NEMA Requirements for Outdoor Digital Signage Enclosures

Protecting screens outdoors requires a lot of thought. A screen requires protection from the weather, temperature control and physical protection. Ensuring the digital signage enclosure is suitable for the application intended needs assessing on an individual basis. Some locations require added cooling to cope with extreme heat, while other locations require heaters for colder climates.

One universal aspect does exist, however, and that is the requirement for the LCD enclosure to protect against ingress of water and small particulates such as dusty, which if allowed to penetrate to the screen, can cause short-circuiting and other problems that can disable the display.

Fortunately, universal guidelines exist, governing enclosures designed to protect LCD screens in outdoor locations; in the United States NEMA generate these guidelines.

The National Electrical Manufacturers Association (NEMA) publishes over 500 standards providing guidance to manufacturers of electrical equipment. For outdoor digital signage enclosures, these NEMA standards are numeric.

NEMA rate enclosures on a 1 to 13 basis: the lower the number, the lower the protection afforded by the enclosure. The types of protection these numeric standards cover include: incidental conduct with personnel (fingers), dust, dirt, water splashes, water jets, oil, corrosives, combustibles, explosive atmospheres and ice.

A NEMA 1 enclosure, for instance, only provides sufficient protection for indoor use, preventing personnel against incidental contact with the enclosed equipment and providing a degree of protection against falling dirt.

For an outdoor digital signage enclosure, the required NEMA standard is NEMA 4. These Type 4 enclosures provide protection to personnel against access to hazardous parts; provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and windblown dust), provide protection against the ingress of water (rain, sleet, snow, splashing water, and hose directed water); and also ensures the external formation of ice on the enclosure will not damage the device inside. NEMA 4X, commonly used in outdoor environments, provided additional protection against corrosion.