Sensors frequently need to be installed in hostile environments that can seriously shorten the life of any electronic component. To withstand these conditions, enclosures for sensors, lighting, remote I/O, and other devices are designed with varying levels of protection against environmental elements. These resistance abilities are denoted using IP and NEMA ratings, the two primary systems used for assessing environmental resistance for enclosures.
Because not all devices need to operate in and withstand the same rigorous environments, not all Banner sensors are water- and dust-tight. For example, if all our sensors were designed to meet IP67, they would not be cost-efficient for a customer whose application doesn’t require a sealed sensor. We give our customers as many choices as we can to best solve their applications.
For applications in which sensor housings, or enclosures, need protection against water or dust, IP and NEMA ratings can help you decide which sensor will function best in your environment, including high-pressure sprays in washdowns. This article explains IP vs NEMA ratings and answers some common questions about when to use IP and NEMA ratings and how to understand these designations.
What is an IP rating?
IP ratings were created by the International Electrotechnical Commission (IEC) to explain an enclosure’s ability to resist the entry of dust and liquids.
There are two numbers in an IP rating. The first represents protection against dust or other dry, solid objects. The scale ranges from 0, no protection, to 6, which is no dust ingress. The second number is the ability to prevent liquids from entry. This scale ranges from 0, no protection, to 9, which prevents high-pressure hot water from multiple angles from entering an enclosure. One thing to note is that higher IP ratings do not necessarily include the abilities of lower IP ratings. This means while an IP69K-rated enclosure may be able to withstand high pressure water jets, it may not stand up to being submerged for any length of time and therefore would not meet IP67 or IP68 requirements. This is why some items are rated both IP65 and IP67 or IP68 because they can withstand both powerful water jets from any direction (IP65) as well as temporary (IP67) or continuous (IP68) immersion in water.
| Level | First Numeral (Protection Against Dust and Other Solids) | Second Numeral (Protection Against Liquids) |
|---|---|---|
| Level 0 | First Numeral (Protection Against Dust and Other Solids) No protection | Second Numeral (Protection Against Liquids) No protection |
| Level 1 | First Numeral (Protection Against Dust and Other Solids) Objects greater than 50 mm | Second Numeral (Protection Against Liquids) Vertically dripping water drops |
| Level 2 | First Numeral (Protection Against Dust and Other Solids) Objects greater than 12 mm | Second Numeral (Protection Against Liquids) Vertically dripping water drops on enclosure tilted up to 15 degrees |
| Level 3 | First Numeral (Protection Against Dust and Other Solids) Objects greater than 2.5 mm | Second Numeral (Protection Against Liquids) Spraying water at an angle of up to 60 degrees on either side of the vertical |
| Level 4 | First Numeral (Protection Against Dust and Other Solids) Objects greater than 1 mm | Second Numeral (Protection Against Liquids) Splashing water from any direction |
| Level 5 | First Numeral (Protection Against Dust and Other Solids) Dust-protected | Second Numeral (Protection Against Liquids) Water jets from any direction |
| Level 6 | First Numeral (Protection Against Dust and Other Solids) Dust-tight | Second Numeral (Protection Against Liquids) Powerful water jets from any direction |
| Level 7 | First Numeral (Protection Against Dust and Other Solids) — | Temporary immersion in water depths up to one meter; tested for at least 30 minutes |
| Level 8 | First Numeral (Protection Against Dust and Other Solids) — | Continuous immersion in water; test conditions set by agreement between manufacturer and user and must be more severe than IPX7 |
| Level 9K | First Numeral (Protection Against Dust and Other Solids) — | Second Numeral (Protection Against Liquids) High temperature, high pressure water jets from any direction |
What is a NEMA rating?
