Guide to NEMA 4 Enclosures

Get your handy guide so you know what to avoid and how to fully understand the NEMA enclosure ratings


Common NEMA Buying Mistakes

How hard can it be to specify the right enclosure? Of the many tasks required of design engineers, the selection of enclosure is typically considered simple. However, at Bud Industries we see smart engineers make common selection mistakes all the time. Often the cost of the enclosure is a significant share of the bill of materials, and getting it wrong leads to unnecessary cost. Sometimes poor choices introduce unnecessary delays. In the worse cases, the protection is inadequate, which compromises the success of the end product.

Terms like “waterproof,” “sealed,” “dust tight” and the like are used to describe electrical and electronic enclosures. Unfortunately, these terms are inherently ambiguous. Is the enclosure merely rain-proof or is it fully submersible? Is it sealed so that no air will transfer, or is it merely sealed against intrusion by objects?


BT Series NEMA 4 waterproof enclosure with water

We are sure you will love the Buying Guide, but if you want even more information, here are some additional
Tips on Selecting a NEMA 4 Enclosure with a handy video.


NEMA Ratings Decoded

To clarify this situation with a clear set of standards, The National Electrical Manufacturer’s Association developed NEMA ratings. The ratings make it easy to specify enclosures with the right level of protection; however they can also be confusing. For example, NEMA 4 offers more stringent protection than NEMA 12. Many times engineers specify the wrong level of protection, either overspending or risking equipment damage.

NEMA 4 (and its sister rating NEMA 4X) is one of the most commonly specified enclosure ratings. It meets the requirements of factory wash down and outdoor applications, and it protects electronics from airborne dust and dirt.

There is a lot more to be said about protection ratings, and which one is optimal for your application. For the full story, get our NEMA 4 Enclosure Rating Buyers Guide.

Get My NEMA 4 Enclosure Buyers Guide

This guide is a handy reference for experience engineers and those new to specifying enclosures. It includes definitions of all the common NEMA ratings, tips on selecting a NEMA 4 enclosure, strategies to minimize cost, and a cross reference to IP ratings.