Why should I care about enclosure conditions?
When starting any project that involves an enclosure the first questions that get asked are about ratings on the enclosure. There are a couple of different rating systems (i.e. UL, IP, NEMA) that need to be taken into account depending on device deployment; however, the first one that is going to be discussed is the Ingress Protection (IP) rating system.
The IP rating system is critical to discuss when taking on a project because it covers the use cases for the product and the potential hazards it will face. The majority of the time IP ratings are used to discuss how an enclosure will handle water in a given situation; however, the IP rating system covers any objects that intrude into the enclosure (i.e. dust, sand, oil).
As the IP rating increases the cost of an enclosure typically does as well because more care has to be taken when choosing materials for the enclosure as well as the sealing of the enclosure.
If this is not discussed at the beginning of a project this shortcoming in a discussion can lead to costly enclosure changes, device critical failure, and costly tooling changes to accommodate.
A great example of this topic being overlooked was an LED light I ran across from a startup years ago in Seattle, WA that had not discussed IP ratings at any point even though their product was made for outdoor/indoor use. When the device was implemented in the field the startup discovered a high failure rate reported by the customer. The issue was two-fold: 1) the farmers were spraying oil onto the fixtures when spraying the fields and 2) moths were getting through the fans then expiring within the case. Both of these caused the device to overheat and fail to cause the entire enclosure to be redesigned for issue accommodation.
What do the numbers mean?
All IP ratings follow the same formatting within the standard and it is important to get acquainted with them because they will mean a lot not only to engineers but to the customers that will buy the product. The rating always starts with the two letters IP followed by a 2 digit number, which contains the meaning. Each individual number has a separate meaning apart from one another.
The first number represents solid object protection for the enclosure and the second number indicates the level of protection against liquid infiltration.
|#||First Digit – SOLIDS||Second Digit – LIQUIDS|
|IPXX||Protection unspecified (untested)||Protection unspecified (untested)|
|IP54||Protected from limited dust ingress||Protected from water spray from any direction|
|IP55||Protected from limited dust ingress||Protected from low-pressure water jets from any direction|
|IP56||Protected from limited dust ingress||Protected from high-pressure water jets from any direction|
|IP57||Protected from limited dust ingress||Protected from immersion between 15 centimeters and 1 meter in depth|
|IP58||Protected from limited dust ingress||Protected from long term immersion up to a specified pressure|
|IP60||Protected from total dust ingress||Not protected from liquids|
|IP61||Protected from total dust ingress||Protected from condensation|
|IP62||Protected from total dust ingress||Protected from water spray less than 15 degrees from vertical|
|IP63||Protected from total dust ingress||Protected from water spray less than 60 degrees from vertical|
|IP64||Protected from total dust ingress||Protected from water spray from any direction|
|IP65||Protected from total dust ingress||Protected from low-pressure water jets from any direction|
|IP66||Protected from total dust ingress||Protected from high-pressure water jets from any direction|
|IP67||Protected from total dust ingress||Protected from immersion between 15 centimeters and 1 meter in depth|
|IP68||Protected from total dust ingress||Protected from long term immersion up to a specified pressure|
|IP69K||Protected from total dust ingress||Protected from steam-jet cleaning|