Comparison chart

NEMA ratings Enclosure types

The question in terms of which electrical enclosures are suitable for your application, environment and give enough protection to your equipment, but not overwhelming and make you overpay for it? Words like “waterproof,” “weatherproof,” “water or rain resistance”, “corrosion resistance” and the like are used to describe the characteristic of electrical and electronic enclosures. Unfortunately, these terms are not clear enough and not clearly comparable to each other, inherently ambiguous indeed. Is the protection from rain, how much rain can it protect? how is it submerge in the water also how long, deep can the enclosure be submerged under the water?

The following charts provide a general comparison of the most common NEMA rated enclosures, defined by The National Electrical Manufacturer’s Association (NEMA). These ratings represent the standard to specify enclosures with the right level of protection from both liquid and solid objects for industrial applications per NEMA 250-2003. Most commercial and industrial facilities require enclosures that can protect electrical wiring & equipment from adverse weather conditions including heavy rain, snow, ice formation and from potentially harmful wash-down cleaning with alkaline solutions. The chart provides short descriptive definitions for each category that is helpful to engineers, designers, equipment installers and other interested individuals. For more detailed information, refer to nema.org (“Enclosures for Electrical Equipment (1000 Volts Maximum)”). Call Nemaco if you have any additional technical questions about electrical enclosures.

Outdoor Nonhazardous Locations

Protection Against the Following Conditions	3R	4	4X	6	6P
Access to hazardous parts	✔︎	✔︎	✔︎	✔︎	✔︎
Ingress of water (Rain, snow, and sleet **)	✔︎	✔︎	✔︎	✔︎	✔︎
Ingress of solid foreign objects (Windblown dust, lint, fibers, and flyings)	✔︎		✔︎	✔︎	✔︎
Ingress of water (Hosedown)			✔︎	✔︎	✔︎
Corrosive agents				✔︎	✔︎
Ingress of water (Occasional temporary submersion)					✔︎
Ingress of water (Occasional prolonged submersion)					✔︎

*Source credits to nema.org “Enclosure Types”

Indoor Nonhazardous Locations

Protection Against the Following Conditions	4	4X	6	6P	12	12k
Access to hazardous parts	✔︎	✔︎	✔︎	✔︎	✔︎	✔︎
Ingress of solid foreign objects (falling dirt)	✔︎	✔︎	✔︎	✔︎	✔︎	✔︎
Ingress of water (Dripping and light splashing)	✔︎	✔︎	✔︎	✔︎	✔︎	✔︎
Ingress of solid foreign objects (Circulating dust, lint, fibers, and flyings **)	✔︎	✔︎	✔︎	✔︎	✔︎	✔︎
Ingress of solid foreign objects (Settling airborne dust, lint, fibers, and flyings **)	✔︎	✔︎	✔︎	✔︎	✔︎	✔︎
Ingress of water (Hosedown and splashing water)	✔︎	✔︎	✔︎	✔︎
Oil and coolant seepage					✔︎	✔︎
Oil or coolant spraying and splashing
Corrosive agents		✔︎			✔︎
Ingress of water (Occasional temporary submersion)				✔︎	✔︎
Ingress of water (Occasional prolonged submersion)				✔︎