SLUAAR5 august   2023 ISO5451 , ISO5452 , ISO5851 , ISO5852S , ISO7741 , ISO7810 , ISO7820 , ISO7821 , ISO7830 , ISO7831 , ISO7840 , ISO7841 , ISO7842 , UCC23513 , UCC5310 , UCC5320 , UCC5350 , UCC5390

 

  1.   1
  2.   Abstract
  3. 1Introduction of Key Terms in IEC60664
    1. 1.1 Clearance and Creepage
    2. 1.2 Insulation Type
    3. 1.3 Decisive Voltage Class and Extra-Low Voltage
    4. 1.4 Protection Class
    5. 1.5 Pollution Degree
    6. 1.6 Overvoltage Category
    7. 1.7 System Voltage
    8. 1.8 Working Voltage and Voltage Block
  4. 2Insulation Distance Definition
    1. 2.1 Clearance and Creepage Determining Process
    2. 2.2 Clearance and Creepage Determining Method Example
  5. 3Summary
  6. 4Reference

1.5 Pollution Degree

Pollution: Any addition of foreign matter, solid, liquid, or gaseous that can result in a reduction of electric strength or surface resistivity of the insulation.

Micro-environment: Immediate environment of the insulation which particularly influences the dimensioning of the creepage distances.

Pollution degree: Numeral characterizing the expected pollution of the micro-environment. This classification is important since it affects creepage and clearance distances required to ensure the safety of a product. Table 1-1 distinguishes the four pollution degrees with examples.

Table 1-1 Degree of Pollution
Pollution
Degree		 Micro-Environment Example

1

 No pollution or only dry, non-conductive pollution occurs. The pollution has no influence. In an air-conditioned lab or by extension for the insulation distance under a protection coating or in internal layer

2

 Normally, only non-conductive pollution occurs. Occasionally, however, a temporary conductivity caused by condensation is to be expected, when the EE is out of operation. In an enclosure or an electrical cabinet or household appliances

3

 Conductive pollution or dry non-conductive pollution occurs which becomes conductive due to condensation which is to be expected Electrical equipment of machine tools

4

 The pollution generates persistent conductivity caused, for example, by conductive dust or rain or snow Electrical equipment for outdoor use