NEMA vs IP Rating: What’s the Difference Between These Two Rating Systems for Industrial Enclosures?

Let’s explore what sets these two enclosure protection ratings apart.

Although the focal point of any electrical device will be the design of the device itself, neglecting the enclosure can be a vital mistake.

That’s why, in this article, we’ll be covering some of the the basic yet important considerations when it comes to choosing the right enclosure for your electrical devices.

What are the two enclosure protection ratings?

Your industrial enclosure will have two rating systems which represent just how protected electrical devices are from solids and liquids entering an enclosure. They are the National Electronic Manufacturers Association (NEMA) ratings and Ingress Protection (IP) ratings.

An IP rating considers protection against ingress of solid foreign objects and ingress of water. NEMA ratings, on the other hand, consider these in addition to other specifics such as corrosion and construction details. Therefore, they are not equivalent.

Let’s go in-depth about the NEMA rating systems and the benefits of each below:

With the NEMA system, are severable variables that will be used to explain enclosures:

  • X = corrosion resistance
  • R = safety from windblown particles
  • S = usable with ice coverage
  • K = made with knockouts (partially punched openings that can be easily removed to accommodate cables, connectors, and/or conduits).

NEMA 1: Made for indoor use. Enclosure provides protection from human contact with live electrical components. They also protect the equipment from debris in the air, such as dirt and dust.

NEMA 2: Same benefits as a NEMA 1 enclosure, but also provides additional protection from light dripping or splashing of water (drip-proof).

NEMA 3R and 3RX: Made for indoor and outdoor use, provides protection from dirt, rain, sleet, and snow. These also built to prevent ice from forming on the enclosure.

NEMA 3 and 3X: Protection from rain, sleet, and dust. Made for indoor and outdoor use. They provide added protection against dust beyond the NEMA 3R or 3RX enclosures.

NEMA 3S and NEMA 3SX: Similar protection as NEMA 3, with the benefit of added protection from ice.

NEMA 4 and NEMA 4X: Made for indoor and outdoor use. These enclosures provide the same protections as a NEMA 3 enclosure, with protection against water intrusion or hose-directed water.

NEMA 5: Made for indoors, protects against falling dirt, airborne dust, and dripping, non-corrosive liquids including water.

NEMA 6 and NEMA 6P: Same protection as a NEMA 4 enclosure but are also able to protect internal electrical components in water submersion up to a certain depth.

NEMA 7: Made for indoor use in hazardous locations. Explosion-proof enclosures.

NEMA 8: Has the same protection as NEMA 7 enclosures, but can be used in both outdoor and indoor locations.

NEMA 9: Made for indoor use with dust ignition-proof.

NEMA 10: Made to meet MSHA (Mine Safety and Health Administration) standards.

NEMA 12 and NEMA 12K: Made for general-purpose indoor use. These protect against dripping and splashing water, are rust resistant, and may include knockouts.

NEMA 13: Has the same protection as NEMA 12 enclosures, but with protection against dripping and/or sprayed coolants and oils.

Now, let’s explore the specifics of the IP rating systems:

First digit: Solids (Protection that the enclosure provides against access to hazardous parts and the ingress of solid foreign objects)

Level Object Size Protected Against

Not protected


> 50 mm (ex. Back of the hand)


> 12.5 mm (ex. fingers)


> 2.5 mm (ex. Thick wires)


> 1 mm (ex. Most wires)


Dust protected (not completely sealed)


Dust-tight (completely sealed)


Level Object Size Protected Against

Not protected


Dripping water


Dripping water when enclosure is at a 15° angle


Spraying water


Splashing water


Water jets


Dust-tight (completely sealed)


Immersion up to 1m


Second digit: Liquids (Protection of the equipment inside the enclosure against harmful ingress of water)


It’s important to keep in mind these other major considerations when choosing an enclosure, as well:


▪ Stainless Steel: A variation of equipment enclosures metal, stainless steel can be a costly option, but it comes with high durability and is corrosive-resistant.

▪ Extruded Aluminum: Does not rust and is lighter than steel. Average price point.

▪ Fiberglass: Offers sound resistance to chemicals and resistance but can produce toxic fumes and scratches relatively easily. Ideal temperature range is from -31-300°F.

▪ PVC (polyvinyl chloride) Plastic: Functions only under temperatures below 140°F. Numerous benefits including high durability, high resistance, good insulation and is fire-safe.

▪ ABS Plastic: The shiny outer coating of these enclosures is resistant to concentrated acid and alkali substances as well as mineral oils. However, ABS Plastic is flammable at high temperatures and degradable with acetone.

▪ Polycarbonate Plastic: Works within -31-180°F and offers sound UV stability. Degrades under exposure to alkalis but is resistance to acid.

▪ Polyester Plastic: Works within a wide temperature range of -40-248°F. Provides chemical and high impact resistance. Resistance is reduced however in cold weather and under direct sunlight.


▪ One of the most basic yet important considerations when choosing an enclosure is sizing.

▪ Purchasers need to consider the minimum dimensions of the enclosure needed to house all components and check this against their physical size restrictions. Is the space tall and thin or open and wide? Will the enclosure fit?


▪ In most cases, crafting customized enclosures to your space and needs will increase costs.

▪ Using standard or modified enclosures allows manufactures to use their own hardware, procedures and approvals to meet your needs at a much cheaper price point.

▪ Prospective buyers need to do their research to see exactly what enclosure they need without over-specification

Need expert help finding the right enclosure for your electrical device?

Our team experts at T&T Power Group are the ones to trust! Let us help you navigate these classifications and find your desired enclosure, so you can feel confident in your selection.

Contact our expert team today to get started.



Posted by Clayton Taylor | Aug 18, 2021 | Categories: Power Distribution