Apparatus for preventing mal-operation of sudden pressure relay system for protecting transformer

PURPOSE: An apparatus for preventing a malfunction of a shock pressure relay system for protecting a transformer is provided to intercept a control signal of a shock pressure relay by detecting a current value and a voltage value of an external line of a transformer. CONSTITUTION: An apparatus for preventing a malfunction of a shock pressure relay system for protecting a transformer includes a first and a second sensors(200,210), a relay unit(300), and a switching unit(400). The first and the second sensors(200,210) are used for sensing a current value and a voltage level of a transformer according to an external line and generating a first and a second sensing signals. The relay unit(300) determines kinds and directions of troubles by extracting a phase and intensity from the current value and the voltage level of the external line of the transformer and generates control signals to states of troubles in order to intercept a control signal output line of the shock pressure relay system. The switching unit(400) intercepts the control signal output line of the shock pressure relay system according to the control signals of the relay unit(300).