Is the UK 230V or 240V?

In Europe, the AC three phase voltage is a “harmonised” 400Vac. Actually, the voltage in mainland Europe is 380Vac and 415Vac in the UK .

The voltage used throughout Europe (including the UK) has been harmonised since January 2003 at a nominal 230v 50 Hz (formerly 240V in UK, 220V in the rest of Europe) but this does not mean there has been a real change in the supply.

UK mains is 230 or 240v ac 50Hz . 50Hz means that the voltage cycles 50 times per second. For UK mains, the peak voltage is around 330v, and the overall ac waveform gives the same heating effect as 240v dc would. It is called 240v because it is equivalent to 240v dc for heating and lighting.

Mains electricity is an AC supply , and the UK mains supply is about 230 volts. It has a frequency of 50Hz (50 hertz), which means it changes direction and back again 50 times a second.