NEMA is the National Electrical Manufacturers Association. They developed a rating system for enclosure use in non-hazardous locations that denotes resistance to environmental elements. For the most part, NEMA ratings range from Type 1 to Type 13, with variations for some types.
| Type | Use and Protection Offered |
|---|---|
| Type Type 1 | First Numeral (Protection Against Dust and Other Solids) Indoor use; protection against falling dirt |
| Type Type 2 | First Numeral (Protection Against Dust and Other Solids) Indoor use; protection against falling dirt, dripping water, and light splashing of water |
| Type Type 3 | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, windblown dust, rain, sleet, snow, and external ice |
| Type Type 3R | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, rain, sleet, snow, and external ice |
| Type Type 3S | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, windblown dust, rain, sleet, and snow; and external mechanisms still operate despite external ice |
| Type Type 3X | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, windblown dust, rain, sleet, snow, and ice; and offers some protection against corrosion |
| Type Type 3RX | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, rain, sleet, snow, and external ice; and offers some protection against corrosion |
| Type Type 3SX | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, windblown dust, rain, sleet, and snow; offers some protection against corrosion; and external mechanisms still operate despite external ice |
| Type Type 4 | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, windblown dust, rain, sleet, snow, splashing water, water sprayed from a hose, and external ice |
| Type Type 4X | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, windblown dust, rain, sleet, snow, splashing water, water sprayed from a hose, and external ice; and offers some protection against corrosion |
| Type Type 5 | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, settling dust and other fibers, dripping water, and light splashing of water |
| Type Type 6 | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, water sprayed from a hose, temporary immersion into water, and external ice |
| Type Type 6P | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use; protection against falling dirt, water sprayed from a hose, temporary immersion into water, longer immersion, external ice; and offers some protection against corrosion |
| Type Type 7 | First Numeral (Protection Against Dust and Other Solids) Indoor use in hazardous locations; containment of internal explosion without causing an external hazard; used for gases and vapors |
| Type Type 8 | First Numeral (Protection Against Dust and Other Solids) Indoor or outdoor use in hazardous locations; prevention of combustion when using oil-immersed equipment |
| Type Type 9 | First Numeral (Protection Against Dust and Other Solids) Indoor use in hazardous locations; prevention of dust from igniting |
| Type Type 10 | First Numeral (Protection Against Dust and Other Solids) Use in hazardous mining locations; containment of internal explosion without causing an external hazard |
| Type Type 12 | First Numeral (Protection Against Dust and Other Solids) Indoor use without knockouts; protection against falling dirt, circulating dust and other fibers, dripping water, and light splashing of water; and some protection from light splashing and leaking of oil and non-corrosive coolants |
| Type Type 12K | First Numeral (Protection Against Dust and Other Solids) Indoor use with knockouts; protection against falling dirt, circulating dust and other fibers, dripping water, and light splashing of water; and some protection from light splashing and leaking of oil and non-corrosive coolants |
| Type Type 13 | First Numeral (Protection Against Dust and Other Solids) Indoor use; protection against falling dirt, circulating dust and other fibers, dripping water, and light splashing of water; and some protection from spraying, splashing, and leaking of oil and non-corrosive coolants |
Comparing IP Ratings vs NEMA Ratings
There is some correspondence between IP and NEMA ratings, although each system uses a very different numbering scheme.
Why do some Banner sensors have both IP and NEMA ratings?
Both IP and NEMA ratings determine how well enclosures for electronic components resist the infiltration of dust and moisture. NEMA ratings are primarily used in North America, while IP ratings are used globally. Banner tests all sensors for IP ratings, and some sensors are also tested for NEMA ratings in order to satisfy our customers’ regional requirements.
Are only enclosures given IP and NEMA ratings?
Yes. Only the enclosure (the sensor housing) is tested to rate how well it protects against the ingress of solids or liquids. The IP69K sensors that Banner offers have quick disconnect cables, as some of the regular integral cabling can be damaged by a high-pressure spray.
Who determines what rating an enclosure has?
Both the IEC and NEMA develop standards, but neither one is a certification body. This means each manufacturer must test their devices according to the IP and NEMA standards to ensure they meet appropriate ratings. This testing can either be done in-house or by a third party. Banner tests all our enclosures so they meet or exceed the IP and NEMA ratings we assign to them.
Which should I use, NEMA or IP?
Your choice primarily depends on where you are. IP ratings were developed in Europe and are used globally. They are intended to determine ingress protection against dust and water. NEMA standards were developed in North America and are most common there. NEMA ratings also include resistance to corrosion and atmospheric gases, as well as use in hazardous environments. Because Banner ships products around the world, you’ll find our products using IP ratings with some also including NEMA types.
Understanding the IP68 Rating
The IP68 rating is commonly used for devices that may be submerged in water for long periods of time. However, there can be differences in protection abilities from product to product and manufacturer to manufacturer.
