According to the National Electrical Manufacturers Association (NEMA), an electrical enclosure or electronic enclosure is a “cabinet or box that protects electrical or electronic equipment,” effectively preventing or reducing the risk of electrical shock. These enclosures are typically made from metals like stainless steel and aluminum, but rigid plastics can be used as well.

But other than that general definition, what are the practical uses of electronic enclosures, and what do you need to know about choosing, purchasing, and installing one?

Electronic Enclosures: A Detailed Definition

Electronic enclosures are generally designed to protect electrical equipment in a wide range of utility, industrial, and diverse building environments. Every enclosure is designated a rating depending on the specific environmental conditions they protect against, such as a hazardous or a non-hazardous environment. 

These enclosures are also capable of shielding equipment from radio frequency interference and electromagnetic interference. Examples of such equipment include:

• Circuit Breakers

• Control Panels

• Printed Circuit Boards (PCBs)

• Panelboards

• Switches

• Telephone Cabinets

• Contactors

• Pressurization Equipment

• Purging Equipment

• Distribution Boards

• Pressurization Systems

• Purging Systems

Electronic enclosures are often used and can be seen in electrical and telecommunication rooms, chemical and manufacturing plants, gas facilities, mining facilities, charging equipment for electric vehicles, oil facilities and similar utilities, and the like.

Furthermore, all electronic enclosures must be installed according to the guidelines and requirements set by the National Electronic Code® (NEC) and all applicable local regulations.

Common Electronic Enclosures

Given the speed at which technology is growing, innovative electronic enclosures are in high demand. Now, more than ever, it’s imperative that people understand how to choose the best enclosure for their situational and environmental needs. The right enclosure can not only save you billions of dollars in operating costs, but it can also potentially save lives.

(Yes, it’s that big a deal).

Ergo, the actual selection process is what most design engineers are challenged with. They must match the electronic enclosure’s unique manufacturing to the intended application and decide whether the two are a good fit.

Believe it or not, electronic enclosures are more than just metal boxes. There are actually different types, and their looks, performance, and function are all radically different.

Here are examples of the more common electronic enclosures.

NEMA Types

NEMA, as mentioned earlier, stands for the National Electrical Manufacturers Association. This organization defines the North American standards for electronic enclosures using NEMA ratings. These NEMA ratings represent, apparently, an electrical enclosure’s “ability to withstand specific environments and hazards.” These ratings make it that much easier for engineers to choose the best enclosure. Here are a few examples of NEMA-rated models:

NEMA 1

Electronic enclosures with a NEMA 1 rating offer minimal protection (compared to all other NEMA-rated enclosures). However, they still offer a decent degree of protection against dirt, dust, and accidental contact with electronic equipment. This makes them best for residential applications such as housing indoor electrical equipment (like variable-frequency drives and valuable electronics).

Benefits of NEMA 1 Electronic Enclosures:

• Cost-effective (if installed in non-hazardous environments)

• Prevent public access to dangerous electrical equipment

• Prevent theft of valuable electrical equipment

Drawbacks of NEMA 1 Electronic Enclosures:

• Offers minimal protection from moderate environmental conditions (i.e., moisture, water, heat, etc.)

• Offers minimal protection/safeguards against overheating (electronic equipment often generate a lot of heat, which leads to overheating)

• May require additional venting accessories to allow air to flow through enclosure and minimize risk of overheating

NEMA 3

NEMA 3 enclosures can be used for both indoor and outdoor applications. However, they’re most commonly utilized as outdoor electronic enclosures even though they have the lowest NEMA rating amongst outdoor enclosures. This is because they’re durable, cost-effective, and capable of providing ample protection against moderate environmental conditions.

Benefits of NEMA 3 Electronic Enclosures:

• Protects against falling dirt, rain, snow, sleet, and external ice formation

• Capable of functioning as outdoor electrical junction boxes

• Suitable for both commercial and industrial applications

• Suitable for both indoor and outdoor applications

Drawbacks of NEMA 3 Electronic Enclosures:

• Lowest rating for outdoor electronic enclosures

• Some NEMA 3 enclosures can warp in direct sunlight

• Ability to protect equipment in extreme heat is heavily dependent on the enclosure’s material

NEMA 4

NEMA 4 electronic enclosures are great for moderate to extreme weather conditions. Like NEMA 3 enclosures, NEMA 4 models are designed for both indoor and outdoor applications. But seeing as they’re both weatherproof and watertight, these enclosures are most efficient—and optimal—protecting electronic equipment in exposed outdoor conditions; think outdoor wiring, power systems, and mounted telecommunications equipment.

Benefits of NEMA 4 Electronic Enclosures:

• Weatherproof

• Watertight

• Offers a degree of protection against hose-directed water sources

• Gaskets on NEMA 4 are specifically designed to prevent water ingress

Drawbacks of NEMA 4 Electronic Enclosures:

• Only NEMA 4 enclosures made out of aluminum specifically offer a natural level of protection against EMI (electromagnetic) and RF (radio frequency) interference

• Not recommended for indoor use (not cost-effective or cost-efficient)

NEMA 4X

NEMA 4X enclosures offer the same degree of protection as NEMA 4 models. The biggest difference is the increased corrosion protection. NEMA 4X enclosures were undoubtedly designed for situations involving corrosive chemicals, intense moisture, and heavy water spray. 

