Patent ID: 7511933

Claim:
A system for protecting a load connected to an electrical system from over-voltage conditions, comprising: a phase bus connected to a phase conductor of said electrical system; one or more transient-suppressing lines connected to said phase bus, each of said one or more transient-suppressing lines including a contactor and a transient-suppressing element connected in series with said contactor; a processing unit, the contactor of each of said one or more transient-suppressing lines being in electronic communication with said processing unit; a memory storing one or more routines executable by said processing unit, said one or more routines being adapted to selectively open and close the contactor of each of said one or more transient-suppressing lines; and wherein each of said one or more transient-suppressing lines has operatively coupled thereto at least one of: (i) a voltage transducer in electronic communication with said processing unit, said voltage transducer generating an AC waveform voltage signal, and (ii) a current transducer in electronic communication with said processing unit, said current transducer generating an AC waveform current signal, wherein said memory stores one or both of a normal AC waveform voltage signature and a normal AC waveform current signature for each of said one or more transient-suppressing lines, and wherein said one or more routines are further adapted to open and close the contactor of each one of said one or more transient-suppressing lines based on at least one of: (i) a first comparison between the AC waveform voltage signal generated by the voltage transducer of the one of said one or more transient-suppressing lines and said normal AC waveform voltage signature, and (ii) a second comparison between the AC waveform current signal generated by the current transducer of the one of said one or more transient-suppressing lines and said normal AC waveform current signature.