The enclosure types listed in Table 110.28 are the National Electrical Manufacturers Association (NEMA) enclosure types.

Finally, look to the right to see which enclosure types can be installed.

Enclosure types with an “X” shall be permitted to be installed, and enclosure types without an “X” shall not be installed for the condition listed (see Figure 1).

The term “watertight” is typically used in conjunction with Enclosure Types 4, 4X, 6 and 6P.

The term “driptight” is typically used in conjunction with Enclosure Types 2, 5, 12, 12K and 13.

To find the enclosure needed, first determine if it will be needed for outdoor use or indoor use.

Next, in the row on the left side of the table, find the environmental condition to which the enclosure will be subjected.The other condition listed in both sections is incidental contact with enclosed equipment.All of these enclosures provide protection against incidental contact with enclosed equipment (see Figure 2).Outdoor-use enclosure types provide a degree of protection against environmental conditions such as rain, sleet, snow and windblown dust.Although the top part of Table 110.28 states the enclosures are for outdoor use, these enclosures can also be used indoors.NEMA uses a standard rating system that defines the types of environments in which an electrical enclosure can be used and frequently signifies a fixed enclosure’s ability to withstand certain environmental conditions.