What is the acceptable NEMA rating for enclosures housing exposed circuit conductors on an outside wall?

The acceptable NEMA rating for enclosures housing exposed circuit conductors on an outside wall is NEMA 3R. This rating specifies enclosures that are designed to protect the enclosed equipment from rain, sleet, and snow, making them suitable for outdoor applications. NEMA 3R enclosures provide a degree of environmental protection while allowing for ventilation and not being completely watertight, which is often adequate for conducting not directly exposed to severe weather conditions.

NEMA 3R enclosures are typically used for various outdoor applications, including service disconnects and junction boxes, making them ideal for housing exposed circuit conductors. The need for resistance to moisture and external environmental factors is essential when placing any electrical components on an exterior wall, thus affirming the suitability of NEMA 3R in this context.