3–12 889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUALFRONT CONTROL PANEL INTERFACE CHAPTER 3: INTERFACESTarget Messages can be cleared either by pressing the PB corresponding to the tab“CLEAR”, or by initiating a RESET command. The “CLEAR” command clears only the TargetMessages, while initiating a RESET clears not only the Target Messages, but also anylatched LEDs and output relays.Self-Test Errors The relay performs self-diagnostics at initialization (after power up), and continuously as abackground task to ensure that the hardware and software are functioning correctly.There are two types of self-test warnings indicating either a minor or major problem. Minorerrors indicate a problem with the relay that does not compromise protection and controlfunctionality of the relay. Major errors indicate a problem with the relay which takes it outof service.CAUTION:Self-Test Warnings may indicate a serious problem with the relay hardware!Upon detection of a minor problem, the relay does the following:• Displays a detailed description of the error on the relay display as a target message• Records the minor self-test error in the Event Recorder• Flashes the “ALARM” LEDUpon detection of a major problem, the relay does the following:• De-energizes critical failure relay• De-energizes all output relays• Blocks protection and control elements• Turns the "IN SERVICE" LED to red• Flashes the "ALARM" LED• Displays “Major Self-test error” with the error code as a target message• Records the major self-test failure in the Event RecorderNOTENOTE:The Critical Failure Relay (Output Relay 8) is energized when the relay is in-service, and nomajor error is presentUnder both conditions, the targets cannot be cleared if the error is still active.Figure 3-13: Minor Errors
