2 DISTRIBUTING BOARD WITH OPENING AND OPENING RISK MONITORING FUNCTION ON SECONDARY SIDE OF CURRENT TRANSFORMER

摘要

A switchgear having a function of monitoring the opening and opening of the secondary side of the current transformer is connected to both terminals of the secondary side of the current transformer and reduces the voltage at the secondary terminal of the current transformer to output a reduced voltage; A first shunt regulating unit having a first predetermined reference voltage and comparing the reduced voltage and the first reference voltage to turn on and output a first shunt voltage when the reduced voltage is greater than the first reference voltage; A first photo coupler connected to an output terminal of the first shunt regulating unit and outputting a first detection signal using an optical signal as the first shunt voltage is provided from the first shunt regulating unit; A second shunt regulation having a second reference voltage predetermined to be greater than the first reference voltage, and comparing the reduced voltage and the second reference voltage to turn on and output a second shunt voltage when the reduced voltage is greater than the second reference voltage part; A second photo coupler connected to the output terminal of the second shunt regulating unit and outputting a second detection signal using an optical signal as the second shunt voltage is provided from the second shunt regulating unit; And (i) if only the first detection signal is provided, it is determined that the secondary terminal of the current transformer is in an open danger state, and the first control signal is output, and (ii) when the first detection signal and the second detection signal are provided simultaneously, And a control unit determining that the secondary terminal is in an open state and outputting a second control signal.