FIELD: fire safety.
SUBSTANCE: invention relates to fire safety, namely to methods and devices preventing fires caused by faults in electric networks and electrical installations. According to the proposed decision during time intervals, approximately equal to ±2 ms around supply voltage transition through zero, threshold device for protection from arcing decreases in relation to the voltage of current sensor signals by ten times relative to its nominal value in the mode of arcing detection. For this purpose an electronic unit is used which releases (affects) the abovesaid time intervals. During given intervals the strobe signal increases the factor of sensor signals amplification by ten times by supplying strobe signal to the unit installed in front of comparison unit.
EFFECT: technical result consists in possibility of identifying presence of large transient resistance in protected circuit in sparkless mode and interruption of protected circuit from power supply in order to prevent fire.
2 cl, 7dwg
