What type of wiring is generally prohibited in wet locations unless appropriately protected?

Non-metallic sheathed cable (NM cable) is generally prohibited in wet locations unless it has been specifically designed or treated for such environments. NM cable consists of insulated conductors wrapped in a plastic sheath, which can degrade when exposed to moisture over time, compromising the cable's integrity and the safety of the electrical system.

In contrast, wiring methods like metallic conduit, when properly installed, offer enhanced protection against moisture and physical damage, making them suitable for wet locations. Flexible cords are usually intended for temporary use and are designed for specific applications, often featuring insulation that allows them to function in various conditions, but they are not suited for fixed installations in wet environments. Low voltage wiring can also be used in certain circumstances where it meets specific requirements and is often rated for exposure to moisture, depending on its design.

Understanding the specific application and regulatory requirements for each wiring type is crucial for ensuring electrical safety, particularly in environments that may experience wet conditions.