Abstract: The present invention relates to a device and method for detecting a surge arrester resistive leakage current for reducing the computational load, which may significantly reduce the computational load as the Fourier transform process need not be repeated in the process of searching to match a section to be Fourier transformed to a section in-phase with AC voltage to extract the resistive leakage current component from the Fourier series of surge arrester leakage current and enables real-time detection of the resistive leakage current by shortening the section searching process of one-period leakage current by searching for the section of one-period leakage current, which is to be initially Fourier-transformed, based on the characteristic pattern that it is repeatedly generated by application of an AC voltage.

Abstract: The present invention relates to a 3 phase electric leakage current circuit breaker with electric shock protection having a first function of detecting a leakage current and operating a circuit breaker to break an electric path if a leakage current exceeds a tolerance and a second function of detecting a leakage current every half cycle intervals of a power source, subtracting two leakage currents detected before and after a half cycle interval from each other as a vector calculus to compute a leakage current change, and operating a circuit breaker to break an electric path if the leakage current change exceeds a tolerance. The former case corresponds to protection against a normal leakage current which gradually increases, and an allowable leakage current is several hundreds of mA. The latter case is for protection against electric shock to a human body when a leakage current abruptly changes due to electric shock to a human body or the like, and an allowable leakage current is several tens of mA.

Abstract: The present invention relates to a 3 phase electric leakage current circuit breaker with electric shock protection having a first function of detecting a leakage current and operating a circuit breaker to break an electric path if a leakage current exceeds a tolerance and a second function of detecting a leakage current every half cycle intervals of a power source, subtracting two leakage currents detected before and after a half cycle interval from each other as a vector calculus to compute a leakage current change, and operating a circuit breaker to break an electric path if the leakage current change exceeds a tolerance. The former case corresponds to protection against a normal leakage current which gradually increases, and an allowable leakage current is several hundreds of mA. The latter case is for protection against electric shock to a human body when a leakage current abruptly changes due to electric shock to a human body or the like, and an allowable leakage current is several tens of mA.