what is nema 3 r…..?

February 12, 2010 - 10:19 pm

it says i have to drill a 1/4 inch hole in this enclosure in order for it to meet the requirements of nema 3 r. should i drill a hole in it? it is regularly exposed to washdown environments.

http://www.nema.org/prod/be/enclosures/upload/NEMA_enclosure_Types.pdf