What is a NEMA 6 Rating?
Nema 6 is a rating scale that indicates the degree to which an enclosure can be safely used in wet locations. The NEMA 6 ratings have been established by the National Electrical Manufacturers Association and are widely used for environmental conditions such as rain, snow, sleet or sprinkler water spray. In general, equipment with a higher NEMA rating will perform better than equipment with a lower one.
Nema 6 ratings come into play when engineers need to determine what type of enclosure their system should use for outdoor, corrosive and wet installation purposes – it will help them choose wisely between enclosures like: metal conduit boxes (NEMA 3), panel boards (NEMAPB) and junction boxes (NEMA 4).
Below is the full list of different NEMA Enclosure types with their associated characteristics:
General-purpose. Protects against dust, light, and indirect splashing but is not dust-tight; primarily prevents contact with live parts; used indoors and under normal atmospheric conditions.
Drip-tight. Similar to Type 1 but with addition of drip shields; used where condensation may be severe (as in cooling and laundry rooms).
Weather-resistant. Protects against falling dirt and windblown dust, against weather hazards such as rain, sleet and snow, and is undamaged by the formation of ice. Used outdoors on ship docks, in construction work, and in tunnels and subways.
As 3, but omits protection against windblown dust.
As 3, but also operable when laden with ice.
3X, 3RX, 3SX
X indicates additional corrosion protection; commonly used near salt water.
4 and 4X
Watertight. Must exclude at least 65 GPM of water from a 1 in nozzle delivered from a distance not less than 10 ft for 5 min. Used outdoors on ship docks, in dairies, in wastewater treatment plants and breweries. X (as 4X) indicates additional corrosion resistance.
Dust-tight. Provided with gaskets or equivalent to exclude dust; used in steel mills and cement plants.
6 and 6P
Submersible. Design depends on specified conditions of pressure and time; submersible in water or oil; used in quarries, mines, and manholes. 6 is temporarily submersible, 6P withstands occasional and prolonged submersion.
Certified and labelled for use in areas with specific hazardous conditions: for indoor use in Class I, Groups A, B, C, and D environments as defined in NFPA standards such as the NEC.
Certified and labeled for use in areas with specific hazardous conditions: for indoor and outdoor use in locations classified as Class I, Groups A, B, C, and D as defined in NFPA standards such as the NFPA 70.
Certified and labelled for use in areas with specific hazardous conditions: for indoor and outdoor use in locations classified as Class II, Groups E, F, or G as defined in NFPA standards such as the NEC.
MSHA. Meets the requirements of the Mine Safety and Health Administration, 30 CFR Part 18 (1978).
General-purpose. Protects against the corrosive effects of liquids and gases. Meets drip and corrosion-resistance tests.
12 and 12K
General-purpose. Intended for indoor use, provides some protection against dust, falling dirt, and dripping non-corrosive liquids. Meets drip, dust, and rust resistance tests.
General-purpose. Primarily used to provide protection against dust, spraying of water and non-corrosive coolants. Meets oil exclusion and rust resistance design tests.
The NEMA 6 rating is the National Electrical Manufacturers Association’s standard for evaluating electrical enclosures. This level of protection means that an enclosure may withstand up to six hours of continual contact with water or steam at a temperature higher than 150 degrees Fahrenheit without sustaining any short circuits, fire, or damage to its contents.
Enclosures that provide protection for greater submersion and exposure to water are designated as NEMA 6P. These types of enclosures are designed for prolonged submersion.
For more information on how this standard applies in your industry and what you need to consider when choosing an enclosure speak to SLAYSON, the global leader in NEMA 6P electrical enclosures.
To review our full range of standard Off the Shelf NEMA 6P Enclosures click below