The National Electrical Code (NEC) Article 690, Solar Photovoltaic (PV) Systems, is the main article to reference when designing and installing PV systems. It supplements and sometimes modifies the general requirements in Chapters 1-4 of the NEC.
The 2020 NEC has several updates that affect the solar industry, including:
- Article 690.8This article has been rearranged for clarity and includes language that provides an alternative to the maximum circuit current calculation.
- Article 690.12This article allows the use of PV hazard control systems that are certified to the UL 3741 standard for conductors inside the array.
The 2023 NEC has many changes and clarifications in Articles 690 and 705, including:
- 690.12, rapid shutdown of PV systems on buildingsSome clarifications have been added, such as non-enclosed detached structures like carports and trellises not needing to comply with 690.12.
- 690.31(c)(2) cable trayThere is more clarification and guidance on installation practices and ampacity calculations.
Solar PV systems are complex and require expert knowledge in electrical, structural, and architectural design and installation.