Seeing as how corrosion is quite a common problem with respect to electrical appliances, it’s no surprise that NEMA 4X enclosures are in high demand.

Benefits of NEMA 4X Electronic Enclosures:

• Weatherproof and watertight

• Offers extra protection against corrosion

• NEMA 4X models with knockouts provide much-needed onsite flexibility

• Versatility improves use value and efficiency

Drawbacks of NEMA 4X Electronic Enclosures:

• Inefficient/overkill for indoor residential use

NEMA 6P

Electronic enclosures with a NEMA 6 rating are used for both indoor and outdoor applications that include temporary water submersion. NEMA 6P enclosures are pretty much the same, only they allow for prolonged water submersion. They also offer enhanced corrosion protection.

Arguably the most rugged waterproof models on the market, electronic enclosures with a NEMA 6P rating can withstand extreme environments and are therefore ideal for housing electrical equipment, instruments, and devices in underground mines or caves. 

They’re typically made of aluminum due to the material’s natural lightweight and corrosion-resistant characteristics. In fact, in marine settings, aluminum is almost always preferable to stainless steel due to the highly corrosive nature of salt spray.

Benefits of NEMA 6P Electronic Enclosure:

• For both indoor and outdoor use

• Corrosion-resistant

• Improved waterproof abilities

• Allows for prolonged water submersion

• Best for maritime transportation

Drawbacks of NEMA 6P Electronic Enclosure:

• Not as efficient in non-maritime or non-marine settings

• Not as efficient in non-corrosive settings

Material Types

For this section, we’ll differentiate enclosures based on their material. While stainless steel and aluminum may seem like the most common materials for electronic enclosures, other models - like multi-box steel and molded plastic - do exist.

Below, we list out the three common electronic enclosures according to their make and material: (1) rackmount, (2) extruded aluminum, and (3) die cast aluminum.

Rackmount Enclosures

Rackmount electronic enclosures are specifically designed for rack mounting in 19-inch racks, hence their name. Typically available in industry-standard rack units; a unit of height measure defined by 44.50 mm (or 1.75 inches).

Rackmount enclosures usually have front panels that are pre-drilled for easy mounting on industry-standard racks. They usually also have ventilation slots at the top and bottom. These are great for regulating the heat and air flow for the electronics being housed, effectively minimizing risk of overheating by keeping them cool.

Rackmount Enclosure Uses:

• Secure equipment

• Save storage

• Protect fragile rack-mounted equipment

• Live performance products

• Test-and-measure products

• Data centers

• Telecom centers

• Central equipment rooms

Extruded Aluminum Enclosures

Extruded aluminum electronic enclosures are so-called due to their two prominent aluminum extrusions (also known as side rails). They also feature front, rear, top, and bottom panels of the same material. These aluminum extrusions have internal slots that are perfectly sized for standard PCBs to slide and slot into without needing screws or other external elements.

What’s more, aluminum is incredibly lightweight, durable, and corrosion-resistant. So regardless of the NEMA rating, rest assured an aluminum enclosure offers some degree of ironclad protection against mild to moderate environmental conditions. And because aluminum itself is UV stable, extruded aluminum enclosures perform well even when left out in the sun.

Extruded Aluminum Enclosure Uses:

• Creating PCB enclosures

• Protecting PCBs and similar electronic devices

• Free standing for desktop applications

• Optional surface-mount kits

• Telecom centers

• Data centers

• Industrial settings

• Residential/at-home settings

Diecast Aluminum Enclosures

Unlike extruded aluminum enclosures, diecast aluminum electronic enclosures do not have any immediately visible extrusions or panels that could be used for slotting third-party electronics. Inside, these models are used for housing sensitive electronic assemblies in both indoor and outdoor settings. 

But just like extruded aluminum, diecast aluminum enclosures have all the benefits and features of aluminum as their material: durability, UV stability, anti-corrosion, and strength. These enclosures can also be made watertight and weatherproof, depending on their NEMA rating.

Diecast Aluminum Enclosure Uses:

• Transportation

• Manufacturing plants/centers

• Electrical environments

• Data centers

• Vehicle tracking

• Navigation controls

• Trucking

• Fuel efficiency tracking

When it comes to choosing electronic enclosures for your project, industry, or situation, there is no cookie-cutter answer to which one is the “best” pick. We would argue that the best model and rating for you highly depends on the environmental conditions and nature of the project. For instance, an diecast aluminum enclosure with a NEMA 6P rating would be considered overkill - and over-budget - for most residential use. However, for commercial maritime use, it would be just fine. 

If you’re still not sure which is the enclosure for you, feel free to browse our selection of electronic enclosures. You’ll find a wide range of different makes and models suited for various environments and situations.