes
Size of copper
grounding conductor
Size of Aluminum
grounding conductor