IP Ratings

An IP (Ingress Protection) rating tells you how well an enclosure keeps solid objects and liquids out, defined by IEC 60529 and used across electrical, electronic, and mechanical equipment worldwide. The rating is written as "IP" followed by two digits — for example, IP65 — where the first digit rates protection against solid objects (including dust) and the second rates protection against water. A dash in place of a digit (such as IPX4) means that aspect hasn't been tested or rated, not that there's no protection at all.

Getting the rating right matters beyond just picking a bigger number: a higher second digit doesn't always imply protection at the lower levels beneath it (the water jet test for IPX6, for instance, doesn't guarantee the enclosure would also pass full immersion under IPX7), so it's worth checking the actual test description for the rating you need rather than assuming higher is a strict superset of lower.

Charts and Tables explaining the IP Rating Sytem ,Code Breakdown, Solid Particle Protection, Liquid Ingress Protection, Additional Letters Coding, Mechanical Impact Resistance, IPX Coding, IP69K Coding and NEMA Coding.

IP RATING SYSTEM

EN 60529 outlines an international classification system for the sealing effectiveness of enclosures of electrical equipment against the intrusion into the equipment of foreign bodies (i.e. tools, dust, fingers)and moisture.

This classification system utilizes the letters "IP" ("Ingress Protection") followed by two or three digits. (A third digit is sometimes used.

An "x" is used for one of the digits if there is only one class of protection; i.e. IPX4 which addresses moisture resistance only.)

CODE BREAKDOWN

SOLID PARTICLE PROTECTION

The first digit of the IP code indicates the degree that persons are protected against contact with moving parts (other than smooth rotating shafts, etc.) and the degree that equipment is protected against solid foreign bodies intruding into an enclosure.

LIQUID INGRESS PROTECTION

The second digit indicates the degree of protection of the equipment inside the enclosure against the harmful entry of various forms of moisture (e.g. dripping, spraying, submersion, etc.)

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:

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.

IPX CODING

The letter X is used in any place in the code where specifying a digit is meant to be avoided (or indicates irrelevance based on the common application).

There may be various reasons for choosing this coding variant, such as marketing considerations. Thus, e.g. an IPX7 rating for a consumer device specifies that the device has water protection up to limited immersion, but gives deliberately no information as to whether the device has any protection against mechanical ingress or dust.

In the case of an IPX7 rating, however, a considerable level of protection against the ingress of solids can be assumed,as where a liquid ingress protection rating equals 7, the rating of protection against solids is rarely below 6, e.g. IP67.

Among other common IP ratings using the letter X are IPX4.

IP2X is frequently used on electrical items to specify the item must prevent finger access to live terminals i.e. plug sockets are IP2X.

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.

Such enclosures must not only be dust-tight (IP6X), but it must also able to withstand high-pressure and steam cleaning.

The test specifies a spray nozzle that is fed with 80°C water at 8-10 MPa (80-100 bar) and a flow rate of 14-16 L/min.

The nozzle is held 10-15cm from the tested device at angles of 0°, 30°, 60° and 90° for 30 seconds each. The test device sits on a turntable that rotates once every 12seconds (5rpm).

The IP69K test specification was initially developed for road vehicles, especially those that need regular intensive cleaning (dump trucks, cement mixers, etc.), but it also finds use in other areas (for example, food industry, and car wash centers).

The IP69K rating is the highest protection available.

NEMA RATING

North American enclosure rating systems are defined in NEMA 250, UL 50, UL 508, and CSA C22.2 No. 94.

RELATED PAGES

• Engineering Glossary — IP Rating
• Hardness Comparison

FREQUENTLY ASKED QUESTIONS

What's the difference between IP65 and IP67?

Both offer full protection against dust (the "6" first digit). IP65 protects against low-pressure water jets from any direction; IP67 instead protects against temporary full immersion in water up to 1 metre deep for up to 30 minutes. IP67 does not necessarily mean an enclosure will also withstand a direct pressure jet — that's covered separately by IPX9K.

What does the "X" mean, as in IPX4?

An X stands in for a digit that hasn't been tested or isn't being rated for that product, most often the solid particle digit when only water resistance has been assessed. It doesn't imply either protection or lack of it for the untested aspect.

Is a higher IP rating always better?

Not necessarily for your application — a higher rating usually means a more sealed enclosure, which can trap heat or add cost and weight. Choose the rating that matches your actual operating environment rather than simply the highest available.

Do IP ratings apply to impact resistance?

No — IP ratings only cover solid particle and liquid ingress. Mechanical impact resistance is rated separately under IK codes (e.g. IK08), which are a different scale entirely.