Summary: Sensors frequently need to be installed in hostile environments that can seriously shorten the life of any electronic component. Banner builds sensors to withstand a variety of industrial environments, and our engineers test and rate all of our sensors using two main enclosure rating systems: IP and NEMA. Use these designations to help decide which sensor will function best in your factory environment. This article answers some common questions about IP and NEMA ratings, when to use them and how to broadly interpret these designations. This article also discusses washdown ratings, especially those for high-pressure sprays.
Q: Why do 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. IP (Ingress Protection) ratings for non-hazardous locations were developed by the International Electrotechnical Commission (IEC) and are primarily used in Europe and Asia. NEMA ratings were developed by the National Electrical Manufacturers Association and are primarily used in the US. We test our sensors to both rating systems simultaneously in order to satisfy our customers' regional requirements.
Q: Why aren't all Banner sensors water and dust-tight?
Not all sensors need to withstand rigorous environments. For example, if we were to design all our sensors to meet IP67, it wouldn't be cost effective for a customer who needed an unsealed sensor. We give our customers as many choices as we can so that they can best solve their application.
Q: What do the numerals following the "IP" stand for?
The rating system is identified by the letters IP followed by two numerals, as in IP67. The first numeral represents the degree of protection against the ingress of dust and other solid objects. The second represents the degree of protection against the ingress of water. Usually the more harsh the environment, the higher the numbers used.
Q: 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 the high-pressure spray.
Q: For how long will my IP68 sensor function while under water?
Keep in mind that the IP ratings signify 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.
That said, IP68 is a manufacturer-specified test, meant to be more stringent than IP67. Banner-defined IP68 means that a sensor should not leak for a minimum of 24 hours of continuous submersion at 2 meters of water. However, moisture ingress by itself does not guarantee sensor malfunction.
Contact Banner directly for specifics about particular products with the IP68 rating.
Q: Is my IP68 sensor protected from corrosion?
The IP rating only gives you a rating for 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.
Q: Why do IP68 products differ so much between manufacturers?
This rating is manufacturer-specified, and it usually stems 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. Please check with each manufacturer of an IP68-rated product to understand their test procedure for this rating.
Q: 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 2 meters of water.
Q: What does the “K” stand for in IP69K?
IP69K is a rating that is not included in the IEC 60529. At present, it can only be found in the DIN standard 40050-9 and in this standard, the suffix “K” signifies high pressure. This means that sensors rated at IP69K are protected against the effects of high-pressure water.
Q: Will an IP69K sensor function even when being blasted by water jets?
With IP69K, we spray a sensor with water at 1500 psi at 4” to 6” from the sensor. The water used is at 176 °F and is blasted at the rotating sensor for 30 seconds from 4 angles (120 seconds in total). The water has a flow rate of 4 gallons per minute. After testing, the sensor is inspected to determine if there is any water inside.
Q: 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 1 m submergence in water.
Q: 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 1 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.
Q: Are NEMA enclosure ratings the same as IP?
There is some correspondence between IP and NEMA ratings, although each system uses a very different numbering scheme.
Q: Which should I use, NEMA or IP?
It depends where you are. In Europe and Asia, IP ratings are used to determine ingress protection. In North America, NEMA is more prevalent. However, more and more companies are standardizing to the IP rating.
At Banner, we test our enclosures for both ratings simultaneously. For example, when we test for IP67 we also test for NEMA 6. The IP67 tests call for immersion in water at a depth of 1 meter, for 30 minutes. The NEMA 6 test calls for immersion in a depth of 1.8 meters. At Banner, we submerge the unit at 2 meters for 30 minutes to cover both requirements.
Q: Do IP ratings take temperature into account?
Most IP and NEMA tests are conducted at 23 °C (room temperature). IP68 and IP69K have specific temperature requirements. IP68 is specified by the manufacturer or the customer and as such, Banner will determine how to test a sensor for this rating. Banner does use an IP68 test which involves a temperature soak at both 70 °C and –25 °C for 24 hours, with a minimum of one hour at each temperature. The IP69K rating requires that the sensor resist high-pressure washdown with 80 °C water.
Q: Are there IP ratings for hazardous locations?
IP ratings relate to all locations. For hazardous ratings, you want a higher IP rating as it is very important that there is no ingress of any type, especially nothing that could create a spark.
Q: Do vision sensors have an IP rating?
Yes, Banner's vision sensors are rated up to IP68 for machine vision inspections in dirty or washdown conditions.
For more information about IP and NEMA ratings, contact one of our experts or sign up below to receive future updates.