METHOD FOR SELF-DIAGNOSING OF DC-OUT RELAY

A method for self-diagnosing a DC-out relay is provided to self-diagnose whether the DC-out relay is normally operated, through the on/off control of the DC-out relay, a DC pulse relay and a DC diagnosis relay in a main test apparatus. A method for self-diagnosing a DC-out relay comprises the following steps of: inputting a reference signal to a DC unit for diagnosing an operating state of the DC-out relay(S1); inputting the reference signal to a pulse driving part through the DC-out relay of the DC unit(S3); outputting the reference signal from the pulse driving part to the DC unit again(S5); measuring an potential difference which is generated while the reference signal passes through the internal resistance of the DC unit(S7); and determining the on/off operating state of the DC-out relay according to a size of the measured potential difference(S9).