Published on: September 15, 2021 by Blair Haas
We are often asked how to choose the best electronic enclosure for an application given that there are so many options. This is especially true given that many engineers have not spent much time on the intricacies of electronic enclosures with most of their focus on technology of the internal components to complete their project. While it may seem simple just to pick out a box, the many options can create anxiety for even the most experienced specifier.
FIRST CRITERIA: WHAT SIZE ELECTRONIC ENCLOSURE IS NEEDED TO HOUSE YOUR COMPONENTS
This may seem a bit basic but in reality, the nature of the electronic enclosure industry makes it a bit daunting. The only standards in enclosure sizes deals with 19” rack mounting equipment and the racks they are mounted into where the “u”, or space between holes of the mounting rails, has been standardized for over 90 years. In typical smaller enclosures, each manufacturer has their own standard sizes which can vary by as little as a fraction of an inch or just a millimeter or two. This makes switching between manufacturer products almost impossible.
On the flip side, Bud Industries offers a very easy to use “size selector” tool which provides a listing of all of the electronic enclosures that meet the specified dimensions. Bud’s tool gives a range which makes it even easier to use so it will include products that might have a dimension of 4.25” when a dimension of up to 4 is input.
SECOND CRITERIA: WHAT MATERIALS MAKE FOR THE BEST ELECTRONIC ENCLOSURE SELECTION FOR YOUR APPICATION
There are many considerations to make the proper material choice. These can include weight (plastic is much lighter than steel, for example), durability, ability to withstand water or other elements, flammability and even impact resistance. Steel is often chosen because it is incredibly strong and durable and the dimensions can usually be modified with limited tooling costs. It is also very heavy limiting its effectiveness for pole or wall mounted applications. It has the challenges of rust if not properly coated unless stainless steel is chosen which is very expensive. Aluminum is lighter weight but more expensive and more flexible. Die cast aluminum is lower priced but visually less appealing and it can have dimensional variability due to shrinkage and draft angles. In plastics, polycarbonate is the dominant material along with ABS. ABS is less expensive but is less flexible and durable than polycarbonate. Plastics and die cast have very expensive tooling that makes any size modifications very expensive. The key issue for consideration is the location and application which helps assist in the proper selection
THIRD CRITERIA: IS YOUR ENCLOSURE BEING USED IN A “HAZARDOUS” ENVIRONMENT OR ARE THERE SPECIAL PROTECTIONS REQUIRED
Electronics is no longer just being used in environmentally controlled situations but with the huge increase in IoT and industrial automation applications, there are many ratings to consider. These range from the various NEMA and IP ratings which provide testing to certify that the enclosure can withstand conditions including sprayed water, snow, or submersion. Other requirements might include flammability ratings on plastics, EMI/RFI protection, and UV protection. Bud has a great guide on selection a NEMA Rated Enclosure for easy download
FOURTH CRITERIA: DOES THE ELECTRONIC ENCLOSURE NEED SPECIFIC FEATURES OR ARE THERE ACCESSORIES THAT YOU REQUIRE.
A typical question for a small or mid-sized electronic enclosure is where is the product being used and does it require mounting provisions? Another question is does the product have availability of panels to allow easy mounting and installation of the components. Features can include clear lids to avoid the need to drill holes in the box for displays to mounting bosses for the boards. Another often sought after feature is a locking mechanism on hinged cover boxes to avoid improper entry.
FIFTH CRITERIA: HOW DO YOU GET SUPPORT FOR MODIFYING THE ENCLOSURE TO ASSIST IN COMPONENT ASSEMBLY
While Bud knows it has very attractive enclosures, very few people need an enclosure that just “sits on their desk” for decoration. The designer wants to install components that include input and output of power or data meaning the use of connectors and cables. Many manufacturers, including Bud, can provide cutouts or slots in the specific locations you need to make final installation and assembly go more rapidly. The manufacturer also knows the proper approaches to avoid cracking or otherwise damaging the product during the modification process. Other modifications can include special color finishes, the installation of pems, providing digital printing on the cover or body and even special packaging. Be sure you can get all of the support you need from your chosen electronic enclosure provider
LAST BUT NOT LEAST: HOW MUCH DOES THE BOX COST AND CAN I GET IT WHEN I NEED IT?
Features, ratings, and even material selection can all have pricing ramifications. Check with your supplier and/or local electronic enclosure distributor to determine how your budget can impact the options or allow you to add extra features. And, of course, given today’s supply chain challenges, there is nothing worse than finding out your chosen box has a lead time that exceeds your needs. Work with your supplier to suggest alternatives in that case and avoid disappointment.
Selecting an electronic enclosure really is not as challenging as it may appear. Don’t hesitate to reach out to the enclosure company’s sales team or that of your chosen distributor to be sure that you design in the perfect enclosure for your application.
