The term IP rating or ingress protection is used to define the level of protection provided by a casing or enclosure. The term is published by the International Electrotechnical Commission (IEC) and allows enclosure manufacturers to clearly label their product with a simple code that is easily identified and interpreted by the consumer when selecting a product.
It is important for the consumer to read and understand the meaning of IP ratings before making any decision regarding an enclosure product, terms such as water resistant, waterproof and dust proof should be considered with caution as they lack any real clarity and can be easily misinterpreted.
The ratings themselves are made using the prefix “IP” followed by two digits i.e. IP65, the first digit indicates the protection against solid objects for example tools and dust while the second digit indicates the protection against liquid ranging from drips to submersion. The below tables should easily explain IP ratings and help you determine the adequate level of protection you require.
First Digit – Defines the protection from solid objects including deliberate and accidental human contact.
| Description | |
| 0 | A zero indicates there is no protection at all against contact from solid objects. Sometimes this zero is replaced by an “X” which indicates there is no available data to offer an IP rating. |
| 1 | Offers protection from solid objects up to a size of 50mm. This can include accidental human contact with a body part such as a hand however does not include protection from deliberate contact. |
| 2 | Provides protection against objects larger 12.5mm including accidental contact from fingers and similar sized objects. |
| 3 | Protects against intrusion from tools and wires with a minimum diameter of 2.5mm. |
| 4 | Protected against intrusion from insects, fixing screws and wires with diameter larger than 1mm. |
| 5 | Protection against the intrusion of dust, limited ingress is permitted in quantities that will not affect the equipment’s operation. |
| 6 | Complete protection against the ingress of dust. |
Second Digit – The second digit of the code defines the protection against liquid including dripping water such as rainfall and prolonged submersion.
| Description | |
| 0 | No protection against the ingress of water, sometimes this zero is replaced by an “X” which indicates there is no available data to offer an IP rating . |
| 1 | Provides protection against vertically falling water droplets equivalent to 1mm rainfall per minute while test subject is rotated at 1 RPM. |
| 2 | Provides protection against vertically falling water droplets equivalent to 3mm rainfall per minute while the test subject is tilted 15 degrees from its usual operating position. |
| 3 | Protection against water falling as a spray up to an angle of 60 degrees ingress is permitted but with no harmful effects. |
| 4 | Test subject provides protection against water splashing in all directions, limited ingress is permitted but with no harmful effects. |
| 5 | Provides protection against low pressure jets in all directions, limited ingress is permitted but should have no harmful effects. |
| 6 | Protection against high pressure water jets in all directions, limited ingress is permitted but should have no harmful effects. |
| 7 | Protection against short periods of submersion at a depth of less than 1 metre. |
| 8 | Test subject is suitable for continuous submersion in water at a depth greater than 1 metre. The maximum submersion depth should be specified by the manufacture, ingress is permitted in some cases however it should not affect the patio of the product. |
| 9 | Protection against high pressure and high temperature spray downs. |
You should first consider the application environment when specifying your IP rating. Is your product going to be susceptible to accidental human contact? Rainwater? Flooding? Taking the time to evaluate and referring to an IP rating chart will ultimately help your choice. In an environment where there is a danger of human contact causing injury or damage to your product the minimum requirement should be IP2X. If the application is external and exposed to rainwater you should specify IPX5 or above to prevent ingress and damage to your electronics
In conclusion using IP ratings to describe a product remove the ambiguity from terms such as ‘waterproof’. For example, showing the consumer the code IP65 along with the information depicted in the IP table will allow you to determine that the IP rated enclosure in question is entirely dust proof and provides some but not complete protection against liquid.