To explain the various NEMA ratings, it makes sense to gain some background. The ratings are established by the National Electrical Manufacturer’s Association and are used to determine levels of protection provided by the enclosure. It can deal with environmental or safety issues and can also change based on whether the product is used indoors or outdoors. However, the rating system can be confusing as the ratings do not go in sequence. That is, the higher the rating does not translate to higher environmental protection.