Aerial cables are mostly used for telecommunication systems or for power transmissions with voltages below 1000 volts.
Aerial cable for voltages up to 69,000 volts has also been built, for the supply of farms, waterworks, transmitters and other facilities outside of urban areas.
Aerial cables are not often used in transmission circuits because of the difficulty in insulating such high voltage wire.
Because of the proven reliability benefits of insulated aerial cables over traditional air-insulated wire, the Electric Power Institute has been working with utility companies to develop better insulating materials.
In 1996 they were able to successfully convert one lower-voltage transmission circuit to insulated cable.