Having a thorough understanding of the needed requirements for your engineering application use is very important, especially when it comes to enclosure ratings. Very specifically when you are trying to look at ways on how to gain an optimum life from the product whilst avoiding any safety problems. In this article, we will discuss on how you can understand how the NEMA and IP ratings functions and how it can contribute to arriving at a good decision regarding enclosure ratings. We will also be discussing the major differences between the two ratings. In addition to this, we will look at the viewpoint of how these ratings are being viewed when it comes to industrial enclosures and what they are usually equated to, good alternatives and how an engineers can choose the right one for their application.
NEMA Ratings Explained
This acronym stands for National Electrical Manufacturers Association. This is by far one of the largest trading associations existing in the United States that is related to qualities of electrical equipment and medical imaging companies. The NEMA rating standard is created, published, and implemented by a governing body that aims to give companies of how an enclosure should be able to protect their equipment from solid or water ingress, and harmful elements existing in harsh weather. This also includes protection for corrosive materials.
There is a complete list and detailed overview in their website. You can check it out for additional information.
A NEMA rating consists of a number and one possible letter combination. This determines the level of degree of protection an electrical box can give from ingress of foreign objects, water proliferation from hose directed water and other things.
With this in mind, let us have NEMA Type 1 or NEMA 1 as an example. This electronics enclosure refers to the protection being given that is very ideal for general indoor use. It has the lowest protection amongst all the NEMA ratings. The second one is NEMA type 9 or NEMA 9, which is a class ii indoor hazardous location explosion-proof enclosure to be used for E, F or G environments. For more detailed information, you can visit the NEMA website.
IP Ratings Explained
In addition to this, the International Electrotechnical Commission (IEC) is a non-profit, non-government entity that created IP ratings for companies to comply with international standards being used for electrical and electronic related manufacturing equipment. The organization is responsible for the Publication 60526 or IEC Publication 60529 Classification of Degrees of Protection, which is also referred to as the IP code. This ratings are being defined internationally in the standard EN 60529 and it describes how an enclosure box is gives protection from liquid or solid ingress that can occur from floating particles or hose-directed water.
The complete and comprehensive IEC 60529 standard can be found in their website. With this type of rating, the IP code is being given two set of digits to identify the level of protection it gives for solid or water ingress. The first number has direct relationship to the level of protection that the enclosure can give from solid intrusion. Whilst, the second digit refers to the level of protection an enclosure can give when it comes to water ingress. With this being said, for example, and enclosure box that has a rating of IP67 refers to an enclosure that has a dust tight sealing that can protect the equipment from water ingress because the enclosure can be immersed up to 1m of water depth.
Are these ratings waterproof?
There are times where the manufacturers of these enclosure will manufacture or announce that their products are weather proof or explosion proof without stating that is has a NEMA or an IP rating.
With this being said, these products is subject for further testing to see if they are within the set standards (such as Underwriters Laboratory (UL) standards.) But it does not mean that it has to conform to a specific IP or NEMA rating to be considered weather proof or explosion proof.
This testing is also applicable for any type of application that calls for a general testing to confirm if the electronics enclosure will be able to withstand the basic environmental harmful factors. Such as rain, ice formation, and possible corrosion formation because of the moisture in the air.
With this in mind, there is one company that features their weatherproof enclosures being manufactures. The weatherproof is a term used to describe a unit that was tested by the Underwriters Laboratory and it is proven to withstand the water exposure by performing series of test to confirm its quality. In this type of testing, the samples of the electronics enclosure are being sprayed by a hose-directed water in a certain flow rate. It also includes a specified distance required for the duration at the joints.
If a product is declared or tested as weatherproof or explosion-proof but it does not have specific NEMA or IP rating, make sure to request the right method of testing being implemented. You might also find out that the electronics enclosure will be able to fit the engineering application needs without the specific NEMA or IEC “IP” rating for it. This both can save the time and money for the company and also the user.
NEMA vs. IP
With this being said, the IEC enclosure classification designations of the IP rating is only applicable to the protection of solids and liquids. It does not give specific protection capabilities from the possible dangers in the environment such as explosions, condensation, or corrosive vapors like the NEMA do.
Also, with this being said, the NEMA rating tends to be used more often in the United States. With its counterpart such as IEC standard of IP, this rating cannot be easily converted form one type of rating to the another. A good example of this would be the usual conversion of length measurement from feet to meters.
In addition to this, using the example above, if you have a NEMA 4X electronics enclosure which has a dust tight protection for equipment needed to be protected from possible water or solid ingress. That would be enough for an IP66 electronics enclosure type which gives protection against power water jets and other possible solid ingress.
It is crucial to have a very thorough understanding of the needed requirements for your engineering application. The general use for these type of indoor applications will require for different set of requirements needed to protect your equipment rather than the number of unites installed outdoors especially in hazardous environments. A thorough understanding of the said requirements would entail the difference between these enclosure ratings will not be only cost efficient, but it will also avoid a premature product failure and other prospective safety concerns.