High and Low Voltage

High and low voltage are the two main voltage classifications. In some uses, medium-voltage is also used.

• High Voltage (HV) – between 35kV and 230kV
• Medium Voltage (MV) – between 1000V and 35kV
• Low Voltage (LV) – Below 1000V

Most domestic and commercial power is supplied at low voltage, while high voltage is used for the transmission network (the national grid). Voltage is transmitted at high voltage due to a range of losses throughout the network, ensuring that voltage is able to be consistently delivered to end users at required levels. Distribution and transmission transformers are used to convert high voltage power from the grid to usable medium (for high-demand industrial and commercial sites) and low voltage supply.