Ever wondered what IP54 means, and how it differs from IP66? Read on for a crash course on the varying types of IP ratings.
IP stands for Ingress Protection – the degree of protection provided by an enclosure containing equipment against intrusion of anything from a finger to fine dust particles or water. Generally, the higher the IP rating the greater the protection provided, but there’s an important difference between the two digits.
The first digit in an IP rating represents solid particle protection – the following table outlines the most common levels.
| First digit | Object size protection | Example |
| 0 | No protection | No protection provided |
| 1 | >50mm | Protected from large body parts, but not from fingers |
| 2 | >12.5mm | Protected from fingers |
| 3 | >2.5mm | Protected from tools such as screwdrivers |
| 4 | >1mm | Protected from very small objects and insects such as ants |
| 5 | Dust protected | Limited ingress of dust – not enough to affect equipment |
| 6 | Dust tight | No ingress of dust – highest level of dust protection |
The second digit of an IP rating represents liquid ingress protection – the following table outlines the most common levels.
| Second digit | Example |
| 0 | No protection provided |
| 1 | Protected from vertically falling dripping water |
| 2 | Protected from vertically falling dripping water, even when the enclosure is tilted up to 15° |
| 3 | Protected from fine water spray, up to 60° from vertical |
| 4 | Protected from water lightly splashing against the enclosure from any direction |
| 5 | Protected against water jets (up to 6.3mm nozzle) from any direction |
| 6 | Protected against high pressure water jets (up to 12.5mm nozzle) from any direction |
| 7 | Protected against immersion in up to 1m of water, usually for up to 30min |
| 8 | Protected against immersion in more than 1m of water, usually for an indefinite time period |
| 9K | Protected against close-range, high pressure, high temperature water jets from any direction. |
It’s important to note the two digits in an IP rating are independent of each other. e.g IP65 doesn’t necessarily offer greater protection than IP56 for a given application.
The following table offers suggestions for selecting a suitable IP rating for your application.
| Application | Suggested minimum IP rating |
| Clean indoor switch room | IP42 |
| Indoor room subject to dust ingress from outside | IP54 |
| Outdoor location under shelter | IP54 |
| Outdoor location subjected to weather | IP55 |
| Outdoor location subjected to weather and dusty/dirty environment | IP66 |
Note: these suggestions are a guide only.