In 2010, the new standard IEC 61439 series was published to replace the IEC 60439 series.
The purpose of the IEC 61439 series of standards is to harmonize as far as practicable, all the general rules and requirements that apply to LV Switchgears and Controlgears (ASSEMBLIES) and to obtain uniformity of requirements, consistency in the verification, and to avoid the need for verification to other standards.
The table below provides a guideline on the minimum size of PE/PEN conductors. This table has been similar to Table 3 IEC 60439-1 (1999) except for the addition of a note about harmonics.
|Cross-sectional area of phase conductors S
|Minimum cross-sectional area of the corresponding protective conductor (PE, PEN) Spa
|S ≤ 16||S|
|16 < S ≤ 35||16|
|35 < S ≤ 400||S/2|
|400 < S ≤ 800||200|
|800 < S||S/4|
|a Current in the neutral may be influenced where there are significant harmonics in the load.|
Source: IEC 61439-1 2011 Table 5