What Regulations Apply to Grounding in Community Solar Projects?

National Electric Code (NEC) Requirements

The National Electric Code (NEC) sets guidelines for grounding and bonding in community solar projects. Article 250 of the NEC requires a 6 AWG (10 mm²) grounding electrode conductor as a minimum size for community solar arrays. Additionally, NEC 250.54 requires that all photovoltaic (PV) arrays be grounded separately, and that the grounding system be sized to accommodate the fault current.

Grounding and Bonding Techniques

According to the NEC, a grounding electrode system consists of a grounding electrode, grounding electrode conductor, and a grounding point. For community solar projects, the grounding electrode can be a grounding rod, plate, or a concrete-encased electrode. It is essential to ensure that the grounding electrode conductor is not smaller than 6 AWG (10 mm²) and that it is sized to accommodate the fault current. The grounding point should be located as close as possible to the main service panel where the PV array is connected. A grounding strap or bonding jumper should be used to connect the PV array to the grounding system. The NEC recommends a grounding strap or bonding jumper with a minimum of 4 AWG (5.3 mm²) for PV arrays.

Local and State Regulations

Local and state regulations may supersede NEC requirements, and it is essential to check with local authorities having jurisdiction (AHJ) to ensure compliance. Some states and local jurisdictions may have specific requirements for grounding and bonding in community solar projects, such as California’s Rule 21, which requires separate grounding systems for PV arrays. It is crucial to verify local and state regulations before designing and installing a community solar project.