Are Local Codes More Stringent for Grounding Solar Arrays?

Understanding NEC Grounding Requirements

The National Electric Code (NEC) Article 705 provides detailed guidelines for grounding solar arrays, with specific requirements for the grounding system, bonding, and bonding to the utility grid. For example, the NEC requires that the grounding electrode system for a solar array be installed and sized according to NEC 250.66, while also taking into account the array’s total current-carrying capacity.

Grounding Techniques for Solar Arrays

Solar array grounding typically involves connecting the array’s grounding system to the utility grid’s grounding system. This is often achieved through a grounding electrode conductor (GEC), which is sized according to the array’s total current-carrying capacity. For example, NEC 250.66 requires a GEC of at least 6 AWG for arrays with a current-carrying capacity of up to 30 amps. It’s essential to consult local codes and standards to ensure compliance, and to work with a qualified electrician to properly install and test the grounding system.

Common Grounding Mistakes to Avoid

A common mistake in solar array grounding is failure to bond the array’s grounding system to the utility grid’s grounding system, which can lead to electrical shock and other safety hazards. To avoid this, it’s essential to ensure that all connections are secure and properly sized, and that the grounding system is regularly inspected and tested to ensure it meets local code requirements. Additionally, failing to account for the array’s total current-carrying capacity can lead to overheating and damage to the grounding system, so it’s crucial to carefully calculate and size the grounding system according to local codes and standards.