IP66 vs. IP68 – Differences and Applications

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The IP (Ingress Protection) enclosure system uses a 2-digit suffix to designate an enclosure’s level of ingress protection. Devices with an IP68 rating offer protection against immersion in liquid up to 1.5 meters deep, vs the IP66 rating which provides shielding from powerful water jets. This article explains the IP protection system, the distinctions between the IP66 and IP68 ratings, and typical IP applications. 

IP Protection System

Ingress Protection meaning
Courtesy: everything RF

The IP rating is an international standard. It determines the degree of protection or sealing efficacy in enclosures against the infiltration of objects, water, dust, and contact. Also, it is compliant with European Standard EN 60529.

Products are noted by the initials IP (Ingress Protection), followed by two digits and an optional letter in the IP code. The two digits denote the level of intrusion protection versus solids and liquids. The optional letter notes the product’s resistance to pressure.

IP Ratings – Intrusion Protection

LevelIntrusion Protection
XNo protection.
1Protection from a large part of the body such as a hand (but no protection from deliberate access); from solid objects greater than 50mm in diameter.
For example, accidental touch by hands.
2Protection against fingers or other objects not greater than 80mm in length and 12mm in diameter. For example, fingers.
3Protection from entry by tools, wires, etc, with a diameter of 2.5 mm or more. For example, tools, and wires.
4Protection against solid objects larger than 1mm. For example, wires, nails, screws, larger insects, and other potentially invasive small objects such as tools/small, etc.
5Partial protection against dust that may harm equipment.
6Totally dust-tight. Full protection against dust and other particulates, including a vacuum seal, tested against continuous airflow.
IP Level for Intrusion Protection

IP ratings – Moisture Protection

LevelMoisture Protection
XNo protection.
1Protection against vertically falling droplets, such as condensation. ensuring that no damage or interrupted functioning of components will be incurred when an item is upright.
2Protection against water droplets deflected up to 15° from vertical
3Protected against spray up to 60° from vertical.
4Protected against water splashes from all directions. Tested for a minimum of 10 minutes with an oscillating spray (limited ingress permitted with no harmful effects).
5Protection against low-pressure jets (6.3 mm) of directed water from any angle (limited ingress permitted with no harmful effects).
6Protection against direct high-pressure jets.
7Protection against full immersion for up to 30 minutes at depths between 15 cm and 1 meter (limited ingress permitted with no harmful effects).
8Protection against extended immersion under higher pressure (i.e. greater depths). Precise parameters of this test will be set and advertised by the manufacturer and may include additional factors such as temperature fluctuations and flow rates, depending on equipment type.
9(K): Protection against high-pressure, high-temperature jet sprays, wash-downs, or steam-cleaning procedures – this rating is most often seen in specific road vehicle applications (standard ISO 20653:2013 Road Vehicles – Degrees of protection).
IP Level for Moisture Protection

IP66 vs. IP68 Difference

IP66 and IP68 offer the same protection against dust ingress. The difference lies in the degree of water protection.

IP66Protected from high-pressure water jets from any direction.Protected from total dust ingress. Full protection against dust and other particulates.
IP68Protected from long-term immersion up to a specified pressure.Protected from total dust ingress. Full protection against dust and other particulates.

Common IP Applications

The universal IP rating system gives buyers confidence that they can use products in certain environments. For example, the term ‘waterproof’ doesn’t provide a clear definition of where and to what extent an item can resist moisture ingress. Therefore, an IP rating provides a far more specific account.

Protective IP cases may apply to lighting, controllers, electric instruments, power supply, industrial camera housings, desktop electronics, and measuring/control equipment, to name a few. Instrument applications such as volt-meters, digital thermometers, and flow readers are also common. Additionally, electrical motors often bear the IP designation.

IP-rated enclosures compete in the industrial market with the NEMA (National Electrical Manufacturers Association) designation.

Common IP66 Applications

IP66 Weather proof outdoor wall socket
Courtesy: AliExpress

An IP66-rated enclosure has a rugged design and construction that’s rated for general outdoor use. An IP66-rated enclosure offers excellent performance for many environments, including:

  • Outdoor security units
  • Control boxes for farm and construction machinery
  • Outdoor scientific instruments
  • Electrical junction boxes
  • Circuit breakers and other electrical equipment
  • A/V gear designed to be used outdoors

Common IP68 Applications 

IP68 rated 156 keys marine equipment
Courtesy: DAVO Lin

IP68 enclosures’ high standard of protection makes them a natural choice for some of the most demanding electrical and electronic applications. These often include:

  • Marine equipment
  • Equipment in areas potentially subject to flooding
  • Water treatment and processing equipment
  • Equipment that will be subject to repeated high-pressure hose-downs

In addition, current iPhone models now boast an IP68 rating.

IP66 VS. IP68 – Which to Choose?

When determining the right IP rating to specify, engineers must be vigilant to consider potential ingress from less obvious sources of moisture or particulates, such as condensation, steam, and accumulating dust in harder-to-reach areas.

The IP68 rating is near the zenith of water protection and for devices that may be near or around water, it provides a better choice. IP66 fits environments where sporadic water exposure may occur but full immersion is unlikely.