The IP degrees of protection (ingress protection) are defined by the International Electrotechnical Commission in its IEC 60529 standard. These protection classes classify the degrees of protection of unprocessed housings of electrical devices with a rated voltage of maximum 72.5 kV. (IEC standard 60529 as well as DIN EN 60529; VDE 0470-1:2000-09)
The abbreviation IP is followed by two digits. The first digit stands for protection against the penetration of solid bodies. The second digit describes the degree of protection against the ingress of water. The numbers have specific descriptions, which you can find in the tables.
First Digit: Solids
The first digit indicates the level of protection that the enclosure provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects.
| Level | Object size protected against | Effective against |
|---|---|---|
| 0 | Not protected | No protection against contact and ingress of objects |
| 1 | >50mm | Any large surface of the body, such as the back of the hand, but no protection against deliberate contact with a body part. |
| 2 | >12.5mm | Fingers or similar objects. |
| 3 | >2.5mm | Tools, thick wires, etc. |
| 4 | >1mm | Most wires, screws, etc. |
| 5 | Dust Protected | Ingress of dust is not entirely prevented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment; complete protection against contact. |
| 6 | Dust Tight | No ingress of dust; complete protection against contact. |
Second Digit: Liquids
Protection of the equipment inside the enclosure against harmful ingress of water.
| Level | Object size protected against | Effective against |
|---|---|---|
| 0 | Not protected | – |
| 1 | Dripping water | Dripping water (vertically falling drops) shall have no harmfull effect. |
| 2 | Dripping water when tilted up to 15° | Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle up to 15° from its normal position. |
| 3 | Spraying water | Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect. |
| 4 | Splashing water | Water splashing against the enclosure from any direction shall have no harmful effect. |
| 5 | Water jets | Water projected by a nozzle (6.3mm) against enclosure from any direction shall have no harmful effects. |
| 6 | Powerful water jets | Water projected in powerful jets (12.5mm nozzle) against the enclosure from any direction shall have no harmful effects. |
| 7 | Immersion up to 1m | 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). |
| 8 | Immersion beyond 1m | The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer. Normally, this will mean that the equipment is hermetically sealed. However, with certain types of equipment, it can mean that water can enter but only in such a manner that it produces no harmful effects. |