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Infographic on NEMA 4x Enclosure Rating is Best

Published on: July 14, 2020 by Blair Haas

Infographics were the hot communications approach a few years back but for some issues, such as describing what the NEMA 4x rating is all about, it is still the perfect vehicle for a quick reminder of what it means and how it is tested.  I recently was faced with this challenge when I was providing information for a distributor website and they were looking for additional content.  It hit me that an infographic would be the simile way to describe this rating and give the key facts required to give an understanding to the engineer.

NEMA 4x Protects the contents of the box from strong water spray and the box from corrosion

As I got my creative juices flowing, I realized that the best way to do this was to set up a few quick topics:  What 4x means, what the water test is, and what other tests are done, where the best applications might be, what industries are the biggest users and what it cannot do.  Let me dig into the first topic.  NEMA 4x is unique in that it not only resists a strong spray of water and keeps the internal components dry, but the box itself also will continue to look good with no corrosion.  Typically this means that the box is either made out of some form of plastic or is coated with a properly rated powder/liquid to resist water and corrosion.  Further, if it is an outdoor rated enclosure (note that 4x does not necessarily mean the box can be used outdoors), it must also be able to withstand snow and ice in addition to rain.

As an engineer, I would like to know what “strong spray” really means and so this infographic gives a brief overview of the test.  Note how specific it is with the water pressure, nozzle size and time required as well as the distance from which it is tested.  Then we provide information on the additional tests that allow it to move from NEMA 4 to NEMA 4X, which deals with corrosion resistance.


We thought it would be helpful to give some examples of the best applications for this type of enclosure as well as industries in which this rated enclosure is often used.  We felt that would clarify the value of this rating.  Finally, we need to confirm what NEMA 4x is not.  We often hear from engineers who need to know if the box is guaranteed to be submersible which it is not.   We listed a few other “nots”.


Our goal is always to make it easy to work with Bud and more important to be a valued source for our customers.  For all of your enclosure needs and for help with any questions, don’t hesitate to reach out to us.