In previous entries, we learned about IP protection ratings, which refer to the levels of protection against the ingress of particles or liquids into enclosures that typically house telecommunications, electrical, or electronic equipment. In this entry, we will learn about the NEMA classification system.
The National Electrical Manufacturers Association, or NEMA as it is known, is the association of American manufacturers of electrical equipment. The standards under which they manufacture their products are based on standards for the United States and Canada. From this comes the NEMA classification, which is more comprehensive than IP, as it even considers protection against corrosion.
There are currently 14 NEMA classifications:
NEMA 1:
Protection against dust, light, and indirect splashing. It is not dust-tight but prevents contact with live parts. It is used indoors and under normal atmospheric conditions.
NEMA 2:
Similar to NEMA 1, but with drip shields. Used in cases where condensation may be severe (such as in refrigeration rooms and laundries).
NEMA 3 and 3S:
Protects against weather hazards such as rain and sleet; used outdoors.
NEMA 3R:
Provides protection against rain and ice formation.
NEMA 4 and 4x:
Must exclude at least 65 GPM of water from 1 nozzle, emitted from a distance of not less than 10 feet.
NEMA 5:
Can withstand light splashing, but cannot be submerged.
NEMA 6 and 6P:
Submersible in water. In the case of 6P, it can be submerged for a longer period of time.
NEMA 7:
For indoor use in Class I Groups A, B, C, and D environments as defined in the National Electrical Code (NEC). They are built for hazardous locations, making them explosion-proof.
NEMA 8:
For indoor and outdoor use in locations classified as Class I Groups A, B, C, and D as defined in the NEC. They offer the same protection as NEMA 7, but can be used in hazardous locations both indoors and outdoors.
NEMA 9:
For indoor and outdoor use in locations classified as Class II Groups E, F, or G as defined in the NEC. Must be dust ignition proof.
NEMA 10:
Complies with the requirements of the Mine Safety and Health Administration, 30 CFR part 18 (1978).
NEMA 11:
Protects against the corrosive effects of liquids and gases. Complies with drip tests and corrosion resistance.
NEMA 12 and 12 K:
Designed for indoor use, provides some protection against dust, falling dirt, and dripping non-corrosive liquids.
NEMA 13:
Used primarily to provide protection against dust, water drips, oil, and non-corrosive coolants. Complies with rust and oil exclusion design tests.
To use the appropriate protection, we must know the environment where electrical or telecommunications installations will be performed. Below, we also show you some of the equivalences between IP and NEMA.
There are several options when choosing the conditions that cabinets, splice boxes, and other devices where we store connections must meet; always remember to check technical data sheets and manufacturer information. Don't forget to follow our blog where you will find interesting information and news.
