I've asked this question elsewhere with no luck!
In EN 60204-1:2009 it says regarding the sizing of protective conductors (8.2.2): "This requirement is met in most cases where the relationship between the cross-sectional area of the phase conductors associated with that part of the equipment and the cross sectional area of the associated protective conductor is in accordance with Table 1" The phrase "associated with that part of the equipment" I take to mean that if, for example, I have a 24V PSU inside my cabinet fed by 1.5mm conductors and appropriately fused, the protective conductor to the PSU can also be 1.5mm, even if the incoming conductors are much bigger.
In EN 60204-1:2018 we are again referred to table 1, but the "associated" statement has gone. Table 1 deals with the sizing of the external protective conductor. Does this mean that all protective conductors inside the enclosure should be sized relative to the incoming phase conductors? To start with they would be too large for the earth terminal on my PSU! Clearly there is a reason why this wording has changed, but what is the difference in application?
