Where are wiring methods with PV system DC circuits greater than 1,000V not permitted?

Wiring methods with photovoltaic (PV) system direct current (DC) circuits greater than 1,000 volts are specifically not permitted on or in single-family dwellings due to safety concerns associated with high voltage systems. The National Electrical Code (NEC) prioritizes residential safety, and when dealing with such high DC voltages, there is a significant risk of electric shock or fire hazards if proper precautions and methods are not followed. By prohibiting these wiring methods in single-family dwellings, the NEC seeks to mitigate these dangers for occupants and first responders.

In contrast, while the other locations mentioned may have their own considerations, they do not face the same level of risk associated with the residential environment. Porches, rooftops, and exterior conduits may be allowed under specific circumstances, provided that appropriate safeguards are in place for installation and maintenance. Thus, focusing on single-family dwellings aligns with the NEC's emphasis on protecting individuals and property from the hazards associated with high-voltage DC circuits.