An IP code says how well an enclosure keeps out solid objects and water, under the tests of IEC 60529. It is printed on nearly every sensor, motor, drive and enclosure, and it is one of the specifications a replacement must meet. This glossary explains the two digits and the ratings met most often on spare parts.
The first digit: solids and touch
- 0: no protection.
- 1: objects over 50 mm, such as the back of a hand.
- 2: objects over 12.5 mm, such as a finger.
- 3: objects over 2.5 mm, such as a tool.
- 4: objects over 1 mm, such as a wire.
- 5: dust-protected; some dust may enter, but not enough to stop the device working.
- 6: dust-tight.
The second digit: water
- 0: no protection.
- 1 and 2: dripping water, falling straight down or with the device tilted by up to 15°.
- 3 and 4: spraying and splashing water.
- 5 and 6: water jets and powerful water jets.
- 7: temporary immersion, to a depth of 1 m for 30 minutes.
- 8: continuous immersion, under conditions the manufacturer states.
- 9: high-pressure, high-temperature water jets, as in washdown.
An X in place of a digit means that property was not tested: IPX4 says nothing about dust.
Ratings met most often on spare parts
- IP20: finger-safe, for mounting inside a control cabinet. Typical of drives, PLCs and terminal blocks.
- IP54: dust-protected and splash-proof. Typical of control cabinets and many motors.
- IP65 and IP67: dust-tight, against jets or brief immersion. Typical of industrial sensors, connectors and field devices.
- IP69K: dust-tight and resistant to hot, high-pressure washdown, from the road vehicle standard ISO 20653. Typical of food and beverage plants and of vehicles.
Higher is not always better
Above 6, the water digits do not build on each other. A device tested only for immersion, IPX7, has not been tested against water jets; one tested for both carries a double code such as IPX6/IPX7. On a machine that is hosed down, replace an IP66 or IP69K part with one that carries the same code, not with an IP67 part that only sounds higher.
IP and NEMA
North American parts are often marked with a NEMA or UL enclosure type instead. NEMA types also cover corrosion, oil and ice, which IP codes do not, so the comparison works in one direction only: a NEMA 4X enclosure roughly meets IP66, but an IP66 part is not automatically NEMA 4X. Order the code the machine’s documentation asks for.
Ordering a replacement
Put the IP code in the request, and the sealing parts with it: a sensor marked IP67 is only IP67 with the right connector and cable gland fitted. Some models exist in an open and a sealed version, as the ABB ACS355 does; the post on the ACS355 type code shows how the option code marks it. Search the full ordering code, which usually tells the versions apart, or post a wanted request if nobody lists it.