In this article, we will be sharing some of the best practices and experience of design engineers in the enclosure industry. These are the practical tips and knowledge about building electrical boxes that can fully withstand some of the environmental hazards. Eventually, the issue of whether to use NEMA or IP ratings will come up, however issues arise form this because there is a great confusion about how these things can work.
In this article, we will help companies in giving good direction for design engineers who are still on the process of handling this type of subject. To make things very simple, we are going to limit the discussion in using NEMA however, the principle will be just as same if you are going to use IP standards. Thus, making this article relevant to everyone.
Before starting on any projects, design engineers should be straightforward in pointing their goals and agendas. They should be blatantly clear about what they are really trying to achieve. Whether they are looking for environmental protection or if they are only trying to meet very formal and set guidelines just to achieve a NEMA standard.
There are thousands of custom enclosure being made day by day that has environmental resistance requirements. Most of these electrical boxes that are being made only need the environmental protection. There are customers that will use NEMA guidelines to explain why they need a certain type of protection (such as solid ingress or corrosion protection) but they don’t want to meet all of the NEMA standard.
There are times that we see customer who will try to meet the formal requirements of a NEMA standard. With this in mind, it only means that it needs the necessary testing for it to assess if the enclosure being made is within the NEMA standard. There are enclosure manufacturing companies that does not offer NEMA testing but the customers are in touch with some of the third-party testing facility for their enclosure. They need a formal certification that their enclosure has successfully met the necessary requirements. With this in mind, I have listed below the different classifications for NEMA electronics enclosure.
Guidelines in understanding NEMA Classification
NEMA has been set to promote a standardized quality of electronics enclosure specification for some of the electrical devices. Its primary role is to identify how the electrical box should effectively perform to meet the right classification of NEMA enclosure. In its most basic sense, NEMA enclosure deals with the following:
- Protecting personnel from unwanted contact with hazardous internal parts
- Protecting equipment housed in the enclosure against hazards that can be present in the environment
However, there is a certain limitation to this. NEMA does not advise how to effectively design and manufacture the electronics enclosure to meet its performance or quality specifications.
There are several NEMA ratings that covers a wide range of uses, protection, and qualities. However in this article we will only deal with the NEMA ratings that are usually used by customers.
NEMA Type 1 –Its primary purpose is to give equipment protection for indoor use and it gives protection for personnel to avoid unauthorized contact with live parts of the equipment. It also gives protection for equipment from solid ingress that can come from floating dust.
NEMA Type 2 –This NEMA enclosure type is used indoors and unlike the NEMA 1 electronics enclosure, it is dip-proof. It has an additional protection for possible water ingress that can occur from splashing or dripping water.
NEMA Type 4, 4X – Both of these ratings are used indoors and outdoors. These two types of enclosure has amazing properties. They are watertight, dust-tight, and it is sleet-resistant. It also offers the protection that both NEMA 1 & 2 offers. It has an additional protection for external ice formation and protection from hose-directed water. The NEMA 4X is a corrosion restant electrical box.
NEMA Type 5 –It offers the protection like the NEMA type 2 enclosure. However, it has additional gaskets that offers above standard ingress protection from settling dust, lint, fibers, and flyings. However, this type of enclosure is mostly used for indoor engineering applications and NEMA 5 enclosure is a dust-tight electrical box.
NEMA Type 6, 6P – This type of electrical box is both used for outdoor and indoor applications. The additional quality that it has it is submersible. NEMA Type 6, 6P offers the same protection as its counterparts (4, 4X) but this electrical enclosure can be submerged in water at limited depth. This is most commonly used in offshore marine applications.