International Protection Rating Explained
Get the Best Environmental Protection
The International Protection Rating (IP Code) classifies the degrees of protection provided against the intrusion of objects like dust, dirt, debris, and moisture—as well as protection from accidental operator contact. Milnec connectors are protected from environmental harm by a variety of measures, including cable bushings on backshells, grommets that individually seal wires and contacts, and O-rings on coupling rings. Through these rugged designs, Milnec connectors are rated to IP67. They are completely protected from dirt and debris and can be submerged in water up to 3.3 ft (1m) deep for a minimum of 30 minutes without damage.
In addition to Milnec connectors’ environmentally resisting design, we recommend using connector accessories for added protection in harsh environments. Gaskets, backshells, and mounting brackets with sealing screws will increase the level of protection provided by your interconnect solution.
IP Ratings Defined
Solids, first digit
The first digit of an IP rating indicates the level of protection that the enclosure or connector provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects.
| Level | Object Size Protection | Effective Against |
|---|---|---|
| 0 | — | No protection against contact and ingress of objects |
| 1 | >50 mm | Any large surface of the body, such as the back of the hand, but no protection against deliberate contact with a body part |
| 2 | >12.5 mm | Fingers or similar objects |
| 3 | <2.5 mm | Tools, thick wires, etc. |
| 4 | >1 mm | 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 |
Liquids, second digit
The second digit indicates the level protection of the parts inside the enclosure or connector against harmful ingress of water.
| Level | Protected Against | Testing For | Details |
|---|---|---|---|
| 0 | Not protected | — | — |
| 1 | Dripping water | Dripping water (vertically falling drops) shall have no harmful effect. | Water equivalent to 1 mm rainfall per minute |
| 2 | Dripping water when tilted up to 15° | Vertically dripping water shall have no harmful effect when the enclosure is titled at an angle up to 15° from its normal position. | Test duration: 10 minutes; water equivalent to 3 mm rainfall per minute |
| 3 | Spraying water | Water falling as spray at any angle up to 60° from the vertical shall have no harmful effect. | Test duration: 5 minutes; water volume: 10 litres per minute; pressure: 80-100 kN/m2 |
| 4 | Splaishing Water | Water splashing against the enclosure or connector from any direction shall have no harmful effect. | Test duration: 5 minutes; water volume: 10 litres per minute; Pressure: 80-100 kN/m2 |
| 5 | Water jets | Water projected by a nozzle (6.3 mm) against the enclosure or connector from any direction shall have no harmful effects. | Test duration: at leaset 3 minutes; water volume 12.5 litres per minute; pressure: 30 kN/m2 at a distance of 3 m |
| 6 | Powerful water jets | Water projected in powerful jets (12.5 mm nozzle) against the enclosure or connector from any direction shall have no harmful effects. | Test duration: at least 3 minutes; water volume 100 litres per minute; pressure: 100 kN/M2 at a distance of 3 m |
| 7 | Immersion up to 1 m (3.3 ft) | In gress of water in harmful quantity shall not be possible when the enclosure or connector 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 1 m |