Equipment Grounding Conductor Sizing
Minimum EGC size from overcurrent device rating.
Example
You enter
- OCPD rating (A) 60
- EGC material copper
You get
- Egc AWG 10
Checked against published worked examples from: NFPA.
Details, formula, and sources
Formula or tableEGC size from NEC Table 250.122, keyed to the upstream OCP rating; min size driven by OCP, parallel runs sized per NEC 250.122(F).
Source and editionNEC 2023 (NFPA 70). Section 250.122 and Table 250.122.
Free accessFree read-only access at nfpa.org/freeaccess.
What governsEstimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.
API field namesocpd_A, material, egc_awg
- Conductor material user-selectable; copper defaultNEC 250.122 row selection