NEMA has provided a set of ratings for cabinets housing voltages less than 1000V AC. The basic classifications are outlined below,
Type 1: General purpose: indoors
Type 2: Dirt and water resistant: indoors
Type 3: Dust-tight, rain-tight and sleet(ice) resistant: outdoors
Type 3R- Rainproof and sleet(ice) resistant: outdoors
Type 3S- Rainproof and sleet(ice) resistant: outdoors
Type 4: Water-tight and dust-tight: indoors and outdoors
Type 4X: Water-tight and Dust-tight: indoors and outdoors
Type 5: Dust-tight and dirt resistant: indoors
Type 6: Waterproof: indoors and outdoors
Type 6P: Waterproof submersible: indoors and outdoors
Type 7: Hazardous locations: class I
Type 8: Hazardous locations: class I
Type 9: Hazardous locations: class II
Type 10: Hazardous locations: class II
Type 11: Gas-tight, water-tight, oiltight: indoors
Type 12: Dust-tight and drip-tight: indoors
Type 13: Oil-tight and dust-tight: indoors