IP protection is one of the most important parameters of electrical and electronic devices. The correct choice determines whether the device will operate reliably in dust, humidity or when exposed to water.
What the IP designation means
The abbreviation IP comes from the English term Ingress Protection. It is a classification system according to standard IEC/EN 60529. The designation has the format:
IP + first digit + second digitFor example IP20, IP44, IP65 or IP67. Each digit has a precisely defined meaning.
First digit – protection against solid objects
The first digit indicates protection against ingress of solid foreign objects and also protection of persons from touching hazardous parts.
| Digit | Protection meaning |
|---|---|
| 0 | No protection |
| 1 | Protection against objects > 50 mm |
| 2 | Protection against fingers > 12.5 mm |
| 3 | Protection against tools > 2.5 mm |
| 4 | Protection against wires > 1 mm |
| 5 | Partial protection against dust (dust may enter but not in quantities to affect operation) |
| 6 | Complete dust tightness |
Second digit – protection against water
The second digit indicates resistance to ingress of water in various forms: drops, rain, splashing, jetting water, pressure water or immersion.
| Digit | Protection against water |
|---|---|
| 0 | No protection |
| 1 | Dripping water (vertical) |
| 2 | Dripping water when tilted |
| 3 | Splashing water |
| 4 | Spraying water |
| 5 | Water jets |
| 6 | Strong water jets |
| 7 | Temporary immersion |
| 8 | Continuous immersion (conditions specified by manufacturer) |
| 9 | High-pressure, high-temperature water (specific industrial applications) |
Most common IP ratings in practice
IP20 – basic protection
- No protection against water
- Protection against finger contact
- Suitable for dry indoor environments
Usage: power supplies, relays, modules for distribution boards, laboratory equipment.
IP44 – basic outdoor protection
- Protection against splashing water
- Basic protection against dirt
- Suitable for covered outdoor areas
Usage: bathrooms, pergolas, under-roof lighting.
IP54 / IP55 – increased resistance
- Improved protection against dust
- Resistance to rain and spray
- Good for workshops and technical rooms
Usage: industrial operations, workshops, outdoor installations with partial protection.
IP65 – professional standard
- Dust-tight design
- Resistance to water jets
- Universal choice for outdoor and industrial use
Usage: LED luminaires, sensors, control elements, outdoor installations without shelter.
IP67 – high protection
- Complete dust tightness
- Resistance to temporary immersion
- Suitable where flooding may occur
Usage: outdoor electrical installations, buried installations, LED modules, garden equipment.
IP68 – maximum protection
- Complete dust tightness
- Continuous operation under water (per manufacturer conditions)
- For pools, fountains and aquariums
Usage: underwater LED lighting, pools, fountains, aquariums.
Common mistakes when choosing IP protection
1) IP does not address mechanical resistance
IP rating indicates protection against dust and water, but does not say anything about impact resistance. Mechanical resistance is indicated by a separate marking IK (e.g. IK08, IK10). A device with a high IP rating can still be vulnerable to impact or drop.
2) IP does not cover chemical resistance
IP rating does not indicate resistance to oils, solvents, cleaning agents or aggressive chemicals. In such environments it is necessary to also verify the enclosure material (plastic, polycarbonate, aluminum, stainless steel) and the type of sealing used.
3) IP applies only if correctly installed
The stated IP rating applies only with correct installation. Poorly tightened cable glands, unsuitable cables, missing seals or incorrectly seated covers can significantly reduce the real protection, even if the product itself is certified.
IP protection is always a property of the entire assembly – that is the device, cable, glands and the method of installation, not just the product itself.
How to choose the correct IP rating
When choosing an IP rating it is useful to ask a few simple questions:
- Will the device be exposed to water (rain, spray, washing)?
- Is condensation likely (e.g. an unheated room, outdoor distribution box)?
- Is the environment dusty (workshop, industry, warehouse)?
- Will the device be outdoors year-round without shelter?
- Is short-term flooding a risk (chamber, buried installation)?
| Environment | Recommended IP |
|---|---|
| Dry indoor | IP20 |
| Bathroom / wet rooms | IP44 |
| Outdoor under shelter (under roof) | IP44–IP54 |
| Outdoor without shelter | IP65 |
| Buried installation / flood risk | IP67 |
| Underwater use | IP68 |
Summary
IP protection is a key parameter for the safe and long-term operation of devices. The first digit indicates protection against solid particles, the second digit the resistance to water. It is essential to select protection according to the environment and also ensure correct installation, because poor sealing can significantly reduce the real protection.