FIELD: electricity.
SUBSTANCE: according to the invention, since occurrence of the first surge of short-circuit (SC) current there started is counting of the delay time of protection actuation of main switch (MS); besides, its disappearance moment is controlled and type of SC is determined, and if SC current flew via two phases and failed at the end moment of time counting, a conclusion is made on switching-off of MS at two-phase SC, from the moment of SC current disappearance, there started is counting of delay time of automatic repeated switching-on (ARS) of MS plus actuation delay time of its protection with acceleration; besides, occurrence of the second surge of SC current and type of closure is controlled, and if SC current appears at the end moment of delay time counting of ARS of MS, flows via three phases and does not fail at the end moment of delay time of protection actuation with acceleration, a conclusion is made on failure of switching-off of MS of a transition line of two-phase SC to three-phase one. The proposed method allows receiving the information on switching-off, automatic repeated switching-on and failure of switching-off of the main switch of the line at transition of two-phase short circuit to three-phase one.
EFFECT: enlarging functional capabilities.
2 dwg
