NEMA 4X ELECTRICAL ENCLOSURE TYPES
NON-HAZARDOUS LOCATION STANDARDS
UNDERWRITERS LABORATORIES, INC. (UL 50 AND UL 508)
Indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, hose-directed water, and corrosion; and that will be undamaged by the external formation of ice on the enclosure.
NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA Standard 250)
Indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside an enclosure against the ingress of solid foreign objects (windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow, splashing water, and hose directed water); that provides an additional level of protection against corrosion; and that will be undamaged by the external formation of ice on the enclosure