Published on: February 19, 2014 by Blair Haas
It is often confusing for an engineer to know what type of IP Rating they need to look for when they desire to have a “waterproof” enclosure. Much like with watches or other sensitive information, there is a big difference between waterproof, water-resistant, and other descriptive but not specific labels. To help out, there are several rating systems that have been developed and several testing agencies that verify the results. Among these, the two best known are NEMA and IP. This article will deal only with the IP system.
An IP Rating (Ingress Protection Rating) is the rating used to classify the different levels of sealing effectiveness provided by an electrical enclosure against foreign bodies such as objects, water, dirt, etc.
For enclosures, the typical waterproof IP ratings are IP67, IP66, and IP65 enclosures. The chart below gives the specifics of what these ratings mean and how they are measured.
|IP Rating||Protection||Description||Test Method|
|IP65 Enclosures||Able to protect against water jets||Water projected by a nozzle (6.3 mm) against enclosure from any direction shall have no harmful effects.||Test duration: at least 15 minutes|
|Water volume: 12.5 litres per minute|
|Pressure: 30 kPa at distance of 3 m|
|IP66 Enclosures||Able to protect against powerful water jets||Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects.||Test duration: at least 3 minutes|
|Water volume: 100 litres per minute|
|Pressure: 100 kPa at distance of 3 m|
|IP67 Enclosures||Able to protect against Immersion up to 1 m||Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion).||Test duration: 30 minutes|
|Immersion at depth of at least 1 m measured at bottom of device, and at least 15 cm measured at top of device|
IP ratings, or ingress protection, were developed by the IEC (International Electrotechnical Commission) and are most heavily used in Europe and Asia, with some adherents in North America as well. Since these are international standards, the testing is often certified by the TUV instead of UL, although both provide stringent testing. One area to note is that while these are developed to deal with harsh environments, they do not address UV protection standards (outdoor) and the engineer should look for or ask about the ability of the enclosure to include UV protection materials.
In a later Blog, I will discuss NEMA ratings and how they relate to the IP standard.