- The testing and certification of IP ratings can be a vital element of mechanical enclosure design.
- IP ratings are extremely important as they indicate environments in which casings and enclosures of electrical and electronic products are safe to use.
- After reading this guide, the next time you’ll see an IP rating, you will understand the limitations of a product at a glance.
- As usual, when explained, IP ratings are extremely easy to understand but respecting these warning signals is a different matter.
Any mechanical design engineer who designs enclosures MUST have a firm grasp of IP ratings. IP stands for “Ingress Protection” and is a standard protection marking for casings and enclosures of electrical and electronic products. It helps to classify them according to their degree of protection against solids and liquids. The standard IP ratings were originally developed by the International Electrotechnical Commission (IEC) and its corresponding code is IEC 60529, while the equivalent European standard is the EN 60529. Simply put, the IP rating indicates the level of dustproofing and waterproofing achieved by a casing/enclosure design, so that the users of a product are aware of the limits of a device/component – and its intended operational scope and conditions.
Decoding IP Ratings
The IP rating consists of two digits, with the first one indicating the ingress protection against solid particles and the second one against liquids. The digits range from zero to six and zero to nine respectively, corresponding to nine different levels of protection from none to ultimate, so the higher the number the better the protectio
The 1st digit: Solids
|The casing doesn’t offer any kind of protection against contacting other objects – no test required
|Protected against objects that are larger than 50 mm (e.g. a hand)
|Protected against bigger than 12.5 mm (e.g. fingers)
|This covers objects larger than 2.5 mm, e.g. tools and wires
|If you are looking for a casing that will keep out wires, screws, screwdrivers, and most insects, then a first IP digit of 4 is the safest choice
|Reflects adequate protection against dust particles under normal atmospheric air pressure conditions, and complete protection against dust even under vacuum pressure conditions respectively
|Generally preferred for products that are never meant to be opened for service/maintenance and cleaning
The 2nd digit: Liquids
Liquids are much harder to keep out of a casing/enclosure, so the classification categories are eleven, starting from zero (no protection) and ending on “9k” (maximum protection). These digits are shown second in the IP rating and are defined as follows:
|No protection – no test required
|Protection against water drops with enclosure in a single orientation
|Protection against water drops with the enclosure in 4 different orientations
|Protection against water spray
|Protection against water spray
|Protection against water jets
6 / 6K
|Protection against particularly powerful water jets
|Protection against water while submerged at a depth of one meter
|Protection against water up to a depth of 3 meters
|Protected against close-range high pressure, high temperature spray downs.
Putting both digits together to form a complete IP rating
For example, when a device has an IP 54 rating, this means that the enclosure is adequately protected against dust and water splashes. Another example could be an IP 68 rating which means that the casing offers ultimate protection against dust and can be safely submerged in water at a maximum depth of up to three meters without risking a short-circuit inducing penetration of liquid.
Keep in mind that the two digits are independent but still logically related since you can’t have ratings such as “IP 47” which would mean that the casing is suitable for immersing in liquids at a depth of one meter, but has no protection against solid particles smaller than 2.5 mm. This would mean that the particular IP rating is a false claim.
Testing and Certification of IP Ratings
For products to be officially released with an IP rating they need to be tested by certified laboratories which perform the tests in accordance with the IEC 60529 standard. Testing the sealing of the enclosure against solids is done by the use of spheres of specific diameters (50, 12.5, and 2.5 mm) and checking whether the spheres can reach the critical parts of the electrical/electronic device. For the dust tests, if a device succeeds in the “5” classification, researchers proceed to apply a vacuum in the casing for eight hours so as to determine whether it is fully dust-tight or not.
The waterproofing tests are performed by setting specific water volumes, water dropping rates, water pressure and test duration. For example, the spraying water for the classification “3” is performed for a duration of 10 minutes, during which water at a pressure range of 50-150 kPa is dropping from a spraying nozzle at a rate of 0.07 litres/minute per nozzle hole. The immersion test of “7” dictates that the specimen must be submerged to a depth of one meter for 30 minutes. Finally, the ultimate test of “9K” must be performed by jetting 80 degree Celsius water in all of the casings angles at a pressure range of 80-100 bars, at a maximum distance of 15 cm.
