Solar

PV Array Grounding Conductor Size Calculator (NEC)

Find the minimum PV equipment grounding conductor size from the circuit overcurrent protection rating.

Circuit Overcurrent Protection

Use the fuse or circuit-breaker rating protecting the PV circuit.

Grounding Conductor Material

Minimum Grounding Conductor

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Minimum wire-type equipment grounding conductor based on the selected protection rating.

Conductor material —

Overcurrent protection —

Minimum conductor —

This calculator covers NEC equipment-grounding-conductor table sizing only. Final PV grounding and bonding design must also verify installation method, equipment listings, conductor protection, local NEC edition and any requirements created by conductor upsizing or other design conditions.

Method: NEC 690.45 requires equipment grounding conductors for PV system circuits to be sized in accordance with NEC 250.122. Table 250.122 selects the minimum copper or aluminum equipment grounding conductor from the rating or setting of the overcurrent protective device ahead of the circuit. Where a PV circuit has no overcurrent protective device, NEC 690.45 requires an assumed overcurrent-device rating determined under the PV overcurrent rules to be used for the table lookup. This tool sizes an equipment grounding conductor. It does not size a grounding electrode conductor, DC current-carrying conductor, lightning-protection conductor or earth electrode.