Size equipment grounding conductors for PV systems per NEC 690.45 and Table 250.122.
Input Parameters
Results
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EGC Size (Table 250.122)
AWG
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Adjusted EGC Size
AWG
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EGC Resistance
Ohms
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Fault Clearing Current
A
Note: EGC must be sized per the OCPD rating, not circuit current. For long runs, increase EGC size to ensure adequate fault clearing. NEC 250.122(B) requires upsizing.
Reference
EGC Size per NEC Table 250.122
Resistance = (Resistivity x Length x 2) / Circular Mils
Fault Clearing Current = Voltage / EGC Resistance
Copper resistivity: 10.4 ohm-cmil/ft
Aluminum: 17.0 ohm-cmil/ft