17 Glossary
100_0000_0005.fm
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17 Glossary
Class rating
The class rating according to DIN EN 61140 specifies the safety measures for electrical equipment to
avoid electrocution. There are four class ratings:
Protection class IP
The protection class according to DIN EN 60529 indicates the suitability of electrical equipment for use
in certain ambient conditions as well as the protection against risks.
The protection class is specified by an IP code according to DIN EN 60529.
Class rating
Meaning
0
No special protection apart from the basic insulation.
No grounded conductor.
Plug connection without grounded conductor contact.
I
Connection of all conductive housing components to the grounded conductor.
Plug connection with grounded conductor contact.
II
Reinforced or double insulation (protective insulation).
No connection to the grounded conductor.
Plug connection without grounded conductor contact.
III
Machines are operated on protective low voltage (< 50 V).
Connection to the grounded conductor is not necessary.
Plug connection without grounded conductor contact.
Code
Meaning 1st number:
Protection against touching hazardous parts.
Protection against permeating foreign objects.
0
Not protected against contact.
Not protected against foreign bodies.
1
Protected against contact with the back of the hand.
Protected against large foreign objects with diameter > 50 mm (1.9 in).
2
Protected against contact with one finger.
Protected against medium-sized foreign objects (diameter > 12.5 mm (0.5 in)).
3
Protected against touch with a tool (diameter > 2.5 mm (0.01 in)).
Protected against small foreign objects with (diameter > 2.5 mm (0.01 in)).
4
Protected against touch with a wire (diameter > 1 mm (0.03 in)).
Protected against granular foreign objects (diameter > 1 mm (0.03 in)).
5
Protected against contact.
Protected against dust depositing inside.
6
Completely protected against any contact.
Protected from dust.
Code
Meaning 2nd number:
Protection against permeating water
0
Not protected against permeating water.
1
Protected against water dropping vertically.
2
Protected against diagonally falling water (15° angle).
3
Protected against spray (60° angle).
4
Protected against spraying water from all directions.
5
Protected against water jets (nozzle) from any angle.
6
Protected against strong water jets (overflow).
7
Protected from temporary immersion in water.
8
Protected from ongoing immersion in water.
