EN 60529 (British Standard BS EN 60529:1992)
This standard defines levels of sealing effectiveness against “ingress” i.e. intrusion from foreign bodies such as tools, dirt and liquid water.
What do the two digits in an IP Rating mean?
The rating consists of the letters IP followed by two digits, the higher the number the better the protection. Sometimes a number is replaced by X, which indicates that the enclosure is not rated for that specification.
IP65 = First Digit – Solids
The first digit indicates the level of protection that the enclosure provides against the ingress of solid foreign objects, from tools or fingers that could be hazardous if they came into contact with electrical conductors or moving parts, to airborne dirt and dust that could damage circuitry.
IP65 = Second Digit – Liquids
The second digit defines the protection of the equipment inside the enclosure against various forms of moisture (drips, sprays, submersion etc).