Patent ID: 7598720

Claim:
A system for detecting the wiring phase of an unknown phase voltage relative to a reference phase voltage in an electrical power distribution system having a single phase or polyphase power line, comprising: transmitting circuitry for transmitting a signal from a first location to a second location, said signal comprising a characteristic signal pattern; a measuring circuit for measuring at said first location a first time interval between the characteristic signal pattern and the occurrence of a reference point in a phase voltage at said first location; a detecting circuit for detecting at said second location the characteristic signal pattern of said signal and for measuring a second time interval between said characteristic signal pattern and the occurrence of a reference point in a second phase voltage at said second location; a determining circuit for determining from said first and said second time intervals the wiring phase of the unknown one of the first and second phase voltages relative to the other one of the first and second phase voltages serving as the reference phase voltage, wherein said determining circuit is located at said first location; and logic circuitry for transmitting information indicative of said second time interval from said second location to said first location.