IP – index of protection(against solid objects or against liquids)

The index of protection – the IP - is an essential characteristic of most of the electrical devices. The IP – index of protection – shows the protection rate of the device from any external agents. It is composed of IP and 2 numbers, which show:

1. the first digit describes the degree of protection rate against solid objects, dust, the solid particles and bodies;
2. the second digit describes the degree of protection offered against liquids.

The IP rating is valid when the environment conditions are standard; in special cases and hazardous environments(intense heat, mines, etc), special protection is required.

The first IP digit – protection against solid object(X – can differ; see below for options)

• IP0X - No protection from solid bodies, no solid protection;
• IP1X - Protection from the objects with a diameter larger than 50 mm(ex. Contact with the hand). It does not include intentional access.
• IP2X - Protection from the objects with a diameter larger than 12 mm(ex. Contact with the finger, or similar objects with a length of max. 80mm). Ex: downlights and light strips (IP20)
• IP3X - Protection from the objects with a diameter larger than 2.5 mm(ex. Contact with wires larger/longer than 2.5mm). Ex: switches and sockets (IP3X)
• IP4X - Protection from the objects with a diameter larger than 1 mm(ex. fine wires or strips larger/longer than 1mm).  Ex: insulated encloser consummer unit (IP40)
• IP5X - Protection from the harmful levels of dust. The dust is not fully stopped from entering in, but it’s intrusion does not block the normal activity of the device. Ex: weatherproof unswitched socket(IP55);
• IP6X - Total protection from dust – no dust enters in. Ex: waterproof sockets, garden spotlights, etc(IP64);

The second IP digit – protection against liquids, water(X – can differ; see below for options)

• IPX0 - No special protection against water or liquids;
• IPX1 - The enclosure provides protection from vertical falling water only, the vertical drops of falling water will not enter in;
• IPX2 - The enclosure provides protection from water falling at up to 15° from vertical; the vertical drops of water have no effect on it, when the device is tilted up to 15° from the normal position;
• IPX3 - The enclosure provides protection from water falling at up to 60° from vertical; the vertical drops of water/water spray have no effect on it, when the device is tilted up to 60° from the normal position;
• IPX4 - The enclosure provides protection from water splashed from all directions;
• IPX5 - The enclosure provides protection from low pressure water jets, like a nozzle;
• IPX6 - The enclosure provides protection from high pressure/powerful water jets, like the sea water, from any direction;
• IPX7 - The enclosure provides protection from temporary submersion in water, up to 1m in depth, when the device is either dropped or placed in water for a limited time and depth=1m;
• IPX8 - The enclosure provides protection from liquids and water for an extended set time of submersion in water, up to a specified depth;

For more info and examples, visit the sparks direct website. This article was also posted on google knol. See below a sample chart with the IP ratings for electrical devices.