The Complete Guide To Electrical Enclosure NEMA Ratings

/ / Electrical Enclosures

 

What is a NEMA Rating?

The National Electrical Manufacturer’s Association (NEMA) standardize product specifications while establishing performance criteria.

NEMA ratings explain what the enclosure’s intended use is for, from small pushbutton boxes to large, full-sized room enclosures.

They ensure consumers are buying the correct enclosure to keep electrical components safe based on the cabinet’s environment and type of equipment inside.

It is important for the enclosure air conditioner or heater has the same NEMA rating as the electrical enclosure. If the climate control system and the enclosure have different ratings it will not meet NEMA standards. This is important because your electrical equipment will not get the correct protection that it needs unless all equipment is specifically for the location and application.

What Do NEMA Ratings mean?

 

NEMA 1: For indoor use. They provide a degree of protection to the equipment inside of the enclosure against the ingress of solid foreign objects, primarily dirt. They also protect employees from accessing hazardous parts.

NEMA 2: For indoor use. They provide a degree of protection against limited amounts of dirt and light exposure to water, like dripping or splashing.

NEMA 3: For indoor or outdoor use. They provide a degree of protection against rain, sleet, wind-blown dust and damage from ice forming on the exterior of the enclosure.

NEMA 3R: For indoor or outdoor use. They provide a degree of protection from rain, sleet and damage from ice forming on the exterior of the enclosure. There is no mention of this in the standard, however, typically there is no gasketing on 3R enclosures.

NEMA 3S: For indoor or outdoor use. They provide a degree of protection against rain, sleet, wind-blown dust and they also provide for the operation of external mechanisms even when the enclosure is ice laden.

NEMA 3X, NEMA 3RX, NEMA 3SX: The addition of the “X” indicates corrosion protection.

NEMA 4: For indoor or outdoor use. They provide a degree of protection against rain, sleet, wind-blown dust, splashing/hose-directed water and damage from ice forming on the exterior of the enclosure.

NEMA 4X: Provides the same protection as NEMA 4 with the inclusion of corrosion protection.

NEMA 5: For indoor use. They provide a degree of protection against settling airborne dust, falling dirt, and dripping non-corrosive liquids, including water.

NEMA 6: For either indoor or outdoor use. They provide a degree of protection against hose-directed water and the ingress of water during occasional temporary submersion at a limited depth and damage from ice forming on the exterior of the enclosure.

NEMA 6P: For either indoor or outdoor use. They provide a degree of protection against hose-directed water and the ingress of water during prolonged submersion at a limited depth and damage from ice forming on the exterior of the enclosure.

** NEMA 7: For indoor use in Class I, Division 1, Groups A, B, C or D hazardous locations according to the National Electric Code (NFPA 70), this is also referred to as explosion proof.

** NEMA 8: For either indoor or outdoor use in Class I, Division 2, Groups A, B, C or D hazardous locations according to NFPA 70, this is also referred to as oil immersed.

**NEMA 9: For indoor use in Class II, Division 1, Groups E, F and G hazardous locations according to NFPA 70, this is also referred to as dust-ignition proof.

** NEMA 10: These enclosures are intended to meet the requirements of the Mine Safety and Health Administration (MSHA).

NEMA 12: Enclosures constructed without knockouts for indoor use. They provide a degree of protection against the ingress of falling dirt and circulating dust, lint, fibers and flyings, as well as, dripping non-corrosive liquids. Despite its large number, this enclosure provides basic levels of protection.

NEMA 12K: Same protections as NEMA 12 rating, but these enclosures are constructed with knockouts.

NEMA 13: For indoor use. They provide a degree of protection against dust, spraying water, oil and non-corrosive coolant.

NEMA Enclosure Ratings Chart

 

Still unsure of which enclosure and associated equipment will fit your needs?

Needs vary so much from application to application it is hard to determine what will work best.

But you’re in luck! The staff at ISC Sales is very knowledgeable, able to answer any of your questions and will ensure that you get the most efficient product for your business. Contact us today and get the equipment that’s perfect for you tomorrow.