Why do IP68 products differ so much between manufacturers?
This rating is manufacturer-specified, often stemming from a customer request. While IP68 products must also meet the requirements of IP67, the manufacturer decides what further ingress protection is required. The manufacturer also determines if the enclosure needs to be tested to withstand temperature constraints. Be sure to check with each manufacturer of an IP68-rated product to understand their test procedure for this rating.
How long will my IP68 sensor function while underwater?
The IP ratings indicate whether a sensor enclosure meets the ingress protection required of the particular rating. IP and NEMA ratings do not describe a sensor’s ability to function.
However, IP68 is a manufacturer-specified test, meant to be more stringent than IP67. Each manufacturer sets their own maximum submersion time and depth, depending on the application. Sometimes moisture may condense inside the enclosure, but this is not considered water ingress for testing purposes.
Is my IP68 sensor protected from corrosion?
The IP rating only indicates how well the sensor’s enclosure protects against ingress of solid particles and liquids. The IP rating does not tell you how the sensor enclosure might hold up in a corrosive environment. IP ratings also don’t take humidity into account, so sometimes humid air can find its way into an enclosure and cause condensation if there are drastic temperature changes. In turn, this condensation may cause erratic sensor operation.
How does Banner test for IP68?
The Banner test for IP68 involves first testing the enclosure to meet IP67. There are also rigorous temperature and submersion tests after which the sensor must still be able to function. Banner-defined IP68 means that a sensor should not leak for a minimum of 24 hours of continuous submersion at two meters of water.
Understanding the IP69K Rating
An IP69K rating indicates different protection than an IP68 rating. Typically, this is used to denote an enclosure’s ability to withstand high-temperature, high-pressure water jets used for cleaning food processing equipment, agricultural machinery, medical devices, and other industrial equipment.
Does the IP69K rating mean that the sensor has met IP67 and IP68 as well?
Not necessarily. IP69K sensors are able to withstand a high-pressure water jet, but may not be able to withstand submersion. IP69K sensors do not have to automatically comply with IP67 and IP68 ratings, but all Banner products which are IP69K rated are tested to at least one meter submergence in water.
Will an IP69K sensor function after being blasted by water jets?
With IP69K, we spray a sensor with water at 1500 psi at four inches to six inches from the sensor. The water used is at 176 °F and is blasted at the rotating sensor for 30 seconds from four angles (120 seconds in total). The water has a flow rate of four gallons per minute. After testing, the sensor is inspected to determine if there is any water inside. An IP69K-rated sensor should continue to function even after exposure to high-pressure, high-temperature water jets.
Is IP69K the only high-pressure washdown rating available?
No, there is a high-pressure washdown NEMA rating. The NEMA ICS 5 rating, also known as PW 12, specifies that a sensor must withstand a water spray of one gallon/minute at 1200 psi and 140 °F. A sensor with this rating is usually adequate for a variety of industrial environments that use high pressure washdown cleaning. The PW 12 designation is usually added to another NEMA rating, for example NEMA 6 PW 12.
More about NEMA and IP Ratings
Do NEMA and IP ratings take temperature into account?
Most IP and NEMA tests are conducted at 23 °C (room temperature). As it refers to use in washdown environments, IP69K has a specific temperature requirement of an enclosure resisting high-pressure, 80 °C water jets. IP68 is specified by an agreement between the manufacturer or the customer and as such, Banner will determine how to test a sensor for this rating. For example, a Banner IP68 test involves a water soak at both 70 °C and –25 °C for 24 hours, with a minimum of one hour at each temperature.
Are there IP ratings for hazardous locations?
IP ratings indicate protection against outside elements and don’t specifically take hazardous environments into account. NEMA ratings, on the other hand, have four specific ratings for enclosures used in hazardous areas: Types 7, 8, 9, and 10.
Choosing Your Sensor
Though there seems to be a lot that goes into determining which sensor enclosure rating you need, it’s not complicated. For many applications, you just have to know what environmental situations you need to protect against. Make a comprehensive assessment, then choose the ratings that offer a level of protection sufficient for that environment. Contact a Banner engineer if you have any questions, and they’ll help you find a sensor solution with the proper level of protection to safely satisfy your application.