The IP Code (or Ingress Protection Rating,^[1] sometimes also interpreted as International Protection Rating^[2]) consists of the letters IP followed by two digits or one digit and one letter and an optional letter. As defined in international standard IEC 60529, IP Code classifies and rates the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in mechanical casings and with electrical enclosures.^[3]

The standard aims to provide users more detailed information than vague marketing terms such as waterproof. However, no edition of the standard is openly published for unlicensed readers.

The digits (characteristic numerals) indicate conformity with the conditions summarized in the tables below. Where there is no protection rating with regard to one of the criteria, the digit is replaced with the letter X.

For example, an electrical socket rated IP22 is protected against insertion of fingers and will not be damaged or become unsafe during a specified test in which it is exposed to vertically or nearly vertically dripping water. IP22 or 2X are typical minimum requirements for the design of electrical accessories for indoor use.

[edit] Code breakdown

[edit] Solid particle protection

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.

[edit] Liquid ingress protection

Protection of the equipment inside the enclosure against harmful ingress of water.^[4]

[edit] Additional letters

The standard defines additional letters that can be appended to classify only the level of protection against access to hazardous parts

 by persons:

Further letters can be appended to provide additional information related to the protection of the device:

[edit] Mechanical impact resistance

An additional number has sometimes been used to specify the resistance of equipment to mechanical impact.

This mechanical impact is identified by the energy needed to qualify a specified resistance level, which is

measured in joules (J). This has now been superseded by the separate IK number specified in EN 62262.

Although dropped from the 3rd edition of IEC 60529 onwards, and not present in the EN version, older enclosure

specifications will sometimes be seen with an optional third IP digit denoting impact resistance. Newer products

are likely to be given an IK rating instead. However there is not an exact correspondence of values between the

old and new standards.

[edit] IP69K

German standard DIN 40050-9 extends the IEC 60529 rating system described above with an IP69K

rating for high-pressure, high-temperature wash-down applications.^[5] Such enclosures must not only

be dust tight (IP6X), but also able to withstand high-pressure and steam cleaning.

The test specifies a spray nozzle that is fed with 80°C water at 8–10MPa (80–100bar) and a flow rate

of 14–16L/min. The nozzle is held 10–15 cm from the tested device at angles of 0°, 40°, 60° and 90° for

30s each. The test device sits on a turntable that rotates once every 12s (5rpm).

The IP69K test specification was initially developed for road vehicles, especially those that need regular

intensive cleaning (dump trucks, cement mixers, etc.), but also finds use in other areas (e.g., food industry, car wash centres).

[edit] NEMA rating

The United States National Electrical Manufacturers Association (NEMA) also publishes protection ratings

for enclosures similar to the IP rating system published by the International Electrotechnical Commission (IEC).

However, it also dictates other product features not addressed by IP codes, such as corrosion resistance,

gasket aging, and construction practices. Thus, while it is possible to map IP Codes to NEMA ratings that

satisfy or exceed the IP Code criteria, it is not possible to map NEMA ratings to IP codes, as the IP Code does

not mandate the additional requirements. The table above indicates the minimum NEMA rating that satisfies

a given IP code, but can only be used in that way, not to map IP to NEMA.^[6]

North American enclosure rating systems are defined in NEMA 250, UL 50, UL 508, and CSA C22.2 N°. 94.