What type of enclosures is required for PV system DC circuits above a certain voltage within buildings?

For photovoltaic (PV) system direct current (DC) circuits operating above a certain voltage within buildings, the National Electrical Code (NEC) specifies the use of metal raceways or enclosures. This requirement is primarily due to the need for safety and protection against potential hazards, such as short circuits and electrical fires.

Metal enclosures offer several advantages in this context. They provide a robust and durable housing for the wiring, serving as a barrier to physical damage and reducing the likelihood of accidental contact. Additionally, metal enclosures can help prevent the ignition of flammable materials in the vicinity by effectively containing any heat generated by electrical faults.

Furthermore, metal can also facilitate grounding, which is crucial for system safety in reducing the risk of electric shock. The conductive nature of metal enclosures helps maintain the integrity of grounding systems, ensuring that any fault currents are safely directed away from users and sensitive equipment.

In contrast, the other options, such as non-metallic enclosures, glass enclosures, and wooden boxes, do not provide the same level of protection and safety features that metal enclosures do for PV system DC circuits. Non-metallic materials may not withstand high temperatures or impact as effectively, glass poses a safety risk due to breakage, and wooden