Published on: February 9, 2022 by Blair Haas
Choosing an electronic enclosure is typically considered to be an easy task. Review the sizes of the components that are to be enclosed, find an enclosure that will fit them all, check on the aesthetics you would like for your finished product, and that will lead you to the right box. In the old days, when all electronics were stored in a safe and secure location such as an electrical closet, that might have given you the perfect choice.
Today, when electronics are everywhere and the electronics within the enclosure often needs to more be vigorously protected due to their location in a harsh environment that is just not enough. When evaluating the enclosure needs in a non-office environment, the decision becomes more complex and meaningful as the wrong choice can be fatal to the end product. In this blog, we will review 5 tips for selecting the best harsh environment enclosure and then we will follow that with the next blog which will provide 5 more.
Electronics now must be able to be used in any environment and the enclosure has to be able to provide complete protection. However, there is a difference between a factory floor and an irrigated field, on a pier or in an arena, or on an outdoor pole or under a stadium seat. The protection levels are typically rated by the NEMA or IP system (see an explanation here.) In simple terms, you need to know where the application is before you make your selection of protection level. You don’t need UV protection on a factory floor but you will need dust and potentially washdown protection there. The decision here can make a significant impact on pricing as well as product flexibility in terms of choice. The challenge is that under-protection can lead to damage of the electronics but over-protection can cause a project to become financially unviable.
Sometimes a designer “overprotects” the enclosure. Typically cost is closely related to the amount and level of protection required. When only one component, such as the circuit board, needs to be protected, it may be more efficient to protect that specific component with a smaller enclosure. This would typically be true when dust is a concern. Many components, such as cabling, are not significantly impacted by dust or floating dirt. A PCB is a very different story so a NEMA/IP rated enclosure used inside a more typical electronic enclosure could do the trick efficiently and cost-effectively. This is most often done when components are installed in a larger product such as a 19” cabinet rack.
An engineer will often select a box with special high-priced materials when they are not needed. UV protection keeps the material from degrading over time due to sun or heat exposure. Often the cost of shifting to a UV material can increase by as much as double. There are different types of high-quality lower-cost polycarbonate and ABS plastic materials that will work perfectly well in an indoor location or one that is protected from the sun, but that may still need protection due to wash down or dust.
One of the difficult truths of many electronic components from power supplies to LED’s is that they will generate heat during operations. This is especially problematic with a NEMA or IP rate enclosure because they are typically tightly sealed. Sometimes, cooling can be relatively simple. In some environments, adding louvered slots can solve the problem. In most cases, however, some sort of air vent must be used. A good air vent can also help equalize the pressure within the box to avoid condensation and moisture build up. Be sure to check with your manufacturer to insure that they offer vents or that their products are compatible with those you are selecting. In a related manner, it is even more difficult to provide air stabilization when the product is used in a wet or even underwater environment. Bud offers a series of great air and moisture vents.
While most people think of electronic components as small and rapidly decreasing in size, that is not always the case. Often designers work to put more electronics in the same size space but create weight issues. It is important to check to ensure that the selected enclosure can hold the weight that is needed. A heavy power supply can pull out of a small enclosure’s mounting bosses, especially if the enclosure is going to be on a mobile device.
This is part one of a two part blog. Please check back as we look at five more issues that need to be considered when choosing a harsh environment enclosure. But don’t wait to see that blog if you have any questions or immediate concerns as Bud and our distributor and rep networks are happy to assist you in any way.
