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What Do Those NEMA Ratings Mean?

What Do Those NEMA Ratings Mean?

Posted by Theresa Hoffman on Mar 6th 2025

With all of the new manufacturers added to our line card, we decided to dig deeper into the world of NEMA ratings. No, it’s not a secret code from a sci-fi movie or a new dance move (though that would be cool). NEMA ratings are all about keeping your electrical goodies safe from the elements. Let’s go on an electrifying journey and dive into NEMA ratings.

What’s a NEMA Rating, Anyway?

National Electrical Manufacturers Association (NEMA), is a group of brilliant minds that decided back in the 1920’s that the electrical world needed some rules. NEMA is a handy guide to tell you how much protection an enclosure offers.

Think of them like a weather forecast for your electrical equipment. Will it survive a dusty warehouse? A splashy factory floor? A full-on outdoor monsoon? These numbers- like NEMA1, 4X, or 12- will tell you what type of protection it offers.


Decoding Popular NEMA Ratings:

Indoor Use

  • NEMA 1: It’s perfect for cozy indoor spots like offices or light-duty warehouses. NEMA 1 enclosures are a great fit for housing variable frequency drives (VFDs) in these chill zones
  • NEMA 2: Tackles falling dirt, incidental contact, and light water drips. Think of it as NEMA 1 with a tiny umbrella!
  • NEMA 5 : Ready for settling dust, light splashes, and accidental bumps, NEMA 5 is a solid indoor pick for slightly grittier spaces.
  • NEMA 12/12X: Handles circulating dust, falling dirt, light splashes, and even oil or coolant seepage. Pfannenbergs NEMA 12 filter fans from keep your gear cool and clean in these dusty, drippy indoor environments.

  • Outdoor Use

    • NEMA 3 : This rating protects from windblown dust, falling dirt, and light weather like rain or sleet. NEMA 3R soft starters (often similar to NEMA 3) are perfect for exterior setups that need a kickstart.
    • NEMA 4 : Watertight and dust-tight, NEMA 4 protects from hose-downs, splashes, and nasty weather like rain, snow, or sleet.
    • NEMA4X : Take NEMA 4, add corrosion resistance, and you’ve got NEMA 4X—ideal for salty air or harsh chemicals. NEMA 4X enclosures from Fibox are lightweight, tough, and ready to take on the toughest conditions.

    Why NEMA Ratings Matter

    So why are NEMA ratings important? Picking the right NEMA rating is like choosing the perfect outfit for the weather—except instead of staying dry, you’re keeping pricey equipment from frying. A dusty motor or a soaked circuit board? No thanks!

    Fun Fact: NEMA vs. IP – Not Quite the Same

    You might see enclosures with both NEMA and IP (Ingress Protection) ratings. Where NEMA ratings cover more ground, like corrosion and ice, IP focuses on water and dust. Most NEMA ratings meet or beat IP standards, but it doesn’t hurt to double-check.

    NEMA ratings sound technical, but they’re about keeping your equipment safe regardless of where it’s located. Whether it’s a dusty factory, splashy washdown area, or a rooftop, there is a NEMA rating that cover just about any harsh condition.

    Contact us for more help on choosing the right NEMA rated product for your application.