The IP rating code is a two-digit (or optionally three-digit) designator to standardize the rating of protection level against intrusion of solids and liquids into mechanical and electrical enclosures. An enclosure can be a piece of equipment, an assembly unit, a cable or simply a connector.
The number designator was originally established by the International Electro-Technical Commission (IEC) and the “IP” letters stand for “International Protection” rating or “Ingress Protection” rating. The third digit in the designator is not part of the official IEC standard and is sometimes included (but more often omitted) to reference additional protections.
The IP designator references as follows:
- First Digit – Protection from solid objects or materials
- Second Digit – Protection from liquids and fluids (water)
- Third Digit – Protection against mechanical impacts
It’s allowable to use a “X” in place of one of the digits if there is only a single class of protection.
Solid objects and materials can be anything from large – body parts (e.g., limbs, hands, feet, fingers), to medium – tools, wires, plants, to small – dust. This doesn’t include a rating for microbe or biological. Those are covered under HEPA standards created by the Department of Energy (DOE).
The two numbers in the IP67 rating code rating refer to:
- 6 – ” Dust Protected “; Totally protected against dust ingress.; complete protection against contact
- 7- ” Immersion Protected “; Protected against short periods of immersion in water. 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). Test duration: 30 minutes; Immersion at depth of at least 1 m measured at bottom of device, and at least 15 cm measured at top of device
The complete listing for each of the three numbers in the IP designator are provided below.
In addition to the IEC standard, the United States National Electrical Manufacturers Association (NEMA) also publishes protection ratings for enclosures. The NEMA standard goes beyond the IP ratings by addressing additional product features such as construction practices, gasket and sealant aging and resistance to corrosion. In general, an IP rating can be considered as a sub-set to the NEMA rating.
In this case, the IP67 rating meets a minimum NEMA Enclosure rating of 6.
|IP #||First digit:||Second digit:|
|Ingress of solid objects||Ingress of liquids|
|0||No protection||No protection|
|1||Protected against solid objects over 50mm e.g. hands, large tools.||Protected against vertically falling drops of water or condensation.|
|2||Protected against solid objects over 12.5mm e.g. hands, large tools.||Protected against falling drops of water, if the case is disposed up to 15 from vertical.|
|3||Protected against solid objects over 2.5mm e.g. wire, small tools.||Protected against sprays of water from any direction, even if the case is disposed up to 60 from vertical.|
|4||Protected against solid objects over 1.0mm e.g. wires.||Protected against splash water from any direction.|
|5||Limited protection against dust ingress.(no harmful deposit)||Protected against low pressure water jets from any direction. Limited ingress permitted.|
|6||Totally protected against dust ingress.||Protected against high pressure water jets from any direction. Limited ingress permitted.|
|7||N/A||Protected against short periods of immersion in water.|
|8||N/A||Protected against long, durable periods of immersion in water|
|IP #||Third digit (optional):|
|Protection against mechanical impacts||Example:|
|1||Protects against impact of 0.225 joule||150 g weight falling from 15 cm height|
|2||Protected against impact of 0.375 joule||250 g weight falling from 15 cm height|
|3||Protected against impact of 0.500 joule||250 g weight falling from 20 cm height|
|4||Protected against impact of 2.0 joule||500 g weight falling from 40 cm height|
|5||Protected against impact of 6.0 joule||1.5 kg weight falling from 40 cm height|
|6||Protected against impact of 20.0 joule||5 kg weight falling from 40 cm height|
Some examples of IP67 rated consumer products and connectors can be found on Amazon:
(Photo Credit – Amphenol )