Electrical circuitry and related equipment are placed inside enclosures for protection from potential dangers such as human tampering and inclement weather. But as some situations call for higher levels of protection than others, not all enclosures are created equal. To provide guidance on levels of protection and construction, the National Electrical Manufacturers Association has issued a set of guidelines that have become accepted across the electrical industry as the de facto standard for electrical enclosures.
Along the spectrum of NEMA enclosures, the NEMA 4 enclosure is frequently sought after for its protection against the elements, including cold weather and the formation of ice on the exterior of the enclosure. The NEMA 4 offers an added degree of protection, and is the lowest-rated dustproof NEMA enclosure. In addition, it can protect against splashing water and even hose-directed water. However, it’s not explosion-proof, so it’s not suited for use in more hazardous applications.
In addition, the NEMA 4X enclosure also exists. As is easily surmised, the NEMA 4X is a subset of the NEMA 4 rating, so it provides the same level of protection against outdoor weather, particularly against dirt, rain, sleet and windblown dust. It also provides the same level of protection against splashing water.
The difference is that the NEMA 4X must provide additional protection against corrosion. As a result, only enclosures manufactured from corrosion-resistant materials, such as aluminum and stainless steel, can earn the NEMA 4X rating.
As is the case with many NEMA enclosures, a range of options may also be added, including forced ventilation and interior lighting.