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Dimensions
Section 12
11
Provided by enclosures
Degrees of
protection
External influences
In many national and international standards, a large number of external influences
to which an electrical installation can be subjected are indexed and coded:
presence of water, presence of solid objects, risk of impact, vibrations, presence
of corrosive substances, etc. These influences may be present with variable
intensity depending on the conditions of installation: The presence of water may
be in the form of a few drops or total immersion.
Protection index
European standard EN60529 gives a protection code (IP) which characterises the
ability of equipment to withstand the following external influences:
n
Presence of solid bodies
n
Presence of water
This code comprises two digits, depending on these external influences. The
protection index is assigned to the equipment following a series of tests laid down
in the respective standards.
Example
IP 55
Test according to EN60529
1st digit
Protection
against solid bodies
2nd digit
Protection
against liquids
no protection
Protection against
solid bodies
greater than 50 mm
Protection against
solid bodies
greater than
12.5mm
Protection against
solid bodies
greater than 2.5 mm
Protection against
solid bodies
greater than 1 mm
Protection against
dust
(no harmful
deposits)
Total protection
against dust
No protection
Protection against
vertical drops of
water (condensation)
Protection against
drops of water falling
up to 15° from
vertical
Protection against
rainwater up to 60°
from vertical
Protection against
water projected from
all directions
protection against
hosing with water
from all directions
Protection against
swamping with water
Protection against
immersion
0
1
2
3
4
5
6
0
1
2
3
4
5
6
7
Protection against hosing
with water from all directions
Protection against dust
(no harmful deposits)
ø 50mm
ø 12.5mm
ø 2.5mm
ø 1mm