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Understanding IEC 60529 IP Coding

05 Oct 2018 | Posted by Sharon Kendal

Simon Winfield, director of MacLellan Rubber, explains how to understand the International Protection Rating Codes and shares extracts from the IEC Standard.

Electrical Enclosures IEC 60529

For electrical enclosures, IEC 60529 classifies the degrees of protection provided against the intrusion of solid objects (including things like body parts such as hands and fingers), dust accidental contact and water in electrical enclosures. It provides detailed definitions on the levels of protection rather than vague terms such as water-tight, dust resistant or impermeable.

International Protection Rating Code

The International Protection (IP) Code consists of the letters IP followed by two digits and an optional letter. The digits indicate conformity with the conditions summarised below and are typical minimum design criteria.

The first digit relates to protection against access to hazardous parts and the ingress of solid objects.

The second digit relates to the protection of the equipment inside the enclosure against harmful ingress of water.

The code can also be suffixed with a letter appertaining to specific information, as detailed after the explanation of the numerical information.

First Digit: Solid Particle Protection

 Level Object Size protected against Effective against
 0 Not protected No protection against contact & 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 the 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: Liquid Ingress Protection

 Level Protection Against Effective Against Details
 0 None - -
 1 Dripping water Dripping water (vertically falling drops) shall have no harmful effect on the specimen when mounted in an upright position onto a turntable and rotated at 1 RPM. Test duration: 10 minutes
Water equivalent to 1mm rainfall per minute

 2 Dripping water when tilted at 15 degrees Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle of 15 degrees from its normal position. A total of four positions are tested within two axes.Test duration: 2.5 minutes for every direction of tilt (10 minutes total)
Water equivalent to 3mm rainfall per minute

 3 Spraying water Water falling as a spray at an angle up to 60 degrees from the vertical shall have no harmful effect, utilising either: a) an oscillating fixture, or b) a spray nozzle with a counterbalanced shield.

Test a) is conducted for 5 minutes, then repeated with the specimen rotated horizontally by 90 degrees for the second 5-minute test. 
Test b) is conducted (with shield in place) for 5 minutes minimum.
 For a Spray Nozzle:
Test duration: 1 minute per square meter for at least 5 minutes (4)
Water volume: 10 litres per minute
Pressure: 50-150 kPa

For an oscillating tube:
Test duration: 10 minutes
Water volume: 0.07 l/min per hole

 4 Splashing of water Water splashing against the enclosure from any direction shall have no harmful effect, utilizing either: a) an oscillating fixture, or b) A spray nozzle with no shield.

Test a) is conducted for 10 minutes
Test b) is conducted (without shield) for 5 minutes minimum.
 Oscillating tube: Test duration: 10 minutes, or spray nozzle (same as IPX3 spray nozzle with the shield removed)

 5 Water jets Water projected by a nozzle (6.3mm) against enclosure from any direction shall have no harmful effects. Test duration: 1 minute per square meter for at least 15 minutes
Water volume: 12.5 litres per minute
Pressure: 30kPa at distance of 3 m
 6 Powerful water jets Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects. Test duration: 1 minute per square meter for at least 3 minutes
Water volume: 100 litres per minute
Pressure: 100 kPa at distance of 3 m
 6K Powerful water jets with increased pressure Water projected in powerful jets (6.3 mm nozzle) against the enclosure from any direction, under elevated pressure, shall have no harmful effects. Found in DIN 40050, and not IEC 60529 Test duration: at least 3 minute(citation needed)
Water volume: 75 litres per minute
Pressure: 1000 kPa at distance of 3 m
 7 Immersion, up to 1 m depth 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 - ref IEC 60529, table 8

Tested with the lowest point of the enclosure 1000 mm below the surface of the water, or the highest point 150 mm below the surface, whichever is deeper
 8 Immersion, 1 m or more in depth The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer. 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. The test depth and duration is expected to be greater than the requirements for IPx7, and other environmental effects may be added, such as temperature cycling before immersion. Test duration: Agreement with Manufacturer

Depth specified by manufacturer, generally up to 3 m

 9K Powerful high temperature water jets Protected against close-range high pressure, high temperature spray downs.

Smaller specimens rotate slowly on a turntable, from 4 specific angles. Larger specimens are mounted upright, no turntable required, and are tested freehand for at least 3 minutes at distance of 0.15-0.2m.

There are specific requirements for the nozzle used for the testing.

This test is identified in IPx9 in IEC 60529.
 Test duration: 30 seconds in each of 4 angles (2 minutes total)

Water volyme: 14-16 litres per minute
Pressure: 8-10 MPa (80-100 bar) at distance of 0.10-0.15m 
Water temperature: 80 degrees Celsius

A typical example of a common IP reference definition as extracted from the information above would be:

 IP Number First Digit - SOLIDS Second Digit - Liquids
 IP56 Protected from limited dust ingress Protected from high pressure water jets from any direction
 IP67 Protected from total dust ingress Protected from immersion between 15 centimeters and 1 meter in depth

Additional Letters

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

 Letter Meaning
 f Oil resistant
 H High voltage device
 M Device moving during water test
 S Device standing still during water test
 W Weather conditions

Source: IEC Standard.

MacLellan Rubber offer a wide range of sealing materials that are suitable for IP rated applications including Solid Rubber Sheeting, Foam Sponge and Expanded PTFE, as well as bespoke extrusions, braided packings and moulded seals.

For technical advice and support in your application contact the Technical Team on 01902 307711