Source: Philipp Riedl
You'll find the "famous" protection class on all devices that have anything to do with electricity. This is always preceded by the IP prefix – which stands for "International Protection" or "Ingress Protection" – followed by two letters. This labeling system has been in place for several decades and can be found on electrical devices in almost every country around the globe.
But what does this term really mean? Everyone knows it, yet most people don't know what to do with it. Generally, when purchasing devices that are vulnerable to water or are used outdoors, you should pay attention to the protection class. Water damage is usually irreparable (or uneconomical), and it's well known that electricity and water don't mix well, which can also pose a personal risk.
That's why we've provided a short list for you to quickly identify the protection class or its combinations. The numbers always consist of contact protection (number 1) and water protection (number 2):
| IP | Contact protection code number 1 |
| 0 | No contact or foreign body protection |
| 1 | Protection against foreign bodies 50 mm |
| 2 | Protection against foreign bodies 12 mm |
| 3 | Protection against foreign bodies 2,5 mm |
| 4 | Protection against foreign bodies 1 mm |
| 5 | Complete contact protection - additional protection against dust deposits inside |
| 6 | Complete contact protection - protection against dust ingress |
| IP | Water protection code number 2 |
| 0 | No water protection |
| 1 | Protects against vertically falling water drops |
| 2 | Protects against obliquely falling water drops (up to 15°) |
| 3 | Protects against spray water (up to 60°) |
| 4 | Protects against spray water |
| 5 | Protected against jet water (regardless of direction) |
| 6 | Protects against water penetration during short floods or strong jets of water |
| 7 | Protected against temporary (short) submersion |
| 8 | Protection against indefinite (continuous) immersion - an additional number indicates the maximum diving depth in meters |
| 9 | Protection against indefinite (continuous) immersion - an additional number indicates the maximum diving depth in meters |