Pollution Levels

Pollution Degrees I-IV

(in accordance with EN 60664-1:2007 and VDE 0110-1)

The environment determines the effect of pollution on the insulation.

Small clearances can be bridged completely by  solid particles, dust and water and therefore  minimum clearances are specified, where pollution may be present in the micro-environment.

For the purpose of evaluating creepage  distances and clearances, the following four degrees of pollution in the micro-environment  are established:

Pollution degree 1 

No pollution or only dry, non-conductive pollution occurs. The pollution has no influence. 

Pollution degree 2

Only non-conductive pollution occurs except  that occasionally a temporary conductivity  caused by condensation is to be expected.

Pollution degree 3

Conductive pollution occurs or dry non-conductive pollution occurs which becomes conductive  due to condensation which is to be expected.

Pollution degree 4

Continuous conductivity occurs due to conductive dust, rain or wet conditions.

The dimensions for creepage distance cannot be specified where permanently conductive pollution is present (Pollution degree 4). For temporarily conductive pollution (Pollution degree 3), the surface of the insulation may be designed to avoid a continuous path of conductive pollution, e.g. by means of ribs and grooves. 

PTR?s approval data are based on pollution degree 3.