FIELD: protective circuit-opening devices.
SUBSTANCE: root-mean-square value of current is determined with time shift by value of next reading; mean weighted value of RMS current relative to each time interval is evaluated for each phase of supply mains, short-circuit and overload setting values are sequentially checked for exceeding normal values. RMS values of currents for disconnecting electrical installation in case of current failure in phases may be additionally checked and initial state of measurement time interval fill-up may correspond to initial rated current of electrical installation.
EFFECT: enhanced speed of response and noise immunity of circuit-breaker electronic release unit.
3 cl, 1 dwg
