Prior to 1995, the UK’s nominal voltage was 415/240V ±6% (227 – 254V) and this is what the distribution network was originally designed to provide. In 1995, this was changed to 400/230V +10% -6% (216 – 253V) in an attempt to get closer to Mainland Europe’s 380/220V ±6% (207 – 233V) and is where we remain today.
To make things easier for buying and selling electrical equipment within the EU, the Low Voltage Directive (LVD) 2006/95/EC was introduced to ensure that any equipment bearing the CE mark shall operate within the proposed harmonised voltage levels of 400/230V ±10% (207 – 253V).
Therefore, with all modern equipment being capable of operating at a nominal voltage of 230V and within 207 – 253V, it’s unnecessary to continue to operate in and around 240V. As stated above, this can cause equipment to consume more energy than required and can shorten life expectancy – this is where voltage optimisation can help.