Industrial Enclosure Selection: Getting Familiar with Standards and Ratings
January 09, 2018
If you are preparing to extend your network into nontraditional environments, Chatsworth Products (CPI) recommends getting a basic understanding of the standards that define degrees of environmental protection. This will greatly help to simplify selection and ensure the enclosure style and size is suitable for your application.
The international standard for ingress protection (IP) ratings is International Electrotechnical Commission (IEC) standard 60529, Degrees of Protection Provided by Enclosures (IP Code). The IP code is stated as two numbers, ex. IP55. The first number identifies the degree of protection against hazardous parts and against solid foreign objects (dust penetration). The second number identifies the degree of protection against ingress of water (liquid penetration). A higher number indicates better protection. IP codes do not address corrosion protection. See Table 1 below for the definitions of IP codes.
In the United States, the National Electrical Manufacturers Association (NEMA) publishes NEMA Standard 250 Enclosures for Electrical Equipment (1,000 V Maximum), which identifies 16 types of enclosures for nonhazardous locations, each providing a different level of protection against dust and liquid penetration. Underwriters Laboratory (UL) has a similar system in UL 50 Enclosures for Electrical Equipment, Non-Environmental Considerations; UL 50E Enclosures for Electrical Equipment, Environmental Considerations; and UL 508A Standard for Industrial Control Panels. The difference between NEMA Type and UL Type is that manufacturers can self-certify NEMA Type enclosures, but UL Type enclosures are verified by UL through a series of design review and performance testing. See Table 2 and Table 3 below for the NEMA types of enclosures used in indoor and outdoor nonhazardous locations.
Selecting an enclosure with the wrong rating is one of the most common errors when specifying a NEMA enclosure. For more information on how to size and select the most appropriate industrial enclosure for your needs, download our selection guide, “Extending the Network into Nontraditional Spaces: An Enclosure Selection Guide for IT Systems Administrators That Support IoT”.