Enclosures: Learn About Enclosures Here > An enclosure, according to the National Electrical Manufacturers Association (NEMA), is a surrounding case constructed to provide a degree of
protection to personnel against incidental contact with the enclosed equipment and to provide a degree of protection to the enclosed
equipment against specified environmental conditions.
While NEMA does not actually test products, it establishes the performance criteria for enclosures intended for specific environments. NEMA
standards describe each type of enclosure in general and functional terms, and specifically omit reference to the construction details. That
means that NEMA specifies what and enclosure must do, not how to manufacture it. Underwriters Laboratories (UL) and Canadian Standards
Association (CSA) use NEMA performance criteria and test methods as guidelines for investigation and listing of electrical enclosures. The
tested enclosures are then authorized to carry a label by UL or CSA to prove it has passed the required tests and meets the applicable UL
and CSA standard.