FIELD: electrical engineering.
SUBSTANCE: invention relates to the field of electrical engineering and can be used in electric power supply networks. In the method of monitoring the power switch (13d) in the power grid, the power supply network is monitored for the occurrence of a malfunction; when a malfunction is detected, a trigger signal is output to the power switch (13d) on the monitored area to limit said area; and generating a switch failure signal indicative of a malfunction when the power switch is opened (13d), if a prolonged current flow through the power switch (13d) is recognized after issuing the initiating signal. In order to be able to quickly and reliably detect a continuous current flow or interruption of current flow in order to monitor the power switch, to recognize the continuous flow of current, the shape of the time curve of the instantaneous current flowing through the power switch (13d) is analyzed. Invention also relates to a security device (16) with a correspondingly executed control device.
EFFECT: technical result is the accelerated and reliable recognition of the continuing current flow or interruption of the current flow.
15 cl, 8 dwg
