Apparatus for detecting arc fault

Abstract

An apparatus for detecting an arc fault. The apparatus comprises a current detector for detecting the amount of change of current flowing on the wire and generating a signal proportional to the amount of change; a signal transformer for passing a high frequency component of the signal outputted from the current detector, and limiting a level of the signal not to exceed a fixed signal level; a first level limit amplifier for amplifying a signal outputted from the signal transformer so as to limit the level of the outputted signal; a signal level detector for determining whether a input signal exceeds a fixed first voltage and generating a detection signal; a pulse generator for transforming the detection signal outputted from the signal level detector into a form of normalized pulse; a first arc determination unit for counting a pulse signal outputted from the pulse generator for a predetermined time, determining whether the arc has been occurred and generating an arc detection signal; and a circuit breaker for breaking the conductive wire when the are detection signal is generated.

1 - 16 . (canceled)  
   
   
       17 . An apparatus for detecting an arc signal in a conductive wire of circuit connecting a source to a load and determining whether or not the detected arc signal is a harmful arc signal, the apparatus comprising: 
 a third current detector for detecting variation of current flowing through the phase conductive wire and generating a signal in proportional to the variation of the current;    21 st  and 22 nd  amplifiers and 21 st  and 22 nd  filters for amplifying and filtering an output signal of the third current detector and outputting the amplified and filtered signal to the arc determination unit;    a first level limiter, which is turned on or off by a predetermined level of output signal of the third current detector, for turning on or off the arc determination unit;    an error preventing unit for outputting a reset signal to the arc determination unit when the predetermined level of output signal is inputted;    a second DC converter for converting the output signal of the third current detector into a DC signal; and    a fourth comparator for turning on or off, or resetting the arc determination unit according to an output signal of the second DC converter.    
   
   
       18 . The apparatus as claimed in  claim 17 , further comprising a neutral wire detector for blocking the neutral wire and the phase conductive wire by a state detection result of the neutral wire to which a power is supplied from the source, and a control of the arc determination unit.