FIELD: electrical equipment.
SUBSTANCE: use: in the field of electrical engineering and power engineering. Control circuit (20) for automatic circuit breaker of differential current (10), said automatic circuit breaker of differential current (10) is configured to transition from closed state to open state for disruption of neutral branch of circuit (1, 11) and phase branch circuit (2, 12) when leakage current is detected, wherein control circuit (20) is configured to supply network voltage coming in phase and neutral branch of circuit, wherein control circuit (20) comprises: first node of input circuit (N1), electrically connected or made with possibility of electrical connection to neutral branch of circuit (1, 11); input circuit (N2) second unit, electrically connected or made with possibility of electric connection to phase branch circuit (2, 12); measuring resistor (Rtest); control switch (C3) controlled by control button (21) for connection of control resistor (Rtest) between first (N1) and second (N2) circuit nodes in order to simulate leakage current; electronic control circuit (22), which is supplied from the neutral branch circuit and from the phase circuit branch and comprises an electronic time counter configured to vary and store the calculated time value, and resetting thereof when pressing control button (21); visual or acoustic signalling device (D5) controlled by electronic control circuit (22) for supplying an acoustic and/or visual signal when the time counter reaches a predetermined counted time value. Electronic time counter comprises volatile storage device configured to store said counted value and reset thereof when pressing control button (21) or in absence of said supply voltage or when opening said automatic circuit breaker of differential current; electronic control circuit (22) contains non-volatile memory and is programmed to perform periodic backup of the time value stored in the volatile memory device into this non-volatile memory device, for storing said counted time value even in the absence of mains voltage or when opening said automatic circuit breaker of differential current; wherein electronic control circuit (22) comprises microcontroller configured to automatically switch from off state caused by faulty said mains voltage or opening said circuit breaker, in on state when said power supply is restored or said differential current circuit breaker is closed, wherein said microcontroller is programmed to automatically copy a counted time value, which is stored in a non-volatile memory device when transitioning from the off state into the on state, into the volatile memory.
EFFECT: technical result is increase of safety of electric plant in areas with frequent mains voltage outages.
11 cl, 2 dwg
