Europe and the UK standardised their declared residential supply voltage as 230V +10%, -6% nearly two decades ago. It's only the fact that the average voltage of supplies with a declared voltage of 230V must be somewhat over 240V that some incorrectly think that the UK still supplies at a nominal 240V. The typical voltages in the UK and Europe are now similar.
The tables of cable sizes etc. are for use with a nominal supply voltage of 230V (unless noted otherwise). They include the assumption that the actual voltage will vary by ±10% or so at the point of use.
The tables of cable sizes etc. are for use with a nominal supply voltage of 230V (unless noted otherwise). They include the assumption that the actual voltage will vary by ±10% or so at the point of use.