NEC Article 690
By Priya Nair · Last reviewed The National Electrical Code article governing solar photovoltaic systems in the US — conductor sizing, disconnects, grounding and installation requirements. Written for hardwired installations, it predates consumer plug-in systems, which is part of the gap UL 3700 was created to fill.
Why it matters
Vendors claiming NEC compliance are referencing design consistency with this article, which is meaningful but is not a product certification. Inspectors and utilities think in NEC terms, so the article shapes how new plug-in rules get interpreted on the ground.