NEMA ELECTRICAL CODES

The National Electrical Manufacturers Association, NEMA, publishes ratings, codes and definitions that help establish standards, safety protocols and user-friendly definitions and ratings for understanding and comprehension. 

NEMA Ratings Codes & Definitions

NEMA receptacles are found installed at different orientations. NEMA, the U.S. National Electrical Code, and the Canadian Electrical Code do not mandate an orientation, as such different orientations can be seen in the same building.  However, the orientation with the ground pin on the bottom is the most common, which places the neutral pin on the upper left and the hot pin on the upper right. All descriptions below assume this orientation.

NEMA 1

Intended for indoor use primarily to provide a degree of protection against (hand) contact with enclosed equipment.  Usually, a low cost enclosure but suitable for clean and dry environments.

NEMA 2

Intended for indoor use primarily to provide a degree of protection against limited amounts of falling dirt and water.

NEMA 3

Intended for outdoor use primarily to provide a degree of protection against windblown dust, rain, and sleet; undamaged by ice which forms on the enclosure.

NEMA 3R

Intended for outdoor use primarily to provide a degree of protection against falling rain and sleet; undamaged by ice which forms on the enclosure.

NEMA 4

Intended for outdoor use primarily to provide a degree of protection against windblown dust and rain, splashing water, and hose directed water; undamage by ice which forms on the enclosure.

NEMA 4X

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; undamaged by ice which forms on the enclosure.

NEMA 6

Intended for indoor or outdoors which occasional temporary submersion is encountered.

NEMA 6P

Intended for indoor or outdoors which occasional prolonged submersion is encountered. Corrosion protection.

NEMA 12

Intended for indoor use to provide a degree of protection against dust, falling dirt, and dripping noncorrosive liquids.

NEMA 13

Intended for indoor use primarily to provide a degree of protection dust, spraying of water, oil, and noncorrosive coolant.