A NEMA 3 outdoor cabinet is an electrical enclosure rated to meet ANSI/NEMA 250-2020 specifications to prevent penetration of enclosed equipment by the effects of falling dirt, windblown dust, rain, sleet, snow, and external ice formation through the enclosure. Discover why IP protection ratings matter for outdoor cabinets. Learn how to choose the right IP class and avoid costly equipment damage. Outdoor cabinets need to handle all kinds of weather—rain, dust, wind, and sun. If they're not protected well, the equipment inside can break down, leading to. An IP rating (also known as Ingress Protection Rating) indicates how well a device is protected against solids and liquids.