46db57fd__IP_Equivalency_Chart___Siemon__NEMA_Definition
[NEMA Rating] 3 [IP Equivalent] IP54 [IP Definition] 5 = Protected against dust - Limited to ingress (no harmful deposit) [4] 4 = Protected against water sprayed from all directions - Limited to ingress permitted. [NEMA Definition] 
Enclosures constructed for either indoor or outdoor used to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to proved a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and that will undamaged by external formation of ice on the enclosure
NEMA Rating and IP Equivalency Chart - Siemon
NEMA Definition