Most outdoor electrical failures start the same way. Water tracks in through a cable entry, dust builds up around a breaker, or a box rated for light splash ends up on a wall that gets hosed down every week. In each case, the problem was decided at the spec stage, when someone read the IP rating on a datasheet.
Here are IP ratings explained in plain terms, with a chart and real site examples you can use when choosing enclosures, plugs and sockets.
What an Ingress Protection Rating Measures
An ingress protection rating comes from IEC 60529, the international standard that defines how well an electrical enclosure keeps out solid objects and water. The code always starts with the letters IP, followed by two digits. The first digit covers solids, from fingers and tools down to fine dust, while the second covers water, from dripping condensation to full submersion.
Each digit is tested on its own, and a higher number means the product passed a tougher test. An X in either position means that property was not tested, so a rating such as IPX4 confirms splash protection but tells you nothing about dust.
Reading the IP Rating Chart
Use this IP rating chart to decode any two-digit code you find on a product label or datasheet.
| Digit | First digit: solids | Second digit: water |
| 0 | No protection | No protection |
| 1 | Objects over 50 mm, such as the back of a hand | Vertically dripping water |
| 2 | Objects over 12.5 mm, such as fingers | Dripping water with the enclosure tilted up to 15° |
| 3 | Objects over 2.5 mm, such as tools and thick wires | Spraying water up to 60° from vertical |
| 4 | Objects over 1 mm, such as small wires and screws | Splashing water from any direction |
| 5 | Dust protected, with no harmful deposits inside | Water jets from a 6.3 mm nozzle |
| 6 | Dust tight | Powerful water jets from a 12.5 mm nozzle |
| 7 | Not used | Temporary immersion up to 1 m for 30 minutes |
| 8 | Not used | Continuous immersion beyond 1 m, under conditions set by the manufacturer |
Matching the IP Rating to the Job Site
The right waterproof electrical rating depends on where the product will be installed, so start with the site conditions rather than the catalog. Here is where the most common codes fit.
• IP44 suits covered areas that only see splash. A covered loading bay or a workshop near a wash sink is a typical example, since water reaches the product as splash rather than direct spray.
• IP54 adds protection against dust. Construction site power points and portable equipment deal with dust and occasional splashing, which is the job Famatel’s IP54 splash-proof mobile plugs are built for.
• IP65 is the baseline for exposed outdoor work. Exterior walls, parking structures and rooftop equipment need a product that is dust tight and protected against water jets, which is why Famatel’s AcquaCOMBI wired enclosures carry this rating.
• IP66 handles heavy weather and hose-down. Solar fields, marine docks and infrastructure sites face driving rain and strong jets, and the Stone Series fiberglass enclosures for outdoor control panels are rated IP66 for that reason.
• IP67 protects against short-term immersion. Pump stations, low-lying yards and other flood-prone locations need a product that stays sealed if water pools around it.
Common Mistakes When Using an IP Code Guide
• A higher water digit does not always include the lower ones. Up to level 6, each rating covers the tests below it. IPX7 and IPX8 test immersion instead, so a product rated only IP67 may not have passed the jet test, which is why some are marked IP66/IP67.
• IP and NEMA ratings are separate systems. NEMA ratings used in North America also consider corrosion, oil and ice, and there is no exact conversion between the two, so check both when a US specification calls for NEMA 4X.
• The weakest point sets the real protection. A rating applies to the product as tested, so an open cable entry, a missing gland or a plug rated lower than the box will still let water in. Check your pin and sleeve connectors and sockets against the same IP level as the enclosure.
• An IP rating says nothing about impact. Impact resistance is measured separately with an IK code, and an enclosure in a busy plant needs both. That is why the Stone Series lists IK10 alongside its IP66 rating.
Conclusion
An IP code tells you exactly which tests a product passed, and reading it correctly is what keeps water and dust out of the panel once it is installed. Famatel USA designs enclosures, industrial plugs and sockets, and power distribution units with clearly stated IP and IK ratings for these sites.
Explore IP-Rated Enclosures from Famatel USA.
Frequently Asked Questions
What does IP65 mean?
The first digit, 6, means the product is dust tight. The second digit, 5, means it resists water jets from a 6.3 mm nozzle, so it can handle rain and light hosing outdoors.
Is IP67 better than IP65?
The two ratings test different things. IP67 covers temporary immersion and IP65 covers water jets, so the right choice depends on whether the product will face standing or sprayed water.
What does the X in an IP code mean?
An X means that category was not tested. A product rated IPX4, for example, is protected against splashing water, but the rating gives no information about dust.