When purchasing costly electronics, understanding their expected longevity and reliability is essential. IP (Ingress Protection) ratings are key for informed consumers and professionals who need to understand how durable and reliable an instrument or device is. With an understanding of the ruggedness of a device, users can recognise when and where their electronics can be used without breaking. This is an essential consideration for anyone purchasing electronics but may be of particular value to maintenance technicians working out on field in a variety of conditions and for whom an understanding of the limits of their technology is vital.
What is an IP rating and what does it measure?
An IP rating refers to an Ingress Protection mark. This is a grading system that is applied to the enclosure of mechanical and electrical devices. It is defined by International Standard EN60529 so that it is understood universally. Typically, an IP rating consists of two digits which provide consumers with an indication as to the resistance of the item to various types of intrusion.
IP ratings highlight three levels of protection including:
- Protection of users
- Protection of equipment to objects such as dust/dirt
- Protection of equipment in enclosures from water
The use of a universal IP rating system is essential as it affords users the confidence to understand how safe a particular device is for certain environments and applications. Terms such as “waterproof” and “weatherproof” are ambiguous and so an IP rating is useful as it provides a more precise and easily understood measure.
IP ratings explained
IP ratings are often shown in the format of “IP67” or similar.
The first number, between 0-6, denotes the degree of protection from ingress of solid objects such as users and intrusion such as dust and dirt.
The second number, between 0-8, indicates the quality of resistance to moisture ingress.
To decide which IP rating is the best choice for your application, you will need to consider the environment in which the technology will be used and ensure that the chosen device is suitable for any potential intrusion that may exist there. Exposed components should have a high enough IP rating to provide the required minimum protection.
As IP ratings only account for the intrusions discussed above, there may be certain circumstances where higher, more specific levels of protection are required. This is made possible with the addition of a letter at the end of the IP rating to indicate certified resistance to a specific material or hazard. Some of these include:
|C||Protection against access with a tool|
|H||High voltage device|
|M||Device moving during water test|
|S||Device standing still during water test|
IPX rating, waterproof and weatherproof ratings
Some IP ratings may include an X in place of one of the digits. This could be shown as IPX7 or IP5X where the X denotes that a numerical rating has only been provided for one of the main ingress types (solid or liquid), but not for them both. It is worth noting that “X” is not the same as “0” as it simply means that the manufacturer has not specifically tested the product for the particular protection indicated, not that the product necessarily provides no protection in that area. IP ratings might also be missing if manufacturers have used alternative certifications or rating standards, so it is worth checking for different ratings such as those provided by the National Electrical Manufacturer Association (NEMA) that may indicate that a product is water or dust-resistant.
Due to a lack of standardisation, terms like “waterproof” are problematic. However, the IP ratings that are widely considered as “waterproof” are:- IP65, IP66, IP67 and IP68.
Understanding the difference between waterproof and water-resistant is essential. Waterproof devices are unaffected by water regardless of submersion whilst water-resistant devices prevent water from entering to some degree but not entirely. A misconception with water resistances is that as the IP rating increases, so too does the device’s resistance. IPX7, IPX8 and IPX9 codes refer to immersion properties but may not meet the criteria for pressurised water jet resistance unlike lower ratings such as IPX5 and IPX6. Other considerations include the fact that IP ratings are assigned and tested on devices in fresh water, which means protection cannot be guaranteed in other liquids such as salt water, drinks and water containing chemicals (e.g. in a swimming pool.) It is also important to consider intrusion from less apparent moisture such as steam and condensation.
The assumption might be made that items intended for long term outdoor use require the highest IP ratings for resistance to moisture. However, this is not strictly true as rain tends to fall vertically and under low pressure so that devices with an IPX2 rating should be protected against 3mm rainfall per minute. Additionally, equipment rated at IPX3 should have resistance to endure continuous spray up to 60° angles. Despite having relatively low IP ratings, such devices are likely to suffice for everyday weatherproofing.
Where manufacturers list products as “weatherproof” or “explosion-proof” without listing an IP rating, it could be that these products have been tested to alternative standards which may suffice for your intended application.
Products and IP rating
Common products and their typical IP ratings include:
- IPX4+ for exposed outdoor use
- IPX5+ for outdoor use and to be cleaned with pressurised jets
- IPX7+ for immersion up to 1m (e.g. pool lighting)
- IP67+ for inside a bath/shower
- IP65+ above a bath/shower
- IP44+ within 60cm radius of bath/shower
- IP20+ for indoor applications
- IP40+ for protection from physical objects but not moisture
- IP54+ for outdoor use as dust and splash proof
- IP66+ for outdoor use as dust tight and water tight
General purpose enclosures such as storage units
- IP43+ for indoor use to protect from moderate physical/water intrusion
- IP65+ for outdoor use
Handheld enclosures to protect controllers and instruments
- IP65+ for most applications to protect both users and equipment
Instrument cases such as housings for everyday electrical products
- IP40+ for indoor use
- IP67+ for full immersion resistance
Power supply cases to house high-voltage components
- IP20+ to allow heat transfer (often includes additional safety features for resistance to corrosion/abrasion.)
Accessories can be added to enhance enclosures and ensure that the best protection is provided for your application. With a broad range of IP-rated enclosures, accessories and fittings available, a number of specifications can be taken into consideration including component type, mounting solution, attachment method and security features. Accessories tend to have corresponding IP ratings to reflect the enclosures that they support. Typical accessories include:
- Brackets, nuts and screws
- Locks, keys and keypads
- Racks, shelves and panels
- Rubber feet
Metallic vs. non-metallic enclosures
IP ratings are essential for maintenance technicians as devices that are ill-protected will be less reliable and more susceptible to damage. Purchasing IP-rated cases is a cost-effective, highly efficient and easy way of protecting equipment to ensure that it is fit for purpose in environments where intrusions may occur.
Offering strength and durability, metal enclosures are a good choice for protecting electrical equipment. Ideal for enduring harsh weather conditions and excessive moisture, metal enclosures are long-lasting and highly effective.
For many engineers, metal may be the first choice for IP-rated enclosures. However, depending on application requirements, other materials may offer cheaper, more flexible alternatives. For instance, plastic enclosures are often lightweight, resistant to corrosion, easily modified, easily mounted and can be transparent so that enclosed electronics can be viewed. The requirements of the intended application will therefore guide the choice of enclosure.
Plastic Enclosure, Light Grey Polycarbonate IP65
This polycarbonate enclosure is sized 230 x 300 x 111mm and rated at IP65. Holes in the enclosure for wall mounting and screws for lid fixing are located outside of the sealing area to protect against moisture and dirt.
Metal Enclosure, Die-cast Aluminium Grey IP54
Highly durable, robust and shock resistant, this metal enclosure is rated at IP54 and can endure temperatures up to 260°C. Guides for PCB fixing and an optional neoprene gasket for IP65 seal are also provided.