Ingress Protection

An important consideration in the selection of electrical equipment is the extent to which the equipment protects against the ingress of solids and water. In extremely dusty or dirty environments, a high degree of protection against ingress of solids will be required. Similarly in external, exposed situations, a high degree of protection against the ingress of water may be required.

The degree of protection against the intrusion of solid and liquid particles into an enclosure is referred to as the Ingress Protection or IP rating. An IP rating comprises the letters ‘IP’ followed by two characteristic numerals. The first numeral represents the degree of protection against solids and the second numeral the protection against water. The two numerals do not combine to form a ‘number’, so, for example IP65 is not ‘higher’ than IP56, the first digit of the two digit code is actually lower giving a lower protection against solids.

It is important to note that while the first numeral is sequential (i.e. each increase in digit value represents an increase in ingress protection), the second numeral is only sequential up to ‘6’. The numerals, 7, 8 and 9 represent different water ingress tests, not increased ingress tests.

The letter ‘X’ appearing in place of one of the numerals indicates that element has not been considered in the IP testing and certification.

The code may also include one additional letter and one supplementary letter

The degrees of protection associated with digits "x" and "y" for solids and liquids respectively are provided in the following table as defined within IEC 60529.

Degrees of Protection  

Degree of protection against ingress of solids Digit  Protection against ingress of liquids Digit 
No protection 0 No protection 0
Protected against large solid objects up to 50mm (eg hands) 1 Protected against vertically falling drops of water 1
Protected against small solid objects up to 12.5 mm (eg fingers) 2 Protection against drops of liquid falling at an angle up to 15 from vertical 2
Protected against solid objects up to 2.5 mm (eg tools) 3 Protection against rain falling at any angle up to 60 from vertical 3
Protected against solid objects up to 1 mm (eg wires) 4 Protection against splashing from all directions 4
Protected against ingress of dust in an amount sufficient to interfere with the satisfactory operation of the equipment 5 Protection against water jets from any direction 5
Totally protected against the ingress of dust (dust-tight) 6 Protection against strong water jets from all direction 6
    Protected against immersion between 15 mm and 1 m in depth 7
    Protected against lengthy immersion under pressure 8
    Protected against high pressure, high temperature water jets 9
Optional Additional Letters    Optional Supplementary Letters   
Protection against access to hazardous parts by the back of a hand High voltage apparatus H
Protection against access to hazardous parts by a finger B Motion during water test M
Protection against access to hazardous parts by a tool C Stationary during water test S
Protection against access to hazardous parts by a wire D Weather conditions W