Industry Definitions

General Definitions Pertaining To Electrical Enclosures

  • Cover: An unhinged portion of an enclosure that covers an opening.
     
  • Degree of Protection: The extent of protection provided by an enclosure against access to hazardous parts, against ingress of foreign solid objects and/or against ingress of water and verified by standardized test methods.
     
  • Design Tests: Tests to demonstrate performance of a product designed to applicable standards. (Note: Design tests are not intended to be production tests.) NEMA 250-2003.
     
  • Door: A hinged portion of an enclosure that covers an opening. NEMA 250-2003.
     
  • Hazardous (Classified) Locations: Those areas, which may contain hazardous (classified) materials in sufficient quantity to create an explosion. See Article 500 of the National Electrical Code. NEMA 250-2003.
     
  • Hazardous (Classified) Materials: Those gases, vapors, combustible dusts, fibers, or flyings, which are explosive under certain conditions. NEMA 250-2003.
     
  • Hazardous Parts: Parts that are hazardous to approach or touch.
     
  • Indoor Locations: Those areas, which are protected from exposure to the weather. NEMA 250-2003.
     
  • Knockout: A portion of the wall of an enclosure so fashioned that it may be removed readily by a hammer, screwdriver, and pliers at the time of installation in order to provide a hole for the attachment of an auxiliary device or raceway, cable, or fitting. NEMA 250-2003.
     
  • Non-Hazardous Locations: Areas, which do not contain hazardous (classified) materials in sufficient quantity to create an explosion. NEMA 250-2003.
     
  • Non-Ventilated: Constructed so as to provide no intentional circulation of external air through the enclosure. NEMA 250-2003.
     
  • Oil-Resistant Gaskets: Those made of material, which is resistant to oil, or oil fumes. NEMA 250-2003.
     
  • Outdoor Locations: Those areas, which are exposed to the weather. NEMA 250-2003.
     
  • Ventilated: Constructed so as to provide for the circulation of external air through the enclosure to remove excess heat, fumes, or vapors. NEMA 250-2003.