Ingress Protection – IP Rating

Products are exposed to different environmental conditions. Depending on the application a device ma need no protection rating at all, or very high protection rating.

Functionality of a device, but even more important safety of operators and bystanders must be guaranteed. Ingress Protection “IP” ratings embrace both of these requirements.

The first relay (!) operated computers had probably an IP rating of IP00. Ingress protection was not in the mind of their creators. However, it should have been: the term “debugging” originates from the need to clean the first computers relays of bugs which somehow found their way into the relays. Bugs in the relays had devastating effects on the operation of these computers.

Standards that define IP ratings are:

BS EN 60529 Specification of Degrees of Protection Provided by Enclosures.

IEC 529 Specification of Degrees of Protection Provided by Enclosures.

Both standards offer a numerical code that classifies the degree of protection. The characters “IP” followed by two digits distinguish products that are IP rated. The first digit specifies the protection against solid objects, the second on against liquids.

IP Rating Table

Solids (first number)	Device Protection	Liquids (second number)	Device Protection
0	No Protection	0	No Protection
1	Protected against solid objects of 50mm or larger. Example: a human and could not reach into the device.	1	Protected against vertically falling drops of water like condensation or dripping water. Test duration 10 mins.
2	Protected against solid objects of 12mm or larger. Human fingers cannot reach into the device	2	Protected against direct sprays of water up to 15 deg from the normal position. Test duration 10 minutes.
3	Protected against solid objects over 2.5mm like tools or screws	3	Protected against direct sprays of water up to 60 deg from the vertical. Test duration 5 minutes.
4	Protected against solid objects over 1mm like small tools or loose wire ends.	4	Protected against water sprayed from all directions – limited ingress permitted. Test duration 5 minutes.
5	Protected against dust – limited ingress are permitted but no harmful deposits are allowed. Full protection against human contact	5	Protected against low pressure jets of water (6.3mm nozzle) from all directions. Limited ingress is permitted. Test duration 3 minutes.
6	Dust tight – totally protected against dust. Complete protection against any human contact.	6	Protected against strong jets of water (e.g. for use on ship decks) – limited ingress permitted. Test duration 3 minutes.
7	N/A	7	Protected against the effects of immersion at a depth of 1 m. Test duration 30 minutes
8	N/A	8	Protected against long periods of immersion under pressure (beyond 1m liquid depth) – depth specified by the manufacturer. Test duration: continuous.