Standard NEMA (National Electrical Manufacturers' Association) Enclosure Ratings Guide

Provides a degree of protection against the following conditions:	Type of Enclosure
	1	4	4X	7	12
Incidental contact with enclosed equipment	X	X	X	X	X
Falling dirt	X	X	X	X	X
Falling liquids and light splashing		X	X	X	X
Dust, lint, and fibers		X	X	X	X
Hosedown (hose directed water)		X	X	X
Oil and coolant seepage				X	X
Corrosive agents			X	X
Potentially explosive gas-air mixture				X
Windblown dust		X	X

Provides a degree of protection against the following conditions:	Type of Enclosure
	3	3R	4	4X
Incidental contact with enclosed equipment	X	X	X	X
Rain, snow and sleet	X	X	X	X
Windblown dust	X		X	X
Hosedown (hose-directed water)			X	X
Corrosive agents				X

Type 1 - General Purpose Enclosures are intended for indoor use primarily to provide a degree of protection against contact with the enclosed equipment in locations where unusual service conditions do not exist.
Type 3 - Weather Resistant & Windblown Dust Resistant Enclosures are intended for outdoor use primarily to provide a degree of protection against windblown dust, rain, and sleet; and to be undamaged by the formation of ice on the enclosure.
Type 3R - Weather Resistant Enclosures are intended for outdoor use primarily to provide a degree of protection against falling rain and sleet, and to be undamaged by the formation of ice on the enclosure.

Type 4 - Moisture & Windblown Dust Resistant Enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against windblown dust and rain, splashing water, and hose-directed water; and to be undamaged by the formation of ice on the enclosure.
Type 4X - Moisture & Corrosion Resistant Enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against corrosion, windblown dust and rain, splashing water, and hose- directed water; and to be undamaged by the formation of ice on the enclosure.

Type 7 - Explosion Resistant Enclosures are capable of withstanding the pressures resulting from an internal explosion of specified gas, and containing such an explosion sufficiently that an explosive gas-air mixture existing in the atmosphere surrounding the enclosure will not be ignited.
Type 12 - Resistant to Dirt & Dripping Non-Corrosive Liquids Enclosures are intended for indoor use primarily to provide a degree of protection against dust, falling dirt, and dripping non-corrosive liquids.