Response at this date may not be helpful, but here goes.
This is a somewhat open-ended question.
The first obvious response is that it depends on the particular standard -- in other words....maybe not...
British Standards that are currently in place, are obviously valid for British installations. However, in other European Community countries, those standards are without merit. Each country may have different methods. This is why harmonized standards are utilized. If in doubt, utilization of the relevant EN would be advised.
The British standard BS 7671 requirements for electrical installations does not translate as a european harmonised standard (EN) due to the peculiarities between electrical supplies of british and other countries.
This is a minefield and we get stuck with the same problem. We manufacture electrical control panels and we refer to BS7671 for UK installations and we use the appropriate international connection symbols and connection circuit diagrams in the written instructions. We also explain the correct type of cabling and glanding techniques to use. This means that qualified personnel have the right information to make an installation judgement. We make reference to installation personnel using the correct national wiring rules for their particular country. The panels could be going in the EC or outside of the EC.
