Another important consideration in the selection of electrical equipment is the extent to which the equipment
protects against the ingress of solids and liquids.
For example where the equipment is to be used in dusty, dirty or wet conditions it is important to know how
well it resists the ingress of dust and water. In some cases the method of explosion protection takes account
of ingress protection.
In some cases the method of explosion protection takes account of ingress protection.
The degree of protection against the intrusion of solid and liquid particles into the electrical equipment is
designated as the Ingress Protection or IP rating. An IP rating has two digits, digit "x" and digit "y" associated with it.
An IP rating is expressed in the form IP"x""y". Digit "x" represents the degree of protection against the ingress of solids. The digit "y" represents the protection provided against the ingress of liquids. The degrees of
protection associated with digits "x" and "y" for solids and liquids respectively are provided in the following
table.
Degrees of Protection
Degree of protection against ingress of solids
No protection
Protected against large solid objects up to
50mm (eg hands)
Protected against small solid objects up to
12.5 mm (eg fingers)
Protected against solid objects up to 2.5 mm
(eg tools)
Protected against solid objects up to 1 mm (eg
wires)
Protected against ingress of dust in an amount
sufficient to interfere with the satisfactory
operation of the equipment
Totally protected against the ingress of dust
Digit Protection against ingress of liquids
Digit
“x”
“y”
0
No protection
0
Protected against vertically falling drops
1
1
of water
Protection against drops of liquid falling
2
2
at an angle up to 15 from vertical
3
Protection against rain falling at any angle
3
up to 60 from vertical
4
Protection against splashing from all
4
directions
Protection against water jets from any
5
direction
5
6
Protection against strong water jets from
all direction
Protected against immersion between 15
mm and 1 m in depth
Protected against lengthy immersion under pressure
6
7
8