Pollution Degree is an Arabic numeral characterizing the expected pollution of the micro-environment. Micro-environmental conditions depend primarily on the macro-environmental conditions in which the equipment is located and in many cases the environments are identical. However, the micro-environment can be better or worse than the macro-environment where, for example, enclosures, heating, ventilation or dust influence the micro-environment.
PD1 – Pollution degree 1 – No pollution or only dry, non-conductive pollution occurs. The pollution has no influence.
PD2 – Pollution degree 2 – Only non-conductive pollution occurs except that occasionally a temporary conductivity caused by condensation is to be expected.
PD3 – Pollution degree 3 – Conductive pollution occurs or dry non-conductive pollution occurs which becomes conductive due to condensation which is to be expected.
PD4 –Pollution degree 4 – Continuous conductivity occurs due to conductive dust, rain or other wet conditions.
* Source: IEC 60664-1