IEC 60529 - Degrees of Protection Provided by Enclosures (IP Code)
Degrees of protection provided by enclosures (IP Code)
How to read an IP code
Key facts
- Full title
- Degrees of protection provided by enclosures (IP Code)
- Published by
- IEC; adopted in Europe by CENELEC as EN 60529
- Code format
- IP + solids digit (0-6) + water digit (0-9), plus an optional access letter (A, B, C, D) and supplementary letter (H, M, S, W)
- What X means
- The characteristic was not declared or not tested - it does not mean zero protection
- The K suffix
- Comes from ISO 20653 (road vehicles), not from IEC 60529; the IEC high-pressure test itself is IPX9
- Applies to
- Enclosures for electrical equipment with a rated voltage up to 72.5 kV
- Does not cover
- Corrosion, icing, oil and coolant, hazardous atmospheres, or mechanical impact (impact is the IK code, IEC 62262)
Reading an IP code
An IP code reads left to right: the letters IP, then a solids digit, then a water digit, and optionally one or two letters. The two digits are independent tests, so each is certified separately.
Where a characteristic was not declared or not tested, its digit is replaced by X. IPX4 means the solids performance was not declared and the water level is 4; IP6X means the enclosure is dust-tight with no declared water rating. X is a placeholder, not a score of zero.
First digit: solids and contact
The first digit runs from 0 to 6 and covers two linked things at once: how well the enclosure keeps out solid foreign objects, and how well it protects people from touching hazardous parts inside.
It climbs from no protection (0), through progressively smaller objects, to dust-protected (5, limited dust ingress with no harmful effect) and finally dust-tight (6, no dust ingress at all). A first digit of 6 is the ceiling; there is no 7, 8 or 9 for solids.
Second digit: water
The second digit runs from 0 to 9. Levels 1 to 4 cover dripping, spraying and splashing water; 5 and 6 cover water jets and powerful water jets; 7 and 8 cover immersion; and 9 covers close-range high-pressure, high-temperature jets.
A common trap is treating the second digit as a single ladder. It is not. Jet tests (5, 6) and immersion tests (7, 8) check different things, so passing one does not imply the other. A product rated for immersion is not automatically rated against high-pressure jets unless it was tested for them as well.
The K suffix, IPX9 and IP69K
IEC 60529 defines a high-pressure, high-temperature close-range jet test as IPX9. The K variant, such as IPX9K, is defined by ISO 20653 for road vehicles, with its own specified test conditions.
In IP69K, the first digit 6 explicitly declares dust-tight protection and the second designation 9K declares the ISO 20653 hot high-pressure water-jet test. When solids protection is not declared, the corresponding notation uses X in the first position, such as IPX9K.
Why an IP rating does not convert back to NEMA
North American NEMA enclosure Types can be cross-referenced to a minimum IP code, but the mapping runs one way only. An IP code cannot be converted back to a NEMA Type.
The reason is scope: NEMA 250 also tests corrosion, external ice formation, oil and coolant, and hazardous atmospheres, none of which the IP code addresses. Two enclosures with the same IP rating can differ in all of those respects, so IP alone does not carry enough information to assign a NEMA Type.
IP code digits at a glance
| Digit | First digit - solids and contact | Second digit - water |
|---|---|---|
| 0 | No protection | No protection |
| 1 | Objects larger than 50 mm (e.g. back of hand) | Vertically dripping water |
| 2 | Objects larger than 12.5 mm (e.g. a finger) | Dripping water with the enclosure tilted up to 15 degrees |
| 3 | Objects larger than 2.5 mm (e.g. a tool) | Spraying water up to 60 degrees from vertical |
| 4 | Objects larger than 1 mm (e.g. a wire) | Splashing water from any direction |
| 5 | Dust-protected (limited ingress, no harmful effect) | Water jets from a 6.3 mm nozzle |
| 6 | Dust-tight (no dust ingress) | Powerful water jets from a 12.5 mm nozzle |
| 7 | Not defined for the first digit | Temporary immersion up to about 1 m |
| 8 | Not defined for the first digit | Continuous immersion beyond 1 m, on conditions set by the manufacturer |
| 9 | Not defined for the first digit | Close-range high-pressure, high-temperature jets (IPX9) |
Tools that use this standard
Related standards
| Standard | Relationship | What it means |
|---|---|---|
| ISO 20653 | Extended by | The road-vehicle ingress standard that defines the K-suffix tests such as IPX9K, at higher pressure and temperature than the matching IEC 60529 digit. |
| NEMA 250 / UL 50E | Cross-referenced with | North American enclosure Types map to a minimum IP code one way only; NEMA also tests corrosion, ice, oil and hazardous atmospheres, which the IP code does not. |
| IEC 62262 (IK code) | Complemented by | Mechanical impact resistance, which IEC 60529 dropped after its second edition, is rated separately by the IK code. |
Related guides
Frequently asked questions
What does IP stand for in an IP rating?
What does the X mean in a rating like IPX4 or IP6X?
What is the difference between IP67 and IP68?
Is IPX5 or IPX7 more waterproof?
What does IP69K mean, and is it part of IEC 60529?
Can I convert an IP rating to a NEMA type?
Does IEC 60529 cover mechanical impact resistance?
Source: IEC webstore. An overview for design reference - verify against the current edition before relying on it for compliance.