Grounding Electrode Calculator

Size grounding electrode conductors (GEC) for solar PV systems per NEC requirements.

Largest DC circuit conductor

NEC 250.66 - GEC Sizing Table

DC Conductor (Cu) GEC Copper GEC Aluminum
2 AWG or smaller8 AWG6 AWG
1 AWG - 1/0 AWG6 AWG4 AWG
2/0 - 3/0 AWG4 AWG2 AWG
4/0 - 350 kcmil2 AWG1/0 AWG
400 - 600 kcmil1/0 AWG3/0 AWG
> 600 kcmil2/0 AWG4/0 AWG

Key NEC References

  • NEC 690.47 - PV System Grounding
  • NEC 250.66 - GEC Sizing
  • NEC 250.52 - Grounding Electrodes
  • NEC 250.53(A) - Rod electrode requirements
  • NEC 250.56 - Supplemental electrodes