Choosing the Right Enclosure for Your Application

Twenty or so years ago, specifying an enclosure involved ordering the correct-size gray box, installing the electronic equipment, and crossing your fingers that the box you ordered would work as intended. Today, you have plenty of options — different types of enclosures, materials, and National Electrical Manufacturers Association (NEMA) ratings. Knowing which enclosure will be the most durable, cost-effective, and reliable can be challenging, but there are some steps you can take to simplify the process.

The Importance of selecting a NEMA Enclosure cannot be overstated. NEMA ratings define the type of environment in which the enclosure can be used. Each NEMA rating was designed for a specific application and environment, helping manufacturers, engineers, and consumers make the right choices.

How to Choose a NEMA Enclosure in 5 Easy Steps

NEMA ratings are a big part of your decision, but the following steps can help you narrow down your choice.

Step 1: Consider Your Surroundings

Your choice of enclosure depends on where your sensitive electronics will be located. Consider whether you need an indoor enclosure or protection from the elements. If indoors, think about its exposure to heat and dust. If outdoors, look for factors like sun exposure, salt water, and other environmental elements. Whether you mount it on a pole or wall also makes a difference.

All of these elements can cause severe damage to an unsuitable enclosure, ultimately destroying the equipment inside. For example, salt spray is highly corrosive. It often causes stainless steel to rust, making a marine-grade 5052 aluminum enclosure more suitable.

NEMA has a nationally accepted ranking system for indoor and outdoor enclosures ranging from 1 to 13. The most common outdoor electrical, data, and security rankings are NEMA 3, 3S, 3X, 3R, 4, and 4X.

• NEMA 3: These enclosures are weather-resistant and protect against hazards such as rain and sleet. They are common in outdoor applications, including tunnels, subways, construction sites, and shipping docks. The 3X models offer corrosion resistance.
• NEMA 4: These watertight enclosures must exclude at least 65 gallons per minute (GPM) for 5 minutes, delivered at a distance of no less than 10 feet from a 1″ nozzle. They are ideal for outdoor applications, including shipping docks, breweries, and dairies. The 4X models also offer corrosion resistance.

Step 2: Consider Enclosure Construction

When installing our outdoor enclosure, how are you going to power what is inside? How many holes will you have to put into the enclosure, which can affect how weatherproof the box is? How hard is it to make those modifications to the material the enclosure is constructed of? Do the boxes come with predetermined punch-out areas, or will you use a special on-site modification tool? How heavy is the weatherproof enclosure before all those electronic devices are going to be added? These are just a few questions the specifier must answer before being able to bid on a project accurately.

Specifiers must also evaluate both the ambient temperature of the surrounding environment and determine how much heat the installed electronics will generate. When these two measurements are combined, the resulting temperatures can be deadly to even hardened electronics. Lightweight enclosures are typically preferred over heavy enclosures for ease of installation but keep in mind weight restrictions. Carefully calculate the weight of the items that will be stored in these boxes to ensure that the enclosure does not fail.

Step 3: Select NEMA Enclosure Materials

Selecting the best material for a NEMA enclosure depends on several factors. For outdoor enclosures, plastics are better insulators, but metals like aluminum dissipate heat best, keeping your equipment cooler. Metal enclosures will also allow heat to dissipate better than plastic and will be cooler overall. Installing enclosure accessories such as thermostats, case fans, and coolers will increase airflow and aid in keeping equipment from frying.

Gauge metals for electrical enclosures include 12-gauge steel, carbon steel, stainless steel, and marine-grade 5052 aluminum. The best gasket materials for an electrical enclosure include closed-cell sponge rubber, cellular urethane, polyethylene, polyurethane, and silicone.

Step 4: Size Your NEMA Enclosure

Knowing how to size an electrical enclosure is essential in your selection process. The electrical components inside the enclosure must be kept under a maximum temperature to perform safely. Reference the manufacturer specifications for these components to find the relevant operating temperatures. From there, you can choose from three general sizes:

• Small enclosures: These enclosures are ideal for setups with limited components. Sizes like 12″ x 12″ x 11″ or 12″ x 12″ x 6″ might be found in this category.
• Medium enclosures: Medium enclosures offer more space for complex systems. Sizes range from 16″ x 16″ x 6″ to 19″ x 19″ x 12″.
• Large enclosures: Large enclosures are essential for large projects, including industrial settings and outdoor installations. Sizes can range from 27″ x 22″ x 13″ to much higher. You can also order custom sizes to suit your unique specifications.

Step 5: Work Within Your Budget

Enclosures are available for almost any budget. Pricing depends on materials, customization, and weight. While fiberglass or polyester can provide cost-effective solutions, outdoor enclosures made of aluminum will perform better in harsh surroundings, such as direct heat, sunlight, and areas near the coast where salt is prevalent.

Find the Ideal NEMA Enclosure for Your Application With ArmorLogix

While there is no “one size fits all” solution, outdoor weatherproof enclosures constructed using 5052 Aluminum meet the major requirements — environmental hardiness and enclosure construction details. They are also cost-effective and reliable. With a combined experience of over 50 years in the integration industry, ArmorLogix is a proud provider of NEMA enclosures for use in various applications.

We offer a range of the highest-quality NEMA 3 and NEMA 4 enclosures for outdoor applications, including custom enclosure builds for your unique needs. Contact us to find the right enclosure for you today!