Topic summary
400 Hz
Extracted from the Wikipedia article Utility frequency.
400 Hz
Power frequencies as high as 400 Hz are used in applications where small size and light weight are priorities; aircraft, spacecraft, submarines, server rooms for computer power, military equipment, and hand-held machine tools. Such high frequencies cannot be economically transmitted long distances; the increased frequency greatly increases series impedance due to the inductance of transmission lines, making power transmission difficult. Consequently, 400 Hz power systems are usually confined to a building or vehicle.