Equipment Grounding Conductor (EGC) Size Calculator | WireStandard
Calculate minimum EGC size per NEC Table 250.122. Supports copper and aluminum, proportional adjustment (NEC 250.122(B)), and IEC/BS/AS-NZS PE sizing.
- OCPD Rating (A)
- Conductor Material
- Copper
- Aluminum / Copper-Clad
- Optional: NEC 250.122(B) Proportional Adjustment
- If ungrounded conductors are increased beyond the minimum required, the EGC must be proportionally increased.
- Min. Required Conductor
- Installed Conductor
- NEC Minimum EGC
- per Table 250.122
- Proportional EGC
- EGC increased proportionally per NEC 250.122(B) — installed conductor exceeds minimum required.
- EGC Size
- Basis
NEC values from Table 250.122 (2023 NEC). IEC/BS/AS-NZS values based on IEC 60364-5-54 Table 54.2 simplified formula.