Guides

Isolation Classes - Transformers

Isolation class I Transformers with protective earth
Isolation class II Double isolated transformers without protective earth


Protection Index

The protection index is related to products for low and medium voltage (to 1000 V and 1500 V defined by the french standard NF C 20-010 och DIN 400500)

In order to define protection index the letters IP are used followed by two digits.
(E.g. IP 44 = Protection against solid objects bigger than 1 mm and protection against water coming from arbitrary direction)

First digit (Protection against solid objects) Second digit (Protection against fluids)
IP Test IP Test
0 No protection 0 No protection
1 Protection against solid objects bigger than 50 mm. (e.g. unvoluntary touch by the hand) 1 Protection against drops of water falling vertically (condensation)
2 Protection against solid objects bigger than 12 mm (e.g. a finger) 2 Protection against water falling not more than 15 degress from the vertical line
3 Protection against solid objects bigger than 2,5 mm (e.g. a tool, threads) 3 Protection against water and rain falling not more than 60 degrees from the vertical line
4 Protection against solid objects bigger than 1 mm (e.g. small tools, small threads) 4 Protection against water coming from arbitrary direction
5 Protection against dust (no harmful deposit) 5 Protection against waterbeams from all directions
6 Complete protection against dust 6 Protection against heavy showers
7 Protection against submerging (15 cm - 1 m)
8 Protection by longer submerging under pressure (Deeper than 1 m)