What is IP69K protection?
The IP69K rating provides protection against ingress of dust and high temperature, high pressure water – making products with this certification ideal for use in conditions where equipment must be carefully sanitized.
In industries such as food processing, where hygiene and cleanliness is paramount, equipment must be able to withstand rigorous high pressure, high temperature wash-down procedures.
In many industries, where dust and dirt can be an issue, it is important to ensure that dust cannot penetrate the casing of a product and cause it to fail.
The IP69K rating is the highest protection available.
What are the advantages of IP69K?
In environments that require heavy washdown, such as in the food processing industry, the combination of water, chemicals, high pressures and temperatures can prove fatal for electronic circuits and instrumentation. The IP69K rating offers complete assurance that the piece of equipment that has undergone that tests is both durable and resistant and conforms to the highest protection rating on the scale.
How does a product achieve the IP69K rating?
Products bearing the IP69K rating undergo a challenging set of tests to ensure that they offer protection against penetration of high pressure, high temperature water and dust.
How is the water intrusion test performed?
The water intrusion tests themselves are done by placing the product on a turntable with a rotational speed of 5 ±1 revolutions per minute. The product is then sprayed at close range at a rate of approximately 4 gallons/16 liters per minute with water pressure of between 1160-1450 psi, at a temperature of 176°F/80°C.
The nozzle from which the water is sprayed is held between 4 and 6 inches from the product, at a variety of angles. Following this rigorous testing procedure, the product is deemed as having successfully achieved the rating if it completely resists water ingress.
High pressure, high temperature wash downIP69K test conditions
- Pressure : 80 – 120 bars
- Distance : 10 ~ 15 cm
- Temperature : 80 °C ± 5 °C (176 °F ± 41 °F)
- Flow : 14 – 16 l/mn
- Duration : 30 seconds per position
What is the IK impact resistance rating?
Degrees of protection provided by enclosures for electrical equipment against external mechanical impacts in accordance with IEC 62262:2002 and IEC 60068-2-75:1997.
This rating can be decisive in a product selection. It doesn’t rate the mechanical life but the capacity of a product to face environmental aggressions.
Therefore it is a key feature for any product intended for consumer goods.
The IK impact resistance is rated through a specific test carried out with a “Charpy pendulum” impact tester.
This device measures the resistance of a product submitted to 3 repeated identical impacts.
The impact energy (in joules) depends on 2 elements:
- The distance between the hammer and the tested sample
- The hammer weight
According to the resistance level rated during the test, an IK code is assigned to the product. This code ranging from IK0 to IK10, determines the energy level the product can absorb.
Table of correspondences
|Protected against 0.14 joules impact.
Equivalent to impact of 0.25kg mass dropped from 56mm above impacted surface.
|Protected against 0.2 joules impact.
Equivalent to impact of 0.25kg mass dropped from 80mm above impacted surface.
|Protected against 0.35 joules impact.
Equivalent to impact of 0.25kg mass dropped from 140mm above impacted surface.
|Protected against 0.5 joules impact.
Equivalent to impact of 0.25kg mass dropped from 200mm above impacted surface.
|Protected against 0.7 joules impact.
Equivalent to impact of 0.25kg mass dropped from 280mm above impacted surface.
|Protected against 1 joules impact.
Equivalent to impact of 0.25kg mass dropped from 400mm above impacted surface.
|Protected against 2 joules impact.
Equivalent to impact of 0.5kg mass dropped from 400mm above impacted surface.
|Protected against 5 joules impact.
Equivalent to impact of 1.7kg mass dropped from 300mm above impacted surface.
|Protected against 10 joules impact.
Equivalent to impact of 5kg mass dropped from 200mm above impacted surface.
|Protected against 20 joules impact.
Equivalent to impact of 5kg mass dropped from 400mm above impacted surface.
Langir’s integrated test laboratory carries out IK impact resistance tests in accordance with the specifications of the EN62262 standard.