Enclosures are housings created to hold, shield or mask electrical components. They are of great value to virtually every industry imaginable, most notably telecommunications, bus and rail service, electronics, sound and music, surveillance and security, domestic and commercial wiring, appliances, food and beverage, defense and aviation. From keeping outlets covered to housing the electrical wiring linking a nuclear reactor and a control room, enclosures are important on many levels. For trustworthy equipment and peace of mind, we recommend you consider purchasing NEMA enclosures.
Quick links to NEMA Enclosures Information
Design of NEMA Enclosures
NEMA enclosures are designed and guaranteed to meet the stringent standards put in place by their namesake, NEMA. NEMA, which stands for National Electrical Manufacturers Association, is an organization of both electrical equipment manufacturers and medical imaging equipment manufacturers that was founded in 1926. As a group, it seeks to bring manufacturers together under the umbrella of collective interests, expand market opportunities and reduce manufacturing costs and business barriers by streamlining industry standards. NEMA enclosure standards help manufacturers work better together and make enclosure installation and maintenance easier for end-users.
Materials Used for NEMA Enclosures
Typically, NEMA enclosures are made from polycarbonate, a thermoplastic with extreme temperature resistance and an impact strength five times that of fiberglass. Enclosures made from polycarbonate because polycarbonate is water resistant, heat resistant, flame retardant, impact resistant and highly insulative. Typically, these durable electrical enclosures are still able to function properly even in working conditions with low temperatures. This makes them the perfect candidate for both indoor and outdoor applications. However, though polycarbonate makes great enclosures, it is not the only material with which NEMA enclosures are made. Rather, NEMA enclosures may also be made from 316 stainless steel, 304 stainless steel, powder coated carbon steel or 5052 aluminum. They can be built using a number of common enclosure designs, including: free standing, free standing with leg kit, wall mount, floor mount, trough and junction box designs.
Types of NEMA Enclosures
NEMA enclosures are available for purchase in approximately twenty different grades. All enclosures, no matter their grade, are designed to shield humans against the possibility of electrical shock. However, each individual grade is designed to accommodate specific application requirements common to industrial electrical settings, all the while satisfying NEMA standards. Examples of these varietal features include: impact resistance, heat resistance, leak-proof/impermeable assembly, drip-tight construction, light protection, dust protection, protection from corrosive substances like acetylene and saltwater, and protection from environmental hazards like rain, snow, sleet. NEMA types are assigned the numbers one through six, along with 3R, 3S, 3X, 3RX, 3SX, 4X, 6P and 12K. Every letter represents a non-standard characteristic or a lack thereof. X, for example, indicates additional corrosion protection, and S informs us that the enclosure can work while laden with ice, while R means that an enclosure does not protect against windblown dust.
Each NEMA enclosure works well in a specific setting, such as in a brewery, a laundry room, a ship dock, a subway, a steel mill, a quarry, a construction zone, a mine, a wastewater treatment plant, a manhole, submerged in oil or under water. Also, some NEMA enclosures are suitable for hazardous environments, while others are not. Those suitable for hazardous environments are equipped to contain internal explosions, prevent combustion by immersing equipment in oil, and/or prevent the ignition of combustible dust. These enclosures are types 7, 8, 9 and 10. All other types (1, 2, 3, 3, 3R, 3S, 3X, 3XR, 3SX, 4, 4X, 5, 6, 6P, 12, 12K and 13) may only be used in non-hazardous environments. In addition, some NEMA enclosures may be suitable for both indoor and outdoor work, while others are confined to work indoor applications only. These distinctions are as follows: Suitable for both indoor and applications are NEMA enclosure types: 3, 3R, 3S, 3X, 3XR, 3SX, 4, 4X, 6, 6P and 8. NEMA enclosure types that may only be used for indoor applications include enclosure types: 1, 2, 5, 7, 9, 10, 12, 12K and 13. The process of selecting a NEMA enclosure is not quick or simple. However, the investment is highly rewarding; with a NEMA enclosure, you may rest assured that your staff and/or the public is safe from exposure to electrical wiring, that your electrical system is properly housed and protected and that you are meeting the strict requirements of NEMA. For that reason, and for the best and most advantageous results, we advise you to consult with a NEMA enclosure specialist. To find a specialist that will work with you to reach your goals, browse our directory.
NEMA Ratings for Electronic Enclosures Explained
In today’s modern society, humans cannot sustain a normal life balance without the use of electricity and electrical components. Electrical wires and components are enclosed cabinets, which are manufactured in compliance with governmental standards. These electrical enclosures ensure the faultless operation of electrical components, protect parts from their environment, and prevent complications that usually arise due to electromagnetic interference.
The National Electrical Manufacturers Association (NEMA) is an organization that has laid out standards regarding manufacturing of electronic enclosures and categorized different types of enclosures for different needs. However, a NEMA rating, given the different types and categories of electronic enclosures, sometimes causes confusion among electrical component buyers. Therefore, the following paragraphs describe several considerations you need to know about NEMA ratings.
- NEMA Organizational Objectives
- For helping manufacturers determine the proper function, safety, and compatibility of electrical and electronic components, NEMA issues technical papers, standards and guides. There is a common notion that NEMA is an agency that tests products and certifies products. However, the organization only defines standards, and a manufacturer can decide voluntarily to comply with those standards. Nonetheless, NEMA ratings are relevant in quality manufacturing and are followed and applied widely.
- How does NEMA Categorize Electronic Enclosures?
- NEMA standard industrial control and systems (ICS) primarily classify electrical enclosures based on the location of installation, whether the location is hazardous or non-hazardous. Furthermore, NEMA classifies electronic enclosures based on their ability to withstand damage due to corrosive compounds, liquid and dust, and their capability to guard against ingress.
The NEMA enclosure classification for non-hazardous locations includes eight major types and subtypes:
- Type 1 and Type 2 are similar and are meant for indoor use and provide protection against ingress and human contact. However, Type 2 is drip-proof.
- All subtypes of 3, 3R, 3 X, 3RX, 3S, and 3SX, are corrosion-resistant, provide protection from rain and snow, and can be installed indoors or outdoors. Among them, 3RX type is manufactured to be resistant against wind. And 3S and 3SX have external auxiliary equipment fitted to make them operable even when ice is present. Wherever “X” is added, it means the enclosure is corrosion resistant.
- Types 4, 4X are the same as Type 3 but also add protection in terms of splashing and hose-directed water resistance.
- Type 5 is manufactured for indoor use and is the same as Type 2, but includes gaskets which prevent ingress of lint, fibers, and dust.
- Type 6 and 6S have aspects similar to type 4, however, they provide protection against submersion. Type 6 can be submerged temporarily and still provide protection, whereas 6 S can sustain prolonged submerged until limited depth.
- Type 12 and 13 are almost the same. Types 12 are meant for indoors and provide protection against all indoor interferences, including dripping and splashing water. Type 13 also provides protection from oil and coolants.
NEMA enclosures for hazardous locations include Type 7 to 10.
- Type 7 is only indoor use and explosion proof, whereas type 8 can be installed outdoors.
- Type 9 provides protection against ignition and is used indoors.
- Type 10 can be made so robust that they can withstand nearly any environment.