Where should PV system DC circuits exceeding 30V or 8A be contained inside buildings?

The requirement for containing photovoltaic (PV) system DC circuits exceeding 30V or 8A inside buildings relates to safety and protection against electrical hazards. The National Electrical Code (NEC) specifies that such circuits must be housed in a manner that minimizes the risk of electrical shock, fire, and mechanical damage.

Metal raceways are preferred for several reasons. They provide a robust physical barrier that protects the conductors from damage and helps to contain any potential arcing. Additionally, metal raceways serve as an effective grounding method, enhancing the safety of the installation. By enclosing the circuits in metal raceways, any fault conditions, such as short circuits, can safely dissipate their energy, reducing the risk of fire or injury.

In contrast, wooden enclosures may not provide adequate protection from moisture and mechanical damage, while plastic conduits, although useful in certain applications, might not offer the same level of fire resistance or grounding properties as metal raceways. Flexible tubing is often unsuitable for permanent installations of higher voltage and current systems due to its lack of durability and grounding capabilities.

Thus, the use of metal raceways is aligned with the NEC’s goals of enhancing safety and ensuring reliable performance in electrical installations, particularly for DC circuits that exceed specified voltage and current