Hertz

Hertz is the SI (International System of Units) unit used to state frequency, with one hertz meaning one cycle per second. In UK electricity supply documents and home energy equipment data, Hz (hertz) is most often seen around AC supply frequency, inverter output frequency, backup supply ratings and other equipment limits. The public low-voltage supply is normally declared at 50 hertz, and National Energy System Operator system-frequency data describes the system frequency as being kept at 50 Hz.