UK Electrical supply

Injuries are classified into high voltage (greater than 1000 volts) or low voltage (less than 1000 volts). In practice, injuries involving over 600 volts behave more like high voltage injuries.

Domestic electricity is supplied in the form of alternating current (AC). In AC, current flows first in one direction and then in the opposite direction. If current flow is plotted against time a sine wave results. The number of complete sine waves per second gives the frequency of the alternating current which is measured in Hertz (Hz). In the UK domestic electricity is supplied at 240 volts with a frequency of 50 Hz.

Direct current involves a steady flow of electrons in one direction. Injuries due to direct current often involve industrial appliances and are more common in workers in the electricity industry and building trade.